Sarcoglycan antibodies and fragments thereof

Abstract

The present disclosure provides compositions related to binding of various sarcoglycan proteins, which are relevant for their role in numerous genetic disorders, including limb girdle muscular dystrophy. The disclosure includes proteins, antibodies and / or fragments thereof and associated polynucleotide constructs. The disclosure further provides methods for manufacturing said compositions and other uses for the same.

Description

SARCOGLYCAN ANTIBODIES AND FRAGMENTS THEREOFCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 63 / 700,915, filed September 30, 2024, the disclosure of which is incorporated herein by reference in its entirety.SEQUENCE LISTING

[0002] The instant application contains a Sequence Listing which has been submitted electronically in XML format and is hereby incorporated by reference in its entirety. Said XML copy, created on September 25, 2025, is named 8209_WO00_SequenceListing_ST26.xml and is 173,810 bytes in size.BACKGROUND

[0003] The sarcoglycan protein complex is a group of transmembrane glycoproteins comprised of various individual proteins in equal stoichiometric ratios (Jung, D., et al.(1996). Journal of Biological Chemistry, 277(50), 32321-32329). Loss of any component protein impacts the functionality of the overall complex, which plays a key role in skeletal muscle function, result in a number of related sarcoglyanopathies (Holt, K. H., & Campbell, K. P. (1998). Journal of Biological Chemistry, 273(52), 34667-34670). Such sarcoglycanopathies include various forms of limb-girdle muscular dystrophy (LGMD), for which there are no approved therapies currently available. Recently, studies have shown promise in using gene therapy to supplement expression of various sarcoglycans in deficient subjects (Pozsgai, E. R., et al. (2020). In Presented at ASGCT 23rd Annual Meeting May (Vol. 12, p. 15)). However, use of such therapies relies upon the ability to specifically and reliably detect these supplemental proteins in biological samples across different species.BRIEF SUMMARY OF THE DISCLOSURE

[0004] The present disclosure relates to a murine, humanized or chimeric antibody that binds an epitope within a sarcoglycan protein (e.g., an alpha sarcoglycan protein or a gamma sarcoglycan protein). More specifically, the present disclosure provides an isolatedanti-sarcoglycan antibody or an antigen-binding fragment thereof capable of specifically binding an epitope of human sarcoglycan protein, wherein the epitope comprises the amino acid sequence GNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1) or a portion thereof. In another aspect, the present disclosure provides an isolated antibody or antigen-binding fragment thereof that comprises a heavy chain variable region that comprises VH CDR1, VH CDR2, and VH CDR3 domains and a light chain variable region that comprises VL CDR1, VL CDR2, and VL CDR3 domains, wherein the VH CDR1 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 8, SEQ ID NO: 24, SEQ ID NO: 40, and SEQ ID NO: 56, the VH CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 10, SEQ ID NO: 26, SEQ ID NO: 42, and SEQ ID NO: 58, the VH CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 12, SEQ ID NO: 28, SEQ ID NO: 44, and SEQ ID NO: 60, the VL CDR1 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 14, SEQ ID NO: 30, SEQ ID NO: 46, and SEQ ID NO: 62, the VL CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 16, SEQ ID NO: 32, SEQ ID NO: 48, and SEQ ID NO: 64, or the VL CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 18, SEQ ID NO: 34, SEQ ID NO: 50, and SEQ ID NO: 66. In another aspect, the disclosure relates to an isolated antibody or antigen-binding fragment thereof comprising a heavy chain variable region that comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 4, SEQ ID NO: 20, SEQ ID NO: 36, and SEQ ID NO: 52 and a light chain variable region that comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 6, SEQ ID NO: 22, SEQ ID NO: 38, and SEQ ID NO: 54. In some embodiments, the human sarcoglycan protein is an alpha sarcoglycan protein. In some embodiments, the heavy chain variable region comprises a VH CDR1 selected from the group consisting of TYDMN (SEQ ID NO: 8), THDMN (SEQ ID NO: 24), TYDMS (SEQ ID NO: 40), and SSYYMC (SEQ ID NO: 56). In some embodiments, the heavy chain variable region further comprises a VH CDR2 selected from the group consisting of AITKNGISSFANWAQG (SEQ ID NO: 10), AITKNGITVYAKWTKG (SEQ ID NO: 26), AITKNGIRTYANWAKG (SEQ ID NO: 42), and CIVTADGTTYYASWAKG (SEQ ID NO: 58). In some embodiments, the heavy chainvariable region further comprises a VH CDR3 selected from the group consisting of PSL (SEQ ID NO: 12) (SEQ ID NO: 28) (SEQ ID NO: 44), and GFAF (SEQ ID NO: 60). In some embodiments, the light chain variable region comprises a VL CDR1 selected from the group consisting of QSSQSVYSNYLS (SEQ ID NO: 14), QSSPSVYNNYLS (SEQ ID NO: 30), QSSQSVYSNYLS (SEQ ID NO: 46), and QSSQSVDGNNDLA (SEQ ID NO: 62). In some embodiments, the light chain variable region further comprises a VL CDR2 selected from the group consisting of DASTLAS (SEQ ID NO: 16), DASTLAS (SEQ ID NO: 32), SASTLDS (SEQ ID NO: 48), and QASKLPS (SEQ ID NO: 64). In some embodiments, the light chain variable region further comprises a VL CDR3 selected from the group consisting of LGTYDCNSADCFV (SEQ ID NO: 18), LGTYDCNSADCFV (SEQ ID NO: 34), LGTYDCNSADCFV (SEQ ID NO: 50), and QGGYNGGVWP (SEQ ID NO: 66). In some embodiments, the antibody comprises a heavy chain variable region that comprises VH CDR1, VH CDR2, and VH CDR3 domains and a light chain variable region that comprises VL CDR1, VL CDR2, and VL CDR3 domains selected from the group consisting of 1) a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 8, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 10, a VH CDR3 having the amino acid sequence PSL (SEQ ID NO: 12), a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 14, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 16, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 18, 2) a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 24, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 26, a VH CDR3 having the amino acid sequence PSL (SEQ ID NO: 28), a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 30, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 32, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 34, 3) a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 40, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 42, a VH CDR3 having the amino acid sequence PSL (SEQ ID NO: 44), a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 46, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 48, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 50, and 4) a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 56, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 58, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 60, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 62,a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 64, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 66. In some embodiments, the antibody or antigen binding fragment thereof comprises 1) a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 4; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 6, 2) a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 20; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 22, 3) a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 36; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 38, or 4) a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 52, and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 54. In some embodiments, the heavy chain variable region of the antibody or antigen binding fragment thereof is selected from the group consisting of SEQ ID NO: 4, SEQ ID NO: 20, SEQ ID NO: 36, and SEQ ID NO: 52. In some embodiments, the light chain variable region of the antibody or antigen binding fragment thereof is selected from the group consisting of SEQ ID NO: 6, SEQ ID NO: 22, SEQ ID NO: 38, and SEQ ID NO: 54. In some embodiments, the heavy chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 4, SEQ ID NO: 20, SEQ ID NO: 36, and SEQ ID NO: 52, and the light chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 6, SEQ ID NO: 22, SEQ ID NO: 38, and SEQ ID NO: 54. In some embodiments, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 4 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 6. In some embodiments, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 20 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 22. In some embodiments, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 36 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 38. In some embodiments, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 52 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 54. In some embodiments, the antibody or antigen binding fragment thereof is labeled with a radioactive, enzymatic, or fluorescent group. In some embodiments, the antibody is a full- length antibody or an antibody fragment selected from the group consisting of Fab, Fab’, Fab’-SH, Fd, Fv, dAb, F(ab’)2, scFv, bispecific single chain Fv dimers, diabodies, triabodies, and sxFv genetically fused to the same or a different antibody. In some embodiments, theantibody is a murine antibody, a chimeric murine / human antibody, a human antibody, an engineered antibody, or a humanized antibody. In some embodiments, the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 4 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 6. In some embodiments, the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 20 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 22. In some embodiments, the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 36 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 38. In some embodiments, the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 52 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 54. In some embodiments, the antibody or antigen binding fragment thereof is a bispecific antibody. In some embodiments, the antibody or antigen binding fragment thereof is a multispecific antibody.

[0005] In another aspect, the disclosure relates to an isolated antibody or antigenbinding fragment thereof capable of specifically binding an epitope of a human sarcoglycan protein, wherein the epitope comprises an amino acid sequence KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQNVTVN ARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVGTDKLRVTGP EGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQAHAGKIEALSQMDIL FHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICVCPDGKLYLSVAGVSTTCQ EHSHICL (SEQ ID NO: 2) or a portion thereof. In another aspect the present disclosure provides for an isolated antibody or antigen-binding fragment thereof that comprises a heavy chain variable region that comprises VH CDR1, VH CDR2, and VH CDR3 domains and a light chain variable region that comprises VL CDR1, VL CDR2, and VL CDR3 domains, wherein the VH CDR1 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 72, SEQ ID NO: 88, SEQ ID NO: 104, SEQ ID NO: 120, and SEQ ID NO: 136, the VH CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 74, SEQ ID NO: 90, SEQ ID NO: 106, SEQ ID NO: 122, and SEQ ID NO: 138, the VH CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 76, SEQ ID NO: 92, SEQ ID NO: 108, AHL, and SEQ ID NO: 140, the VL CDR1 domain comprises an amino acid sequence selected from thegroup consisting of SEQ ID NO: 78, SEQ ID NO: 94, SEQ ID NO: 110, SEQ ID NO: 126, and SEQ ID NO: 142, the VL CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 80, SEQ ID NO: 96, SEQ ID NO: 112, SEQ ID NO: 128, and SEQ ID NO: 144, or the VL CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 82, SEQ ID NO: 98, SEQ ID NO: 114, SEQ ID NO: 130, and SEQ ID NO: 146. In another aspect, the disclosure includes an isolated antibody or antigen-binding fragment thereof comprising a heavy chain variable region that comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 68, SEQ ID NO: 84, SEQ ID NO: 100, SEQ ID NO: 116, and SEQ ID NO: 132, and a light chain variable region that comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 70, SEQ ID NO: 86, SEQ ID NO: 102, SEQ ID NO: 118, and SEQ ID NO: 134. In some embodiments, the human sarcoglycan protein is a gamma sacroglycan protein. In some embodiments, the heavy chain variable region comprises a VH CDR1 selected from the group consisting of SDAMT (SEQ ID NO: 72), SYHMI (SEQ ID NO: 88), SYSMS (SEQ ID NO: 104), DNGVI (SEQ ID NO: 120), and NNPIT (SEQ ID NO: 136). In some embodiments, the heavy chain variable region further comprises a VH CDR2 selected from the group consisting of TIYVSGNTYYASWATG (SEQ ID NO: 74), IISTGGDTYYASWAKG (SEQ ID NO: 90), YIVSDSRTWYASWAKG (SEQ ID NO: 106), YIHIDGRTYYATWAKS (SEQ ID NO: 122), and GIGASGRAYYANWAKS (SEQ ID NO: 138). In some embodiments, the heavy chain variable region further comprises a VH CDR3 selected from the group consisting of WGNL (SEQ ID NO: 76), DAGNSGI (SEQ ID NO: 92), LGGRASLDI (SEQ ID NO: 108), AHL, and LNGWHYAYV (SEQ ID NO: 140). In some embodiments, the light chain variable region comprises a VL CDR1 selected from the group consisting of QSSQSVYSDNQFT (SEQ ID NO: 78), QSSESVLDDGNWLA (SEQ ID NO: 94), QSSESVYNNNYLS (SEQ ID NO: 110), QASQSISNLLT (SEQ ID NO: 126), and QASQSVWDNKDLA (SEQ ID NO: 142). In some embodiments, the light chain variable region further comprises a VL CDR2 selected from the group consisting of DATTLAS (SEQ ID NO: 80), AASKLAS (SEQ ID NO: 96), GASTLAS (SEQ ID NO: 112), KASTLES (SEQ ID NO: 128), and ETSKLAS (SEQ ID NO: 144). In some embodiments, the light chain variable region further comprises a VL CDR3 selected from the group consisting of AGVYFGNILT (SEQ ID NO: 82), QGAGRGNIYP (SEQ ID NO: 98), AGAYSSNDKA (SEQ ID NO: 114), QSYVYGSSLDYGNT (SEQ ID NO: 130), and LGEFSCASADCAA(SEQ ID NO: 146). In some embodiments, the antibody comprises a heavy chain variable region that comprises VH CDR1, VH CDR2, and VH CDR3 domains and a light chain variable region that comprises VL CDR1, VL CDR2, and VL CDR3 domains selected from the group consisting of 1) a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 72, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 74, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 76, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 78, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 80, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 82, 2) a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 88, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 90, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 92, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 94, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 96, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 98, 3) a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 104, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 106, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 108, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 110, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 112, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 114, 4) a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 120, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 122, a VH CDR3 having the amino acid sequence AHL, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 126, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 128, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 130, and 5) a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 136, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 138, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 140, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 142, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 144, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 146. In some embodiments, the antibody or antigen binding fragment thereof comprises 1) a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 68; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 70, 2) a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 84; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 86, 3) a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 100; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 102, 4) a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 116; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 118, or 5) a heavy chainvariable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 132; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 134. In some embodiments, the heavy chain variable region of the antibody or antigen binding fragment thereof is selected from the group consisting of SEQ ID NO: 68, SEQ ID NO: 84, SEQ ID NO: 100, SEQ ID NO: 116, and SEQ ID NO: 132. In some embodiments, the light chain variable region of the antibody or antigen binding fragment thereof is selected from the group consisting of SEQ ID NO: 70, SEQ ID NO: 86, SEQ ID NO: 102, SEQ ID NO: 118, and SEQ ID NO: 134. In some embodiments, the heavy chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 68, SEQ ID NO: 84, SEQ ID NO: 100, SEQ ID NO: 116, and SEQ ID NO: 132; and the light chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 70, SEQ ID NO: 86, SEQ ID NO: 102, SEQ ID NO: 118, and SEQ ID NO: 134. In some embodiments, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 68 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 70. In some embodiments, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 84 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 86. In some embodiments, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 100 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 102. In some embodiments, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 116 and a light chain variable region comprising the amino acid sequence set forth in SEQ IDNO: 118. In some embodiments, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 132 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 134. In some embodiments, the antibody or antigen binding fragment thereof is labeled with a radioactive, enzymatic, or fluorescent group. In some embodiments, the antibody is a full-length antibody or an antibody fragment selected from the group consisting of Fab, Fab’, Fab’-SH, Fd, Fv, dAb, F(ab’)2, scFv, bispecific single chain Fv dimers, diabodies, triabodies, and sxFv genetically fused to the same or a different antibody. In some embodiments, the antibody is a murine antibody, a chimeric murine / human antibody, a human antibody, an engineered antibody, or a humanized antibody. In some embodiments, the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 68 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 70. In some embodiments, the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 84 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 86. In some embodiments, the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 100 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 102. In some embodiments, the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 116 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 118. In some embodiments, the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 132 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 134. In some embodiments, the antibody or antigen binding fragment thereof is a bispecific antibody. In some embodiments, the antibody or antigen binding fragment thereof is a multispecific antibody.

[0006] In another aspect, the present disclosure relates to an isolated polynucleotide comprising a nucleic acid sequence encoding a previously described antibody or antigen binding fragment thereof. In some embodiments, the nucleic acid sequence encodes a 1) a VH CDR1 domain comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 7, SEQ ID NO: 23, SEQ ID NO: 39, SEQ ID NO: 55, SEQ ID NO: 71, SEQ ID NO: 87, SEQ ID NO: 103, SEQ ID NO: 119, and SEQ ID NO: 135, 2) a VH CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 9, SEQ ID NO: 25, SEQ ID NO: 41, SEQ ID NO: 57, SEQ ID NO: 73, SEQ ID NO: 89, SEQ ID NO:105, SEQ ID NO: 121, and SEQ ID NO: 137, 3) a VH CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 11, SEQ ID NO: 27, SEQ ID NO: 43, SEQ ID NO: 59, SEQ ID NO: 75, SEQ ID NO: 91, SEQ ID NO: 107, SEQ ID NO: 123, and SEQ ID NO: 139, 4) a VL CDR1 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 13, SEQ ID NO: 29, SEQ ID NO: 45, SEQ ID NO: 61, SEQ ID NO: 77, SEQ ID NO: 93, SEQ ID NO: 109, SEQ ID NO: 125, and SEQ ID NO: 141, 5) a VL CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 15, SEQ ID NO: 31, SEQ ID NO: 47, SEQ ID NO: 63, SEQ ID NO: 79, SEQ ID NO: 95, SEQ ID NO: 111, SEQ ID NO: 127, and SEQ ID NO: 143, or 6) a VL CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 17, SEQ I DNO: 33, SEQ ID NO: 49, SEQ ID NO: 65, SEQ ID NO: 81, SEQ ID NO: 97, SEQ ID NO: 113, SEQ ID NO: 129, and SEQ ID NO: 145. In some embodiments, the nucleic acid encoding the heavy chain variable region comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 3, SEQ ID NO: 19, SEQ ID NO: 35, SEQ ID NO: 51, SEQ ID NO: 67, SEQ ID NO: 83, SEQ ID NO: 99, SEQ ID NO: 115, and SEQ ID NO: 131, and the nucleic acid encoding the light chain variable region comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 5, SEQ ID NO: 21, SEQ ID NO: 37, SEQ ID NO: 53, SEQ ID NO: 69 SEQ ID NO: 85, SEQ ID NO: 101, SEQ ID NO: 117, and SEQ ID NO: 133. In some embodiments, the present disclosure further provides a vector comprising a previously described polynucleotide. In some embodiments, the present disclosure further provides a host cell comprising a previously described vector. In some embodiments, the present disclosure further provides an in vitro detection kit comprising a previously described antibody or antigen binding fragment thereof. In some embodiments, the kit further comprises a second antibody or antigen binding fragment thereof labeled with a radioactive, enzymatic and / or fluorescent group.

[0007] In another aspect, the present disclosure provides a method for detecting the presence of a human sarcoglycan protein in a sample, comprising contacting the sample with a composition comprising a previously described isolated antibody or antigen binding fragment thereof. In some embodiments, the presence of a human sarcoglycan protein in the sample is indicated by detecting the presence of the antibody or antigen binding fragment thereof. In some embodiments, the presence of the antibody or antigen binding fragmentthereof is detected by an immunoassay. In some embodiments, the immunoassay comprises one or more of an immunofluorescence assay, an immunohistochemical assay, a Western blot, a direct enzyme-linked immunosorbent assay (ELISA), an indirect ELISA, a sandwich ELISA, a competitive ELISA, a reverse ELISA, a chemiluminescence assay, a radioimmunoassay, or an immunoprecipitation assay.

[0008] The present disclosure further provides a method of making an anti- sarcoglycan antibody or antigen binding fragment thereof, comprising (a) administering to a non-human vertebrate animal an immunogenic amount of a polypeptide comprising the amino acid sequence GNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1), (b) recovering spleen cells from the animal, (c) fusing the recovered spleen cells with myeloma cells to generate hybridomas, (d) screening for hybridomas that produce an antibody that specifically binds human sarcoglycan protein, and (e) recovering the antibody. The present disclosure further provides a method of making an anti-sarcoglycan antibody or antigen binding fragment thereof, comprising (a) administering to a non-human vertebrate animal an immunogenic amount of a polypeptide comprising the amino acid sequence KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQNVTVN ARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVGTDKLRVTGP EGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQAHAGKIEALSQMDIL FHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICVCPDGKLYLSVAGVSTTCQ EHSHICL (SEQ ID NO: 2), (b) recovering spleen cells from the animal, (c) fusing the recovered spleen cells with myeloma cells to generate hybridomas, (d) screening for hybridomas that produce an antibody that specifically binds human sarcoglycan protein, and (e) recovering the antibody. In some embodiments, the non-human vertebrate animal is a transgenic animal, and wherein the transgenic animal expresses human immunoglobulin genes. In some embodiments, the method further comprises administering to the non-human vertebrate animal one or more immune adjuvants. In some embodiments, the non-human vertebrate animal is selected from a mouse, rat, hamster, guinea pig, rabbit, chicken, non- human primate, pig, goat, cow, and horse.

[0009] The present disclosure further provides a method of making an anti- sarcoglycan antibody or antigen binding fragment thereof, comprising (a) immobilizing on a solid support an antigen comprising the amino acid sequenceGNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1), (b) applying a phage display antibody library to the immobilized antigen, (c) screening the library for phage that bind the antigen; and (d) recovering antigen-binding phage. In some embodiments, the solid support is selected from the group consisting of a microtiter plate well, polyvinylidene fluoride (PVDF) membrane, column matrix, immunotube, and magnetic bead. In some embodiments, the phage display antibody library is derived from a non-human vertebrate animal previously immunized with a composition comprising an immunogenic amount of a polypeptide comprising the amino acid sequence GNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1). In some embodiments, the non-human vertebrate animal is selected from a mouse, rat, hamster, guinea pig, rabbit, chicken, non-human primate, pig, goat, cow, and horse.

[0010] The present disclosure further provides a method of making an anti- sarcoglycan antibody or antigen binding fragment thereof, comprising (a) immobilizing on a solid support an antigen comprising the amino acid sequence KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQNVTVN ARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVGTDKLRVTGP EGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQAHAGKIEALSQMDIL FHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICVCPDGKLYLSVAGVSTTCQ EHSHICL (SEQ ID NO: 2), (b) applying a phage display antibody library to the immobilized antigen, (c) screening the library for phage that bind the antigen, and (d) recovering antigenbinding phage. In some embodiments, the solid support is selected from the group consisting of a microtiter plate well, polyvinylidene fluoride (PVDF) membrane, column matrix, immunotube, and magnetic bead. In some embodiments, the phage display antibody library is derived from a non-human vertebrate animal previously immunized with a composition comprising an immunogenic amount of a polypeptide comprising the amino acid sequence KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQNVTVN ARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVGTDKLRVTGP EGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQAHAGKIEALSQMDIL FHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICVCPDGKLYLSVAGVSTTCQ EHSHICL (SEQ ID NO: 2). In some embodiments, the non-human vertebrate animal is selected from a mouse, rat, hamster, guinea pig, rabbit, chicken, non-human primate, pig, goat, cow, and horse.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 illustrates the workflow for generating monoclonal antibodies in rabbits.

[0012] Figure 2 illustrates ELISA results for the indicated anti-alpha sarcoglycan antibody hybridoma clones.

[0013] Figure 3 illustrates ELISA results for the indicated anti-gamma sarcoglycan antibody hybridoma clones.

[0014] Figure 4 illustrates ELISA results assessing the ability of the indicated chimeric antibodies to specifically bind alpha sarcoglycan protein.

[0015] Figure 5 illustrates ELISA results assessing the ability of the indicated chimeric antibodies to specifically bind gamma sarcoglycan protein.DETAILED DESCRIPTION OF THE DISCLOSUREDefinitions

[0016] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. In case of conflict, the present application including the definitions will control. Unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular. All publications, patents and other references mentioned herein are incorporated by reference in their entireties for all purposes as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference.

[0017] Throughout this disclosure, the term “a” or “an” entity refers to one or more of that entity; for example, “a polynucleotide,” is understood to represent one or more polynucleotides. As such, the terms “a” (or “an”), “one or more,” and “at least one” can be used interchangeably herein.

[0018] Furthermore, “and / or” where used herein is to be taken as specific disclosure of each of the two specified features or components with or without the other. Thus, the term “and / or” as used in a phrase such as “A and / or B” herein is intended to include “A and B,” “A or B,” “A” (alone), and “B” (alone). Likewise, the term “and / or” as used in a phrase suchas “A, B, and / or C” is intended to encompass each of the following aspects: A, B, and C; A, B, or C; A or C; A or B; B or C; A and C; A and B; B and C; A (alone); B (alone); and C (alone).

[0019] The term “about” is used herein to mean approximately, roughly, around, or in the regions of. When the term “about” is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values set forth. In general, the term “about” is used herein to modify a numerical value above and below the stated value by a variance of 10 percent, up or down (higher or lower).

[0020] As used herein, “antibody” means an intact immunoglobulin, an antigenbinding fragment thereof, or an antigen-binding molecule. Antibodies of this disclosure can be of any isotype or class (e.g., IgM, IgD, IgG, IgE and IgA) or any subclass (e.g., IgGl-4, IgAl-2) or any type of subclass (e.g., IgG2a, IgG2b) and can have either a kappa (K) or lambda ( ) light chain. An antigen-binding fragment of an antibody includes, e.g., Fab, Fv, scFv, and Fd fragments, chimeric antibodies, humanized antibodies, single-chain antibodies (scAb), single domain antibodies (dAb), single domain heavy chain antibodies, a single domain light chain antibodies, bi-specific antibodies, multi-specific antibodies, and fusion proteins comprising an antigen-binding portion of an antibody and a non-antibody protein. The antibodies of the disclosure can be labelled with, e.g., a radioactive, enzymatic, or fluorescent group. The antibodies of the disclosure can also be conjugated to other moieties, such as members of specific binding pairs, e.g., biotin (member of biotin-avidin specific binding pair). The antibodies of the disclosure can also be bound to a solid support, such as, e.g., polystyrene plates or beads, and the like.

[0021] As used herein, a “monoclonal antibody” is an antibody produced by a group of identical cells, all of which were produced from a single cell by repetitive cellular replication. That is, the clone of cells only produces a single antibody species. A monoclonal antibody can be produced using hybridoma production technology or using other production methods known to those skilled in the art, including e.g., antibody phage display libraries.

[0022] As used herein, the term “heavy chain” refers to an antibody heavy chain, consisting of a variable region and a constant region. As used herein, the term “light chain” refers to an antibody light chain, consisting of a variable region and a constant region.

[0023] The term “full-length antibody” denotes an antibody including two full-length antibody heavy chains and two full-length antibody light chains. For example, a full-lengthIgG antibody heavy chain is a polypeptide consisting in N-terminal to C- terminal direction of an antibody heavy chain variable domain (VH), an antibody constant heavy chain domain 1 (CHI), an antibody hinge region (HR), an antibody heavy chain constant domain 2 (CH2), and an antibody heavy chain constant domain 3 (CH3), abbreviated as VH-CH-HR-CH2- CH3. A full-length antibody light chain is a polypeptide consisting in N-terminal to C- terminal direction of an antibody light chain variable domain (VL), and an antibody light chain constant domain (CL), abbreviated as VL-CL. The antibody light chain constant domain (CL) can be K (kappa) or (lambda). The two full-length antibody domains are linked together via inter-polypeptide disulphide bonds between the CL domain and the CHI domain and between the hinge regions of the full-length antibody heavy chains. Full-length antibodies can be any isotype or class (e.g., IgM, IgD, IgG, IgE and IgA) or any subclass (e.g., IgGl-4, IgAl-2) or any type of subclass (e.g., IgG2a, IgG2b).

[0024] As used herein and mentioned above, the terms “sarcoglycan” or “sarcoglycan protein” refer generally to the protein products (including partially or fully functionally protein domains) of at least any one of the following genes: SGCA (NCBI Gene ID: 6442; e.g., NCBI Protein Accession No.: NP_000014.1; UniProt: Q16586), SGCB (NCBI Gene ID: 6443; e.g. NCBI Protein Accession No.: NP_000223.1; UniProt: Q6IBJ4), SGCG (NCBI Gene ID: 6445; e.g., NCBI Protein Accession No.: NP_000222.2; UniProt: Q13326), and SGCD (NCBI Gene ID: 6444; e.g., NCBI Protein Accession No.: NP_000328.2; UniProt: Q92629). Collectively, sarcoglycan proteins form a protein complex that functions with dystrophin and associated proteins to link actin cytoskeleton to the extracellular matrix. Genetic defects in particular sarcoglycans are associated with various musculoskeletal disorders (collectively sarcoglycanopathies), such as limb-girdle muscular dystrophy (LGMD).

[0025] As used herein and mentioned above, “complementarity determining region(s)" ("CDR") describe the non-contiguous antigen combining sites (also known as antigen binding regions) found within the variable region of both heavy and light chain polypeptides. This particular region has been described by Kabat et al., J. Biol. Chem. 252:6609-6616 (1977); Kabat et al., U.S. Dept, of Health and Human Services, “Sequences of proteins of immunological interest” (1991) (also referred to herein as Kabat 1991); by Chothia et al., J. Mol. Biol. 196:901-917 (1987) (also referred to herein as Chothia 1987); and MacCallum et al., J. Mol. Biol. 262:732-745 (1996), where the definitions includeoverlapping or subsets of amino acid residues when compared against each other. Nevertheless, application of either definition to refer to a CDR of an antibody or grafted antibodies or variants thereof is intended to be within the scope of the term as defined and used herein. The exact residue numbers which encompass a particular CDR will vary depending on the sequence and size of the CDR. Those skilled in the art can routinely determine which residues comprise a particular CDR given the variable region amino acid sequence of the antibody. As used herein the term the terms “CDRL1”, “CDRL2”, and “CDRL3” refer to the first, second, and third CDRs in a light chain variable region, respectively. As used herein, the terms “CDRH1”, “CDRH2”, and “CDRH3” refer to the first, second, and third CDRs in a heavy chain variable region, respectively.

[0026] An “isolated” antibody is one that has been identified and separated and / or recovered from a component of its natural environment. In some aspects, the term “isolated” is used interchangeably with the term “recombinant.” As used herein, the terms “isolated” and “recombinant” refer to polypeptides or nucleotides formed by laboratory methods, such as molecular cloning. In some aspects, the antibody will be purified (a) to greater than 90%, greater than 95%, or greater than 98%, by weight of antibody as determined by the Lowry method, for example, more than 99% by weight, (b) to a degree sufficient to obtain at least 15 residues of N-terminal or internal amino acid sequence by use of a spinning cup sequenator, or (c) to homogeneity by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS- PAGE) under reducing or nonreducing conditions using Coomassie blue or silver stain.Isolated antibody includes the antibody in situ within recombinant cells since at least one component of the antibody's natural environment will not be present. In some aspects, isolated antibody will be prepared by at least one purification step.

[0027] The terms “percent identity” and / or “percent identical,” as used herein are defined as the percentage of nucleotide or amino acid residues in a sequence that are identical with the nucleotide or amino acid residues of the reference sequence after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity , as calculated by a pairwise alignment using the Needleman-Wunsch algorithm using a generally available alignment program, e.g., the Needle (EMBOSS) program. For example, the percent (%) amino acid sequence identity of an antibody refers to an antibody sequence that are identical with the amino acid residues in the reference antibody sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequenceidentity, and not considering any conservative substitutions as part of the sequence identity. Those skilled in the art can determine additional appropriate parameters for aligning sequences needed to achieve maximal alignment over the full length of the sequences being compared.

[0028] One skilled in the art will appreciate that the generation of a sequence alignment for the calculation of a percent sequence identity is not limited to binary sequencesequence comparisons exclusively driven by primary sequence data. Sequence alignments can be derived from multiple sequence alignments. One suitable program to generate multiple sequence alignments is ClustalW2, available from clustal.org. Another suitable program is MUSCLE, available from drive5.com / muscle / . ClustalW2 and MUSCLE are alternatively available, e.g., from the EBI.

[0029] As used herein, the term “80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identity” as used in the disclosure means that all such sequences are either of at least about 80% identity, at least about 81% identify, at least about 82% identity, at least about 83% identity, at least about 84% identity, at least about 85% identity, at least about 86% identity, at least about 87% identity, at least about 88% identity, at least about 89% identity, at least about 90% identity, at least about 91% identity, at least about 92% identity, at least about 93% identity, at least about94% identity, at least about 95% identity, at least about 96% identity, at least about 97% identity, at least about 98% identity, at least about 99% identity, or 100% identity (fully identical).

[0030] The term “epitope” refers to a region of an antigen that is bound by an antibody. An epitope may be defined as structural or functional. Functional epitopes are generally a subset of structural epitopes and have those residues that directly contribute to the affinity of the interaction. Epitopes may also be conformational, that is, composed of nonlinear amino acids. In certain embodiments, epitopes may include determinants that are chemically active surface groupings of molecules such as amino acids, sugar side chains, phosphoryl groups, or sulfonyl groups, and, in certain embodiments, may have specific three- dimensional structural characteristics, and / or specific charge characteristics.

[0031] The term “binding” refers to a direct association between two molecules, due to, for example, covalent, electrostatic, hydrophobic, and ionic and / or hydrogen-bond interactions, including interactions such as salt bridges and water bridges. A subject anti- AAV antibody binds specifically to an epitope within AAVrh74 capsid protein.

[0032] The term “murine antibody” as used herein includes antibodies in which the variable region sequences and the constant region sequences are derived from a mouse.

[0033] The term “chimeric antibody” as used herein includes antibodies in which the variable region sequences are derived from one species and the constant region sequences are derived from another species, such as an antibody in which the variable region sequences are derived from a mouse antibody and the constant region sequences are derived from a human antibody.

[0034] The term “humanized antibody” as used herein includes antibodies in which CDR sequences derived from the germline of another mammalian species, such as a mouse, have been grafted onto human framework sequences. Additional framework region modifications may be made within the human framework sequences as well as within the CDR sequences derived from the germline of another mammalian species.

[0035] The term “human antibody” as used herein means an antibody having an amino acid sequence corresponding to that of an antibody produced by a human and / or has been made using any of the techniques for making human antibodies known in the art or disclosed herein. This definition of a human antibody includes antibodies comprising at least one human heavy chain polypeptide or at least one human light chain polypeptide.

[0036] As used herein, the term “subject” includes any human or nonhuman animal. The term "nonhuman animal" includes all vertebrates, e.g., mammals and non-mammals, such as nonhuman primates, sheep, dogs, cats, horses, cows, chickens, amphibians, reptiles, etc. Preferably the subject is human.Anti-Alpha Sarcoglycan antibodies

[0037] The present disclosure provides an isolated anti-alpha sarcoglycan antibody or an antigen-binding fragment thereof capable of specifically binding an epitope of the alpha sarcoglycan protein or a fragment thereof. In particular aspects, the epitope within human alpha sarcoglycan protein comprises an amino acid sequence having at least about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, or 100% identity to the amino acid sequenceGNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1) or a portion thereof. In some aspects, the amino acid sequence of the epitope within human alpha sarcoglycan protein isGNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1).

[0038] In some aspects, the present disclosure provides an isolated anti-sarcoglycan antibody or antigen binding fragment thereof that specifically binds an epitope within human sarcoglycan protein, wherein the antibody competes for binding the epitope with a reference antibody. Competing antibodies or antigen-binding fragments thereof can be identified, for example, by using an antibody competition assay. Details of procedures for carrying out such competition assays are well known in the art and can be found, for example, in Harlow and Lane (1988) Antibodies, A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, pages 567-569. For purposes of the present disclosure, anti- sarcoglycan antibodies or fragments thereof that compete with a reference antibody are those that decrease the binding of the reference antibody to the target polypeptide by at least about 50%, about 60%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, or about 99%.

[0039] The present disclosure further provides an isolated anti-sarcoglycan antibody or antigen-binding fragment thereof that binds the same epitope within human sarcoglycan protein as a reference antibody. Assays for identifying antibodies that bind the same epitope within a particular protein are known to those of skill in the art. For example, such assays are detailed in Harlow and Lane (1988) Antibodies, A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, Chapter 14.

[0040] The isolated anti-sarcoglycan antibodies or antigen binding fragment thereof of the present disclosure specifically bind an epitope within a human alpha-sarcoglycan protein.

[0041] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR1 selected from the group consisting of TYDMN (SEQ ID NO: 8), THDMN (SEQ ID NO: 24), TYDMS (SEQ ID NO: 40), and SSYYMC (SEQ ID NO: 56).

[0042] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR2 selected from the group consisting of AITKNGISSFANWAQG (SEQ ID NO: 10), AITKNGITVYAKWTKG (SEQ ID NO: 26), AITKNGIRTYANWAKG (SEQ ID NO: 42), and CIVTADGTTYYASWAKG (SEQ ID NO: 58).

[0043] In some aspects of the disclosure, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR3 selected from the group consisting of PSL and GFAF (SEQ ID NO: 60).

[0044] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 8, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 10, and a VH CDR3 having the amino acid sequence PSL.

[0045] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 24, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 26, a VH CDR3 having the amino acid sequence PSL.

[0046] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 40, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 42, a VH CDR3 having the amino acid sequence PSL.

[0047] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 56, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 58, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 60.

[0048] In some aspects of the disclosure, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR1 selected from the group consisting of QSSQSVYSNYLS (SEQ ID NO: 14), QSSPSVYNNYLS (SEQ ID NO: 30), QSSQSVYSNYLS (SEQ ID NO: 46), and QSSQSVDGNNDLA (SEQ ID NO: 62).

[0049] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR2 selected from the group consisting of of DASTLAS (SEQ ID NO: 16), DASTLAS (SEQ ID NO: 32), SASTLDS (SEQ ID NO: 48), and QASKLPS (SEQ ID NO: 64).

[0050] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR3 selected from the group consisting of LGTYDCNSADCFV (SEQ ID NO: 18), LGTYDCNSADCFV (SEQ ID NO: 34), LGTYDCNSADCFV (SEQ ID NO: 50), and QGGYNGGVWP (SEQ ID NO: 66).

[0051] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 14, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 16, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 18.

[0052] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 30, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 32, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 34.

[0053] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 46, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 48, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 50.

[0054] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 62, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 64, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 66.

[0055] In some aspects of the disclosure the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region that comprises VH CDR1, VH CDR2, and VH CDR3 domains and a light chain variable region that comprises VL CDR1, VL CDR2, and VL CDR3 domains selected from the group consisting of: a. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 8, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 10, a VH CDR3 having the amino acid sequence PSL, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 14, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 16, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 18; b. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 24, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 26, a VH CDR3 having the amino acid sequence PSL, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 30, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 32, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 34; c. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 40, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 42, a VH CDR3 having the aminoacid sequence PSL, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 46, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 48, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 50; and d. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 56, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 58, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 60, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 62, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 64, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 66.

[0056] In some aspects, the isolated antibody or antigen binding fragment thereof comprises: a. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 4; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 6; b. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 20; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 22; and c. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the aminoacid sequence set forth in SEQ ID NO: 36; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 38; or d. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 52; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 54.

[0057] In some aspects of the disclosure, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof has an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence selected from the group consisting of SEQ ID NO: 4, SEQ ID NO: 20, SEQ ID NO: 36, and SEQ ID NO: 52; and further comprises a VH CDR1, VH CDR2, and VH CDR3 from an amino acid sequence selected from the group consisting of SEQ ID NO: 8, SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 24, SEQ ID NO: 26, SEQ ID NO: 28, SEQ ID NO: 40, SEQ ID NO: 42, SEQ ID NO: 44, SEQ ID NO: 56, SEQ ID NO: 58, and SEQ ID NO: 60.

[0058] In some aspects of the disclosure, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof is selected from the group consisting of SEQ ID NO: 4, SEQ ID NO: 20, SEQ ID NO: 36, SEQ ID, and SEQ ID NO: 52.

[0059] In some aspects of the disclosure, the light chain variable region of the isolated antibody or antigen binding fragment thereof has an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to an amino acid sequenceselected from the group consisting of SEQ ID NO: 6, SEQ ID NO: 22, SEQ ID NO: 38, and SEQ ID NO: 54; and further comprises a VL CDR1, VL CDR2, and / or VL CDR3 from an amino acid sequence selected from the group consisting of SEQ ID NO: 14, SEQ ID NO: 16, SEQ ID NO: 18, SEQ ID NO: 30, SEQ ID NO: 32, SEQ ID NO: 34, SEQ ID NO: 46, SEQ ID NO: 48, SEQ ID NO: 50, SEQ ID NO: 62, SEQ ID NO: 64, and SEQ ID NO: 66.

[0060] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof is selected from the group consisting of SEQ ID NO: 6, SEQ ID NO: 22, SEQ ID NO: 38, and SEQ ID NO: 54.

[0061] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 4, SEQ ID NO: 20, SEQ ID NO: 36, and SEQ ID NO: 52; and the light chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 6, SEQ ID NO: 22, SEQ ID NO: 38, and SEQ ID NO: 54.

[0062] In some aspects, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 4 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 6.

[0063] In some aspects, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 20 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 22.

[0064] In some aspects, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 36 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 38.

[0065] In some aspects, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 52 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 54.

[0066] In some aspects, the isolated antibody or antigen-binding fragment thereof comprises a heavy chain variable region that comprises VH CDR1, VH CDR2, and VH CDR3 domains and a light chain variable region that comprises VL CDR1, VL CDR2, andVL CDR3 domains selected from the sequences presented in Table 1. In some aspects, the isolated antibody of the present disclosure is an antibody presented below in Table 2.

[0067] Standard assays to evaluate the binding ability of the antibodies toward sarcoglycan proteins are known in the art, including for example, ELISAs, BIAcore®, Western blots, RIAs, and flow cytometry analysis. The binding kinetics (e.g., binding affinity like KD) of the antibodies also can be assessed by standard assays known in the art, such as by Scatchard or BIAcore® system analysis. The relative binding affinity Ki can be assessed by standard competition assays known in the art.

[0068] In some aspects, the isolated antibody or antigen-binding fragment thereof is labeled with a radioactive, enzymatic, or fluorescent group. Examples of groups for purposes of labeling antibodies include various enzymes, binding pairs, fluorescent materials, luminescent materials, bioluminescent materials, and radioactive materials. Examples of suitable enzymes include but are not limited to horseradish peroxidase, alkaline phosphatase, P-galactosidase, or acetylcholinesterase; examples of suitable binding pairs include but are not limited to streptavidin / biotin and avidin / biotin; examples of suitable fluorescent groups include but are not limited to umbelliferone, fluorescein, fluorescein isothiocyanate, rhodamine, dichlorotriazinylamine fluorescein, dansylchloride or phycoerythrin; an example of a luminescent material includes but is not limited to luminol; examples of bioluminescent materials include but are not limited to luciferase, luciferin, and aequorin; and examples of suitable radioactive material include125I,133I,35S, or3H.

[0069] In some embodiments, the isolated antibody is a full-length antibody or an antibody fragment selected from the group consisting of Fab, Fab’, Fab’-SH, Fd, Fv, dAb, F(ab’)2, scFv, bispecific single chain Fv dimers, diabodies, triabodies, and sxFv genetically fused to the same or a different antibody.

[0070] In some embodiments, the isolated antibody is a murine antibody, a chimeric antibody, a human antibody, an engineered antibody, or a humanized antibody. In some aspects, the chimeric antibody is a chimeric rabbit / human antibody.

[0071] In some aspects, the isolated antibody is a chimeric antibody comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 147. In some aspects, the isolated antibody is a chimeric antibody comprising a light chain comprising the amino acid sequence set forth in SEQ ID NO: 148. In some aspects, the isolated antibody is a chimeric antibody comprising a heavy chain comprising the amino acid sequence set forth inSEQ ID NO: 147 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 148.

[0072] In some aspects, the isolated antibody is a chimeric antibody comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 149. In some aspects, the isolated antibody is a chimeric antibody comprising a light chain comprising the amino acid sequence set forth in SEQ ID NO: 150. In some aspects, the isolated antibody is a chimeric antibody comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 149 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 150.

[0073] In some aspects, the isolated antibody is a chimeric antibody comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 151. In some aspects, the isolated antibody is a chimeric antibody comprising a light chain comprising the amino acid sequence set forth in SEQ ID NO: 152. In some aspects, the isolated antibody is a chimeric antibody comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 151 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 152.

[0074] In some aspects, the isolated antibody is a chimeric antibody presented in Table 2 below. In some embodiments, the isolated antibody or antigen binding fragment thereof is a bispecific antibody. In some embodiments, the isolated antibody or antigen binding fragment thereof is a multispecific antibody.Anti-Gamma Sarcoglycan antibodies

[0075] The present disclosure provides an isolated anti-gamma sarcoglycan antibody or an antigen-binding fragment thereof capable of specifically binding an epitope of the gamma sarcoglycan protein or a fragment thereof. In particular aspects, the epitope within human gamma sarcoglycan protein comprises an amino acid sequence having at least about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, or 100% identity to the amino acid sequence KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQNVTVN ARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVGTDKLRVTGP EGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQAHAGKIEALSQMDIL FHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICVCPDGKLYLSVAGVSTTCQEHSHICL (SEQ ID NO: 2) or a portion thereof. In some aspects, the amino acid sequence of the epitope within human alpha sarcoglycan protein is KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQNVTVN ARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVGTDKLRVTGP EGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQAHAGKIEALSQMDIL FHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICVCPDGKLYLSVAGVSTTCQ EHSHICL (SEQ ID NO: 2).

[0076] In some aspects, the present disclosure provides an isolated anti-sarcoglycan antibody or antigen binding fragment thereof that specifically binds an epitope within human sarcoglycan protein, wherein the antibody competes for binding the epitope with a reference antibody. Competing antibodies or antigen-binding fragments thereof can be identified, for example, by using an antibody competition assay. Details of procedures for carrying out such competition assays are well known in the art and can be found, for example, in Harlow and Lane (1988) Antibodies, A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, pages 567-569. For purposes of the present disclosure, anti- sarcoglycan antibodies or fragments thereof that compete with a reference antibody are those that decrease the binding of the reference antibody to the target polypeptide by at least about 50%, about 60%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, or about 99%.

[0077] The present disclosure further provides an isolated anti-sarcoglycan antibody or antigen-binding fragment thereof that binds the same epitope within human sarcoglycan protein as a reference antibody. Assays for identifying antibodies that bind the same epitope within a particular protein are known to those of skill in the art. For example, such assays are detailed in Harlow and Lane (1988) Antibodies, A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, Chapter 14.

[0078] The isolated anti-sarcoglycan antibodies or antigen binding fragment thereof of the present disclosure specifically bind an epitope within a human gamma-sarcoglycan protein.

[0079] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR1 selected from the group consisting of SDAMT (SEQ ID NO: 72), SYHMI (SEQ ID NO: 88), SYSMS (SEQ ID NO: 104), SEQ ID DNGVI (NO: 120), and NNPIT (SEQ ID NO: 136).

[0080] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR2 selected from the group consisting of TIYVSGNTYYASWATG (SEQ ID NO: 74), IISTGGDTYYASWAKG (SEQ ID NO: 90), YIVSDSRTWYASWAKG (SEQ ID NO: 106), YIHIDGRTYYATWAKS (SEQ ID NO: 122), and GIGASGRAYYANWAKS (SEQ ID NO: 138).

[0081] In some aspects of the disclosure, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR3 selected from the group consisting of WGNL (SEQ ID NO: 76), DAGNSGI (SEQ ID NO: 92), LGGRASLDI (SEQ ID NO: 108), AHL, and LNGWHYAYV (SEQ ID NO: 140).

[0082] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR1 having the amino acid sequence SDAMT (SEQ ID NO: 72), a VH CDR2 having the amino acid sequence TIYVSGNTYYASWATG (SEQ ID NO: 74), and a VH CDR3 having the amino acid sequence WGNL (SEQ ID NO: 76).

[0083] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR1 having the amino acid sequence SYHMI (SEQ ID NO: 88), a VH CDR2 having the amino acid sequence IISTGGDTYYASWAKG (SEQ ID NO: 90), and a VH CDR3 having the amino acid sequence DAGNSGI (SEQ ID NO: 92).

[0084] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR1 having the amino acid sequence SYSMS (SEQ ID NO: 104), a VH CDR2 having the amino acid sequence YIVSDSRTWYASWAKG (SEQ ID NO: 106), and a VH CDR3 having the amino acid sequence LGGRASLDI (SEQ ID NO: 108).

[0085] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR1 having the amino acid sequence SEQ ID DNGVI (NO: 120), a VH CDR2 having the amino acid sequence YIHIDGRTYYATWAKS (SEQ ID NO: 122), and a VH CDR3 having the amino acid sequence AHL.

[0086] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VH CDR1 having the amino acid sequence NNPIT (SEQ ID NO: 136), a VH CDR2 having the amino acid sequenceGIGASGRAYYANWAKS (SEQ ID NO: 138), and a VH CDR3 having the amino acid sequence LNGWHYAYV (SEQ ID NO: 140).

[0087] In some aspects of the disclosure, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR1 selected from the group consisting of QSSQSVYSDNQFT (SEQ ID NO: 78), QSSESVLDDGNWLA (SEQ ID NO: 94), QSSESVYNNNYLS (SEQ ID NO: 110), QASQSISNLLT (SEQ ID NO: 126), and QASQSVWDNKDLA (SEQ ID NO: 142).

[0088] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR2 selected from the group consisting of DATTLAS (SEQ ID NO: 80), AASKLAS (SEQ ID NO: 96), GASTLAS (SEQ ID NO: 112), KASTLES (SEQ ID NO: 128), and ETSKLAS (SEQ ID NO: 144).

[0089] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR3 selected from the group consisting of AGVYFGNILT (SEQ ID NO: 82), QGAGRGNIYP (SEQ ID NO: 98), AGAYSSNDKA (SEQ ID NO: 114), QSYVYGSSLDYGNT (SEQ ID NO: 130), and LGEFSCASADCAA (SEQ ID NO: 146).

[0090] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR1 having the amino acid sequence QSSQSVYSDNQFT (SEQ ID NO: 78), a VL CDR2 having the amino acid sequence DATTLAS (SEQ ID NO: 80), and a VL CDR3 having the amino acid sequence AGVYFGNILT (SEQ ID NO: 82).

[0091] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR1 having the amino acid sequence QSSESVLDDGNWLA (SEQ ID NO: 94), a VL CDR2 having the amino acid sequence AASKLAS (SEQ ID NO: 96), and a VL CDR3 having the amino acid sequence QGAGRGNIYP (SEQ ID NO: 98).

[0092] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR1 having the amino acid sequence QSSESVYNNNYLS (SEQ ID NO: 110), a VL CDR2 having the amino acid sequence GASTLAS (SEQ ID NO: 112), and a VL CDR3 having the amino acid sequence AGAYSSNDKA (SEQ ID NO: 114).

[0093] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR1 having the amino acid sequence QASQSISNLLT (SEQ ID NO: 126), a VL CDR2 having the amino acid sequence KASTLES (SEQ ID NO: 128), and a VL CDR3 having the amino acid sequence QSYVYGSSLDYGNT (SEQ ID NO: 130).

[0094] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof comprises a VL CDR1 having the amino acid sequence QASQSVWDNKDLA (SEQ ID NO: 142), a VL CDR2 having the amino acid sequence ETSKLAS (SEQ ID NO: 144), and a VL CDR3 having the amino acid sequence LGEFSCASADCAA (SEQ ID NO: 146).

[0095] In some aspects of the disclosure the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region that comprises VH CDR1, VH CDR2, and VH CDR3 domains and a light chain variable region that comprises VL CDR1, VL CDR2, and VL CDR3 domains selected from the group consisting of: a. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 72, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 74, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 76, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 78, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 80, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 82; b. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 88, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 90, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 92, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 94, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 96, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 98; c. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 104, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 106, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 108, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 110, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 112, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 114; and d. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 120, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 122, a VH CDR3 having the aminoacid sequence AHL, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 126, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 128, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 130; and e. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 136, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 138, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 140, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 142, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 144, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 146.

[0096] In some aspects, the isolated antibody or antigen binding fragment thereof comprises: a. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 68; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 70; b. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 84; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 86; and c. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the aminoacid sequence set forth in SEQ ID NO: 100; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 102; d. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 116; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 118; or e. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 132; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 134.

[0097] In some aspects of the disclosure, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof has an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence selected from the group consisting of SEQ ID NO: 68, SEQ ID NO: 84, SEQ ID NO: 100, SEQ ID NO: 116, and SEQ ID NO: 132; and further comprises a VH CDR1, VH CDR2, and VH CDR3 from an amino acid sequence selected from the group consisting of SEQ ID NO: 72, SEQ ID NO: 74, SEQ ID NO: 76, SEQ ID NO: 88, SEQ ID NO: 90, SEQID NO: 92, SEQ ID NO: 104, SEQ ID NO: 106, SEQ ID NO: 108, SEQ ID NO: 120, SEQ ID NO: 122, AHL, SEQ ID NO: 136, SEQ ID NO: 138, and SEQ ID NO: 140.

[0098] In some aspects of the disclosure, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof is selected from the group consisting of SEQ ID NO: 68, SEQ ID NO: 84, SEQ ID NO: 100, SEQ ID NO: 116, and SEQ ID NO: 132.

[0099] In some aspects of the disclosure, the light chain variable region of the isolated antibody or antigen binding fragment thereof has an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to an amino acid sequence selected from the group consisting of SEQ ID NO: 70, SEQ ID NO: 86, SEQ ID NO: 102, SEQ ID NO: 118, and SEQ ID NO: 134; and further comprises a VL CDR1, VL CDR2, and / or VL CDR3 from an amino acid sequence selected from the group consisting of SEQ ID NO: 78, SEQ ID NO: 80, SEQ ID NO: 82, SEQ ID NO: 94, SEQ ID NO: 96, SEQ ID NO: 98, SEQ ID NO: 110, SEQ ID NO: 112, SEQ ID NO: 114, SEQ ID NO: 126, SEQ ID NO: 128, SEQ ID NO: 130, SEQ ID NO: 142, SEQ ID NO: 144, and SEQ ID NO: 146.

[0100] In some aspects, the light chain variable region of the isolated antibody or antigen binding fragment thereof is selected from the group consisting of SEQ ID NO: 70, SEQ ID NO: 86, SEQ ID NO: 102, SEQ ID NO: 118, and SEQ ID NO: 134.

[0101] In some aspects, the heavy chain variable region of the isolated antibody or antigen binding fragment thereof comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 68, SEQ ID NO: 84, SEQ ID NO: 100, SEQ ID NO: 116, and SEQ ID NO: 132; and the light chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 70, SEQ ID NO: 86, SEQ ID NO: 102, SEQ ID NO: 118, and SEQ ID NO: 134.

[0102] In some aspects, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 68 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 70.

[0103] In some aspects, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQID NO: 84 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 86.

[0104] In some aspects, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 100 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 102.

[0105] In some aspects, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 116 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 118.

[0106] In some aspects, the isolated antibody or antigen binding fragment thereof comprises a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 132 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 134.

[0107] In some aspects, the isolated antibody or antigen-binding fragment thereof comprises a heavy chain variable region that comprises VH CDR1, VH CDR2, and VH CDR3 domains and a light chain variable region that comprises VL CDR1, VL CDR2, and VL CDR3 domains selected from the sequences presented in Table 3. In some aspects, the isolated antibody of the present disclosure is an antibody presented below in Table 4.

[0108] Standard assays to evaluate the binding ability of the antibodies toward sarcoglycan proteins are known in the art, including for example, ELISAs, BIAcore®, Western blots, RIAs, and flow cytometry analysis. The binding kinetics (e.g., binding affinity like KD) of the antibodies also can be assessed by standard assays known in the art, such as by Scatchard or BIAcore® system analysis. The relative binding affinity Ki can be assessed by standard competition assays known in the art.

[0109] In some aspects, the isolated antibody or antigen-binding fragment thereof is labeled with a radioactive, enzymatic, or fluorescent group. Examples of groups for purposes of labeling antibodies include various enzymes, binding pairs, fluorescent materials, luminescent materials, bioluminescent materials, and radioactive materials. Examples of suitable enzymes include but are not limited to horseradish peroxidase, alkaline phosphatase, P-galactosidase, or acetylcholinesterase; examples of suitable binding pairs include but are not limited to streptavidin / biotin and avidin / biotin; examples of suitable fluorescent groupsinclude but are not limited to umbelliferone, fluorescein, fluorescein isothiocyanate, rhodamine, dichlorotriazinylamine fluorescein, dansylchloride or phycoerythrin; an example of a luminescent material includes but is not limited to luminol; examples of bioluminescent materials include but are not limited to luciferase, luciferin, and aequorin; and examples of suitable radioactive material include125I,13fl,35S, or3H.

[0110] In some embodiments, the isolated antibody is a full-length antibody or an antibody fragment selected from the group consisting of Fab, Fab’, Fab’-SH, Fd, Fv, dAb, F(ab’)2, scFv, bispecific single chain Fv dimers, diabodies, triabodies, and sxFv genetically fused to the same or a different antibody.[OHl] In some embodiments, the isolated antibody is a murine antibody, a chimeric antibody, a human antibody, an engineered antibody, or a humanized antibody. In some aspects, the chimeric antibody is a chimeric rabbit / human antibody.

[0112] In some aspects, the isolated antibody is a chimeric antibody comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 153. In some aspects, the isolated antibody is a chimeric antibody comprising a light chain comprising the amino acid sequence set forth in SEQ ID NO: 154. In some aspects, the isolated antibody is a chimeric antibody comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 153 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 154.

[0113] In some aspects, the isolated antibody is a chimeric antibody comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 155. In some aspects, the isolated antibody is a chimeric antibody comprising a light chain comprising the amino acid sequence set forth in SEQ ID NO: 156. In some aspects, the isolated antibody is a chimeric antibody comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 155 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 156.

[0114] In some aspects, the isolated antibody is a chimeric antibody comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 157. In some aspects, the isolated antibody is a chimeric antibody comprising a light chain comprising the amino acid sequence set forth in SEQ ID NO: 158. In some aspects, the isolated antibody is a chimeric antibody comprising a heavy chain comprising the amino acid sequence set forth inSEQ ID NO: 157 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 158.

[0115] In some aspects, the isolated antibody is a chimeric antibody presented in Table 4 below. In some embodiments, the isolated antibody or antigen binding fragment thereof is a bispecific antibody. In some embodiments, the isolated antibody or antigen binding fragment thereof is a multispecific antibody.Nucleic acids, vectors and host cells

[0116] The present disclosure also provides isolated polynucleotides that comprise nucleic acids encoding the antibodies and fragments thereof that bind to sarcoglycan proteins, vectors, and host cells comprising the polynucleotides or the vector. The nucleic acids may be present in whole cells, in a cell lysate, or in a partially purified or substantially pure form. A nucleic acid is “isolated” or “rendered substantially pure” when purified away from other cellular components or other contaminants, e.g., other cellular nucleic acids or proteins, by standard techniques, including alkaline / SDS treatment, CsCl banding, column chromatography, agarose gel electrophoresis and others well known in the art, see e.g. F. Ausubel, et al., ed. (1987) Current Protocols in Molecular Biology, Greene Publishing and Wiley Interscience, New York. A nucleic acid of the invention can be, for example, DNA or RNA and may or may not contain intron sequences. In a preferred embodiment, the nucleic acid is a cDNA molecule.

[0117] Nucleic acids of the invention can be obtained using standard molecular biology techniques e.g. cDNAs encoding the light and / or heavy chains of the antibody or encoding VH and / or VL segments can be obtained by standard PCR amplification or cDNA cloning techniques. For antibodies obtained from an immunoglobulin gene library (e.g., using phage display techniques), one or more nucleic acids encoding the antibody can be recovered from the library. The methods of introducing exogenous nucleic acid into host cells are well known in the art, and will vary with the host cell used. Techniques include but are not limited to dextran-mediated transfection, calcium phosphate precipitation, calcium chloride treatment, polyethylenimine mediated transfection, polybrene mediated transfection, protoplast fusion, electroporation, viral or phage infection, encapsulation of the polynucleotide(s) in liposomes, and direct microinjection of the DNA into nuclei. In the case of mammalian cells, transfection may be either transient or stable.

[0118] In some aspects, the polynucletoide of the disclosure comprises a nucleic acid sequence that encodes a VH CDR1 domain comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 7, SEQ ID NO: 23, SEQ ID NO: 39, SEQ ID NO: 55, SEQ ID NO: 71, SEQ ID NO: 87, SEQ ID NO: 103, SEQ ID NO: 119, and SEQ ID NO: 135.

[0119] In some aspects, the polynucleotide of the disclosure comprises a nucleic acid sequence that encodes a VH CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 9, SEQ ID NO: 25, SEQ ID NO: 41, SEQ ID NO: 57, SEQ ID NO: 73, SEQ ID NO: 89, SEQ ID NO: 105, SEQ ID NO: 121, and SEQ ID NO: 137.

[0120] In some aspects, the polynucleotide of the disclosure comprises a nucleic acid sequence that encodes a VH CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 11, SEQ ID NO: 27, SEQ ID NO: 43, SEQ ID NO: 59, SEQ ID NO: 75, SEQ ID NO: 91, SEQ ID NO: 107, SEQ ID NO: 123, and SEQ ID NO: 139.

[0121] In some aspects, the polynucleotide of the disclosure comprises a nucleic acid sequence that encodes a VL CDR1 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 13, SEQ ID NO: 29, SEQ ID NO: 45, SEQ ID NO: 61, SEQ ID NO: 77, SEQ ID NO: 93, SEQ ID NO: 109, SEQ ID NO: 125, and SEQ ID NO: 141.

[0122] In some aspects, the polynucleotide of the disclosure comprises a nucleic acid sequence that encodes a VL CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 15, SEQ ID NO: 31, SEQ ID NO: 47, SEQ ID NO: 63, SEQ ID NO: 79, SEQ ID NO: 95, SEQ ID NO: 111, SEQ ID NO: 127, and SEQ ID NO: 143.

[0123] In some aspects, the polynucleotide of the disclosure comprises a nucleic acid sequence that encodes a VL CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 17, SEQ I DNO: 33, SEQ ID NO: 49, SEQ ID NO: 65, SEQ ID NO: 81, SEQ ID NO: 97, SEQ ID NO: 113, SEQ ID NO: 129, and SEQ ID NO: 145.

[0124] In some aspects, the polynucleotide of the disclosure comprises a nucleic acid sequence that encodes (a) a VH CDR1 domain comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 7, SEQ ID NO: 23, SEQ ID NO: 39, SEQ ID NO: 55, SEQ ID NO: 71, SEQ ID NO: 87, SEQ ID NO: 103, SEQ ID NO: 119, and SEQ ID NO: 135; (b) a VH CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 9, SEQ ID NO: 25, SEQ ID NO: 41, SEQ ID NO: 57, SEQ ID NO: 73, SEQ ID NO: 89, SEQ ID NO: 105, SEQ ID NO: 121, and SEQ ID NO: 137; (c) a VH CDR3 domain comprises an amino acid sequence selected from the group consisting ofSEQ ID NO: 11, SEQ ID NO: 27, SEQ ID NO: 43, SEQ ID NO: 59, SEQ ID NO: 75, SEQ ID NO: 91, SEQ ID NO: 107, SEQ ID NO: 123, and SEQ ID NO: 139; (d) a VL CDR1 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 13, SEQ ID NO: 29, SEQ ID NO: 45, SEQ ID NO: 61, SEQ ID NO: 77, SEQ ID NO: 93, SEQ ID NO: 109, SEQ ID NO: 125, and SEQ ID NO: 141; (e) a VL CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 15, SEQ ID NO: 31, SEQ ID NO: 47, SEQ ID NO: 63, SEQ ID NO: 79, SEQ ID NO: 95, SEQ ID NO: 111, SEQ ID NO: 127, and SEQ ID NO: 143; and (f) a VL CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 17, SEQ I DNO: 33, SEQ ID NO: 49, SEQ ID NO: 65, SEQ ID NO: 81, SEQ ID NO: 97, SEQ ID NO: 113, SEQ ID NO: 129, and SEQ ID NO: 145.

[0125] In some aspects of the disclosure, the nucleic acid encoding the heavy chain variable region of the antibody of fragment thereof comprises a nucleotide sequence selected from the group consisting of of SEQ ID NO: 3, SEQ ID NO: 19, SEQ ID NO: 35, SEQ ID NO: 51, SEQ ID NO: 67, SEQ ID NO: 83, SEQ ID NO: 99, SEQ ID NO: 115, and SEQ ID NO: 131.

[0126] In some aspects of the disclosure, the nucleic acid encoding the light chain variable region comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 5, SEQ ID NO: 21, SEQ ID NO: 37, SEQ ID NO: 53, SEQ ID NO: 69 SEQ ID NO: 85, SEQ ID NO: 101, SEQ ID NO: 117, and SEQ ID NO: 133.

[0127] In some aspects of the disclosure, the nucleic acid encoding the heavy chain variable region of the antibody of fragment thereof comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 3, SEQ ID NO: 19, SEQ ID NO: 35, SEQ ID NO: 51, SEQ ID NO: 67, SEQ ID NO: 83, SEQ ID NO: 99, SEQ ID NO: 115, and SEQ ID NO: 131; and the nucleic acid encoding the light chain variable region comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 5, SEQ ID NO: 21, SEQ ID NO: 37, SEQ ID NO: 53, SEQ ID NO: 69 SEQ ID NO: 85, SEQ ID NO: 101, SEQ ID NO: 117, and SEQ ID NO: 133.

[0128] In some aspects, the nucleic acid encoding the heavy chain variable region of the antibody of fragment thereof comprises the nucleotide sequence of SEQ ID NO: 3 and the nucleic acid encoding the light chain variable region comprises the nucleotide sequence of SEQ ID NO: 5.

[0129] In some aspects, the nucleic acid encoding the heavy chain variable region of the antibody of fragment thereof comprises the nucleotide sequence of SEQ ID NO: 19 and the nucleic acid encoding the light chain variable region comprises the nucleotide sequence of SEQ ID NO: 21.

[0130] In some aspects, the nucleic acid encoding the heavy chain variable region of the antibody of fragment thereof comprises the nucleotide sequence of SEQ ID NO: 35 and the nucleic acid encoding the light chain variable region comprises the nucleotide sequence of SEQ ID NO: 37.

[0131] In some aspects, the nucleic acid encoding the heavy chain variable region of the antibody of fragment thereof comprises the nucleotide sequence of SEQ ID NO: 51 and the nucleic acid encoding the light chain variable region comprises the nucleotide sequence of SEQ ID NO: 53.

[0132] In some aspects, the nucleic acid encoding the heavy chain variable region of the antibody of fragment thereof comprises the nucleotide sequence of SEQ ID NO: 67 and the nucleic acid encoding the light chain variable region comprises the nucleotide sequence of SEQ ID NO: 69.

[0133] In some aspects, the nucleic acid encoding the heavy chain variable region of the antibody of fragment thereof comprises the nucleotide sequence of SEQ ID NO: 83 and the nucleic acid encoding the light chain variable region comprises the nucleotide sequence of SEQ ID NO: 85.

[0134] In some aspects, the nucleic acid encoding the heavy chain variable region of the antibody of fragment thereof comprises the nucleotide sequence of SEQ ID NO: 99 and the nucleic acid encoding the light chain variable region comprises the nucleotide sequence of SEQ ID NO: 101.

[0135] In some aspects, the nucleic acid encoding the heavy chain variable region of the antibody of fragment thereof comprises the nucleotide sequence of SEQ ID NO: 115 and the nucleic acid encoding the light chain variable region comprises the nucleotide sequence of SEQ ID NO: 117.

[0136] In some aspects, the nucleic acid encoding the heavy chain variable region of the antibody of fragment thereof comprises the nucleotide sequence of SEQ ID NO: 131 and the nucleic acid encoding the light chain variable region comprises the nucleotide sequence of SEQ ID NO: 133.

[0137] Once DNA fragments encoding VH and / or VL segments are obtained, these DNA fragments can be further manipulated by standard recombinant DNA techniques, for example to convert a heavy chain variable region DNA sequence into a heavy chain full- length variable and constant region sequences, or to sequences encoding fragments corresponding to the fragments described herein such as Fab or scFv. In these manipulations, a VL- or VH-encoding DNA fragment is operatively linked to another DNA fragment encoding another protein, such as an antibody constant region or a flexible linker. The term “operatively linked”, as used in this context, is intended to mean that the two DNA fragments are joined such that the amino acid sequences encoded by the two DNA fragments remain inframe. The isolated DNA encoding the VH region can be converted to a full-length heavy chain gene by operatively linking the VH-encoding DNA to another DNA molecule encoding heavy chain constant regions (CHI, CH2, CH3). The sequences of human heavy chain constant region genes are known in the art (see e.g., Kabat EA et al., supra} and DNA fragments encompassing these regions can be obtained by standard PCR amplification. The heavy chain constant region can be an IgGl (IGHG1), IgG2 (IGHG2), IgG3 (IGHG3), IgG4 (IGHG4), IgAl (IGHA1), IgA2 (IGHA2), IgM (IGHM), IgD (IGHD), or IgE (IGHE) constant region.

[0138] For a nucleic acid encoding a Fab fragment heavy chain, the VH-encoding DNA can be operatively linked to another DNA molecule encoding only the heavy chain CHI constant region. The isolated DNA encoding the VL region can be converted to a full- length light chain (as well as a Fab light chain) by operatively linking the VL-encoding DNA to another DNA molecule encoding the light chain constant region, CL. The sequences of human light chain constant region genes are known in the art (see e.g., Kabat EA et al., supra} and DNA fragments encompassing these regions can be obtained by standard PCR amplification. In some embodiments, the light chain constant region can be a kappa or lambda constant region, preferably a kappa constant region.

[0139] For a nucleic acid encoding a scFv, the VH- and VL-encoding DNA fragments are operatively linked to another fragment encoding a flexible linker, e.g., encoding an amino acid linker sequence , such that the VH and VL sequences can be expressed as a contiguous single-chain protein, with the VL and VH regions joined by the flexible linker (see e.g., Bird RE et al., (1988) Science, 242: 423-426; Huston JS et al., (1988) Proc. Natl. Acad. Sci. USA, 85: 5879-83; McCafferty J et al., (1990) Nature, 348: 552-554). Various techniques havebeen developed for the production of antibody fragments of antibodies. Traditionally, these fragments were derived via proteolytic digestion of intact antibodies (see, e.g., Morimoto K etal., (1992) J. Biochem. & Biophysical Methods, 24: 107-117 and Brennan M et al., (1985) Science, 229: 81-3). However, these fragments can now be produced directly by recombinant host cells. For example, the antibody fragments can be isolated from antibody phage libraries. Alternatively, Fab'-SH fragments can be directly recovered from E. coli and chemically coupled to form F(ab')2 fragments (Carter P et al., (1992) Bio / Technology, 10: 163-167). According to another approach, F(ab')2 fragments can be isolated directly from recombinant host cell culture. Other techniques for the production of antibody fragments will be apparent to the skilled practitioner. In some embodiments, the antibody of choice is a single-chain Fv fragment (scFv).

[0140] The nucleic acids that encode the antibodies of the present disclosure may be incorporated into a vector, preferably an expression vector in order to express the protein. A variety of expression vectors may be utilized for protein expression. Expression vectors may comprise self-replicating extra- chromosomal vectors or vectors which integrate into a host genome. Expression vectors are constructed to be compatible with the host cell type. Thus vectors, preferably expression vectors, which find use in the present invention include but are not limited to those which enable protein expression in mammalian cells, bacteria, insect cells, yeast, and in in vitro systems. As is known in the art, a variety of expression vectors are available, commercially or otherwise, that may find use in the present disclosure for expressing antibodies. An example of a suitable expression vector is a pcDNA3.1 expression vector (Thermo Fisher Scientific).

[0141] Expression vectors typically comprise a protein operably linked with control or regulatory sequences, selectable markers, any fusion partners, and / or additional elements. By “operably linked” herein is meant that the nucleic acid is placed into a functional relationship with another nucleic acid sequence. The term “regulatory sequence” is intended to include promoters, enhancers and other expression control elements (e.g., polyadenylation signals) that control the transcription or translation of the antibody chain genes. Such regulatory sequences are described, for example, in Goeddel (Gene Expression Technology, Methods in Enzymology 185, Academic Press, San Diego, CA (1990)). Generally, these expression vectors include transcriptional and translational regulatory nucleic acid operably linked to the nucleic acid encoding the antibody and are typically appropriate to the host cellused to express the protein. In general, the transcriptional and translational regulatory sequences may include promoter sequences, ribosomal binding sites, transcriptional start and stop sequences, translational start and stop sequences, and enhancer or activator sequences. As is also known in the art, expression vectors typically contain a selection gene or marker to allow the selection of transformed host cells containing the expression vector. Selection genes are well known in the art and will vary with the host cell used. For example, typically the selectable marker gene confers resistance to drugs, such as G418, hygromycin or methotrexate, on a host cell into which the vector has been introduced. Preferred selectable marker genes include the dihydrofolate reductase (DHFR) gene (for use in dhfr- host cells with methotrexate selection / amplification) and the neo gene (for G418 selection).

[0142] Suitable host cells for cloning or expressing the DNA in the vectors herein are prokaryote, yeast, or higher eukaryote cells. Suitable prokaryotes for this purpose include eubacteria, including gram-negative or gram-positive organisms, for example, Enterobacteriaceae such as Escherichia, e.g., E. coli, Enterobacter, Klebsiella, Proteus, Salmonella, e.g., Salmonella typhimurium, Serratia, e.g., Serratia mar ce scans, and Shigella, as well as Bacilli such as B. subtilis and B. licheniformis, Pseudomonas such as P. aeruginosa, and Streptomyces. Suitable E. coli cloning hosts include E. coli 294 (ATCC 31,446), E. coli B, E. coli X1776 (ATCC 31,537), and A. coli W3110 (ATCC 27,325).

[0143] In addition to prokaryotes, eukaryotic microbes such as filamentous fungi or yeast are suitable cloning or expression hosts. Saccharomyces cerevisiae, or common baker's yeast, is the most commonly used among lower eukaryotic host microorganisms. However, a number of other genera, species, and strains are commonly available and useful, such as Schizosaccharoriyces pombe; Kluyveromyces hosts including K. lactis, K. fragilis (ATCC 12,424), K. bulgaricus (ATCC 16,045), K. wickeramii (ATCC 24,178), K. WaltH (AJCC 56,500), K. drosopmarum (ATCC 36,906), K. thermotolerans, or K. marxianusyarrowia (EP402226); Pichia pastoris (EP183070); Candida; Trichoderma reesia (EP244234);Neurospora crassa; Schwanniomyces such as Schwanniomyces occidentalis; and filamentous fungi including Neurospora, Penicillium, Tolypocladium, or Aspergillus hosts such as A. nidulans or A. niger.

[0144] Suitable host cells for the expression of the antibodies of the invention are derived from multicellular organisms. Examples of invertebrate cells include plaril and insect cells. Numerous baculoviral strains and variants and corresponding permissive insect hostcells from hosts such as Spodoptera frugiperda (caterpillar), Aedes augypti (mosquito), Aedes albopictus (mosquito), Drosophila melanogaster (fruitfly) and Bombyx mori have been identified. A variety of viral strains for transfection are publicly available, for example, the L- 1 variant of Autographa californica NPV and the Bm-5 strain of Bombyx mori NPV, and such viruses may be used, particularly for transfection of Spodoptera frugiperda cells. Plant cell cultures of cotton, corn, potato, soybean, petunia, tomato, and tobacco can also be utilized as hosts.

[0145] Host cells for expressing the recombinant antibodies of the invention also include mammalian host cells which include but are not limited to Chinese Hamster Ovary (CHO cells), NSO myeloma cells, COS cells and SP2 cells. When recombinant antibody genes are introduced into mammalian host cells, the antibodies are produced by culturing the host cells for a period of time sufficient to allow for expression of the antibody in the host cells or, more preferably, for secretion of the antibody into the culture medium in which the host cells are grown. Host cells useful for producing antibodies that bind AAVrh74 capsid protein may be cultured in a variety of media. Commercially available media such as Ham's F10 (Sigma-Aldrich Chemie GmbH, Buchs, Switzerland), Minimal Essential Medium (MEM; Sigma-Aldrich Chemie GmbH), RPMI-1640 (Sigma- Aldrich Chemie GmbH, Basel, Switzerland), and Dulbecco's Modified Eagle's Medium ((DMEM; Sigma-Aldrich Chemie GmbH) are suitable for culturing the host cells. Antibodies can be recovered from the culture medium using standard protein purification methods.

[0146] Antibodies may be operably linked to a fusion partner to enable targeting of the expressed protein, purification, screening, display, and the like. Fusion partners may be linked to the antibody sequence via a linker sequence. The linker sequence will generally comprise a small number of amino acids, typically less than ten, although longer linkers may also be used. Typically, linker sequences are selected to be flexible and resistant to degradation. As will be appreciated by those skilled in the art, any of a wide variety of sequences may be used as linkers. For example, a common linker sequence comprises the amino acid sequence G4S. A fusion partner may be a targeting or signal sequence that directs antibody and any associated fusion partners to a desired cellular location or to the extracellular media. As is known in the art, certain signalling sequences may target a protein to be either secreted into the growth media, or into the periplasmic space, located between the inner and outer membrane of the cell. A fusion partner may also be a sequence that encodes apeptide or protein that enables purification and / or screening. Such fusion partners include but are not limited to polyhistidine tags (His-tags) (for example H6 and H10 or other tags for use with Immobilized Metal Affinity Chromatography (IMAC) systems (e.g. Ni+2affinity columns)), GST fusions, MBP fusions, Strep-tag, the BSP biotinylation target sequence of the bacterial enzyme BirA, and epitope tags which are targeted by antibodies (for example c-myc tags, flag-tags, and the like). As will be appreciated by those skilled in the art, such tags may be useful for purification, for screening, or both.Construction and production of antibodies

[0147] The present disclosure further provides a method of making an anti- sarcoglycan antibody or antigen binding fragment thereof. In some aspects, the methods of the present disclosure comprise using hybridoma technology to make the antibodies. Techniques for making hybridoma cells are well known to those of skill in the art. In some aspects, the disclosure provides a method of making the antibody comprising (a) administering to a non-human vertebrate animal an immunogenic amount of a polypeptide comprising the amino acid sequence (e.g., GNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1) or KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQNVTVN ARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVGTDKLRVTGP EGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQAHAGKIEALSQMDIL FHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICVCPDGKLYLSVAGVSTTCQ EHSHICL (SEQ ID NO: 2)); (b) recovering spleen cells from the animal; (c) fusing the recovered spleen cells with myeloma cells to generate hybridomas; (d) screening the hybridomas for hybridomas that produce an antibody that specifically binds a sarcoglycan protein; and (e) recovering the antibody. Administering polypeptides to an animal can be done using well-known and routine protocols, see for example Handbook of Experimental Immunology (Weir DM (ed.), Vol 4, Blackwell Scientific Publishers, Oxford, England, 1986).

[0148] In some embodiments, the animal is a non-human vertebrate animal. In some embodiments, the non-human vertebrate animal is a transgenic animal, and wherein thetransgenic animal expresses human immunoglobulin genes. In such aspects, the transgenic animal produces human antibodies directed to a human sarcoglycan protein.

[0149] In some embodiments, the methods of the disclosure further comprise administering to the non-human vertebrate animal one or more immune adjuvants.

[0150] In some embodiments, the non-human vertebrate animal is selected from a mouse, rat, hamster, guinea pig, rabbit, chicken, non-human primate, pig, goat, cow, and horse. In one particular aspect, the non-human vertebrate animal is a mouse. In one particular aspect, the non-human vertebrate animal is a rat.

[0151] In some embodiments, the antibody or antigen binding fragment thereof specifically binds one sarcoglycan protein but does not bind a different sarcoglycan protein.

[0152] In some aspects, the hybridoma that expresses the antibody of the disclosure is a rabbit hybridoma. In some aspects, the hybridoma is a hybridoma selected from the group consisting of 14F1-2, 25G11-1, 13B5-1, 1F12-I, 9C12-1, 30H2-1, 29H9-1, 7E12-1, and 19G1-1.

[0153] The present disclosure further provides a method of making an anti- sarcoglycan antibody or antigen binding fragment thereof using a phage display antibody library. Techniques for making antibodies using a phage display antibody library are well known to those of skill in the art. In some aspects of the disclosure, the methods comprise (a) immobilizing on a solid support an antigen comprising the amino acid sequence (e.g., GNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1) or KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQNVTVN ARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVGTDKLRVTGP EGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQAHAGKIEALSQMDIL FHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICVCPDGKLYLSVAGVSTTCQ EHSHICL (SEQ ID NO: 2)); (b) applying a phage display antibody library to the immobilized antigen; (c) screening the library for phage that bind the antigen; and (d) recovering antigen-binding phage.

[0154] Suitable supports are well known in the art and comprise, inter alia, commercially available column materials, polystyrene beads, latex beads, magnetic beads, colloid metal particles, glass and / or silicon chips and surfaces, nitrocellulose strips, nylon membranes, sheets, duracytes, wells of reaction trays (e.g., multi-well plates), plastic tubes,etc. A solid support can comprise any of a variety of substances, including, e.g., glass, polystyrene, polyvinyl chloride, polypropylene, polyethylene, polycarbonate, dextran, nylon, amylose, natural and modified celluloses, polyacrylamides, agaroses, and magnetite. Suitable methods for immobilizing a subject antibody onto a solid support are well known and include, but are not limited to ionic, hydrophobic, covalent interactions and the like. Solid supports can be soluble or insoluble, e.g., in aqueous solution. In some aspects, a suitable solid support is generally insoluble in an aqueous solution. In some embodiments, the solid support is selected from the group consisting of a microtiter plate well, polyvinylidene fluoride (PVDF) membrane, column matrix, immunotube, and magnetic bead.

[0155] In some embodiments, the phage display antibody library is derived from a non-human vertebrate animal previously immunized with a composition comprising an immunogen. In some aspects, the immunogen comprises an immunogenic amount of a polypeptide comprising the amino acid sequence GNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1). In some aspects, the immunogen comprises an immunogenic amount of a polypeptide comprising the amino acid sequence KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQNVTVN ARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVGTDKLRVTGP EGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQAHAGKIEALSQMDIL FHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICVCPDGKLYLSVAGVSTTCQ EHSHICL (SEQ ID NO: 2).

[0156] In some embodiments, the non-human vertebrate animal is selected from a mouse, rat, hamster, guinea pig, rabbit, chicken, non-human primate, pig, goat, cow, and horse.

[0157] In some embodiments, the antibody or antigen binding fragment thereof specifically binds a human sarcoglycan protein (e.g., an alpha-sarcoglycan protein or a gamma sarcoglycan protein). In some embodiments, the antibody or antigen binding fragment thereof binds one sarcoglycan protein but does not bind a different sarcoglycan protein.

[0158] The present disclosure further provides an in silico method of making an anti- sarcoglycan antibody or antigen binding fragment thereof. In silico techniques for designing antibodies are known to those of skill in the art. In some aspects, the method comprises (a)designing CDRs in silico that specifically bind to an epitope on a human sarcoglycan protein; (b) grafting the CDRs onto single-chain variable fragments (scFvs); (c) screening the scFvs for binding to a target polypeptide using antibody phage display; and (d) selecting scFvs that bind to the target polypeptide, wherein the sarcoglycan protien is an alpha-sarcoglycan protein and wherein the epitope on the human alpha-sarcoglycan protein and the target polypeptide each comprises the amino acid sequence GNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1). In some aspects, the human sarcoglycan protein is a gamma-sarcoglycan protein, and the epitope on the gamma-sarcoglycan protein and the target polypeptide each comprises the amino acid sequenceKVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQNVTVN ARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVGTDKLRVTGP EGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQAHAGKIEALSQMDIL FHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICVCPDGKLYLSVAGVSTTCQ EHSHICL (SEQ ID NO: 2).

[0159] In some embodiments, the antibody or antigen binding fragment thereof specifically binds one sarcoglycan protein but does not bind a different sarcoglycan protein.

[0160] Humanized antibodies of the present disclosure may be constructed by transferring one or more CDRs or portions thereof from VH and / or VL regions from a nonhuman animal (e.g., mouse) to one or more framework regions from human VH and / or VL regions. Optionally, human framework residues thus present in the VH and / or VL regions may be replaced by corresponding non-human (e.g., mouse) residues when needed or desired for decreasing immunogenicity of the antibody and / or maintaining binding affinity.Optionally, non-human amino acid residues present in the CDRs may be replaced with human residues. Chimeric or humanized antibodies of the present invention can be prepared based on the sequence of a non-human monoclonal antibody prepared as described above. DNA encoding the heavy and light chain immunoglobulins can be obtained from the non- human hybridoma of interest and engineered to contain non-murine (e.g., human) immunoglobulin sequences using standard molecular biology techniques. For example, to create a chimeric antibody, rabbit or murine variable regions can be linked to human constant regions using methods known in the art (see e.g., U.S. Patent No. 4,816,567 to Cabilly et al). To create a humanized antibody, murine CDR regions can be inserted into a humanframework using methods known in the art (see e.g., U.S. Patent No. 5,225,539 to Winter, and U.S. Patent Nos. 5,530,101; 5,585,089; 5,693,762 and 6,180,370 to Queen et al).

[0161] The present disclosure provides a method of producing an antibody or fragment thereof that binds to a human sarcoglycan protein comprising culturing a host cell comprising an isolated nucleic acid encoding the antibody or fragment thereof that binds to human sarcoglycan proteins (e.g., an alpha-sarcoglycan protein or a gamma-sarcoglycan protein) or a vector comprising an isolated nucleic acid encoding the antibody or fragment thereof that binds to the human sarcoglycan protein so that the nucleic acid is expressed and the antibody produced. Preferably the antibody is isolated. For host cells, nucleic acids and vectors, the ones described above can be used. Expression of the nucleic acids can be obtained by, e.g. a combination of recombinant DNA techniques and gene transfection methods as is well known in the art (e.g., Morrison S (1985) Science 229: 1202) and as further outlined above. For example, to express the antibodies, or antibody fragments thereof, DNAs encoding partial or full-length light and heavy chains, can be obtained by standard molecular biology techniques (e.g., PCR amplification or cDNA cloning using a hybridoma that expresses the antibody of interest) and the DNAs can be inserted into vectors such as expression vectors. The expression vector and expression control sequences are chosen to be compatible with the expression host cell used. The antibody light chain gene and the antibody heavy chain gene can be inserted into separate vector or, more typically, both genes are inserted into the same expression vector. The antibody genes are inserted into the expression vector by standard methods (e.g., ligation of complementary restriction sites on the antibody gene fragment and vector, or blunt end ligation if no restriction sites are present). The light and heavy chain variable regions of the antibodies described herein can be used to create full- length antibody genes of any antibody isotype by inserting them into expression vectors already encoding heavy chain constant and light chain constant regions of the desired isotype such that the VH segment is operatively linked to the CHI segment(s) within the vector and the VK segment is operatively linked to the CK segment within the vector.Purification of Anti-sarcoglycan antibodies

[0162] Screening for antibodies can be performed using antibody binding assays known to those of skill in the art. Detailed methods for performing antibody screening assays are found in, e.g., Harlow and Lane (1988) Antibodies, A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York. Such assays can be used tomeasure antibody binding to sarcoglycan proteins. An example of a binding assay is an enzyme-linked immunosorbent assay (ELISA). In some aspects, the ELISA comprises a fusion protein of sarcoglycan protein and human Fc, which is immobilized on a solid support, and employing a conjugated secondary antibody to detect anti-sarcoglycan antibody bound to the fusion protein. The antibodies of the present invention may be used as a positive control for the measurement of anti-sarcoglycan antibody in a sample (e.g., muscle tissue). In one embodiment, the ELISA is a direct ELISA, an indirect ELISA, a sandwich ELISA, a reverse ELISA, or a competitive ELISA. In one embodiment, the sarcoglycan antibody of this disclosure can be used in assays to detect pre-existing antibodies against sarcoglycan proteins, in serum or plasma from a subject; including mice, non-human primates, and a human. In one aspect, for any embodiment directed to detection of pre-existing antibodies, the pre-existing antibodies are contained in sera or plasma of such subject, that has been treated with an AAV-based gene therapy. In another aspect of any embodiment directed to detection of pre-existing antibodies, the subject has not been treated with such gene therapy. The assays can be ELISA or ElectroChemiLuminiescence Immunoassay (ECLIA). In such assays, sarcoglycan antibodies serve as positive controls or capture. The ELISA approach optionally utilizes either serum or plasma known to have antibodies against AAVrh74 as an optional positive control. The assays comprise binding the antibody found in test serum or plasma to the antigen (alpha- or gamma-sarcoglycan), followed by the detection of the antibodies using a substrate to quantify the antibody through an absorbance reading. The average optical density (OD) of wells receiving antigen is calculated against the OD of noncoated wells to determine the antibody endpoint titer. The ECLIA assay follows the same concept as the indirect ELISA and can identify samples with or without anti-sarcoglycan antibodies, determine specificity of positive samples through competitive binding, and determine levels of antibody through titration methods.

[0163] Additionally, the anti-sarcoglycan antibody can be used to verify efficacy of gene transduction following administration of one or more gene therapy products through a sandwich ELISA, wherein the sarcoglycan antibody is bound to the capture antibody, followed by the addition of a detector antibody, enzyme and substrate and quantified through an absorbance reading. In some embodiments, one or more tissue samples from a subject are analyzed with an anti-sarcoglycan antibody of the present disclosure by techniques well known in the art, such as Western blotting or immunohistochemical assay, and / orimmunofluorescent staining, to confirm the presence of sarcoglycan expression and to quantify said expression. In some embodiments, the one or more tissue samples from a subject are further analyzed with a second sarcoglycan of the present disclosure to compare expression of endogenous and supplemental sarcoglycan complex proteins.

[0164] Antibodies of the present invention may be isolated or purified in a variety of ways known to those skilled in the art. Standard purification methods include chromatographic techniques, including ion exchange, hydrophobic interaction, affinity, sizing or gel filtration, and reversed-phase, carried out at atmospheric pressure or at high pressure using systems such as FPLC and HPLC. Purification methods also include electrophoretic, immunological, precipitation, dialysis, and chromatofocusing techniques. Ultrafiltration and diafiltration techniques, in conjunction with protein concentration, are also useful. To purify sarcoglycan antibodies, selected host cells can be grown in e.g. spinner-flasks for monoclonal antibody purification. Supernatants can be filtered and concentrated before affinity chromatography with protein A-sepharose (Pharmacia, Piscataway, NJ). Eluted antibodies can be checked by gel electrophoresis and high performance liquid chromatography (HPLC) to ensure purity. A preferred antibody of the present disclosure is thus an isolated and / or purified antibody that binds to a human sarcoglycan protein selected from an alpha- sarcoglycan or a gamma-sarcoglycan protein.Immunological assays

[0165] The present disclosure also provides methods for detecting the presence of human sarcoglycan protein in a sample, comprising contacting the sample with a composition comprising the antibody or antigen binding fragment thereof as described herein. In some aspects, the sample is an environmental sample. In some aspects, the sample is a biological sample, including but not limited to, blood, e.g., whole blood, urine, saliva, plasma, lung washings, or lymph. In some embodiments, the biological sample is solid tissue (e.g. skeletal muscle, cardiac muscle or smooth muscle tissue) or cells thereof. In some embodiments, the presence of alpha- or gamma-sarcoglycan protein in the sample is indicated by detecting the presence of the antibody or antigen binding fragment thereof.

[0166] In some aspects of the disclosure, the presence of the antibody or antigen binding fragment thereof is detected by immunoassay. Suitable immunoassays for detecting the presence of the antibody or antigen binding fragment are known to those of skill in theart. Examples of suitable immunoassays include, but are not limited to, an immunofluorescence assay, an immunohistochemical assay, a Western blot, a direct enzyme- linked immunosorbent assay (ELISA), an indirect ELISA, a sandwich ELISA, a competitive ELISA, a chemiluminescence assay, a radioimmunoassay, and an immunoprecipitation assay. Methods for performing exemplary suitable immunoassays of the present disclosure are found in, e.g., Harlow and Lane (1988) Antibodies, A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York.

[0167] An immunofluorescence assay detects the expression and / or cellular location of a protein of interest. In a direct immunofluorescence assay, a primary detection antibody is coupled with a fluorophore. Labeled antibody bound to the protein of interest is then detected using fluorescent microscopy. In an indirect immunofluorescence assay, a secondary antibody is coupled to a fluorophore and specifically binds the primary antibody. The secondary antibody is then detected using fluorescent microscopy.

[0168] In some aspects, the anti-sarcoglycan antibodies disclosed herein comprise the primary antibody in an immunofluorescence assay to detect the presence of a human sarcoglycan protein (e.g., an alpha-sarcoglycan protein or a gamma-sarcoglycan protein) in a sample. In one embodiment, the anti-sarcoglycan antibody is an anti-alpha-sarcoglycan antibody. In one embodiment, the anti-sarcoglycan antibody is an anti-gamma-sarcoglycan antibody.

[0169] An immunohistochemical (IHC) assay detects the expression and / or cellular location of a protein of interest. In a direct immunohistochemical assay, a primary detection antibody coupled with an enzyme binds to the protein of interest. Detection is accomplished by assessing the presence of the conjugated enzyme via incubation with a substrate to produce a measurable product, such as color. In an indirect IHC assay, a secondary antibody is coupled to an enzyme and specifically binds the primary antibody. Detection of the secondary antibody is accomplished by assessing the presence of the conjugated enzyme via incubation with a substrate to produce a measurable product, such as color.

[0170] In some aspects, the anti-sarcoglycan antibodies disclosed herein comprise the primary antibody in an immunohistochemical assay to detect the presence of a human sarcoglycan protein (e.g., an alpha-sarcoglycan protein or a gamma-sarcoglycan protein) in a sample. In one embodiment, the anti-sarcoglycan antibody is an anti-alpha-sarcoglycanantibody. In one embodiment, the anti-sarcoglycan antibody is an anti-gamma-sarcoglycan antibody.

[0171] A Western blot is used to detect a specific protein or proteins in a sample. In a Western blot, a protein sample is treated with a detergent to unfold the proteins. The linear proteins are separated by size via gel electrophoresis (e.g., polyacrylamide gel electrophoresis, or PAGE) and then transferred to a blotting membrane (e.g., polyvinylidene difluoride - PVDF). The membrane is then incubated with a primary antibody that binds to the protein of interest. The primary antibody is then bound by a labeled secondary antibody. The labeled secondary antibody is linked to a reporter enzyme. Detection is accomplished by assessing the presence of the conjugated enzyme on the secondary antibody via incubation with a substrate to produce a measurable product, such as color or light.

[0172] In some aspects, the anti-sarcoglycan antibodies disclosed herein comprise the primary antibody of a Western blot to detect the presence of a human sarcoglycan protein (e.g., an alpha-sarcoglycan protein or a gamma-sarcoglycan protein) in a sample. In one embodiment, the anti-sarcoglycan antibody is an anti-alpha-sarcoglycan antibody. In one embodiment, the anti-sarcoglycan antibody is an anti-gamma-sarcoglycan antibody.

[0173] Sarcoglycan proteins are administered as a gene therapy to those in need thereof, whereby the supplemental protein is expressed in muscle tissue to ameliorate disease. Therefore, in another aspect, the disclosure relates to a method of detecting the presence of a sarcoglycan protein in a sample by an immunoassay, wherein the immunoassay uses a composition comprising the isolated antibody or antigen binding fragment thereof in this disclosure. In some embodiments, the sarcoglycan protein is an alpha-sarcoglycan protein. In some embodiments, the sarcoglycan protein is a gamma-sarcoglycan antibody. In some embodiments, the sample is a biological sample from a subject. In some embodiments, the sample is blood, serum, plasma, a body fluid, urine, or a tissue from a subject. In some embodiments, the subject is a mammal carrying a genetic disorder. In some embodiments, the patient suffers from limb-girdle muscular dystrophy (LGMD). In one embodiment, the patient suffers from LGMD2C. In one embodiment, the patient suffers from LGMD2D.

[0174] In another embodiment, the immunoassay comprises one or more of enzyme immunoassay (EIA), radioimmunoassay (MA), neutralization assay, fluoroimmunoassay (FIA) which uses fluorescent materials, chemiluminescent immunoassay (CLIA) which uses chemiluminescent materials and counting immunoassay (CIA) which employs particle-counting techniques, other modified assays such as western blot, immunohistochemistry (IHC) and agglutination. One of the most common enzyme immunoassays is enzyme-linked immunosorbent assay (ELISA). In one embodiment, the immunoassay comprises one or more of an immunofluorescence assay, an immunohistochemical assay, a Western blot, a direct enzyme-linked immunosorbent assay (ELISA), an indirect ELISA, a sandwich ELISA, a competitive ELISA, a reverse ELISA, an ECLIA, a chemiluminescence assay, a radioimmunoassay, or an immunoprecipitation assay.

[0175] ELISA is an assay designed for detecting and quantifying substances such as peptides, proteins, and antibodies. In an ELISA, an antigen is immobilized on a solid surface and then complexed with an antibody that is linked to an enzyme. Detection is accomplished by assessing the presence of the conjugated enzyme via incubation with a substrate to produce a measurable product, such as color. The detection enzyme can be linked directly to the primary antibody (direct ELISA) or introduced through a secondary antibody that recognizes the primary antibody (indirect ELISA).

[0176] In some aspects, the anti-sarcoglycan antibodies disclosed herein comprise the primary antibody in a direct or indirect ELISA to detect the presence of a human sarcoglycan protein in a sample. In one embodiment, the anti-sarcoglycan antibody is an anti-alpha sarcoglycan antibody. In one embodiment, the anti-sarcoglycan antibody is an anti-gamma sarcoglycan antibody.

[0177] A sandwich ELISA is an ELISA in which a capture antibody is first immobilized on a solid support, followed by addition of the protein of interest and the secondary antibody. In a sandwich ELISA, the protein of interest is bound between the capture antibody, which is immobilized on the solid surface, and the detection antibody, which binds the protein of interest.

[0178] In some aspects, the anti-sarcoglycan antibodies disclosed herein comprise the primary antibody in a sandwich ELISA to detect the presence of a human sarcoglycan protein in a sample. In one embodiment, the anti-sarcoglycan antibody is an anti-alpha sarcoglycan antibody. In one embodiment, the anti-sarcoglycan antibody is an anti-gamma sarcoglycan antibody.

[0179] A competitive ELISA, also known as an inhibition ELISA or a competitive immunoassay, measures the concentration of an antigen by detection of signal interference. The sample antigen competes with a reference antigen for binding to a specific amount oflabeled antibody. The reference antigen is pre-coated on a multi-well plate. The sample is pre-incubated with labeled antibody and added to the wells. Depending on the amount of antigen in the sample, more or less free antibodies will be available to bind the reference antigen. Therefore, the more antigen there is in a sample, the less references antigen will be detected and the weaker the signal.

[0180] In some aspects, the anti-sarcoglycan antibodies disclosed herein comprise the primary antibody in a competitive ELISA to detect the presence of a human sarcoglycan protein in a sample. In one embodiment, the anti-sarcoglycan antibody is an anti-alpha sarcoglycan antibody. In one embodiment, the anti-sarcoglycan antibody is an anti-gamma sarcoglycan antibody.

[0181] A chemiluminescence assay utilizes a luminescent chemical as a substrate instead of a chromogen. Common enzymes which are conjugated to detection antibodies include, but are not limited to, horseradish peroxidase (HRP) and alkaline phosphatase (AP). Luminol is a common chemiluminescent substrate used for detection of HRP.

[0182] In some aspects, the anti-sarcoglycan antibodies disclosed herein are conjugated to an enzyme that catalyzes a chemiluminescent reaction to detect the presence of a human sarcoglycan protein in a sample. In one embodiment, the anti-sarcoglycan antibody is an anti-alpha sarcoglycan antibody. In one embodiment, the anti-sarcoglycan antibody is an anti-gamma sarcoglycan antibody.

[0183] In a radioimmunoassay, a known quantity of an antigen is radiolabeled and mixed with a known amount of antibody for that antigen. A sample containing an unknown amount of unlabeled antigen is then added. The unlabeled and radiolabeled antigen compete for antibody binding sites. As the concentration of unlabeled antigen increases, more of the radiolabeled antigen is displaced and the ration of antibody-bound radiolabeled antigen to free radiolabeled antigen is reduced. The bound radiolabeled antigens are then separated and the radioactivity of the free (unbound) radiolabeled antigen remaining in the supernatant is measured using a gamma counter.

[0184] In some aspects, the anti-sarcoglycan antibodies disclosed herein are used in a radioimmunoassay to detect the presence of a human sarcoglycan protein in a sample. In one embodiment, the anti-sarcoglycan antibody is an anti-alpha sarcoglycan antibody. In one embodiment, the anti-sarcoglycan antibody is an anti-gamma sarcoglycan antibody.

[0185] An immunoprecipitation assay uses an antibody specific for a protein of interest to isolate that protein form a solution containing many different proteins, such as crude lysate of plant or animal cells or tissue, or bodily fluids. In a direct immunoprecipitation assay, antibodies specific for a protein of interest are immobilized on a solid phase substrate, such as superparamagnetic microbeads or microscopic agarose beads. The beads with bound antibody are then added to the solution and the protein of interest binds the antibody and is captured by the beads. The protein of interest is then eluted from the beads.

[0186] In an indirect immunoprecipitation assay, antibodies specific for a protein of interest are added directly to the solution. The antibodies have not yet been attached to a solid-phase support. Beads coated in protein A / G are then added to the mixture and the antibodies, which are now bound to the protein of interest, bind to the beads. The protein of interest is then eluted from the beads.

[0187] In some aspects, the anti-sarcoglycan antibodies as disclosed herein can be used to isolate a human sarcoglycan protein in a sample. In one embodiment, the anti- sarcoglycan antibody is an anti-alpha sarcoglycan antibody. In one embodiment, the anti- sarcoglycan antibody is an anti-gamma sarcoglycan antibody.

[0188] The immunoassays and methods described above are intended to be exemplary and non-limiting.

[0189] The methods of the present disclosure specifically detect the presence of a human sarcoglycan protein (e.g., an alpha-sarcoglycan protein or a gamma-sarcoglycan protein) in a sample.Kits

[0190] An embodiment of the present disclosure is directed to an in vitro detection kit comprising the antibody or antigen binding fragment thereof as described herein as an active agent and instructions for use. Kits of the present disclosure may include, but are not limited to, kits for use in an immunofluorescence assay, an immunohistochemical assay, a Western blot, a direct enzyme-linked immunosorbent assay (ELISA), an indirect ELISA, a sandwich ELISA, a reverse ELISA, a competitive ELISA, a chemiluminescence assay, a radioimmunoassay, and an immunoprecipitation assay. In some aspects, the kit can further contain a second antibody or antigen binding fragment thereof labeled with a radioactive,enzymatic or fluorescent group. In some aspects, the kit contains additional reagents, such as buffers, enzymes, and / or substrates, as well as a user manual for the kit.

[0191] In one embodiment, the disclosure provides a method for detecting the presence of a human sarcoglycan protein in a sample, comprising detecting the sarcoglycan protein by an immunoassay, wherein the immunoassay uses a composition comprising the isolated antibody or antigen binding fragment thereof of the disclosure. In some embodiments, the sarcoglycan protein is an alpha-sarcoglycan protein. In some embodiments, the sarcoglycan protein is a gamma-sarcoglycan protein. In some embodiments, the immunoassay comprises enzyme immunoassay (EIA), radioimmunoassay (MA), fluoroimmunoassay (FIA), chemiluminescent immunoassay (CLIA) and counting immunoassay (CIA), neutralization assay, or immunohistochemistry (IHC). In another embodiment, the immunoassay comprises one or more of an immunofluorescence assay, an immunohistochemical assay, a Western blot, a direct enzyme-linked immunosorbent assay (ELISA), an indirect ELISA, a sandwich ELISA, a competitive ELISA, a reverse ELISA, an ECLIA, a chemiluminescence assay, a radioimmunoassay, or an immunoprecipitation assay. In some embodiments, the sample is a biological sample from a subject. In some embodiments, the subject is a mammal carrying a genetic disorder. In one embodiment, the mammal is human, pig, horse, cow, sheep, goat, monkey, rat, mouse, cat, or dog. In some embodiments, the subject is a human patient. In some embodiments, the patient suffers from limb-girdle muscular dystrophy (LGMD). In some embodiments, the composition comprising the isolated antibody or antigen binding fragment thereof of the disclosure serves as a positive control or a capture.EXAMPLES

[0192] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the present invention, and are not intended to limit the scope of what the inventors regard as their invention nor are they intended to represent that the experiments below are all or the only experiments performed. Efforts have been made to ensure accuracy with respect to numbers used (e.g. amounts, temperature, etc.) but some experimental errors and deviations should be accounted for.Example 1: Binding of anti-alpha sarcoglycan antibodies via immunassay

[0193] Antibodies were made according to the methods of the present disclosure (see generally Figure 1) and were tested for their specific binding to full length human alpha sarcoglycan protein.

[0194] An enzyme-linked immunosorbent assay (ELISA) was performed to measure the binding of antibody to the putative target protein (alpha sarcoglycan). Briefly, Immulon- 4 HBX 96-well plates were coated with 100 ng / well of recombinant alpha sarcoglycan protein in 100 pl bicarbonate buffer (pH 9.4) per well. Plates were sealed and stored overnight at 4 °C. Plates were then blocked with 100 pl per well of a 5% nonfat dry milk and 1% normal goat serum in DPBS for 1 hour ± 10 minutes at 37 °C. The antibody stocks or samples were diluted to the same starting dilution of lOOOng / mL before being serially diluted (2-fold) in the blocking solution to a final concentration on 1.95ng / mL. 100 pl of dilute antibody was added in duplicate to both wells coated with alpha sarcoglycan along with wells with buffer alone (background reading). Plates were incubated at RT for 1 hour ± 10 minutes. Post incubation, wells were washed five times with 200 pl of PBS-T (0.05% Tween). Blocking solution was used again to dilute the secondary antibody, goat anti-rabbit antibody with HRP conjugate at a 1 : 10,000 dilution. Wells received 100 pl of the secondary antibody and were incubated at RT for 30 minutes before being washed five times and blotted dry. Tetramethybenzidine substrate (100 pl / well) was added and incubated at RT for 2-3 minutes in the dark, before the addition of 100 pl of 1 N H2SO4 to stop the reaction. The absorbance at 450 nm was measured using the ELISA plate reader.

[0195] Absorbance data was collected while screening antibodies for binding to alpha sarcoglycan, particularly at the lowest concentration (1.95ng / mL), and the associated signal- to-background ratio based on subtraction of signal from the negative control wells (Figure 2). As such, a higher optical density (OD) reading and higher signal-to-background ratio was indicative of higher antibody avidity with alpha sarcoglycan. Clones 14F1-2 and 25G11-1 exhibited the highest OD readings and ratios; however, all clones tested demonstrated specific binding to alpha sarcoglycan. These results showed that all antibodies tested were capable of binding alpha sarcoglycan to varying degress, though Clones 14F1 and 25G11 did so with the highest avidity.Example 2: Binding of anti-gamma sarcoglycan antibodies via immunoassay

[0196] Antibodies were made according to the methods of the present disclosure (see generally Figure 1) and were tested for their specific binding to gamma sarcoglycan protein.

[0197] An ELISA was performed as previously described, diluting the antibodies to a starting dilution of lOOOng / mL before serial 2-fold dilutions and measurements of absorbance at 450 nm.

[0198] Absorbance data was collected during the screening antibodies of for binding to gamma sarcoglycan (Figure 3). While all five antibodies tested demonstrated specific binding, Clone 9C12-1 exhibited both the highest absorbance and ratio. Clone 30H2-1 followed closely behind in terms of absorbance and had the second best signal-to-background ratio. These results showed that all of the antibodies tested were capable of binding gamma sarcoglycan, though Clones 9C12 and 30H2 did so at the highest avidity.Example 3: Production and testing of chimeric anti-sarcoglycan antibodies

[0199] Previously described rabbit monoclonal antibody clone 14F1-2, which was capable of specifically binding human alpha-sarcoglycan (SGCA) protein, and rabbit monoclonal antibody clone 9C12-1, which was capable of specifically binding human gamma-sarcoglycan (SGCG) protein, were then chimerized for use in clinical, non-human primate and murine studies. Briefly, the rabbit constant regions were exchanged for those of human (Homo sapiens IgG), a non-human primate (NHP) (Macaca mulatto IgG), or mouse (Mus musculus IgG) constant regions using techniques well known in the art, such that the resulting chimeric antibodies have the variable region of the rabbit antibody clones and constant regions of a different species (amino acid sequences in Tables 2 [anti-SGCA] and 4 [anti-SGCG]) for use in the sera of each specific animal and recognition by species-specific secondary antibodies.

[0200] Endpoint titers were determined by absorbance readings at 450 nm, which were collected as previously described. Briefly, chimeric antibodies were diluted to a starting dilution of lOOOng / mL before being added to antigen-coated plates in serial 2-fold dilutions. Appropriate secondary antibodies were used based upon the chimeric antibody (e.g., antimouse IgG, anti-human IgG, or anti-monkey IgG). All anti-alpha sarcoglycan chimeric antibodies demonstrated specific antigen binding at low dilutions, including 0.244ng / mL,0.488ng / mL, and 3.9ng / mL for human, mouse and NHP chimeric antibodies, respectively (Figure 4). For the gamma-sarcoglycan antibodies, both human and mouse chimeric antibodies demonstrated specific binding to a dilution of 0.488ng / mL, while the NHP chimeric antibody specifically bound antigen at concentrations as low as 15.62ng / mL (Figure 5). Collectively, these results showed that the chimerization process did not impact the specific antigen binding observed in the rabbit monoclonal antibodies.

[0201] It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. The foregoing description of the specific embodiments will so fully reveal the general nature of the disclosure such that others can, by applying knowledge within the skill of the art, readily modify and / or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance.

[0202] All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety for all purposes.TABLESTable 1: Exemplary anti-alpha sarcoglycan sequencesTable 2: Chimeric alpha-sarcoglycan antibody sequencesTable 3: Exemplary anti-gamma sarcoglycan sequencesTable 4: Chimeric gamma-sarcoglycan antibody sequences

Claims

CLAIMS1. An isolated antibody or antigen-binding fragment thereof capable of specifically binding an epitope of a human sarcoglycan protein, wherein the epitope comprises an amino acid sequence GNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1) or a portion thereof.

2. An isolated antibody or antigen-binding fragment thereof that comprises a heavy chain variable region that comprises VH CDR1, VH CDR2, and VH CDR3 domains and a light chain variable region that comprises VL CDR1, VL CDR2, and VL CDR3 domains, wherein: a. the VH CDR1 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 8, SEQ ID NO: 24, SEQ ID NO: 40, and SEQ ID NO: 56; b. the VH CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 10, SEQ ID NO: 26, SEQ ID NO: 42, and SEQ ID NO: 58; c. the VH CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 12, SEQ ID NO: 28, SEQ ID NO: 44, and SEQ ID NO: 60; d. the VL CDR1 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 14, SEQ ID NO: 30, SEQ ID NO: 46, and SEQ ID NO: 62; e. the VL CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 16, SEQ ID NO: 32, SEQ ID NO: 48, and SEQ ID NO: 64; or f. the VL CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 18, SEQ ID NO: 34, SEQ ID NO: 50, and SEQ ID NO: 66.

3. An isolated antibody or antigen-binding fragment thereof comprising: a. a heavy chain variable region that comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 4, SEQ ID NO: 20, SEQ ID NO: 36, and SEQ ID NO: 52; and b. a light chain variable region that comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 6, SEQ ID NO: 22, SEQ ID NO: 38, and SEQ ID NO: 54.

4. The isolated antibody or antigen binding fragment of any one of claims 1 to 3, wherein the human sarcoglycan protein is an alpha sarcoglycan protein.

5. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to 4, wherein the heavy chain variable region comprises a VH CDR1 selected from the group consisting of TYDMN (SEQ ID NO: 8), THDMN (SEQ ID NO: 24), TYDMS (SEQ ID NO: 40), and SSYYMC (SEQ ID NO: 56).

6. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to 5, wherein the heavy chain variable region further comprises a VH CDR2 selected from the group consisting of AITKNGISSFANWAQG (SEQ ID NO: 10), AITKNGITVYAKWTKG (SEQ ID NO: 26), AITKNGIRTYANWAKG (SEQ ID NO: 42), and CIVTADGTTYYASWAKG (SEQ ID NO: 58).

7. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to 6, wherein the heavy chain variable region further comprises a VH CDR3 selected from the group consisting of PSL, and GFAF (SEQ ID NO: 60).

8. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to 7, wherein the light chain variable region comprises a VL CDR1 selected from the group consisting of QSSQSVYSNYLS (SEQ ID NO: 14), QSSPSVYNNYLS (SEQ ID NO: 30), QSSQSVYSNYLS (SEQ ID NO: 46), and QSSQSVDGNNDLA (SEQ ID NO: 62).

9. The antibody or antigen binding fragment thereof of any one of claims 1 to 8, wherein the light chain variable region further comprises a VL CDR2 selected from the groupconsisting of DASTLAS (SEQ ID NO: 16), DASTLAS (SEQ ID NO: 32), SASTLDS (SEQ ID NO: 48), and QASKLPS (SEQ ID NO: 64).

10. The antibody or antigen binding fragment thereof of any one of claims 1 to 9, wherein the light chain variable region further comprises a VL CDR3 selected from the group consisting of LGTYDCNSADCFV (SEQ ID NO: 18), LGTYDCNSADCFV (SEQ ID NO: 34), LGTYDCNSADCFV (SEQ ID NO: 50), and QGGYNGGVWP (SEQ ID NO: 66).

11. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to 10, wherein the antibody comprises a heavy chain variable region that comprises VH CDR1, VH CDR2, and VH CDR3 domains and a light chain variable region that comprises VL CDR1, VL CDR2, and VL CDR3 domains selected from the group consisting of: a. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 8, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 10, a VH CDR3 having the amino acid sequence PSL, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 14, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 16, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 18; b. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 24, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 26, a VH CDR3 having the amino acid sequence PSL, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 30, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 32, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 34; c. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 40, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 42, a VH CDR3 having the amino acid sequence PSL, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 46, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 48, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 50; andd. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 56, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 58, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 60, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 62, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 64, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 66.

12. The isolated antibody or antigen binding fragment thereof of claim 11, wherein the antibody or antigen binding fragment thereof comprises: a. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 4; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 6; b. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 20; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 22; c. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%,about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 36; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 38; or d. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 52; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 54.

13. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to12, wherein the heavy chain variable region of the antibody or antigen binding fragment thereof is selected from the group consisting of SEQ ID NO: 4, SEQ ID NO: 20, SEQ ID NO: 36, and SEQ ID NO: 52.

14. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to13, wherein the light chain variable region of the antibody or antigen binding fragment thereof is selected from the group consisting of SEQ ID NO: 6, SEQ ID NO: 22, SEQ ID NO: 38, and SEQ ID NO: 54.

15. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to14, wherein a. the heavy chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 4, SEQ ID NO: 20, SEQ ID NO: 36, and SEQ ID NO: 52; andb. the light chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 6, SEQ ID NO: 22, SEQ ID NO: 38, and SEQ ID NO: 54.

16. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to 15, comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 4 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 6.

17. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to 15, comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 20 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 22.

18. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to 15, comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 36 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 38.

19. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to 15, comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 52 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 54.

20. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to19, wherein the antibody or antigen binding fragment thereof is labeled with a radioactive, enzymatic, or fluorescent group.

21. The isolated antibody or antigen-binding fragment thereof of any one of claims 1 to20, wherein the antibody is a full-length antibody or an antibody fragment selected from the group consisting of Fab, Fab’, Fab’-SH, Fd, Fv, dAb, F(ab’)2, scFv, bispecific single chain Fv dimers, diabodies, triabodies, and sxFv genetically fused to the same or a different antibody.

22. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to 4, wherein the antibody is a murine antibody, a chimeric murine / human antibody, a human antibody, an engineered antibody, or a humanized antibody.

23. The isolated antibody of claim 22, wherein the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 4 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 6.

24. The isolated antibody of claim 22, wherein the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 20 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 22.

25. The isolated antibody of claim 22, wherein the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 36 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 38.

26. The isolated antibody of claim 22, wherein the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 52 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 54.

27. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to26, wherein the antibody or antigen binding fragment thereof is a bispecific antibody.

28. The isolated antibody or antigen binding fragment thereof of any one of claims 1 to27, wherein the antibody or antigen binding fragment thereof is a multispecific antibody.

29. An isolated antibody or antigen-binding fragment thereof capable of specifically binding an epitope of a human sarcoglycan protein, wherein the epitope comprises an amino acid sequence KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQNVTVNARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVG TDKLRVTGPEGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQA HAGKIEALSQMDILFHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICV CPDGKLYLSVAGVSTTCQEHSHICL (SEQ ID NO: 2) or a portion thereof.

30. An isolated antibody or antigen-binding fragment thereof that comprises a heavy chain variable region that comprises VH CDR1, VH CDR2, and VH CDR3 domains and a light chain variable region that comprises VL CDR1, VL CDR2, and VL CDR3 domains, wherein: a. the VH CDR1 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 72, SEQ ID NO: 88, SEQ ID NO: 104, SEQ ID NO: 120, and SEQ ID NO: 136; b. the VH CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 74, SEQ ID NO: 90, SEQ ID NO: 106, SEQ ID NO: 122, and SEQ ID NO: 138; c. the VH CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 76, SEQ ID NO: 92, SEQ ID NO: 108, AHL, and SEQ ID NO: 140; d. the VL CDR1 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 78, SEQ ID NO: 94, SEQ ID NO: 110, SEQ ID NO: 126, and SEQ ID NO: 142; e. the VL CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 80, SEQ ID NO: 96, SEQ ID NO: 112, SEQ ID NO: 128, and SEQ ID NO: 144; or f. the VL CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 82, SEQ ID NO: 98, SEQ ID NO: 114, SEQ ID NO: 130, and SEQ ID NO: 146.

31. An isolated antibody or antigen-binding fragment thereof comprising: a. a heavy chain variable region that comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 68, SEQ ID NO: 84, SEQ ID NO: 100, SEQ ID NO: 116, and SEQ ID NO: 132; andb. a light chain variable region that comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 70, SEQ ID NO: 86, SEQ ID NO: 102, SEQ ID NO: 118, and SEQ ID NO: 134.

32. The isolated antibody or antigen binding fragment of any one of claims 29 to 31, wherein the human sarcoglycan protein is a gamma sacroglycan protein.

33. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to32, wherein the heavy chain variable region comprises a VH CDR1 selected from the group consisting of SDAMT (SEQ ID NO: 72), SYHMI (SEQ ID NO: 88), SYSMS (SEQ ID NO: 104), DNGVI (SEQ ID NO: 120), and NNPIT (SEQ ID NO: 136).

34. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to33, wherein the heavy chain variable region further comprises a VH CDR2 selected from the group consisting of TIYVSGNTYYASWATG (SEQ ID NO: 74), IISTGGDTYYASWAKG (SEQ ID NO: 90), YIVSDSRTWYASWAKG (SEQ ID NO: 106), YIHIDGRTYYATWAKS (SEQ ID NO: 122), and GIGASGRAYYANWAKS (SEQ ID NO: 138).

35. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to34, wherein the heavy chain variable region further comprises a VH CDR3 selected from the group consisting of WGNL (SEQ ID NO: 76), DAGNSGI (SEQ ID NO: 92), LGGRASLDI (SEQ ID NO: 108), AHL, and LNGWHYAYV (SEQ ID NO: 140).

36. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to35, wherein the light chain variable region comprises a VL CDR1 selected from the group consisting of QSSQSVYSDNQFT (SEQ ID NO: 78), QSSESVLDDGNWLA (SEQ ID NO: 94), QSSESVYNNNYLS (SEQ ID NO: 110), QASQSISNLLT (SEQ ID NO: 126), and QASQSVWDNKDLA (SEQ ID NO: 142).

37. The antibody or antigen binding fragment thereof of any one of claims 29 to 36, wherein the light chain variable region further comprises a VL CDR2 selected from the group consisting of DATTLAS (SEQ ID NO: 80), AASKLAS (SEQ ID NO: 96), GASTLAS (SEQ ID NO: 112), KASTLES (SEQ ID NO: 128), and ETSKLAS (SEQ ID NO: 144).

38. The antibody or antigen binding fragment thereof of any one of claims 29 to 37, wherein the light chain variable region further comprises a VL CDR3 selected from the group consisting of AGVYFGNILT (SEQ ID NO: 82), QGAGRGNIYP (SEQ ID NO: 98), AGAYSSNDKA (SEQ ID NO: 114), QSYVYGSSLDYGNT (SEQ ID NO: 130), and LGEFSCASADCAA (SEQ ID NO: 146).

39. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to 38, wherein the antibody comprises a heavy chain variable region that comprises VH CDR1, VH CDR2, and VH CDR3 domains and a light chain variable region that comprises VL CDR1, VL CDR2, and VL CDR3 domains selected from the group consisting of: a. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 72, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 74, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 76, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 78, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 80, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 82; b. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 88, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 90, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 92, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 94, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 96, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 98; c. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 104, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 106, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 108, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 110, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 112, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 114; and d. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 120, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 122, a VH CDR3having the amino acid AHL, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 126, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 128, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 130; and e. a VH CDR1 having the amino acid sequence set forth in SEQ ID NO: 136, a VH CDR2 having the amino acid sequence set forth in SEQ ID NO: 138, a VH CDR3 having the amino acid sequence set forth in SEQ ID NO: 140, a VL CDR1 having the amino acid sequence set forth in SEQ ID NO: 142, a VL CDR2 having the amino acid sequence set forth in SEQ ID NO: 144, and a VL CDR3 having the amino acid sequence set forth in SEQ ID NO: 146.

40. The isolated antibody or antigen binding fragment thereof of claim 39, wherein the antibody or antigen binding fragment thereof comprises: a. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 68; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 70; b. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 84; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 86; c. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 100; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 102; d. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 116; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 118; or e. a heavy chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 132; and a light chain variable region comprising an amino acid sequence that is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% identical to the amino acid sequence set forth in SEQ ID NO: 134.

41. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to40, wherein the heavy chain variable region of the antibody or antigen binding fragment thereof is selected from the group consisting of SEQ ID NO: 68, SEQ ID NO: 84, SEQ ID NO: 100, SEQ ID NO: 116, and SEQ ID NO: 132.

42. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to41, wherein the light chain variable region of the antibody or antigen binding fragment thereof is selected from the group consisting of SEQ ID NO: 70, SEQ ID NO: 86, SEQ ID NO: 102, SEQ ID NO: 118, and SEQ ID NO: 134.

43. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to42, wherein a. the heavy chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 68, SEQ ID NO: 84, SEQ ID NO: 100, SEQ ID NO: 116, and SEQ ID NO: 132; and b. the light chain variable region comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 70, SEQ ID NO: 86, SEQ ID NO: 102, SEQ ID NO: 118, and SEQ ID NO: 134.

44. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to43, comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 68 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 70.

45. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to 43, comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 84 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 86.

46. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to 43, comprising a heavy chain variable region comprising the amino acid sequence setforth in SEQ ID NO: 100 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 102.

47. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to 43, comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 116 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 118.

48. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to 43, comprising a heavy chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 132 and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO: 134.

49. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to48, wherein the antibody or antigen binding fragment thereof is labeled with a radioactive, enzymatic, or fluorescent group.

50. The isolated antibody or antigen-binding fragment thereof of any one of claims 29 to49, wherein the antibody is a full-length antibody or an antibody fragment selected from the group consisting of Fab, Fab’, Fab’-SH, Fd, Fv, dAb, F(ab’)2, scFv, bispecific single chain Fv dimers, diabodies, triabodies, and sxFv genetically fused to the same or a different antibody.

51. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to 31, wherein the antibody is a murine antibody, a chimeric murine / human antibody, a human antibody, an engineered antibody, or a humanized antibody.

52. The isolated antibody of claim 51, wherein the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 68 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 70.

53. The isolated antibody of claim 51, wherein the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 84 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 86.

54. The isolated antibody of claim 51, wherein the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 100 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 102.

55. The isolated antibody of claim 51, wherein the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 116 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 118.

56. The isolated antibody of claim 51, wherein the antibody comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 132 and a light chain comprising the amino acid sequence set forth in SEQ ID NO: 134.

57. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to56, wherein the antibody or antigen binding fragment thereof is a bispecific antibody.

58. The isolated antibody or antigen binding fragment thereof of any one of claims 29 to57, wherein the antibody or antigen binding fragment thereof is a multispecific antibody.

59. An isolated polynucleotide comprising a nucleic acid sequence encoding the antibody or antigen binding fragment thereof of any one of claims 1 to 28 or 29 to 58.

60. The polynucleotide of claim 59, wherein the nucleic acid sequence encodes a. a VH CDR1 domain comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 7, SEQ ID NO: 23, SEQ ID NO: 39, SEQ ID NO: 55, SEQ ID NO: 71, SEQ ID NO: 87, SEQ ID NO: 103, SEQ ID NO: 119, and SEQ ID NO: 135; b. a VH CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 9, SEQ ID NO: 25, SEQ ID NO: 41, SEQ ID NO: 57, SEQ ID NO: 73, SEQ ID NO: 89, SEQ ID NO: 105, SEQ ID NO: 121, and SEQ ID NO: 137; c. a VH CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 11, SEQ ID NO: 27, SEQ ID NO: 43, SEQ ID NO: 59, SEQ ID NO: 75, SEQ ID NO: 91, SEQ ID NO: 107, SEQ ID NO: 123, and SEQ ID NO: 139;d. a VL CDR1 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 13, SEQ ID NO: 29, SEQ ID NO: 45, SEQ ID NO: 61, SEQ ID NO: 77, SEQ ID NO: 93, SEQ ID NO: 109, SEQ ID NO: 125, and SEQ ID NO: 141; e. a VL CDR2 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 15, SEQ ID NO: 31, SEQ ID NO: 47, SEQ ID NO: 63, SEQ ID NO: 79, SEQ ID NO: 95, SEQ ID NO: 111, SEQ ID NO: 127, and SEQ ID NO: 143; or f. a VL CDR3 domain comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 17, SEQ I DNO: 33, SEQ ID NO: 49, SEQ ID NO: 65, SEQ ID NO: 81, SEQ ID NO: 97, SEQ ID NO: 113, SEQ ID NO: 129, and SEQ ID NO: 145.

61. The polynucleotide of claim 59 or 60, wherein: a. the nucleic acid encoding the heavy chain variable region comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 3, SEQ ID NO: 19, SEQ ID NO: 35, SEQ ID NO: 51, SEQ ID NO: 67, SEQ ID NO: 83, SEQ ID NO: 99, SEQ ID NO: 115, and SEQ ID NO: 131; and b. the nucleic acid encoding the light chain variable region comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 5, SEQ ID NO: 21, SEQ ID NO: 37, SEQ ID NO: 53, SEQ ID NO: 69 SEQ ID NO: 85, SEQ ID NO: 101, SEQ ID NO: 117, and SEQ ID NO: 133.

62. A vector comprising the polynucleotide of any one of claims 59 to 61.

63. A host cell comprising the vector of claim 62.

64. An in vitro detection kit comprising the antibody or antigen binding fragment thereof of any one of claims 1 to 28 or 29 to 58.

65. The kit of claim 64, further comprising a second antibody or antigen binding fragment thereof labeled with a radioactive, enzymatic and / or fluorescent group.

66. A method for detecting the presence of a human sarcoglycan protein in a sample, comprising contacting the sample with a composition comprising the isolated antibody or antigen binding fragment thereof of any one of claims 1 to 28 or 29 to 58.

67. The method of claim 66, wherein the presence of a human sarcoglycan protein in the sample is indicated by detecting the presence of the antibody or antigen binding fragment thereof.

68. The method of claim 67, wherein the presence of the antibody or antigen binding fragment thereof is detected by an immunoassay.

69. The method of claim 68, wherein the immunoassay comprises one or more of an immunofluorescence assay, an immunohistochemical assay, a Western blot, a direct enzyme-linked immunosorbent assay (ELISA), an indirect ELISA, a sandwich ELISA, a competitive ELISA, a reverse ELISA, a chemiluminescence assay, a radioimmunoassay, or an immunoprecipitation assay.

70. A method of making an anti-sarcoglycan antibody or antigen binding fragment thereof, comprising (a) administering to a non-human vertebrate animal an immunogenic amount of a polypeptide comprising the amino acid sequence GNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1); (b) recovering spleen cells from the animal; (c) fusing the recovered spleen cells with myeloma cells to generate hybridomas; (d) screening for hybridomas that produce an antibody that specifically binds human sarcoglycann protein; and (e) recovering the antibody.

71. A method of making an anti-sarcoglycan antibody or antigen binding fragment thereof, comprising (a) administering to a non-human vertebrate animal an immunogenic amount of a polypeptide comprising the amino acid sequence KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQN VTVNARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVG TDKLRVTGPEGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQA HAGKIEALSQMDILFHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICV CPDGKLYLSVAGVSTTCQEHSHICL (SEQ ID NO: 2); (b) recovering spleen cells from the animal; (c) fusing the recovered spleen cells with myeloma cells to generatehybridomas; (d) screening for hybridomas that produce an antibody that specifically binds human sarcoglycan protein; and (e) recovering the antibody.

72. The method of claims 70 or 71, wherein the non-human vertebrate animal is a transgenic animal, and wherein the transgenic animal expresses human immunoglobulin genes.

73. The method of claim 72, further comprising administering to the non-human vertebrate animal one or more immune adjuvants.

74. The method of claim any one of claims 72 or 73, wherein the non-human vertebrate animal is selected from a mouse, rat, hamster, guinea pig, rabbit, chicken, non-human primate, pig, goat, cow, and horse.

75. A method of making an anti-sarcoglycan antibody or antigen binding fragment thereof, comprising (a) immobilizing on a solid support an antigen comprising the amino acid sequence GNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1); (b) applying a phage display antibody library to the immobilized antigen; (c) screening the library for phage that bind the antigen; and (d) recovering antigenbinding phage.

76. A method of making an anti-sarcoglycan antibody or antigen binding fragment thereof, comprising (a) immobilizing on a solid support an antigen comprising the amino acid sequence KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQN VTVNARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVG TDKLRVTGPEGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQA HAGKIEALSQMDILFHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICV CPDGKLYLSVAGVSTTCQEHSHICL (SEQ ID NO: 2); (b) applying a phage display antibody library to the immobilized antigen; (c) screening the library for phage that bind the antigen; and (d) recovering antigen-binding phage.

77. The method of claims 75 or 76, wherein the solid support is selected from the group consisting of a microtiter plate well, polyvinylidene fluoride (PVDF) membrane, column matrix, immunotube, and magnetic bead.

78. The method of claim 75 or 77, wherein the phage display antibody library is derived from a non-human vertebrate animal previously immunized with a composition comprising an immunogenic amount of a polypeptide comprising the amino acid sequence GNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1).

79. The method of claim 76 or 77, wherein the phage display antibody library is derived from a non-human vertebrate animal previously immunized with a composition comprising an immunogenic amount of a polypeptide comprising the amino acid sequence KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQN VTVNARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVG TDKLRVTGPEGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQA HAGKIEALSQMDILFHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICV CPDGKLYLSVAGVSTTCQEHSHICL (SEQ ID NO: 2).

80. The method of claims 78 or 79, wherein the non-human vertebrate animal is selected from a mouse, rat, hamster, guinea pig, rabbit, chicken, non-human primate, pig, goat, cow, and horse.

81. An in silico method of making an anti-sarcoglycan antibody or antigen binding fragment thereof, comprising (a) designing CDRs in silico that specifically bind to an epitope on AAV capsid protein; (b) grafting the CDRs onto single-chain variable fragments (scFvs); (c) screening the scFvs for binding to a target polypeptide using antibody phage display; and (d) selecting scFvs that bind to the target polypeptide, wherein the epitope on a human sarcoglycan protein and the target polypeptide each comprises the amino acid sequence GNTEELRQMAASREVPRPLSTLPMFNVHTGERLPPRVDSAQVPLILDQH (SEQ ID NO: 1).

82. An in silico method of making an anti-sarcoglycan antibody or antigen binding fragment thereof, comprising (a) designing CDRs in silico that specifically bind to an epitope on AAV capsid protein; (b) grafting the CDRs onto single-chain variable fragments (scFvs); (c) screening the scFvs for binding to a target polypeptide using antibody phage display; and (d) selecting scFvs that bind to the target polypeptide, wherein the epitope on a human sarcoglycan protein and the target polypeptide each comprises the amino acid sequence KVMWFSPAGMGHLCVTKDGLRLEGESEFLFPLYAKEIHSRVDSSLLLQSTQN VTVNARNSEGEVTGRLKVGPKMVEVQNQQFQINSNDGKPLFTVDEKEVVVG TDKLRVTGPEGALFEHSVETPLVRADPFQDDLRLESPTRSLSMDAPRGVHIQA HAGKIEALSQMDILFHSSDGMLVLDAETVCLPKLVQGTWGPSGSSQSLYEICV CPDGKLYLSVAGVSTTCQEHSHICL (SEQ ID NO: 2).

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