Use of CXCL13-binding molecules to promote peripheral nerve regeneration

Abstract

Provided herein is a method for promoting axonal regeneration of sensory neurons and functional recovery of neurons after peripheral nerve injury in a subject experiencing age-dependent decline in neuronal regeneration capacity, comprising administering to a subject in need thereof an effective amount of an isolated binding molecule that specifically binds to CXCL13. TIFF2023530255000006.tif139170

Description

[Background technology]

[0001] background With the expansion of the aging population, the incidence of axonal injury in the nervous system is increasing (DeVivo, MJ, and Chen, Y. (2011). Archives of Physical Medicine and Rehabilitation 92, 332-338 (Non-Patent Document 1); Singh et al., (2014). Clinical Epidemiology 6, 309 (Non-Patent Document 2)). Unfortunately, axonal regeneration and repair processes decline with age, resulting in diminished functional recovery and increased long-term disability (Nagano, A. (1998). Journal of Orthopaedic Science 3, 71-80 (Non-Patent Document 3); Pestronk et al., (1980). Experimental Neurology 70, 65-82 (Non-Patent Document 4); Tanaka and deF. Webster, (1991). Journal of Comparative Neurology 308, 180-187 (Non-Patent Document 5); Vaughan, 1992. Journal of Comparative Neurology, 323, 219-237 (Non-Patent Document 6); Verdu et al., (2000). Journal of the Peripheral Nervous System 5, 191-208 (Non-Patent Document 7)).

[0002] The cellular and molecular mechanisms underlying this age-dependent decline in regenerative capacity are poorly understood. Studies have shown that age-related impairments in Schwann cell (SC) dedifferentiation and activation limit axonal regrowth in injured peripheral nervous systems (PNS), impairing sensory and motor recovery (Kang and Lichtman, (2013). Journal of Neuroscience 33, 19480-19491 (Non-Patent Document 8); Painter et al., (2014). Neuron 83, 331-343 (Non-Patent Document 9)). In the central nervous system, loss of phosphatase and tensine homolog (PTEN) and the concomitant increase in mTOR signaling only partially limit the age-dependent decline in axonal regeneration capacity of the corticospinal tract after spinal cord injury (Geoffroy et al., (2016). Cell Reports 15, 238-246 (Non-Patent Document 10)). Although these studies have elucidated some of the molecular mechanisms underlying age-dependent molecular changes after injury, aging itself leads to profound modifications of cell signaling, metabolism, immunity, gene regulation, and protein translation in all tissues, affecting homeostasis and predisposing to disease (Barzilai et al., (2012). Diabetes 61, 1315-1322 (Non-Patent Document 11); Lardenoije et al., (2015). Progress in Neurobiology 131, 21-64 (Non-Patent Document 12); Pomatto and Davies, (2017). The Journal of Physiology 595, 7275-7309 (Non-Patent Document 13); Taylor and Dillin, (2011). Cold Spring Harbor Perspectives in Biology 3, a004440 (Non-Patent Document 14); Weiskopf et al., (2009). Transplant International 22, 1041-1050 (Non-Patent Document 15).

[0003] Therefore, there is a need to determine the factors that drive age-dependent regulation in neurons and their role in regulating axonal regeneration so that therapies targeting such factors can be developed for the treatment of peripheral nervous system injury. [Technical Field]

[0004] Field The present invention relates to the use of binding molecules, such as antibodies and antigen-binding fragments thereof, that neutralize CXCL13 for promoting peripheral nerve regeneration in subjects with age-dependent decline in regenerative capacity. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] DeVivo, MJ, and Chen, Y. (2011). Archives of Physical Medicine and Rehabilitation 92, 332-338. [Non-patent document 2] Singh et al.,(2014).Clinical Epidemiology 6,309 [Non-patent document 3] Nagano, A. (1998).Journal of Orthopedic Science 3,71-80 [Non-patent document 4] Pestronk et al.,(1980).Experimental Neurology 70,65-82 [Non-Patent Document 5] Tanaka and deF. Webster, (1991). Journal of Comparative Neurology 308, 180-187 [Non-patent document 6] Vaughan, 1992. Journal of Comparative Neurology, 323, 219-237. [Non-Patent Document 7] Verdu et al.,(2000).Journal of the Peripheral Nervous System 5,191-208 [Non-Patent Document 8] Kang and Lichtman,(2013).Journal of Neuroscience 33,19480-19491 [Non-Patent Document 9] Painter et al.,(2014).Neuron 83,331-343 [Non-Patent Document 10] Geoffroy et al.,(2016).Cell Reports 15,238-246 [Non-Patent Document 11] Barzilai et al.,(2012).Diabetes 61,1315-1322 [Non-Patent Document 12] Lardenoije et al.,(2015).Progress in Neurobiology 131,21-64[[ID=二十一]] [[ID=二十二]][Non-Patent Document 13][[ID=二十三]] [[ID=二十四]]Pomatto and Davies,(2017).The Journal of Physiology 595,7275-7309[[ID=二十五]] [[ID=二十六]][Non-Patent Document 14][[ID=二十七]] [[ID=二十八]]Taylor and Dillin,(2011).Cold Spring Harbor Perspectives in Biology 3,a004440[[ID=二十九]] [[ID=三十]][Non-Patent Document 15][[ID=三十一]] [[ID=三十二]]Weiskopf et al.,(2009).Transplant International 22,1041-1050[[ID=三十三]] ][[ID=三十四]][Summary of the Invention][[ID=三十五]] [[ID=三十六]] [[ID=三十七]]

[0006] [[ID=三十八]] [[ID=三十九]]Summary of the Disclosure[[ID=四十]] Disclosed herein is a method for using a CXCL13-binding molecule to promote peripheral nerve regeneration in a subject with age-dependent decline in regenerative capacity. According to aspects of the disclosure exemplified herein, there is provided a method for improving peripheral nerve regeneration in a subject with peripheral nerve injury and age-dependent decline in regenerative capacity, comprising administering to the subject an effective amount of an isolated binding molecule that specifically binds to CXCL13 and inhibits, suppresses, prevents, reverses, or slows down the effect of CXCL13.

[0007] A method for promoting nerve regeneration of an injured peripheral nerve in a subject with age-related decline in regenerative capacity is provided, comprising administering to the subject an effective amount of an antibody or antigen-binding fragment thereof that specifically binds to CXCL13. In certain embodiments of the method, the antibody or antigen-binding fragment thereof inhibits CXCL13 activity. In certain embodiments of the method, the inhibited CXCL13 activity is the recruitment of CXCR5+CD8+ T cells to the dorsal root ganglia (DRG) of the injured peripheral nerve. In certain embodiments of the method, the isolated antibody or antigen-binding fragment thereof inhibits the interaction of CXCL13 with its receptor. In certain embodiments of the method, the CXCL13 receptor is CXCR5. In certain embodiments of the method, the isolated antibody or antigen-binding fragment thereof competitively inhibits the specific binding to CXCL13 of a reference monoclonal antibody selected from the group consisting of Mab 5378, MAb 5261, MAb5080, MAb 1476, 3D2, 3C9, MAb 5091, MAb 1758, or MAb 0745. In certain embodiments of any one of the foregoing methods, the isolated antibody or antigen-binding fragment thereof specifically binds to the same CXCL13 epitope as a reference monoclonal antibody selected from the group consisting of Mab 5378, MAb 5261, MAb 5080, MAb 1476, 3D2, 3C9, MAb 5091, MAb 1758, or MAb 0745.In certain embodiments of the method, the antibody or antigen-binding fragment thereof comprises: (A) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 26, 30, and 33, respectively; (B) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 27, 30, and 33, respectively; or (D) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 19, 22, and 25; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 28, 31, and 34, respectively; or (E) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 20, 23, and 25, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 29, 31, and 34, respectively. In certain embodiments, the VH and VL of the antibody or antigen-binding fragment thereof comprise amino acid sequences identical to the VH and VL sequences selected from the group consisting of: (i) SEQ ID NO:6 and SEQ ID NO:7, respectively; (ii) SEQ ID NO:8 and SEQ ID NO:9, respectively; (iii) SEQ ID NO:10 and SEQ ID NO:11, respectively; (iv) SEQ ID NO:12 and SEQ ID NO:12, respectively; (v) SEQ ID NO:14 and SEQ ID NO:15, respectively; and (vi) SEQ ID NO:16 and SEQ ID NO:17, respectively.In certain embodiments, the isolated binding molecule is MAb 5261, MAb 5091, or MAb 1476, MAb 1758. In certain embodiments of any one of the foregoing methods, the injured peripheral nerve is selected from the group consisting of the sciatic nerve, peroneal nerve, spinal accessory nerve, and brachial plexus. In certain embodiments of any of the foregoing methods, the method results in complete or partial regeneration of the injured nerve, reinnervation of epidermal tissue, or complete or partial restoration of neurological function of the injured nerve, or a combination thereof.

[0008] Methods for treating peripheral nerve injury in a subject with age-dependent decline in regenerative capacity and peripheral nerve injury are provided, comprising administering to the subject an effective amount of an isolated antibody or antigen-binding fragment thereof that specifically binds to CXCL13. In certain embodiments of the methods, the peripheral nerve injury is the result of compression, stretching, or severing of the peripheral nerve. In certain embodiments of the methods, the peripheral nerve injury is injury to the sciatic nerve, brachial plexus, peroneal nerve, or spinal accessory nerve. In certain embodiments of the methods, the peripheral nerve injury is sciatic nerve injury. In certain embodiments of any of the aforementioned methods, the antibody or antigen-binding fragment thereof inhibits the interaction of CXCL13 with its receptor. In certain embodiments of any of the aforementioned methods, the receptor is CXCR5.In certain embodiments of any of the foregoing methods, the antibody or antigen-binding fragment thereof comprises: (A) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 26, 30, and 33, respectively; (B) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 26, 30, and 33, respectively; (C) a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 27, 30, and 33; (C) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 19, 22, and 25, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 28, 31, and 34, respectively; or (D) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 20, 23, and 25, respectively; and a VL comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 28, 31, and 34, respectively. and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 29, 31, and 34.In certain embodiments of any of the foregoing methods, the VH and VL of the antibody or antigen-binding fragment thereof comprise amino acid sequences identical to the VH and VL sequences selected from the group consisting of: (i) SEQ ID NO:6 and SEQ ID NO:7, respectively; (ii) SEQ ID NO:8 and SEQ ID NO:9, respectively; (iii) SEQ ID NO:10 and SEQ ID NO:11, respectively; (iv) SEQ ID NO:12 and SEQ ID NO:12, respectively; (v) SEQ ID NO:14 and SEQ ID NO:15, respectively; and (vi) SEQ ID NO:16 and SEQ ID NO:17, respectively. In certain embodiments of any of the foregoing methods, the isolated binding molecule is a human or humanized antibody that competitively inhibits the specific binding to CXCL13 of a reference monoclonal antibody selected from the group consisting of MAb 5378, MAb 5261, MAb5080, MAb1476, MAb 5091, MAb 1758, 3D2, and 3C9. In certain embodiments of any of the foregoing methods, the isolated binding molecule is MAb 5261, MAb 5091, MAb 1476, or MAb 1758.

[0009] Methods for reversing age-related regenerative decline in a subject in need thereof are provided, comprising administering to the subject an effective amount of an isolated antibody or antigen-binding fragment thereof that specifically binds to CXCL13. In certain embodiments of the methods, the antibody or antigen-binding fragment thereof inhibits the interaction of CXCL13 with its receptor. In certain embodiments of the methods, the receptor is CXR5. In certain embodiments of any of the foregoing methods, the isolated antibody or antigen-binding fragment thereof competitively inhibits the specific binding to CXCL13 of a reference monoclonal antibody selected from the group consisting of MAb 5378, MAb 5261, MAb 5080, MAb 1476, MAb 5091, MAb 1748, 3D2, and 3C9.In certain embodiments of any of the foregoing methods, the antibody or antigen-binding fragment thereof comprises: (A) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 26, 30, and 33, respectively; (B) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 26, 30, and 33, respectively; (C) a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 27, 30, and 33; (C) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 19, 22, and 25, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 28, 31, and 34, respectively; or (D) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 20, 23, and 25, respectively; and a VL comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 28, 31, and 34, respectively. and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 29, 31, and 34.In certain embodiments of any of the foregoing methods, the VH and VL of the antibody or antigen-binding fragment thereof comprise amino acid sequences identical to the VH and VL sequences selected from the group consisting of: (i) SEQ ID NO:6 and SEQ ID NO:7, respectively; (ii) SEQ ID NO:8 and SEQ ID NO:9, respectively; (iii) SEQ ID NO:10 and SEQ ID NO:11, respectively; (iv) SEQ ID NO:12 and SEQ ID NO:12, respectively; (v) SEQ ID NO:14 and SEQ ID NO:15, respectively; and (vi) SEQ ID NO:16 and SEQ ID NO:17, respectively. In certain embodiments of any of the foregoing methods, the isolated binding molecule is MAb 5261, MAb 5091, MAb 1476, or MAb 1758. In certain embodiments of any of the foregoing methods, the subject has a peripheral nerve injury. In certain embodiments of any of the aforementioned methods, the peripheral injury is a sciatic nerve injury, a brachial plexus injury, a spinal accessory nerve injury, or a peroneal nerve injury. In certain embodiments of any of the aforementioned methods, the peripheral nerve injury is a sciatic nerve injury. [The present invention 1001] An antibody or antigen-binding fragment thereof that specifically binds to CXCL13 for use in treating peripheral nerve injury in a subject with age-dependent decline in regenerative capacity. [The present invention 1002] An antibody or antigen-binding fragment thereof for use in the present invention 1001, which inhibits CXCL13 activity. [The present invention 1003] The antibody or antigen-binding fragment thereof for use in the present invention 1002, wherein the CXCL13 activity that is inhibited is the recruitment of CXCR5+CD8+ T cells to the dorsal root ganglia (DRG) of injured peripheral nerves. [The present invention 1004] An antibody or antigen-binding fragment thereof for use in the present invention 1001, which inhibits the interaction of CXCL13 with its receptor. [The present invention 1005] The antibody or antigen-binding fragment thereof for use in the present invention 1004, wherein the CXCL13 receptor is CXCR5. [The present invention 1006] An antibody or antigen-binding fragment thereof for use in any of the present inventions 1001 to 1005, which competitively inhibits the specific binding to CXCL13 of a reference monoclonal antibody selected from the group consisting of MAb 5378, MAb 5261, MAb5080, MAb1476, 3D2, 3C9, MAb 5091, MAb 1758, or MAb 0745. [The present invention 1007] An antibody or antigen-binding fragment thereof for use in any of claims 1001 to 1005 of the present invention, which specifically binds to the same CXCL13 epitope as a reference monoclonal antibody selected from the group consisting of MAb 5378, MAb 5261, MAb5080, MAb1476, 3D2, 3C9, MAb 5091, MAb 1758, or MAb 0745. [The present invention 1008] (A) VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 26, 30, and 33, respectively; (B) VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 27, 30, and 33, respectively; (C) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 19, 22, and 25, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 28, 31, and 34, respectively; or (D) VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 20, 23, and 25, respectively; and VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 29, 31, and 34, respectively. An antibody or antigen-binding fragment thereof for use in any one of the present inventions 1001 to 1005, comprising: [The present invention 1009] An antibody or antigen-binding fragment thereof for use in any of the present inventions 1001 to 1005, wherein the VH and VL of the antibody or antigen-binding fragment thereof comprise amino acid sequences identical to the VH and VL sequences selected from the group consisting of: (i) SEQ ID NO:6 and SEQ ID NO:7, respectively; (ii) SEQ ID NO:8 and SEQ ID NO:9, respectively; (iii) SEQ ID NO:10 and SEQ ID NO:11, respectively; (iv) SEQ ID NO:12 and SEQ ID NO:13, respectively; (v) SEQ ID NO:14 and SEQ ID NO:15, respectively; and (vi) SEQ ID NO:16 and SEQ ID NO:17, respectively. [The present invention 1010] An antibody or antigen-binding fragment thereof for use in any of the present inventions 1001 to 1005, which is MAb 5261, MAb 5091, MAb 1476, or MAb 1758. [The present invention 1011] An antibody or antigen-binding fragment thereof for use in any of the present inventions 1001 to 1010, wherein the peripheral nerve injury is selected from the group consisting of sciatic nerve injury, peroneal nerve injury, spinal accessory nerve injury, and brachial plexus injury. [The present invention 1012] The antibody or antigen-binding fragment thereof for use in accordance with the present invention, wherein said use results in complete or partial regeneration of damaged nerves, reinnervation of epidermal tissue, or complete or partial restoration of neurological function of damaged nerves, or a combination thereof. [The present invention 1013] An effective amount of an isolated antibody or antigen-binding fragment thereof that specifically binds to CXCL13 for use in treating peripheral nerve damage in a subject with age-dependent decline in regenerative capacity and peripheral nerve damage. [The present invention 1014] The antibody or antigen-binding fragment thereof for use in the present invention 1013, wherein the peripheral nerve injury is the result of compression, stretching, or severing of the peripheral nerve. [The present invention 1015] The antibody or antigen-binding fragment thereof for use in the present invention 1013 or 1014, wherein the peripheral nerve injury is an injury to the sciatic nerve, brachial plexus, peroneal nerve, or spinal accessory nerve. [The present invention 1016] The antibody or antigen-binding fragment thereof for use in the present invention 1015, wherein the peripheral nerve injury is sciatic nerve injury. [The present invention 1017] An antibody or antigen-binding fragment thereof for use in any of the present inventions 1013 to 1016, which inhibits the interaction between CXCL13 and its receptor. [The present invention 1018] The antibody or antigen-binding fragment thereof for use in the present invention 1017, wherein the receptor is CXCR5. [The present invention 1019] (A) VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 26, 30, and 33, respectively; (B) VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 27, 30, and 33, respectively; (C) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 19, 22, and 25, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 28, 31, and 34, respectively; or (D) VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 20, 23, and 25, respectively; and VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 29, 31, and 34, respectively. An antibody or antigen-binding fragment thereof for use in any one of the present inventions 1013 to 1018, comprising: [The present invention 1020] An antibody or antigen-binding fragment thereof for use in any of the present inventions 1013 to 1018, wherein the VH and VL of the antibody or antigen-binding fragment thereof comprise amino acid sequences identical to the VH and VL sequences selected from the group consisting of: (i) SEQ ID NO:6 and SEQ ID NO:7; (ii) SEQ ID NO:8 and SEQ ID NO:9, respectively; (iii) SEQ ID NO:10 and SEQ ID NO:11, respectively; (iv) SEQ ID NO:12 and SEQ ID NO:13, respectively; (v) SEQ ID NO:14 and SEQ ID NO:15, respectively; and (vi) SEQ ID NO:16 and SEQ ID NO:17, respectively. [The present invention 1021] An antibody or antigen-binding fragment thereof for use in any of the present inventions 1013 to 1018, which is a human antibody or humanized antibody that competitively inhibits the specific binding to CXCL13 of a reference monoclonal antibody selected from the group consisting of MAb 5378, MAb 5261, MAb5080, MAb1476, MAb 5091, MAb 1758, 3D2, and 3C9. [The present invention 1022] The antibody or antigen-binding fragment thereof for use in the present invention 1021 is MAb 5261, MAb 5091, MAb 1476, or MAb 1758. [The present invention 1023] An isolated antibody or antigen-binding fragment thereof that specifically binds to CXCL13 for use in treating age-dependent regenerative decline in a subject in need thereof. [The present invention 1024] An antibody or antigen-binding fragment thereof for use in the present invention 1023, which inhibits the interaction of CXCL13 with its receptor. [The present invention 1025] The antibody or antigen-binding fragment thereof for use in the present invention 1024, wherein the receptor is CXR5. [The present invention 1026] An antibody or antigen-binding fragment thereof for use in any of the present inventions 1023 to 1025, wherein the isolated antibody or antigen-binding fragment thereof competitively inhibits the specific binding to CXCL13 of a reference monoclonal antibody selected from the group consisting of Mab 5378, MAb 5261, MAb5080, MAb1476, MAb 5091, MAb 1748, 3D2, and 3C9. [The present invention 1027] (A) VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 26, 30, and 33, respectively; (B) VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 27, 30, and 33, respectively; (C) a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 19, 22, and 25, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 28, 31, and 34, respectively; or (D) VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 20, 23, and 25, respectively; and VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 29, 31, and 34, respectively. An antibody or antigen-binding fragment thereof for use in any of the present inventions 1023 to 1026, comprising: [The present invention 1028] An antibody or antigen-binding fragment thereof for use in any of the present inventions 1023 to 1026, wherein the VH and VL of the antibody or antigen-binding fragment thereof comprise amino acid sequences identical to the VH and VL sequences selected from the group consisting of: (i) SEQ ID NO:6 and SEQ ID NO:7; (ii) SEQ ID NO:8 and SEQ ID NO:9, respectively; (iii) SEQ ID NO:10 and SEQ ID NO:11, respectively; (iv) SEQ ID NO:12 and SEQ ID NO:13, respectively; (v) SEQ ID NO:14 and SEQ ID NO:15, respectively; and (vi) SEQ ID NO:16 and SEQ ID NO:17, respectively. [The present invention 1029] An antibody or antigen-binding fragment thereof for use in any of the present inventions 1023 to 1028, wherein the isolated antibody or antigen-binding fragment thereof is MAb 5261, or MAb 5091, Man 1476, or MAb 1758. [The present invention 1030] An antibody or antigen-binding fragment thereof for use in any of the present inventions 1023 to 1029, wherein the subject has peripheral nerve damage. [The present invention 1031] The antibody or antigen-binding fragment thereof for use in the present invention 1030, wherein the peripheral injury is a sciatic nerve injury, a brachial plexus injury, a spinal accessory nerve injury, or a peroneal nerve injury. [The present invention 1032] The antibody or antigen-binding fragment thereof for use in the present invention 1031, wherein the peripheral nerve injury is sciatic nerve injury. [Brief explanation of the drawings]

[0010] [Figure 1]Figures 1A-E show that aging induces enrichment of chemokines / cytokines and adaptive immunity in the dorsal root ganglia (DRG) before and after sciatic nerve injury. Figure 1A is a heatmap showing the fold change of differentially expressed (DE) cytokines in protein-protein networks from sciatic nerve injury (SNI) young and SNI-aged mice compared to sham-young mice. Figure 1B shows SCG10 immunostaining of longitudinal sections of the sciatic nerve from young and aged mice 3 days after sciatic crush injury. Figure 1C shows SCG10 intensity normalized to the proximal crush site from young and aged mice (N = 5, two-way ANOVA with post-hoc Sidak test, **P < 0.01; ****P < 0.0001). Figure 1D, Quantification of CXCL13 expression shown by fold change in normalized fluorescence intensity compared to sham juveniles (N=4, one-way ANOVA with post hoc Tukey's test, ****P<0.0001). Figure 1E, CXCL13 ELISA from sciatic DRG (N=3, one-way ANOVA with post hoc Tukey's test, ****P<0.0001). [Figure 2A] Figure 2A-D shows that CXCL13 is a chemoattractant for CXCR5+CD8+ T cells that is enhanced in aged dorsal root ganglia (DRG). Figure 2A: Quantification of CXCR5+CD8+ T cell numbers normalized to counting beads in sciatic DRG (N=3, unpaired Student's t-test, *P<0.05). [Figure 2B] Figure 2B: Percentage of CXCR5+CD8+ T cells relative to total T cells in sciatic DRG (N=3, unpaired Student's t-test, *P<0.05). [Figure 2C] Figure 2C: Quantification of the number of CXCR5+CD8+ T cells in young and old DRG 3 days after sciatic nerve injury (N=4, unpaired Student's t-test, ****P<0.0001). [Figure 2D]Figure 2D: Percentage of CXCR5+CD8+ T cells relative to total CD8 T cells from young and old DRG sections immunostained for CXCR5 and CD8 3 days after nerve injury (N=3, unpaired Student's t-test, ***P<0.001). [Figure 3] Figures 3A-C demonstrate that CD8 T cells prevent axon regeneration in aged sciatic nerves. Figure 3A: SCG10 immunostaining of longitudinal sections of sciatic nerves from aged mice 3 days after crush injury after control IgG or anti-CD8 monoclonal antibody. The dashed line indicates the proximal crush site. Scale bar: 500 μm. Figure 3B: SCG10 intensity normalized to the proximal crush site in aged mice treated with control IgG (N = 6) or anti-CD8 (N = 6) monoclonal antibody (two-way ANOVA with post-hoc Sidak test, *P < 0.05, ***P < 0.001). Figure 3C: Quantification of the number of CD8 T cells in sciatic DRG sections 3 days after sciatic nerve injury after control IgG or anti-CD8 monoclonal antibody (N = 3, using unpaired Student's t-test, ****P < 0.0001). [Figure 4]Figures 4A-G demonstrate that MHC-I expression is induced in aged DRG and is required for degenerative decline in mice after sciatic nerve injury. Figure 4A: Co-immunostaining for MHC-I and Tuj1 and DAPI in sciatic DRG from young or aged mice before or 3 days after sciatic nerve injury. Fold change in normalized fluorescence intensity of MHC-I (N = 3, one-way ANOVA with post-hoc Tukey's test, *P < 0.05). Figure 4B: Percentage of antigen-presenting (AP) DRG neurons showing cell surface MHC-I expression in sciatic DRG from young or aged mice (N = 3, one-way ANOVA with post-hoc Tukey's test, ****P < 0.0001). Figure 4C: Linear diagram of the dual-vector doxycycline-inducible immune evasion GAr system containing a luciferase reporter delivered by AAV viral particles. Figure 4D: Experimental scheme. Figure 4E: Changes in normalized fluorescence intensity of MHC-I and cleaved caspase 3 in DRG sections 3 days after sciatic nerve injury following infection with AAV-rtTA or AAV-Gar-rtT in aged mice (N = 6, two-way ANOVA with post-hoc Sidak test, ****P < 0.0001). Figure 4F: SCG10 intensity normalized to the proximal crush site in aged mice infected with AAV-rtTA or AAV-GAr-rtTA (N = 6, two-way ANOVA with post-hoc Sidak test, ***P < 0.001, ****P < 0.0001). Figure 4G: Regeneration index, indicated by the distance from the crush site at which SCG10 intensity decreases to 50% compared to the proximal injury site (N = 5, using unpaired Student's t-test, **P < 0.01). [Figure 5-1]Figures 5A-L: Demonstrating the effect of CXCL13 neutralization. Figure 5A: Overview of the procedure for assessing sensory function by chronic administration of anti-CXCL13 antibody after sciatic nerve crush injury. Figure 5B: SCG10 immunostaining of longitudinal sciatic nerve sections from control IgG or anti-CXCL13 monoclonal antibody 3 days after sciatic nerve injury (SNI) in young and old mice. Dashed line indicates the proximal injury site. Scale bar: 100 μm. Figure 5C: SCG10 intensity normalized to the proximal crush site from young or old mice treated with IgG or anti-CXCL13 monoclonal antibody (N = 6, two-way ANOVA with post hoc Sidak test, *P (bold) < 0.05, **P (bold) < 0.01, IgG-Y vs. IgG-O; *P (black) < 0.05, **P (black) < 0.01, anti-CXCL13-Y vs. IgG-O; *P (gray) < 0.05, anti-CXCL13-O vs. IgG-O). Figure 5D: FACS quantification of the number of CXCR5+ B cells, CD8+ T cells, and CD4+ T cells derived from the DRG 3 days after sciatic nerve injury in old mice (N = 3, two-way ANOVA with post hoc Sidak test, **P < 0.01, ***P < 0.001, ****P < 0.0001). Figure 5E: Mechanical sensitivity as measured by paw withdrawal threshold of the hindpaw after stimulation with von Frey filaments following unilateral sciatic nerve crush (N(IgG-Y) = 10, N(anti-CXCL13-Y) = 10, N(IgG-O) = 11, N(anti-CXCL13-O) = 10; two-way ANOVA with post hoc Sidak's test, **P<0.01, ****P<0.0001, IgG-Y vs. IgG-O; $P<0.05, $$$$$P<0.0001, anti-CXCL13-Y vs. IgG-O; ##P<0.01, ####P<0.0001, anti-CXCL13-O vs. IgG-O). Figure 5F: Thermal sensitivity analysis by Hargreaves test measuring paw withdrawal latency of the hind paw after unilateral sciatic nerve crush (N=10, two-way ANOVA with post-hoc Sidak's test; ***P<0.001, ****P<0.0001, IgG-Y vs. IgG-O; $P<0.05, $$$$$P<0.0001, anti-CXCL13-Y vs. IgG-O; ####P<0.0001, anti-CXCL13-O vs. IgG-O).Figure 5G: Sensory response measured by latency to touch adhesive tape applied to the hind paw after unilateral sciatic nerve crush in aged mice treated with control IgG or anti-CXCL13 antibody (N = 10, two-way ANOVA with post hoc Sidak's test, **P < 0.01). Figure 5H: Sensory response measured by latency to remove adhesive tape applied to the hind paw after unilateral sciatic nerve crush in aged mice treated with control IgG or anti-CXCL13 antibody (N = 10, two-way ANOVA with post hoc Sidak's test, **P < 0.01). Figure 5I: Sensory response measured by latency to touch adhesive tape applied to the hind paw after unilateral sciatic nerve crush in aged mice treated with control IgG or anti-CXCL13 antibody (N = 10, two-way ANOVA with post hoc Sidak's test, **P < 0.01). Figure 5J: Sensory response measured by latency to remove adhesive tape applied to the hind paw after unilateral sciatic nerve crush in aged mice treated with control IgG or anti-CXCL13 antibody (N = 10, two-way ANOVA with post-hoc Sidak test, **<0.01). Figure 5K: PGP9.5 immunostaining counterstained with DAPI shows epidermal innervation of the hind paw interdigital skin 18 days after sciatic nerve crush. The dashed line indicates the border between the epidermis and dermis. Scale bar: 500 μm. Figure 5L: Quantification of the number of intraepidermal nerve fibers (IENFs) per mm of interdigital skin after IgG or anti-CXCL13 antibody (N = 6, one-way ANOVA with post-hoc Tukey test, *P<0.5, **P<0.01, ****P<0.0001). [Figure 5-2] See description of Figure 5-1. DETAILED DESCRIPTION OF THE INVENTION

[0011] Detailed Description I. Definition An entity followed by the term "a" or "an" refers to one or more of that entity; for example, "an anti-CXCL13 antibody" is understood to refer to one or more anti-CXCL13 antibodies. Thus, the terms "a" (or "an"), "one or more," and "at least one" can be used interchangeably herein. Furthermore, "and / or," as used herein, should be interpreted as a specific disclosure of each of the two specified features or components, with or without the other. Thus, the term "and / or," as used herein in phrases such as "A and / or B," is intended to include "A and B," "A or B," "A" (alone), and "B" (alone). Similarly, the term "and / or" as used in phrases such as "A, B, and / or C" is intended to include each of the following embodiments: 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).

[0012] The term "neuron regeneration" refers to the regrowth or repair of nerve tissue, cells, or cell products. Such mechanisms may include the generation of new neurons, glia, axons, myelin, or synapses. Nerve regeneration differs between the peripheral nervous system (PNS) and the central nervous system (CNS) depending on the functional mechanisms involved, particularly the extent and speed of repair. The processes occurring in peripheral regeneration can be divided into the following major events: Wallerian degeneration, axonal regeneration / growth, and reinnervation. When an axon is injured, the distal segment undergoes Wallerian degeneration and loses its myelin sheath. The proximal segment can either die by apoptosis or undergo chromatolysis, i.e., dissolution and degradation of neuronal chromatin, an attempt at repair. Events occurring in peripheral regeneration occur relative to the axis of nerve injury. The proximal stump refers to the end of the injured neuron that is still attached to the neuronal cell body and is the part that regenerates. The distal stump refers to the end of an injured neuron that is still attached to the end of its axon; it is the part of the neuron that degenerates but remains in the area, and towards which the regenerating axon grows.

[0013] As used herein, the term "peripheral nerve" refers to one of several nerves that branch off from the spinal cord and spread to all parts of the body. Unlike the central nervous system, regeneration of the peripheral nervous system is more common.

[0014] As used herein, the term "peripheral nerve injury" refers to damage to one or more of the 43 pairs of motor and sensory nerves of the peripheral nervous system, which connect the brain and spinal cord (central nervous system) to the entire human body. Peripheral nerve injury is commonly caused by transection (cutting or disruption of nerve tissue); severe contusion (contusion); injury to surrounding tissue during surgery; stretching (traction); injury from drug injection; and electrical injury. The symptoms of peripheral nerve injury vary depending on the type of nerve (motor, sensory, or autonomic) injured. Motor nerves control all consciously controlled muscle movements and are used, for example, for walking, grasping, or speaking. Sensory nerves transmit information such as light touch from a cut, temperature sensation, or pain sensation. Autonomic nerves innervate organs, controlling activities not consciously controlled by animals, such as breathing, digestion, and heart and gland function. Peripheral nerves control sensory, motor, and motor coordination functions. They are fragile and can be easily injured. Non-limiting examples of common peripheral nerve injuries include injuries to the brachial plexus, sciatic nerve, peroneal nerve, and spinal accessory nerve.

[0015] The term "sciatic nerve" refers to the major peripheral nerve in humans and other vertebrates that originates in the lower sacral plexus and runs down the leg through the hip joint. The sciatic nerve, also called the ischiatic nerve, is the longest and widest single nerve in the human body, running posteriorly from the top of the leg to the foot.

[0016] The term "sciatic nerve injury" refers to damage to the sciatic nerve, including damage caused by trauma to the nerve (e.g., compression, stretching, or severance). This type of injury can cause some loss of muscle strength and altered sensation. The cause of sciatic nerve injury can be spinal, non-spinal, or iatrogenic, including, but not limited to, spinal stenosis (due to degenerative bone disorders, trauma, inflammatory diseases); spondylolisthesis; growths in the spinal canal (e.g., abscess); non-spinal causes that compress or injure the nerve, such as piriformis syndrome, pregnancy, lumbar radiculopathy, leg trauma, pelvic or sciatic nerve tumors, or those caused by medical examinations, procedures, or treatments.

[0017] The term "spinal accessory nerve injury" refers to damage to the spinal accessory nerve, the 11th of 12 cranial nerves originating in the brain. The spinal accessory nerve functions two sets of muscles in the neck: the sternocleidomastoid, which allows the head to tilt and rotate, and the trapezius, which allows some movements, such as shrugging the shoulders and moving the scapula. The spinal accessory nerve can be injured by trauma or during surgery when surgeons operate on lymph nodes or jugular veins in the neck. Symptoms include shoulder pain, outward "winging" of the scapula, and weakness or atrophy of the trapezius muscle.

[0018] The term "brachial plexus injury" refers to damage to the brachial plexus, a network of nerves that sends signals from the spinal cord to the shoulder, arm, and hand. Brachial plexus injuries occur when these nerves are stretched, compressed, or, most severely, torn or detached from the spinal cord. Symptoms of more severe injuries can include weakness or inability to use certain muscles in the hand, arm, or shoulder, complete loss of movement and sensation in the arm, including the shoulder and hand, and severe pain. Common causes of brachial plexus injuries include contact sports injuries, difficult births, trauma, and tumors, and / or chemotherapy.

[0019] The term "peroneal nerve" refers to the common peroneal nerve, which branches off from the sciatic nerve and provides sensation to the front and sides of the leg and the top of the foot. This nerve also innervates the leg muscles that lift the ankle and toes upward. Injury to the peroneal nerve can cause numbness, tingling, pain, weakness, and a gait abnormality called foot drop. The peroneal nerve can be damaged by trauma and nerve compression, including knee dislocation, knee or leg fracture, knee or hip replacement, compression of the peroneal nerve in the leg, and compression of the peroneal nerve by a nerve sheath tumor or nerve cyst.

[0020] As used herein, the term "dorsal root ganglion" (DRG) refers to the enlargement of the dorsal root of a spinal nerve, which represents the cell bodies of primary somatosensory neurons. The DRG is responsible for sensory functions; it transmits nerve signals from the peripheral nervous system to the central nervous system (spinal cord, brain). The DRG itself is a node containing spinal nerve cells. The cell bodies of sensory neurons, known as primary neurons, are located in the dorsal root ganglion.

[0021] The term "therapeutically effective amount" refers to an amount of an antibody, polypeptide, polynucleotide, small organic molecule, or other drug that is effective for "treating" a condition or disorder in a subject or mammal. In the case of peripheral nerve injury or damage, such as sciatic nerve injury, a therapeutically effective amount of a drug can promote axonal regeneration of sensory neurons, epidermal innervation, and functional recovery of neurons after nerve injury in a subject with impaired nerve regeneration capacity, for example, by increasing proliferation, differentiation, migration, and / or survival of neural stem / progenitor cells; reducing, delaying, or stopping neuronal cell loss; inhibiting, for example, suppressing, delaying, preventing, stopping, or reversing neuronal cell loss; increasing the number, density, and / or concentration of neuronal cells; changing the morphology or function of neuronal cells; or changing the interaction between neuronal cells; alleviating to some extent one or more symptoms associated with nerve injury, such as pain; improving quality of life; or a combination of such effects.

[0022] Terms such as "treating" or "treatment" or "treat" or "palliating" or "alleviating" refer to both (1) therapeutic measures that cure, slow, relieve symptoms, reverse, and / or halt the progression of a diagnosed pathological condition of an injured nerve, and (2) prophylactic or preventative measures that prevent and / or slow peripheral nerve regeneration. Thus, those in need of treatment include those who already have peripheral nerve injury; and those who are susceptible to peripheral nerve injury (e.g., sciatic nerve injury). Beneficial or desired clinical results include, but are not limited to, alleviation of symptoms, which may or may not be detectable, reduction in the extent of damaged nerve tissue, stabilization of the nerve injury state (i.e., no progression), delay or slowing of injury progression, remission or alleviation of nerve injury, and regeneration (which may be partial or complete) of the injured nerve. Those in need of treatment include those who already have or are suspected of having peripheral nerve damage, as well as those prone to peripheral nerve damage, e.g., sciatica, or those in whom a condition or injury or further damage is to be prevented. Specifically, those in need of treatment include animals experiencing an age-dependent decline in nerve regenerative function.

[0023] "Subject" or "individual" or "animal" or "patient" or "mammal" means any subject for whom treatment is desired, particularly a mammalian subject. Mammalian subjects include humans, farm animals, livestock, zoo animals, sport animals, or pet animals, such as dogs, cats, guinea pigs, rabbits, rats, mice, horses, cattle, cows, bears, etc.

[0024] As used herein, phrases such as "subject that would benefit from administration of an anti-CXCL13 antibody" and "animal in need of treatment" include subjects, such as mammalian subjects, who would benefit from administration of an anti-CXCL13 antibody or other CXCL13-binding molecule used to detect levels of CXCL13 polypeptide (e.g., for diagnostic procedures) and / or treatment, i.e., alleviation or prevention, of a pathological condition affecting peripheral nerves with an anti-CXCL13 antibody or other CXCL13-binding molecule. Such subjects include animals experiencing an age-dependent decline in the naturally occurring nerve regeneration process that promotes neurological recovery after nerve injury.

[0025] As used herein, the term "age-dependent regenerative decline" or "age-dependent axonal regenerative decline" refers to a naturally occurring condition in animals associated with the aging process, in which axonal regeneration capacity and axonal repair processes decline with age. Whether a subject is affected by age-dependent regenerative decline can be assessed by a medical professional by determining the subject's age, overall health, observing the extent of nerve damage, and the time required for repair. A subject with age-dependent regenerative decline can be of any chronological age, depending on the subject's other physiological or genetic traits. Any such subject would benefit from the treatments described herein for peripheral nerve injury.

[0026] The term "binding molecule" or "antigen-binding molecule" of the present disclosure refers, in the broadest sense, to a molecule that specifically binds to an antigenic determinant. In one embodiment, the binding molecule specifically binds to CXCL13 (also known as BCA-1). In another embodiment, the binding molecule of the present disclosure is an antibody or antigen-binding fragment thereof, e.g., an anti-CXCL13 antibody. In another embodiment, the binding molecule of the present disclosure comprises at least one heavy or light chain CDR of an antibody molecule. In another embodiment, the binding molecule of the present disclosure comprises at least two CDRs from one or more antibody molecules. In another embodiment, the binding molecule of the present disclosure comprises at least three CDRs from one or more antibody molecules. In another embodiment, the binding molecule of the present disclosure comprises at least four CDRs from one or more antibody molecules. In another embodiment, the binding molecule of the present disclosure comprises at least five CDRs from one or more antibody molecules. In another embodiment, the binding molecule of the present disclosure comprises at least six CDRs from one or more antibody molecules. In certain embodiments, one or more of the CDRs are derived from MAb 5261, MAb 5378, MAb 5080, MAb 1476, 3D2, 3C9, MAb 1758, MAb 5091, or MAb 0745. Exemplary anti-CXCL13 antibodies are disclosed, for example, in U.S. Patent No. 9,963,504, which is incorporated herein by reference in its entirety.

[0027] "Inhibit," as used herein, can include, for example, partial or complete prevention of binding, activity, function, interaction, or other measurable characteristic.

[0028] The present disclosure relates to methods of promoting axonal regeneration of sensory neurons, epidermal innervation, and / or functional recovery of neurons after peripheral nerve injury in a subject experiencing age-dependent decline in neuronal regenerative capacity, e.g., an elderly subject or a subject diagnosed as such by a healthcare provider, comprising administering to the subject an anti-CXCL13 binding molecule, e.g., an antibody, or an antigen-binding fragment, variant, or derivative thereof. Unless a full-size antibody, such as a naturally occurring antibody, is specifically referenced, the term "anti-CXCL13 antibody" encompasses full-size antibodies and antigen-binding fragments, variants, analogs, or derivatives of such antibodies, e.g., naturally occurring antibodies or immunoglobulin molecules, or recombinant antibody molecules or fragments that bind to an antigen in a manner similar to the antibody molecule.

[0029] As used herein, a "human" or "fully human" antibody includes antibodies having the amino acid sequence of a human immunoglobulin, including antibodies isolated from a human immunoglobulin library or from an animal transgenic for one or more human immunoglobulins that does not express endogenous immunoglobulins, as described infra, e.g., U.S. Patent No. 5,939,598 to Kucherlapati et al. "Human" or "fully human" antibodies also include antibodies comprising at least the variable domain of a heavy chain, or comprising at least the variable domains of a heavy chain and a light chain, wherein the variable domain has the amino acid sequence of a human immunoglobulin variable domain.

[0030] "Human" or "fully human" antibodies also include those that comprise, consist essentially of, or consist of variants (including derivatives) of the antibody molecules (e.g., VH and / or VL regions) described herein, where the antibody or fragment thereof immunospecifically binds to a CXCL13 polypeptide, or a fragment or variant thereof. Standard techniques known to those skilled in the art, including but not limited to site-directed mutagenesis and PCR-mediated mutagenesis that result in amino acid substitutions, can be used to introduce mutations into the nucleotide sequence encoding a human anti-CXCL13 antibody. In certain embodiments, variants (including derivatives) encode fewer than 50 amino acid substitutions, fewer than 40 amino acid substitutions, fewer than 30 amino acid substitutions, fewer than 25 amino acid substitutions, fewer than 20 amino acid substitutions, fewer than 15 amino acid substitutions, fewer than 10 amino acid substitutions, fewer than 5 amino acid substitutions, fewer than 4 amino acid substitutions, fewer than 3 amino acid substitutions, or fewer than 2 amino acid substitutions compared to a reference VH region, VHCDR1, VHCDR2, VHCDR3, VL region, VLCDR1, VLCDR2, or VLCDR3.

[0031] In certain embodiments, the amino acid substitutions are conservative amino acid substitutions, as further described below. Alternatively, mutations can be introduced randomly along all or part of the coding sequence, e.g., by saturation mutagenesis, and the resulting mutants screened for biological activity to identify variants that retain activity (e.g., the ability to bind to a CXCL13 polypeptide, e.g., human CXCL13, mouse CXCL13, or both human CXCL13 and mouse CXCL13). Such variants of "human" or "fully human" antibodies (or derivatives thereof) are also referred to as "optimized" or "antigen-binding optimized" human antibodies or fully human antibodies, and include antibodies with improved affinity for antigen.

[0032] The terms "antibody" and "immunoglobulin" are used interchangeably herein. An antibody or immunoglobulin comprises at least a heavy chain variable domain, and typically comprises at least heavy and light chain variable domains. Basic immunoglobulin structure in vertebrate systems is relatively well understood. See, e.g., Harlow et al. (1988) Antibodies: A Laboratory Manual (2nd ed.; Cold Spring Harbor Laboratory Press).

[0033] As used herein, the term "immunoglobulin" encompasses a wide variety of biochemically distinguishable polypeptide classes. Those skilled in the art will understand that heavy chains are classified as gamma, mu, alpha, delta, or epsilon (γ, μ, α, δ, ε), with several subclasses (e.g., γ1-γ4) within them. It is the nature of this chain that determines the "class" of an antibody: IgG, IgM, IgA, IgG, or IgE, respectively. Immunoglobulin subclasses (isotypes), e.g., IgG1, IgG2, IgG3, IgG4, IgA1, etc., are well characterized and are known to confer functional specialization. Modified versions of each of these classes and isotypes are readily discernible to those skilled in the art in light of the present disclosure and, therefore, are within the scope of the present disclosure. While all immunoglobulin classes are clearly within the scope of the present disclosure, the following description generally relates to the IgG class of immunoglobulin molecules. For IgG, a standard immunoglobulin molecule contains two identical light polypeptide chains with a molecular weight of approximately 23,000 daltons and two identical heavy polypeptide chains with a molecular weight of 53,000-70,000. The four chains are typically joined by disulfide bonds in a "Y" configuration, with the light chains flanking the heavy chains, starting at the opening of the "Y" and continuing through the variable region.

[0034] Light chains are classified as either kappa or lambda (K, λ). Each heavy chain class can associate with either kappa or lambda light chains. When immunoglobulins are produced by either hybridomas, B cells, or genetically engineered host cells, the light and heavy chains are generally covalently linked to each other, and the "tails" of the two heavy chains are linked to each other by covalent disulfide bonds or non-covalent bonds. In the heavy chains, the amino acid sequence runs from the N-terminus at the forked end of the Y to the C-terminus at the bottom of each chain.

[0035] Both light and heavy chains are divided into structurally and functionally homologous regions. The terms "constant" and "variable" are used functionally. In this regard, it will be understood that the variable domains of both the light chain (VL or VK) and the heavy chain (VH) determine antigen recognition and specificity. Conversely, the constant domains of the light chain (CL) and heavy chain (CH1, CH2, or CH3) confer important biological properties, such as secretion, transplacental transfer, Fc receptor binding, and complement binding. By convention, the numbering of constant region domains increases distally from the antigen-binding site or amino terminus of the antibody. The N-terminal portion is the variable region, and the C-terminal portion contains the constant region; the CH3 and CL domains actually comprise the carboxy termini of the heavy and light chains, respectively.

[0036] As noted above, the variable region enables an antibody to selectively recognize and specifically bind to an epitope on an antigen. That is, the VL and VH domains of an antibody, or a subset of the complementarity-determining regions (CDRs) of these variable domains, combine to form the variable region that defines the three-dimensional antigen-binding site. This quaternary antibody structure forms the antigen-binding site present at the end of each arm of the Y. More specifically, the antigen-binding site is defined by three CDRs in each of the VH and VL chains. In some instances, for example, certain immunoglobulin molecules derived from Camelidae species or engineered based on Camelidae immunoglobulins can consist of only heavy chains, without light chains. See, e.g., Hamers-Casterman et al., Nature 363:446-448 (1993).

[0037] In naturally occurring antibodies, each antigen-binding domain contains six "complementarity-determining regions" or "CDRs," short, noncontiguous sequences of amino acids specifically positioned to form the antigen-binding domain when the antibody assumes its three-dimensional configuration in an aqueous environment. The remaining amino acids of the antigen-binding domain, called "framework" regions, exhibit less intermolecular variability. The framework regions primarily adopt a β-sheet conformation, while the CDRs form loops that connect, and in some cases form part of, the β-sheet structure. Thus, the framework regions act as a scaffold that provides proper orientation of the CDRs through interchain noncovalent interactions. The antigen-binding domain formed by the positioned CDRs defines a surface complementary to the epitope on the immunoreactive antigen. This complementary surface promotes noncovalent binding of the antibody to its cognate epitope. Because the amino acids that constitute the CDRs and framework regions are precisely defined, they can be readily identified for any given heavy or light chain variable domain by those skilled in the art (see below).

[0038] When a term has more than one definition used and / or accepted in the art, that definition of the term, as used herein, is intended to include all such meanings unless expressly stated otherwise. A specific example is the use of the term "complementarity-determining region" ("CDR") to describe the non-contiguous antigen-binding sites found in the variable regions of both heavy and light chain polypeptides. This particular region is described by Kabat et al. (1983) U.S. Department of Health and Human Services, "Sequences of Protein of Immunological Interest," and Chothia and Lesk, J. Mol. Biol. 196:901-917 (1987), both of which are incorporated herein by reference, and the definitions include overlapping amino acid residues or subsets of amino acid residues when compared with each other. Nevertheless, application of either definition to refer to the CDRs of an antibody or variants thereof is intended to be within the scope of the term as defined and used herein. The appropriate amino acid residues encompassing the CDRs defined by each of the above-cited references are set forth below in Table 1 for comparison. The exact residue numbers which encompass a particular CDR will vary depending on the sequence and size of the CDR, and one of ordinary skill in the art can routinely determine which residues make up a particular CDR, given the variable region amino acid sequence of an antibody.

[0039] The numbering of all CDR definitions in Table 1 follows the numbering convention described by Kabat et al. (see below).

[0040] (Table 1) TIFF0007748728000001.tif41128 1 The numbering of all CDR definitions in Table 1 follows the numbering convention described by Kabat et al. (see below).

[0041] Antibody variable domains may be analyzed to identify variable region segments containing the CDRs (see, e.g., Brochet et al., Nucl. Acids Res., 36:W503-508, 2008), for example, using the IMGT information system (www: / / imgt.cines.fr / ) (IMGT® / V-Quest).

[0042] Kabat et al. also defined a numbering system for variable domain sequences that is applicable to any antibody. One of skill in the art can unambiguously assign this "Kabat numbering" system to any variable domain sequence without reliance on experimental data beyond the sequence itself. As used herein, "Kabat numbering" refers to the numbering system described by Kabat et al. (1983) US Department of Health and Human Services, "Sequence of Proteins of Immunological Interest." Unless otherwise specified, references to the numbering of specific amino acid residue positions in anti-CXCL13 antibodies, or antigen-binding fragments, variants, or derivatives thereof, of the present disclosure are in accordance with the Kabat numbering system.

[0043] Antibodies, or antigen-binding fragments, variants, or derivatives thereof of the present disclosure include, but are not limited to, polyclonal, monoclonal, multispecific, human, humanized, primatized, or chimeric antibodies, single-chain antibodies, epitope-binding fragments such as Fab, Fab', and F(ab')2, Fd, Fv, single-chain Fv (scFv), disulfide-linked Fv (sdFv), fragments comprising either the VL or VH domain, fragments produced by a Fab expression library, and anti-idiotypic (anti-Id) antibodies (including, for example, anti-Id antibodies to the anti-CXCL13 antibodies disclosed herein). ScFv molecules are known in the art and are described, for example, in U.S. Patent No. 5,892,019. The immunoglobulin or antibody molecules of the present disclosure can be of any type (e.g., IgG, IgE, IgM, IgD, IgA, and IgY), class (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2, etc.), or subclass of immunoglobulin molecule.

[0044] As used herein, the term "heavy chain portion" includes an amino acid sequence derived from an immunoglobulin heavy chain. In certain embodiments, a polypeptide comprising a heavy chain portion comprises at least one of a VH domain, a CH1 domain, a hinge (e.g., the upper, middle, and / or lower part of the hinge region), a CH2 domain, a CH3 domain, or a variant or fragment thereof. For example, a binding polypeptide for use in the present disclosure may include a polypeptide chain comprising a CH1 domain; a polypeptide chain comprising a CH1 domain, at least a portion of the hinge domain, and a CH2 domain; a polypeptide chain comprising a CH1 domain and a CH3 domain; a polypeptide chain comprising a CH1 domain, at least a portion of the hinge domain, and a CH3 domain, or a polypeptide chain comprising a CH1 domain, at least a portion of the hinge domain, a CH2 domain, and a CH3 domain. In another embodiment, a polypeptide of the present disclosure includes a polypeptide chain comprising a CH3 domain. Furthermore, a binding polypeptide for use in the present disclosure may lack at least a portion of the CH2 domain (e.g., all or part of the CH2 domain). As noted above, it will be understood by those skilled in the art that these domains (eg, heavy chain portions) may be modified so that they differ in amino acid sequence from naturally occurring immunoglobulin molecules.

[0045] In certain anti-CXCL13 antibodies, or antigen-binding fragments, variants, or derivatives thereof, disclosed herein, the heavy chain portion of one polypeptide chain of a multimer is identical to that of a second polypeptide chain of the multimer. Alternatively, the heavy chain portion-containing monomers of the present disclosure are not identical. For example, each monomer may contain a different target binding site, forming, for example, a bispecific antibody.

[0046] The heavy chain portion of the binding molecule for use in the methods disclosed herein can be derived from different immunoglobulin molecules. For example, the heavy chain portion of the polypeptide can include a CH1 domain derived from an IgG1 molecule and a hinge region derived from an IgG3 molecule. In another example, the heavy chain portion can include a hinge region partially derived from an IgG1 molecule and partially derived from an IgG3 molecule. In another example, the heavy chain portion can include a chimeric hinge partially derived from an IgG1 molecule and partially derived from an IgG4 molecule.

[0047] As used herein, the term "light chain portion" includes amino acid sequences derived from an immunoglobulin light chain, e.g., a kappa light chain or a lambda light chain. In some embodiments, the light chain portion includes at least one of a VL domain or a CL domain.

[0048] CXCL13 is a small chemokine belonging to the CXC chemokine family. It is selectively chemotactic for B cells belonging to both the B-1 and B-2 subsets, and exerts its effects by interacting with the chemokine receptor CXCR5 (Legler DF, Loetscher M, Roos RS, Clark-Lewis I, Baggiolini M, Moser B (February 1998). J. Exp. Med. 187(4):655-60; Ansel KM, Harris RB, Cyster JG (January 2002). Immunity. 16(1):67-76). CXCL13 and its receptor CXCR5 regulate the organization of B cells within lymphoid follicles (Ansel KM, Ngo VN, Hyman PL, Luther SA, Forster R, Sedgwick JD, Browning JL, Lipp M, Cyster JG (July 2000. Nature. 406(6793):309-14). CXCL13 is highly expressed in the human liver, spleen, lymph nodes, and intestine (Legler DF, Loetscher M, Roos RS, Clark-Lewis I, Baggiolini M, Moser B (February 1998). J. Exp. Med. 187(4):655-60). As described herein, CXCL13 can also be chemotactic for CXCR5-expressing T lymphocytes, specifically CD8+ T lymphocytes, in certain circumstances.

[0049] The anti-CXCL13 antibodies disclosed herein, or antigen-binding fragments, variants, or derivatives thereof, may be described or specified in terms of the epitope or portion of the antigen disclosed herein, e.g., the target polypeptide (e.g., CXCL13), that they recognize or specifically bind. The portion of the target polypeptide that specifically interacts with the antigen-binding domain of the antibody is the "epitope" or "antigenic determinant." A target polypeptide may contain a single epitope, but typically contains at least two epitopes, and may contain any number of epitopes depending on the size, conformation, and type of antigen. Furthermore, it should be noted that an "epitope" on a target polypeptide may be or include non-polypeptide elements; for example, an epitope may include a carbohydrate side chain.

[0050] The minimum size of a peptide or polypeptide epitope for an antibody is believed to be about 4 to 5 amino acids. A peptide or polypeptide epitope may contain at least 7, at least 9, or at least about 15 to about 30 amino acids. Because CDRs can recognize tertiary forms of antigenic peptides or polypeptides, the amino acids constituting the epitope need not be contiguous, and in some cases may not even be on the same peptide chain. A peptide or polypeptide epitope recognized by an anti-CXCL13 antibody of the present disclosure may contain a sequence of at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 15, at least 20, at least 25, or about 15 to about 30 contiguous or non-contiguous amino acids of CXCL13.

[0051] "Specifically binds" generally means that an antibody binds to an epitope via its antigen-binding domain, and that binding requires a certain degree of complementarity between the antigen-binding domain and the epitope. According to this definition, an antibody is said to "specifically bind" to an epitope when it binds to that epitope via its antigen-binding domain more readily than it would to a random, unrelated epitope. The term "specificity" is used herein to describe the relative affinity with which a particular antibody binds to a particular epitope. For example, antibody "A" may have higher specificity for a given epitope than antibody "B," or antibody "A" may bind to epitope "C" with higher specificity than it has for the related epitope "D."

[0052] "Preferentially binds" means that an antibody specifically binds to an epitope more readily than it binds to a related, similar, homologous, or analogous epitope. Thus, an antibody that "preferentially binds" to a given epitope is more likely to bind to that epitope than to a related epitope, even if such an antibody may cross-react with the related epitope.

[0053] As a non-limiting example, the antibody may be selected from the group consisting of a dissociation constant (K D ) lower K D In another non-limiting example, the antibody binds to the first epitope preferentially if it binds to the first epitope at a K of the antibody against the second epitope. D In another non-limiting example, an antibody preferentially binds to a first antigen if it binds to the first epitope with an affinity at least one order of magnitude lower than the K of the antibody for the second epitope. D A first epitope is preferentially bound if it binds the first epitope with at least two orders of magnitude lower affinity than the first epitope.

[0054] In another non-limiting example, an antibody preferentially binds a first epitope if it binds to the first epitope with a lower k(off) than the antibody's off rate (k(off)) for the second epitope. In another non-limiting example, an antibody preferentially binds a first epitope if it binds to the first epitope with an affinity that is at least one order of magnitude lower than the antibody's k(off) for the second epitope. In another non-limiting example, an antibody preferentially binds a first epitope if it binds to the first epitope with an affinity that is at least two orders of magnitude lower than the antibody's k(off) for the second epitope. An antibody, or antigen-binding fragment, variant, or derivative disclosed herein may have a binding affinity of 5×10 -2 sec -1 , 10 -2 sec -1 , 5×10 -3 sec -1 , or 10 -3 sec -1 In some embodiments, the antibodies of the present disclosure bind to a target polypeptide (e.g., CXCL13, e.g., human CXCL13, mouse CXCL13, or both human CXCL13 and mouse CXCL13), or a fragment or variant thereof, disclosed herein, with an off-rate (k(off)) of 5×10 -4 sec -1 , 10 -4 sec -1 , 5×10 -5 sec -1 , or 10 -5 sec -1 , 5×10 -6 sec -1 , 10 -6 sec -1 , 5×10 -7 sec -1 , or 10 -7 sec -1 It is said to bind to a target polypeptide disclosed herein (e.g., CXCL13, e.g., human CXCL13, mouse CXCL13, or both human CXCL13 and mouse CXCL13), or a fragment or variant thereof, with the following off-rate (k(off)):

[0055] In certain embodiments, the antibodies, or antigen-binding fragments, variants, or derivatives disclosed herein are 3 M -1 sec -1 , 5×10 3 M -1 sec -1 , 10 4 M -1 sec -1 , or 5 × 10 4 M -1 sec -1 In some embodiments, the antibodies of the present disclosure bind to a target polypeptide (e.g., CXCL13, e.g., human CXCL13, mouse CXCL13, or both human CXCL13 and mouse CXCL13), or a fragment or variant thereof, disclosed herein, with an on rate (k(on)) of 10 or greater. 5 M -1 sec -1 , 5×10 5 M -1 sec -1 , 10 6 M -1 sec -1 , or 5 × 10 6 M -1 sec -1 , or 10 7 M -1 sec -1 The compound binds to a target polypeptide disclosed herein (e.g., CXCL13, e.g., human CXCL13, mouse CXCL13, or both human CXCL13 and mouse CXCL13), or a fragment or variant thereof, with an on rate (k(on)) of at least 100 s.

[0056] An antibody is said to competitively inhibit the binding of a reference antibody to a given epitope if it preferentially binds to that epitope to such an extent that it blocks, to some extent, the binding of the reference antibody to that epitope. Competitive inhibition can be determined by any method known in the art, for example, by competitive ELISA assay. An antibody is said to competitively inhibit the binding of a reference antibody to a given epitope by at least 90%, at least 80%, at least 70%, at least 60%, or at least 50%.

[0057] As used herein, the term "affinity" refers to a measure of the strength of binding between an individual epitope and the CDR of an immunoglobulin molecule. See, e.g., Harlow et al. (1988) Antibodies: A Laboratory Manual (Cold Spring Harbor Laboratory Press, 2nd ed.), pp. 27-28. As used herein, the term "avidity" refers to the overall stability of the complex between an immunoglobulin population and an antigen, i.e., the functional binding strength between an immunoglobulin mixture and an antigen. See, e.g., Harlow, pp. 29-34. Avidity relates to the affinity of individual immunoglobulin molecules within a population for a particular epitope and is also related to the valency of the immunoglobulin-antigen interaction. For example, the interaction between a bivalent monoclonal antibody and an antigen with a highly repetitive epitope structure, such as a polymer, would have high avidity.

[0058] The anti-CXCL13 antibody of the present disclosure, or its antigen-binding fragment, variant, or derivative, can also be described or specified in terms of cross-reactivity.As used herein, the term "cross-reactivity" refers to the ability of an antibody specific to one antigen to react with a second antigen; it is a measure of the relationship between two different antigenic substances.Thus, an antibody is cross-reactive when it binds to an epitope other than the epitope that induced its formation.A cross-reactive epitope generally contains many of the same complementary structural features as the induced epitope, and in some cases, may actually fit better than the original one.

[0059] For example, a particular antibody has some degree of cross-reactivity in that it binds to epitopes that are related but not identical to the reference epitope, such as epitopes that have at least 95%, at least 90%, at least 85%, at least 80%, at least 75%, at least 70%, at least 65%, at least 60%, at least 55%, and at least 50% identity (as calculated using methods known in the art and described herein). An antibody can be said to have little or no cross-reactivity if it does not bind to epitopes that have less than 95%, less than 90%, less than 85%, less than 80%, less than 75%, less than 70%, less than 65%, less than 60%, less than 55%, and less than 50% identity to the reference epitope (as calculated using methods known in the art and described herein). An antibody can be considered "highly specific" for a particular epitope if it does not bind to any other analogs, orthologs, or homologs of that epitope.

[0060] Anti-CXCL13 binding molecules, e.g., antibodies, or antigen-binding fragments, variants, or derivatives thereof, of the disclosure may also be described or specified in terms of their binding affinity to a polypeptide of the disclosure, e.g., CXCL13, e.g., human CXCL13, murine CXCL13, or both human and murine CXCL13. Exemplary binding affinities include those with a binding affinity of 5×10 -2 M, 10 -2 M, 5 x 10-3 M, 10 -3 M, 5 x 10 -4 M, 10 -4 M, 5 x 10 -5 M, 10 -5 M, 5 x 10 -6 M, 10 -6 M, 5 x 10 -7 M, 10 -7 M, 5 x 10 -8 M, 10 -8 M, 5 x 10 -9 M, 10 -9 M, 5 x 10 -10 M, 10 -10 M, 5 x 10 -11 M, 10 -11 M, 5 x 10 -12 M, 10 -12 M, 5 x 10 -13 M, 10 -13 M, 5 x 10 -14 M, 10 -14 M, 5 x 10 -15 M, or 10 -15 In one embodiment, an anti-CXCL13 binding molecule of the disclosure, e.g., an antibody or antigen-binding fragment thereof, has a dissociation constant or Kd of less than about 5×10 -9 M ~ approx. 5×10 -10 The antibody binds to human CXCL13 with a Kd of less than M, e.g., MAb 5261, with a Kd of approximately 5×10 -9 In another embodiment, the anti-CXCL13 binding molecule of the disclosure, e.g., an antibody or antigen-binding fragment thereof, is about 5×10 -7 M ~ approx. 9×10 -9 The antibody binds to mouse CXCL13 with a Kd of less than 1 M, e.g., MAb 5261, with a Kd of approximately 8×10 -9 M or less. See, for example, U.S. Patent No. 9,963,504.

[0061] As used herein, the term "chimeric antibody" is intended to mean any antibody in which the immunoreactive region or site is obtained or derived from a first species and the constant region (which may be complete, partial, or modified in accordance with the present disclosure) is obtained from a second species. In some embodiments, the target binding region or site is derived from a non-human source (e.g., mouse or primate) and the constant region is human.

[0062] As used herein, the term "recombinant antibody" refers to an antibody in which one or both heavy or light chain variable domains have been modified by at least partial replacement of one or more CDRs from an antibody with known specificity, and optionally by partial framework region replacement and sequence changes. The CDRs can be derived from an antibody of the same class or even the same subclass as the antibody from which the framework regions are derived, but it is contemplated that the CDRs may be derived from an antibody of a different class, for example, an antibody from a different species. Recombinant antibodies in which one or more "donor" CDRs from a non-human antibody with known specificity have been grafted onto the framework regions of a human heavy or light chain are referred to herein as "humanized antibodies." In certain embodiments, to transfer the antigen-binding capacity of one variable domain to another, it is not necessary to replace all CDRs with the complete CDRs from the donor variable domain. Rather, it may be necessary to transfer only the residues necessary to maintain the activity of the target binding site.

[0063] It is further recognized that the framework regions of the variable domains of the heavy and / or light chains of a humanized antibody may comprise only residues of human origin, in which case these framework regions of the humanized antibody are referred to as "fully human framework regions." Alternatively, where necessary to maintain proper binding to the CXCL13 antigen or to enhance binding, one or more residues of the framework regions of the donor variable domain can be recombined at corresponding positions in the human framework regions of the variable domains of the heavy and / or light chains of the humanized antibody. Thus, such recombined human framework regions comprise a mixture of human and donor framework residues and are referred to herein as "partially human framework regions."

[0064] For example, humanization of anti-CXCL13 antibodies can be essentially carried out by substituting rodent or mutant rodent CDRs or CDR sequences for the corresponding sequences of a human anti-CXCL13 antibody according to the method of Winter et al. (Jones et al., Nature 321:522-525 (1986); Riechmann et al., Nature 332:323-327 (1988); Verhoeyen et al., Science 239:1534-1536 (1988)). See also U.S. Patent Nos. 5,225,539; 5,585,089; 5,693,761; 5,693,762; and 5,859,205, which are incorporated herein by reference. The resulting humanized anti-CXCL13 antibody will comprise at least one rodent or mutant rodent CDR in fully human framework regions in the heavy and / or light chain variable domains of the humanized antibody. In some situations, residues in the framework regions of one or more variable domains of the humanized anti-CXCL13 antibody will be replaced with corresponding non-human (e.g., rodent) residues (see, e.g., U.S. Patent Nos. 5,585,089; 5,693,761; 5,693,762; and 6,180,370), in which case the resulting humanized anti-CXCL13 antibody will comprise partially human framework regions in the heavy and / or light chain variable domains.

[0065] Furthermore, humanized antibodies can comprise residues that are not found in the recipient antibody or in the donor antibody. These modifications are made to further refine antibody performance (e.g., to obtain a desired affinity). Generally, a humanized antibody will comprise substantially all of at least one, and typically two, variable domains, in which all or substantially all of the CDRs correspond to those of a non-human immunoglobulin and all or substantially all of the framework regions are those of a human immunoglobulin sequence. A humanized antibody will optionally also comprise at least a portion of an immunoglobulin constant region (Fc), typically that of a human immunoglobulin. For further details, see Jones et al., Nature 331:522-525 (1986); Riechmann et al., Nature 332:323-329 (1988); and Presta, Curr. Op. Struct. Biol. 2:593-596 (1992), which are incorporated herein by reference. Thus, such "humanized" antibodies can include antibodies in which substantially less than an entire human variable domain has been substituted by the corresponding sequence from a non-human species. In practice, humanized antibodies are typically human antibodies in which some CDR residues, and possibly some framework residues, are substituted by residues from analogous sites in rodent antibodies. See, e.g., U.S. Pat. Nos. 5,225,539; 5,585,089; 5,693,761; 5,693,762; and 5,859,205. See also U.S. Pat. No. 6,180,370 and International Publication No. WO 01 / 27160, in which humanized antibodies and techniques for producing humanized antibodies with improved affinity for a predetermined antigen are disclosed.

[0066] II. Description of the Target Polypeptide CXCL13 is a small chemokine shown herein to promote migration of B lymphocytes (and subsets of T cells) (Figures 2A, 2B, and 5D), likely by stimulating calcium influx into and chemotaxis of Burkitt lymphoma receptor 1 (BLR-1)-expressing cells. Thus, it may function in homing B lymphocytes to cysts.

[0067] As used herein, the terms "CXCL13" and "CXCL13 polypeptide" are used interchangeably. In certain embodiments, CXCL13 may include a full-size CXCL13 polypeptide or a fragment thereof, or a CXCL13 variant polypeptide, wherein the CXCL13 fragment or CXCL13 variant polypeptide retains some or all of the functional properties of the full-size CXCL13. The polypeptide and polynucleotide sequences of human CXCL13 (SEQ ID NOs: 1 and 2, respectively) have been described (see, e.g., Legler, et al., J. Exp. Med. 187(4):655-660(1998)). The polypeptide and polynucleotide sequences of mouse CXCL13 (SEQ ID NOs: 3 and 4, respectively) have been described (see, e.g., Gunn, et al., Nature 391(6669):799-803(1998)). Additionally, the cynomolgus monkey CXCL13 polypeptide sequence shown in SEQ ID NO:5 is described.

[0068] III. Axon regeneration In young mammals, axons readily regenerate after peripheral nerve injury. Distal portions of axons that are detached from the cell body undergo Wallerian degeneration. This active process results in axon fragmentation and collapse. Debris is removed by glial cells, such as Schwann cells and macrophages. Proximal axons can then regenerate, reinnervating targets and allowing functional recovery. However, axonal repair processes and axonal regeneration capacity decline with the aging process. Aging profoundly affects several morphological and functional features of the peripheral nervous system (PNS). In aged animals, Wallerian degeneration after injury is delayed, and macrophages accumulate greater amounts of myelin debris than in young animals. In aged subjects, the interaction between Schwann cells and regenerating axons takes longer than in young subjects, and the reactive Schwann cells and target organs secrete fewer trophic and tropic factors. In aging animals, the rate of axonal regeneration slows and the density of regenerating axons decreases. Aging also determines a decline in sprouting of regenerated fiber terminals and collaterals, further limiting the ability to target reinnervate and functionally recover. These age-related changes do not progress linearly with age; axonal regeneration and reinnervation abilities are maintained throughout life, but tend to be delayed and less effective with age (E Verdu, et al., J Peripher. Nerv Syst. 2000 December; 5(4):191-208; Fenrich K. et al., Can J Neurol Sci. 2004 May; 31(2):142-56). These observations suggest that aging, combined with injury-specific cellular signals, results in the development of unique molecular and cellular mechanisms that render neurons unable to regenerate.

[0069] To test this hypothesis, we performed RNA sequencing experiments in the sciatic dorsal root ganglion (DRG), which showed age-dependent enrichment of immune and cytokine / chemokine signaling pathways both before and after sciatic nerve injury. The main age-associated molecular signature was represented by increased T cell activation and signaling. Mechanistically, we found that age-dependent increases in inflammatory cytokines, including lymphotoxin, activate NFκB (nuclear factor kappa-light-chain-enhancer of activated B cells) in DRG, which upregulates the chemokine CXCL13, which in turn recruits CXCR5+CD8+ T cells to the vicinity of neurons that act as antigen-presenting cells (APCs) by expressing MHC-I. Activated CD8 + T cells then suppress axon regeneration of sensory DRG neurons by inhibiting regenerative signals through caspase-3-dependent downregulation of pAKT and pS6. Surprisingly, in vivo antibody-mediated specific CD8+ T cell depletion or CXCL13 neutralization was shown to restore axon regeneration of sensory neurons above young levels, promoting functional recovery. These results indicate that a unique mechanism exists in elderly subjects that limits axon regeneration capacity, and suggest that antibody-mediated manipulation of neuron-immune cell communication may be used clinically to counter the decline in regenerative capacity observed in elderly subjects and promote repair after peripheral nerve injury, such as sciatic nerve injury.

[0070] IV. Anti-CXCL13 antibody The antibody that binds to CXCL13 has been described in the art.For example, see US9,963,504, which is incorporated herein by reference in its entirety.Commercially available antibodies that bind to CXCL13, such as rat anti-mouse MAb 470 (R&D Systems) and mouse anti-human MAb 801 (R&D Systems), have also been disclosed in the art.Other anti-CXCL13 binding molecules are disclosed in, for example, US patent application US2008 / 0227704 and US2008 / 0199481, and PCT publication number WO2020057540A1.

[0071] Antibodies of the disclosure include anti-CXCL13 antibodies, or antigen-binding fragments, variants, or derivatives thereof that bind to CXCL13, such as MAb 5261 (human), MAb 5378 (VH and VL of MAb 5261 with murine constant regions), MAb 5080 (humanized parent antibody of MAb 5261), MAb 1476 (chimeric antibody with VH and VL of 3D2 and with human constant regions), 3D2 (parent murine monoclonal antibody of 5261 and 5080), MAb 5091 (human), 3C9 (murine monoclonal antibody), MAb 1758 (humanized 3C9), or MAb 0745 (3C9 hybridoma). In certain embodiments, the anti-CXCL13 antibody binds to human CXCL13, primate CXCL13, mouse CXCL13, or both human and mouse CXCL13. In certain embodiments, the anti-CXCL13 antibody of the present disclosure is humanized. In other embodiments, the anti-CXCL13 antibody blocks the binding of CXCL13 to its receptor, such as CXCR5. In certain embodiments, the anti-CXCL13 antibody of the present disclosure is MAb 5261, MAb 5378, MAb 5080, MAb 1476, 3D2, 3C9, MAb 1758, MAb 0745, MAb 5091, or an antigen-binding fragment, variant, or derivative thereof.

[0072] The present disclosure generally relates to a method for promoting axonal regeneration, epidermal innervation, and functional recovery of sensory neurons after peripheral nerve injury in a subject experiencing age-related decline in neuronal regeneration capacity. The method comprises administering to the subject an effective amount of an isolated binding molecule that specifically binds to CXCL13, or an antigen-binding fragment, variant, or derivative thereof. In certain embodiments, the antibody blocks the interaction of CXCL13 with its receptor CXCR5. Antibodies with these properties can be used in the methods provided herein. Antibodies that can be used include, but are not limited to, MAb 5261, MAb 5378, MAb 5080, MAb 1476, MAb 3D2, MAb 3C9, MAb 0745, MAb 5091, or MAb 1758, which are fully described in US Pat. No. 9,963,504, which is incorporated herein by reference.

[0073] In certain embodiments, the anti-CXCL13 antibody for use in the methods provided herein binds to human CXCL13 or mouse CXCL13, or both human CXCL13 and mouse CXCL13. Antibodies that bind to the same epitope as any of the above antibodies and / or that competitively inhibit any of the above antibodies are also useful. In certain embodiments, the antigen-binding molecule specifically binds to the same CXCL13 epitope as MAb 5261 and MAb 5378. The amino acid sequences of the variable heavy and variable light chains of MAb 5261, MAb 5378, MAb 5080, MAb 1476, MAb 3D2, MAb 3C9, MAb 745, MAb 5091, and MAb 1758 are shown in Table 2 below. The complementarity-determining regions (CDRs) are underlined. The CDR sequences are also shown in Table 3 below.

[0074] Table 2. CXCL13 antibody variable domains TIFF0007748728000002.tif232161TIFF0007748728000003.tif35161

[0075] (Table 3) TIFF0007748728000004.tif126161

[0076] In one embodiment, the present disclosure provides isolated binding molecules, e.g., antibodies, or antigen-binding fragments, variants, and derivatives thereof, that specifically bind to the same CXCL13 epitope as a reference antibody, e.g., MAb 5261, MAb 5378, MAb 5080, MAb 1476, MAb 5091, MAb 1758, 3D2, or 3C9. In another aspect, the present disclosure provides an isolated binding molecule, e.g., an antibody or antigen-binding fragment thereof, that specifically binds to CXCL13 and competitively inhibits the specific binding of a reference antibody, e.g., MAb 5261, MAb 5378, MAb 5080, MAb 1476, MAb 5091, MAb 1758, 3D2, or 3C9, to CXCL13, e.g., human CXCL13, primate CXCL13, mouse CXCL13, or both human CXCL13 and mouse CXCL13.

[0077] In certain embodiments, a binding molecule of the present disclosure has an amino acid sequence that shares at least about 80%, about 85%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, or about 95% sequence identity with the amino acid sequence of a reference anti-CXCL13 antibody molecule. In further embodiments, the binding molecule shares at least about 96%, about 97%, about 98%, about 99%, or 100% sequence identity with the reference antibody. In certain embodiments, the reference antibody is MAb 5261, MAb 5378, MAb 5080, MAb 1476, MAb 5091, MAb 1758, 3D2, or 3C9.

[0078] In certain aspects, the present disclosure provides an isolated antibody or antigen-binding fragment thereof comprising, consisting essentially of, or consisting of an immunoglobulin heavy chain variable domain (VH domain), wherein at least one of the CDRs of the VH domain has an amino acid sequence that is at least about 80%, about 85%, about 90%, about 95%, about 96%, about 97%, about 98%, about 99%, or identical to CDR1, CDR2, or CDR3 of SEQ ID NO:6, 8, 10, 12, 14, or 16.

[0079] In another aspect, the disclosure provides an isolated antibody or antigen-binding fragment thereof comprising, consisting essentially of, or consisting of an immunoglobulin heavy chain variable domain (VH domain), wherein at least one of the CDRs of the VH domain has an amino acid sequence that is at least about 80%, about 85%, about 90%, about 95%, about 96%, about 97%, about 98%, about 99%, or identical to SEQ ID NO:18, 19, 20, 21, 22, 23, 24, or 25.

[0080] In another aspect, the disclosure provides an isolated antibody or antigen-binding fragment thereof comprising, consisting essentially of, or consisting of an immunoglobulin heavy chain variable domain (VH domain), wherein the VH domain has an amino acid sequence that is at least about 80%, about 85%, about 90%, about 95%, about 96%, about 97%, about 98%, about 99%, or identical to SEQ ID NO:6, 8, 10, 12, 14, or 16.

[0081] In another aspect, the disclosure provides an isolated antibody or antigen-binding fragment thereof comprising, consisting essentially of, or consisting of an immunoglobulin heavy chain variable domain (VH domain), wherein at least one of the CDRs of the VH domain has an amino acid sequence identical to CDR1, CDR2, or CDR3 of SEQ ID NO:6, 8, 10, 12, 14, or 16, except for one, two, three, four, or five conservative amino acid substitutions.

[0082] In another aspect, the disclosure provides an isolated antibody or antigen-binding fragment thereof comprising, consisting essentially of, or consisting of an immunoglobulin heavy chain variable domain (VH domain), wherein at least one of the CDRs of the VH domain has an amino acid sequence identical to SEQ ID NO:18, 19, 20, 21, 22, 23, 24, or 25 except for one, two, three, four, or five conservative amino acid substitutions.

[0083] In another aspect, the disclosure provides an isolated antibody or antigen-binding fragment thereof comprising, consisting essentially of, or consisting of a VH domain having an amino acid sequence that is at least about 80%, about 85%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, or 100% identical to SEQ ID NO:6, 8, 10, 12, 14, or 16, wherein an anti-CXCL13 antibody comprising the encoded VH domain specifically or preferentially binds to CXCL13.

[0084] In another aspect, the disclosure provides an isolated antibody or antigen-binding fragment thereof comprising, consisting essentially of, or consisting of an immunoglobulin light chain variable domain (VL domain), wherein at least one of the CDRs of the VL domain has an amino acid sequence that is at least about 80%, about 85%, about 90%, about 95%, about 96%, about 97%, about 98%, about 99%, or identical to CDR1, CDR2, or CDR3 of SEQ ID NO:7, 9, 11, 13, 15, or 17.

[0085] In another aspect, the disclosure provides an isolated antibody or antigen-binding fragment thereof comprising, consisting essentially of, or consisting of an immunoglobulin light chain variable domain (VL domain), wherein at least one of the CDRs of the VL domain has an amino acid sequence that is at least about 80%, about 85%, about 90%, about 95%, about 96%, about 97%, about 98%, about 99%, or identical to SEQ ID NO:26, 27, 28, 29, 30, 31, 32, 33, or 34.

[0086] In another aspect, the disclosure provides an isolated antibody or antigen-binding fragment thereof comprising, consisting essentially of, or consisting of an immunoglobulin light chain variable domain (VL domain), wherein the VL domain has an amino acid sequence that is at least about 80%, about 85%, about 90%, about 95%, about 96%, about 97%, about 98%, about 99%, or identical to SEQ ID NO:7, 9, 11, 13, 15, or 17.

[0087] In another aspect, the disclosure provides an isolated antibody or antigen-binding fragment thereof comprising, consisting essentially of, or consisting of an immunoglobulin light chain variable domain (VL domain), wherein at least one of the CDRs of the VL domain has an amino acid sequence identical to CDR1, CDR2, or CDR3 of SEQ ID NO:7, 9, 11, 13, 15, or 17, except for one, two, three, four, or five conservative amino acid substitutions.

[0088] In another aspect, the disclosure provides an isolated antibody or antigen-binding fragment thereof comprising, consisting essentially of, or consisting of an immunoglobulin light chain variable domain (VL domain), wherein at least one of the CDRs of the VL domain has an amino acid sequence identical to SEQ ID NO:26, 27, 28, 29, 30, 31, 32, 33, or 34 except for one, two, three, four, or five conservative amino acid substitutions.

[0089] In a further aspect, the disclosure includes an isolated antibody or antigen-binding fragment thereof comprising, consisting essentially of, or consisting of a VL domain having an amino acid sequence that is at least about 80%, about 85%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, or 100% identical to SEQ ID NO:7, 9, 11, 13, 15, or 17, wherein the anti-CXCL13 antibody comprising the encoded VL domain specifically or preferentially binds to CXCL13.

[0090] Suitable biologically active variants of the anti-CXCL13 antibodies of the present disclosure can be used in the methods of the present disclosure. Such variants will retain the desired binding properties of the parent anti-CXCL13 antibody. Methods for generating antibody variants are generally available in the art.

[0091] V. Methods of Treatment Using Therapeutic Anti-CXCL13 Antibodies The lymphoid chemokine CXCL13 is expressed by follicular dendritic cells (FDCs) and macrophages. Through its receptor CXCR5, found on a variety of immune cells (e.g., B cells, follicular helper T cells, and newly activated T cells), CXCL13 induces intracellular changes required for maintaining immune system homeostasis, lymphoid organogenesis, leukocyte trafficking and chemotactic migration, and the development of secondary lymphoid tissues (e.g., germinal centers). Overexpression of CXCL13 and its receptor CXCR5 has been implicated in a variety of autoimmune diseases, such as multiple sclerosis (see, e.g., Corcione et al., PNAS 101(30):11064-11069(2004); Serafini et al., Brain Pathol. 14:164-174(2004); Magliozzi et al., Brain 130:1089-1104(2007)), arthritis, such as rheumatoid arthritis (see, e.g., Rioja et al., Arthritis & Rheumatism 58(8):2257-2267(2008); Shi et al., J. Immuno. 166:650-655(2001); Schmutz et al., Arthritis Restearch and Therapy 7:R217-R229 (2005); Hjelmstrom et al., J. Leukocyte Bio. 69:331-339 (2001)), chronic gastritis (see, e.g., Hjelmstrom et al.; Mazzucchelli et al., Brain 130:1089-1104 (2007)), gastric lymphoma (see, e.g., id.; Nobutani et al., FEMS Immunol Med Microbiol 60:156-164 (2010)), graft rejection (see, e.g., Steinmetz et al., Kidney International 67:1616-1621 (2005)), Sjögren's syndrome (SS) (see, e.g., Barone et al., J. Immuno. 180:5130-5140 (2008); Hjelmstrom et al. al.), systemic lupus erythematosus (SLE) (see, e.g., Steinmetz et al., Lee et al., J.Rheum. 37(1):45-52 (2010); Schiffer et al., J. Immun. 171:489-497 (2003)), active mixed cryoglobulinemic (MC) vasculitis in hepatitis C virus infection (see, e.g., Sansonno et al., Blood 112(5):1620-1627 (2008)), juvenile dermatomyositis (see, e.g., de Padilla et al., Arthritis & Rheumatism 60(4):1160-1172 (2009)), and myasthenia gravis (see, e.g., Matsumoto et al., J. Immuno. 176:5100-5107 (2006); Meraouna et al., Blood 108(2):432-440 (2006); Saito et al. al., J. Neuroimmunol 170:172-178 (2005)), and certain cancers (e.g., Burkitt's lymphoma (see, e.g., Forster et al., Blood 84:830-840 (1994); Forster et al., Cell 87:1037-1047 (1996)), non-Hodgkin's lymphoma (see, e.g., Trentin et al., Ann. Rev. Immunol. 6:251-81 (1988); Gong et al., J. Immunol. 174:817-826 (2005); Hamaguchi et al., J. Immunol. 174:4389-4399 (2005)), carcinomas (e.g., colon and pancreas) (see, e.g., Gunther et al., Int. J. Cancer 116:726-733 (2005); Meijer et al., Cancer Res. 66:9576-9582 (2006)), breast cancer (see, e.g., Panse et al., British Journal of Cancer 99:930-938 (2008)), chronic lymphocytic leukemia (CLL) (see, e.g., Burkle et al., Blood 110:3316-3325 (2007)), and prostate cancer (see, e.g., Singh et al., Cancer Letters 283(1):29-35(2009)).

[0092] Previously, it was not known that neuronal expression of CXCL13 is associated with age-dependent enrichment of T cell signaling pathways. The present disclosure demonstrates that the inflammatory cytokine lymphotoxin activates NFκB, which induces neuronal expression of CXCL13, which in turn induces CXCR5 expression in the vicinity of MHC-1-expressing DRG neurons. + CD8 + We demonstrate that CD8+ T cells suppress axon regeneration of sensory DRG neurons by inhibiting the regenerative signals pAKT and pS6 via caspase 3 activation. Neutralization by anti-CXCL13 binding molecules inhibits CXCR5 + CD8 + It is shown herein that preventing the recruitment of T cells to the DRG, thereby reversing the age-dependent decline in regenerative capacity and promoting neurobiological recovery after peripheral nerve injury, such as sciatic nerve injury.

[0093] Certain methods of the present disclosure relate to the use of anti-CXCL13 binding molecules, e.g., antibodies (including antigen-binding fragments, variants, and derivatives thereof), to promote peripheral nerve regeneration in subjects with age-dependent decline in axonal regeneration capacity after peripheral nerve injury, such as sciatic nerve injury.

[0094] Although the following description refers to diagnostic methods and treatment of peripheral nerves to promote axonal regeneration with the anti-CXCL13 antibodies of the present disclosure, the methods described herein are also applicable to antigen-binding fragments, variants, and derivatives of these anti-CXCL13 antibodies that retain the desired properties of the anti-CXCL13 antibodies of the present disclosure and that are capable of specifically binding to CXCL13, e.g., human CXCL13, primate CXCL13, or mouse CXCL13, or human CXCL13 and mouse CXCL13, and have CXCL13-neutralizing activity, e.g., activity to block the binding of CXCL13 to CXCR5.

[0095] In one embodiment, treatment involves application or administration of an anti-CXCL13 binding molecule of the present disclosure, e.g., an antibody or antigen-binding fragment thereof, to a patient, or application or administration of the anti-CXCL13 binding molecule to a tissue or cell line isolated from a patient, where the patient has or is suspected of having an age-dependent decline in axonal regeneration capacity and has or is suspected of having a predisposition to peripheral nerve injury, damage, or peripheral nerve damage, such as sciatic nerve injury. In another embodiment, treatment also involves application or administration of a pharmaceutical composition comprising an anti-CXCL13 binding molecule of the present disclosure, e.g., an antibody or antigen-binding fragment thereof, to a patient, or application or administration of a pharmaceutical composition comprising the anti-CXCL13 binding molecule to a tissue or cell line isolated from a patient, where the patient has or is suspected of having an age-dependent decline in axonal regeneration capacity and has or is suspected of having a peripheral nerve injury, such as sciatic nerve injury, or a predisposition to peripheral nerve injury.

[0096] The anti-CXCL13 binding molecules of the present disclosure, e.g., antibodies or binding fragments thereof, are useful for treating peripheral nerve injury or conditions requiring axonal regeneration. For example, treatment with at least one anti-CXCL13 antibody induces physiological responses beneficial to axonal regeneration in patients with age-dependent decline in axonal regeneration capacity.

[0097] In one embodiment, the present disclosure relates to an anti-CXCL13 binding molecule according to the present disclosure, e.g., an antibody or binding fragment thereof, for use as a medicament or for the manufacture of a medicament, particularly for use in the treatment or prevention of peripheral nerve injury, such as sciatic nerve injury. In certain embodiments, an anti-CXCL13 binding molecule of the present disclosure, e.g., an antibody or antigen-binding fragment thereof, e.g., MAb 5261, MAb 5378, MAb 5080, MAb 1476, 3D2, or 3C9, is used to promote axonal regeneration in patients with peripheral nerve injury and age-dependent decline in axonal regeneration capacity.

[0098] The effectiveness of anti-CXCL13 binding molecules, such as antibodies or their binding fragments, for promoting axon regeneration after peripheral nerve injury can be demonstrated using animal models.For example, the effectiveness of the anti-CXCL13 binding molecules, such as antibodies or their antigen-binding fragments, of the present disclosure for treating peripheral nerve injury can be demonstrated using an animal model of sciatic nerve injury, such as mice that have been subjected to sciatic nerve "crush" as described herein below and treated with the anti-CXCL13 binding molecules of the present disclosure.Other animal models of peripheral nerve injury, such as brachial plexus injury, spinal accessory nerve injury, and peroneal nerve injury, are also known to those skilled in the art.

[0099] According to the methods of the present disclosure, at least one anti-CXCL13 binding molecule, e.g., an antibody or antigen-binding fragment thereof, as defined elsewhere herein, is used to promote a positive therapeutic response to peripheral nerve injury or damage. A "positive therapeutic response" with respect to peripheral nerve injury refers to an improvement in the damaged tissue associated with nerve regeneration and / or an improvement in symptoms associated with the injury. That is, regenerative effects, reversal of age-dependent decline in regenerative capacity, epidermal reinnervation, restoration of neurological function of the damaged nerve, and / or a reduction in one or more symptoms associated with nerve injury, such as a decrease in associated pain, muscle weakness, tingling, or loss of sensation, may be observed. Thus, for example, an improvement in the damaged tissue may be characterized as a complete response. A "complete response" refers to a restoration of neurological function and a lack of associated pain, tingling, or other side effects of the injury. Alternatively, an improvement in the injury may be broadly classified as a partial response. By "partial response," we mean a decrease in associated pain, some epidermal innervation and nerve regeneration, an improvement in muscle strength, and at least a partial recovery of neurological function.

[0100] In one embodiment, the anti-CXCL13 binding molecule of the present disclosure, for example, antibody or antigen-binding fragment, is used to treat sciatic nerve damage or injury.The sciatic nerve is located in the back of the leg and provides sensation to the thigh, lower leg, and sole of the foot.The sciatic nerve is connected to and supplies the muscles of the knee and lower leg, so severe damage to the nerve can cause knee weakness, difficulty bending the knee, difficulty bending the foot, and / or weakness in foot movement.It can also cause reflex abnormalities, and the knee or leg may not respond properly when touched.Patients may experience severe pain or tingling as a result of sciatic nerve injury.

[0101] Sciatic nerve injury can be caused by many factors, including injury (such as a pelvic fracture or other pelvic injury); a herniated disc; degenerative disc disease; spinal stenosis; or a tumor. Sciatic nerve injury can cause a patient to experience pain, tingling, or a burning sensation in one or both legs. The pain may be localized to one leg or one side of the leg, lower back, calf, or sole of the foot, or pain may be present in both legs. When sciatic nerve injury is extreme, the patient may be unable to move their leg. When the nerve is injured, pain may begin gradually and gradually worsen.

[0102] "Sciatica" is a term used to describe the symptoms that occur when the sciatic nerve is injured. It is not a separate medical condition, but rather a general term for the numbness, pain, tingling, or weakness that patients who have experienced sciatic nerve injury experience in one or both legs.

[0103] Neutralization of CXCL13 using an anti-CXCL13 monoclonal antibody or antigen-binding fragment thereof of the present disclosure, e.g., MAb 5261 or Mab 5378, can reduce the severity of sciatica through several different mechanisms, e.g., blocking the interaction of CXCL13 with its receptor or blocking the homing of CXCR5+CD8+ T cells to the DRG of the sciatic nerve.

[0104] In one embodiment, the anti-CXCL13 binding molecule of the present disclosure, for example, antibody or antigen-binding fragment, is used to treat spinal accessory nerve physical damage in subjects with age-related regenerative capacity decline.Spinal accessory nerve damage can cause dull and mild pain in the shoulder, increased pain during movement, numbness in the deltoid region, difficulty in moving the affected arm, fatigue of the deltoid muscle in long-term injury, and weakness of the affected shoulder.

[0105] Neutralization of CXCL13 using an anti-CXCL13 monoclonal antibody or antigen-binding fragment thereof of the present disclosure, e.g., MAb 5378 or MAb 5261, can reduce the severity of spinal accessory nerve injury or regenerate damaged nerve tissue through one or more mechanisms described herein, e.g., blocking the interaction of CXCL13 with its receptor or blocking the homing of CXCR5+CD8+ T cells to the DRG of the spinal accessory nerve.

[0106] In one embodiment, the anti-CXCL13 binding molecule of the present disclosure, e.g., an antibody or antigen-binding fragment, is used to treat brachial plexus injury in a subject with age-dependent decline in regenerative capacity, e.g., to regenerate injured nerve tissue in the brachial plexus, through one or more mechanisms described herein, e.g., by blocking the interaction of CXCL13 with its receptor or by blocking the homing of CXCR5+CD8+ T cells to the DRG of the brachial plexus network. The brachial plexus originates from the fifth, sixth, seventh, and eighth cervical nerves (C5-C8) and the first thoracic nerve (T1) and innervates the muscles and skin of the chest, shoulder, arm, and hand. Brachial plexus injury is the most severe nerve injury in the limbs. Depending on the location of the nerve injury, brachial plexus injury can affect part or the entire arm. For example, musculocutaneous nerve injuries can weaken the elbow flexors, median nerve injuries can cause pain in the proximal forearm, and ulnar nerve palsy can cause grip weakness and numbness in the fingers (Lorei, Matthew P.; Hershman, Elliott B. (1993) "Peripheral Nerve Injuries in Athletes". Sports Medicine. 16(2):130-47). In some cases, these injuries limit the use of these limbs and cause pain. Injuries often cause arm weakness, decreased reflexes, and corresponding sensory impairment.

[0107] Neutralization of CXCL13 using an anti-CXCL13 monoclonal antibody or antigen-binding fragment thereof of the present disclosure, e.g., MAb 5378 or MAb 5261, can reverse the decline in regenerative capacity in subjects with brachial plexus injuries through several different mechanisms, e.g., blocking the interaction of CXCL13 with its receptor or blocking the homing of CXCR5+CD8+ T cells to the DRGs of the brachial plexus, thereby allowing the damaged nerve tissue to regenerate and reducing the severity of or eliminating the associated pain and muscle weakness.

[0108] In another embodiment, the anti-CXCL13 binding molecule of the present disclosure, e.g., an antibody or antigen-binding fragment, is used to treat peroneal nerve injury in a subject with age-dependent decline in regenerative capacity, e.g., to regenerate damaged nerve tissue of the peroneal nerve, through one or more mechanisms described herein, e.g., by blocking the interaction of CXCL13 with its receptor or by blocking the homing of CXCR5+CD8+ T cells to the DRG of the peroneal nerve. Peroneal nerve injury, also known as peroneal neuropathy, can result in numbness or tingling in the front and / or side of the lower leg, decreased sensitivity in the injured and surrounding areas, weakness in bending the foot up and out, an inability to lift the foot sufficiently off the floor when walking (foot drop), or can cause slapping gait.

[0109] Clinical response to the treatments described herein may be assessed using screening techniques, such as magnetic resonance imaging (MRI) scans, MRI neurography, electrodiagnostic testing, X-ray images, computed tomography (CT) scans, flow cytometry or fluorescence activated cell sorter (FACS) analysis, histology, gross pathology, and blood chemistry, and includes, but is not limited to, changes detectable by ELISA, RIA, chromatography, etc. In addition to these positive therapeutic responses, subjects treated with anti-CXCL13 binding molecules, e.g., antibodies or antigen-binding fragments thereof, may experience beneficial effects such as improvement in symptoms associated with the injury.

[0110] A further aspect of the present disclosure is the use of anti-CXCL13 binding molecules, e.g., antibodies or antigen-binding fragments thereof, for diagnostic monitoring of protein levels in tissues as part of a clinical testing procedure, e.g., to determine whether a subject will benefit from a treatment described herein or to determine the effectiveness of a given treatment regimen. For example, detection of CXCL13 levels in a subject, e.g., in a specific DRG or tissue nearby, can be facilitated by coupling the anti-CXCL13 antibody to a detectable substance. Examples of detectable substances include various enzymes, prosthetic groups, fluorescent materials, luminescent materials, bioluminescent materials, and radioactive materials. Examples of suitable enzymes include horseradish peroxidase, alkaline phosphatase, β-galactosidase, or acetylcholinesterase; examples of suitable prosthetic group complexes include streptavidin / biotin and avidin / biotin; examples of suitable fluorescent materials include umbelliferone, fluorescein, fluorescein isothiocyanate, rhodamine, dichlorotriazinylamine fluorescein, dansyl chloride, or phycoerythrin; an example of a luminescent material includes luminol; examples of bioluminescent materials include luciferase, luciferin, and aequorin; examples of suitable radioactive materials include 125 I, 131 I, 35 S, or 3 Contains H.

[0111] VI. Pharmaceutical Compositions and Methods of Administration Methods for preparing and administering the anti-CXCL13 binding molecules, e.g., antibodies, or antigen-binding fragments, variants, or derivatives thereof, of the present disclosure to subjects in need thereof are well known to, or can be easily determined by, those skilled in the art. The route of administration of the anti-CXCL13 binding molecules, e.g., antibodies, or antigen-binding fragments, variants, or derivatives thereof, can be, for example, oral, parenteral, inhalation, or topical. As used herein, the term parenteral includes, for example, intravenous, intraarterial, intraperitoneal, intramuscular, subcutaneous, rectal, or vaginal administration. While all of these administration modes are expressly contemplated within the scope of the present disclosure, an example of a form for administration would be an injectable solution, specifically a solution for intravenous, intraperitoneal, or intraarterial injection or infusion. Generally, suitable pharmaceutical compositions for injection include a buffer (e.g., acetate buffer, phosphate buffer, or citrate buffer), a surfactant (e.g., polysorbate), and may optionally include a stabilizer (e.g., human albumin), etc. However, in other methods consistent with the teachings herein, the anti-CXCL13 binding molecules of the present disclosure, e.g., antibodies, or antigen-binding fragments, variants, or derivatives thereof, can also be delivered directly to the site of peripheral nerve injury, thereby increasing the exposure of the damaged tissue to the therapeutic agent.

[0112] As described herein, the anti-CXCL13 binding molecules of the present disclosure, e.g., antibodies, or antigen-binding fragments, variants, or derivatives thereof, can be administered in a pharmaceutically effective amount for in vivo treatment of peripheral nervous system (PNS) injuries, e.g., injured peripheral nerves, e.g., injured sciatic nerves. In this regard, it will be understood that the binding molecules of the present disclosure are formulated to facilitate administration and promote stability of the active agent. In certain embodiments, the pharmaceutical compositions of the present disclosure comprise a pharmaceutically acceptable, non-toxic, sterile carrier, e.g., saline, non-toxic buffers, preservatives, etc. For purposes of this application, a pharmaceutically effective amount of a conjugated or unconjugated anti-CXCL13 binding molecule, e.g., an antibody, or antigen-binding fragment, variant, or derivative thereof, shall mean an amount sufficient to achieve effective binding to the target and achieve a benefit, e.g., regeneration of an injured nerve, innervation of the surrounding epidermis, restoration of neurological function, and / or amelioration of symptoms of peripheral nerve injury, e.g., pain or tingling, or to detect levels of CXCL13 in a tissue.

[0113] Pharmaceutical compositions used in the present disclosure include pharmaceutically acceptable carriers, such as ion exchangers, alumina, aluminum stearate, lecithin, serum proteins such as human serum albumin, buffer substances such as phosphoric acid, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts, or electrolytes such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinylpyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene block polymers, polyethylene glycol, and wool fat.

[0114] Preparations for parenteral administration include sterile aqueous or non-aqueous solutions, suspensions, and emulsions. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. Aqueous carriers include, for example, water, alcoholic / aqueous solutions, emulsions, or suspensions, such as saline and buffered media. In this disclosure, pharmaceutically acceptable carriers include, but are not limited to, 0.01-0.1 M, e.g., 0.05 M phosphate buffer or 0.8% saline. Other common parenteral vehicles include sodium phosphate solution, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's, or fixed oils. Intravenous vehicles include fluid and nutrient replenishers, electrolyte replenishers, e.g., those based on Ringer's dextrose, and the like. Preservatives and other additives, such as antimicrobials, antioxidants, chelating agents, and inert gases, may also be present.

[0115] More specifically, pharmaceutical compositions suitable for injectable use include sterile aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In such cases, the composition must be sterile and fluid to the extent that easy syringability exists. It should be stable under the conditions of manufacture and storage and may be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (e.g., glycerol, propylene glycol, and liquid polyethylene glycol, etc.), and suitable mixtures thereof. Proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants. Suitable formulations for use in the therapeutic methods disclosed herein are described in Remington's Pharmaceutical Sciences (Mack Publishing Co.), 16th ed. (1980).

[0116] Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, thimerosal, etc. For example, the formulation may include isotonic agents, for example, sugars, polyalcohols such as mannitol, sorbitol, or sodium chloride in the composition. Prolonged absorption of the injectable compositions can be brought about by including in the composition an agent which delays absorption, for example, aluminum monostearate and gelatin.

[0117] In any case, sterile injectable solutions can be prepared by incorporating the active compound (e.g., an anti-CXCL13 antibody, or antigen-binding fragment, variant, or derivative, alone or in combination with other active agents) in the required amount in an appropriate solvent, optionally with one or a combination of the ingredients listed herein, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the active compound into a sterile vehicle containing a basic dispersion medium and the required other ingredients listed above. In the case of sterile powders for preparing sterile injectable solutions, methods of preparation can include vacuum drying and lyophilization, which yield a powder of the active ingredient and any additional desired ingredients from a previously sterile-filtered solution. Injectable preparations are processed according to methods known in the art, filled into containers such as ampoules, bags, bottles, syringes, or vials, and sealed under aseptic conditions. Furthermore, the preparations can be packaged and sold in the form of a kit, such as those described in U.S. Patent Application No. 09 / 259,337. Such products may have a label or package insert indicating that the associated composition is useful for treating subjects suffering from or predisposed to a particular type of peripheral nerve injury or damage.

[0118] Parenteral formulations can be a single bolus dose, an infusion, or an initial bolus dose followed by one or more maintenance doses. These compositions can be administered at specific fixed or variable intervals, for example, once daily, or "as needed."

[0119] Certain pharmaceutical compositions used in the present disclosure can be orally administered in acceptable dosage forms, including, for example, capsules, tablets, aqueous suspensions, or solutions. Certain pharmaceutical compositions can be administered by nasal aerosol or inhalation. Such compositions can be prepared as saline solutions, utilizing benzyl alcohol or other suitable preservatives, absorption enhancers to enhance bioavailability, and / or other conventional solubilizers or dispersants.

[0120] The amount of anti-CXCL13 binding molecule, e.g., antibody, or fragment, variant, or derivative thereof, that can be combined with the carrier material to produce a single dosage form will vary depending on the host treated and the particular mode of administration. The composition can be administered once, multiple times, or over an established period of time by infusion. Dosage regimens can also be adjusted to provide the optimum desired response (e.g., therapeutic or prophylactic response).

[0121] Consistent with the scope of the present disclosure, an anti-CXCL13 antibody, or antigen-binding fragment, variant, or derivative thereof, of the present disclosure can be administered to a human or other animal in an amount sufficient to produce a therapeutic effect, according to the aforementioned treatment method. The anti-CXCL13 antibody, or antigen-binding fragment, variant, or derivative thereof, of the present disclosure can be administered to such a human or other animal in a conventional dosage form prepared by combining an antibody of the present disclosure, e.g., MAb 5261 or MAb 5378, with a conventional pharmaceutically acceptable carrier or diluent, according to known techniques. Those skilled in the art will recognize that the form and characteristics of the pharmaceutically acceptable carrier or diluent are dictated by the amount of active ingredient to be combined therewith, the route of administration, and other well-known variables. Those skilled in the art will further appreciate that cocktails containing one or more of the anti-CXCL13 binding molecules, e.g., antibodies, or antigen-binding fragments, variants, or derivatives thereof, of the present disclosure, can prove particularly effective.

[0122] A "therapeutically effective dose or amount" or "effective amount" means the amount of an anti-CXCL13 binding molecule, e.g., an antibody or antigen-binding fragment thereof, that, when administered, results in a positive therapeutic response for the treatment of a patient having a peripheral nerve injury being treated.

[0123] The therapeutically effective dose of the composition of the present disclosure for treating peripheral nerve injury varies depending on many different factors, including administration means, target site, patient's physiological condition, whether the patient is human or animal, other medications administered, whether the treatment is preventive or therapeutic, the age of the subject, and the level of CXCL13 detected in the subject before treatment.Generally, the patient is human, but non-human mammals, including transgenic mammals, can also be treated.The treatment dosage can be titrated using routine methods known to those skilled in the art to optimize safety and effectiveness.

[0124] The amount of at least one anti-CXCL13 binding molecule, for example, an antibody, or its antigen-binding fragment, to be administered can be easily determined by those skilled in the art without undue experimentation, given the disclosure of the present disclosure.Factors that affect the administration mode and amount of at least one anti-CXCL13 binding molecule, for example, an antibody, its antigen-binding fragment, variant, or derivative, include, but are not limited to, the severity of the injury, the site of the injury, the injured peripheral nerve, the history of the injury, and the age, height, weight, health status, and physical condition of the individual to be treated, for example, the level of CXCL13 detected in the subject.Similarly, the amount of anti-CXCL13 binding molecule, for example, an antibody, or its fragment, variant, or derivative, to be administered will depend on the administration mode and whether the subject receives a single or multiple doses of this agent.

[0125] The disclosure also provides the use of an anti-CXCL13 binding molecule, eg, an antibody, or antigen-binding fragment, variant, or derivative thereof, in the manufacture of a medicament for treating peripheral nerve injury, eg, sciatic nerve injury.

[0126] IX. Diagnosis The present disclosure further provides a method useful for diagnosing peripheral nerve injury in a subject to determine whether the subject would benefit from treatment with an anti-CXCL13 binding molecule, e.g., whether the subject is experiencing age-dependent decline in nerve regeneration capacity. The method includes measuring the expression level of CXCL13 protein or transcript in tissues, such as the DRG of an injured peripheral nerve or nearby tissues, or other cells or body fluids, from an individual who has or is suspected of having a peripheral nerve injury, e.g., a sciatic nerve injury, and comparing the measured expression level with a standard CXCL13 expression level in normal tissues or body fluids from a young subject, wherein an increased expression level in the sample compared to the standard indicates that the subject would benefit from treatment with the anti-CXCL13 antibody disclosed herein. In certain embodiments, the anti-CXCL13 antibodies of the present disclosure, or antigen-binding fragments, variants, and derivatives thereof, such as MAb 5261, MAb 5378, MAb 5080, MAb 1476, 3D2, or 3C9, are used in diagnosing the presence of age-dependent neuroregenerative decline.

[0127] The anti-CXCL13 antibodies of the present disclosure, as well as antigen-binding fragments, variants, and derivatives thereof, can be used to assay CXCL13 protein levels in biological samples using classical immunohistological methods known to those skilled in the art (see, e.g., Jalkanen, et al., J. Cell. Biol. 101:976-985 (1985); Jalkanen et al., J. Cell Biol. 105:3087-3096 (1987)). Other antibody-based methods useful for detecting CXCL13 protein expression include immunoassays, such as enzyme-linked immunosorbent assays (ELISAs), immunoprecipitation, Western blotting, flow cytometry, PCR techniques, and the like. Suitable assays are described in more detail elsewhere herein.

[0128] "Assaying the expression level of CXCL13 polypeptide" refers to qualitatively or quantitatively measuring or estimating the level of CXCL13 polypeptide in a first biological sample, either directly (e.g., by determining or estimating absolute protein levels) or relatively (e.g., by comparing with the relevant polypeptide level in a second biological sample). In one embodiment, the CXCL13 polypeptide expression level in a first biological sample is measured or estimated and compared with a standard CXCL13 polypeptide level, where the standard is obtained from a biological sample obtained from a young individual who does not have age-dependent regenerative capacity decline, or is determined by averaging levels from a population of young individuals who do not have age-dependent neuroregenerative capacity decline. As understood in the art, once a "standard" CXCL13 polypeptide level is known, it can be repeatedly used as a standard for comparison. As used herein, the term "young individual" is an arbitrary designation determined by a health care provider based on chronological age and other criteria, such as overall health or genetics. In certain embodiments, a "young individual" can be, for example, a subject under the age of 40 or under the age of 35, eg, between the ages of 20 and 35.

[0129] By "biological sample" is meant any biological sample obtained from an individual, cell line, tissue culture, or other cellular source that may express CXCL13. Methods for obtaining tissue biopsies and body fluids from mammals are well known in the art.

[0130] All references cited above and all references cited herein are incorporated by reference in their entirety.

[0131] The following examples are offered by way of illustration and not by way of limitation. [Example]

[0132] Example 1. Experimental Materials and Methods The following materials, methods and protocols were applied in the examples below.

[0133] mouse Wild-type C57 / BL6J mice, 8–10 weeks old, were obtained from Charles River. Older mice (20–22 months old) were supplied by either Charles River or Jucker's laboratory, HIH (Tuebingen). OT1 mice on a B57 / BL6 genetic background were provided by Botto's laboratory, Imperial College London. All animal procedures were performed in accordance with the UK Animals Scientific Procedures Act (1986) and approved by the ethical committee of Imperial College London.

[0134] DRG cell culture In a 24-well plate, sterile 15 mm coverslips were coated with 0.003% poly-L-ornithine (Sigma) diluted in HO for 1 hour at 37°C. After washing three times with water, the coverslips were coated with 1 μg / ml laminin (Millipore) prepared in PBS (Invitrogen) for 3 hours at room temperature. After two washing steps with PBS, the wells were filled with DMEM and kept at 37°C until cell seeding. DRGs were dissected and collected in Hank's balanced salt solution (HBSS) (Invitrogen) on ice. The HBSS was then removed and replaced with 500 μl of digestion solution (5 mg / ml Dispase II (Sigma), 2.5 mg / ml Collagenase type II (Worthington) in DMEM (Invitrogen)) for 40 minutes in a 37°C water bath, gently tapping the tube every 5 minutes. After digestion, DRGs were collected by centrifugation at 800 rpm for 2 minutes and washed once with warm DRG medium (DMEM / F12 (Invitrogen), 1x B27 (Invitrogen), 10% fetal bovine serum (FBS) (Sigma)). The DRGs were then resuspended in 1 ml of warm DRG medium and disrupted by pipetting 15 times with a fire-polished Sigmacote (Sigma)-coated glass pipette. Undissociated tissue was filtered through a 100 μm cell strainer (BD Falcon), and cells were counted under a bright-field microscope using a hemocytometer. After cell counting, the cells were spun down, resuspended in warm DRG culture medium (DMEM / F12 (Invitrogen), 1x B27 (Invitrogen), 1% penicillin and streptomycin (Invitrogen)), and seeded (4000 cells per well). DRG cells were cultured at 37°C in 5% CO for 24 hours.

[0135] DRG neurite outgrowth analysis The average neurite length of cultured DRG cells was measured by using Neurolucida software (MBF Bioscience) with at least 100 cells for each condition (five fields per randomly selected coverslip) in triplicate technical and triplicate biological replicates.

[0136] immunocytochemistry Cultured DRG cells were fixed with ice-cold 4% paraformaldehyde (PFA) (Sigma) in 1x PBS for 30 minutes on ice and washed three times with 1x PBS. Cells were blocked with 1x PBS, 0.1% Triton X, and 5% normal goat serum (Abcam) for 1 hour at room temperature, followed by incubation overnight at 4°C with primary antibodies in 1x PBS, 0.1% Triton X, and 2% normal goat serum. Cells were then washed three times with 1x PBS and incubated with secondary antibodies in 1x PBS, 0.1% Triton X, in the dark for 2 hours at room temperature. Cells were washed three times with 1x PBS and incubated with 4-6-diamidino-2-phenylindole (DAPI, Molecular Probes, 1:5000) in 1x PBS, 0.1% Triton X for 10 minutes, followed by two washes with PBS. The coverslips were transferred to slides with the cells facing downwards and mounted with Antifade mounting medium (Vectashield, H-1000).

[0137] Sciatic nerve crush Sciatic nerve crush injuries were administered according to a previously described protocol (Bauder and Ferguson, (2012). JoVE (Journal of Visualized Experiments), e3606). Mice were deeply anesthetized with 2% isoflurane in 1 L / min oxygen and subcutaneously injected with 0.1 mg / kg buprenorphine and 5 mg / kg rimadyl for analgesia. The sciatic nerve was exposed by incising the skin across the midline, opening the fascial plane, and making a small, deeper incision between the gluteus maximus and the anterior head of the biceps femoris.

[0138] The exposed nerve, with its three bundles in a row, was positioned proximal to the bottom jaw of a fine hemostat (Fine Science Tools, 13020-12) 1.5 mm from the tip. The nerve was crushed with three clicks of the forceps for 30 seconds without nerve stretching. The skin was then closed with suture clips.

[0139] Mice received 0.1 mg / kg buprenorphine twice daily and 5 mg / kg Rimadyl daily by sc injection for 3 days after surgery. Sham surgery was performed to expose the nerve without injury.

[0140] RNA preparation and sequencing RNA sequencing was performed using RNA derived from whole sciatic DRG tissue from young or aged mice 24 hours after sham or sciatic nerve injury. Specifically, sciatic DRGs were dissected from one mouse per sample and preserved in RNAlater stabilization solution (ThermoFisher). Tissues were homogenized with an RNase-free micropestle, and RNA was extracted using the RNeasy kit (Qiagen) according to the manufacturer's protocol. To remove DNA, on-column DNase digestion was performed for 15 minutes using the RNase-free DNase kit (Qiagen). RNA concentration and purity were measured using an Agilent 2100 Bioanalyzer (Agilent). RNA with an RNA integrity number (RIN) greater than 7.5 was used for library preparation. Libraries were prepared in Ospedale San Raffaele (Milan) using the TruSeq mRNA Sample Preparation kit (Illumina) and sequenced using an Illumina HiSeq 2500, 100 cycles, paired-end sequencing.

[0141] Bioinformatic analysis FDR (false discovery rate)-corrected P values ​​were calculated using the Benjamini-Hochberg (BH) correction. Using all expressed genes in the dataset as a background, differentially expressed (DE) genes (FDR < 0.05) from the three comparisons (SNI-young, Sham-aged, and SNI-aged vs. Sham-young) were analyzed for Gene Ontology (GO) and KEGG pathways using DAVID v6.7 (Huang et al., Systematic and integrative analysis of large gene lists using DAVID Bioinformatics Resources. Nature Protoc. 2009;4(1):44-57; Huang et al., Bioinformatics enrichment tools: paths toward the comprehensive functional analysis of large gene lists. Nucleic Acids Res. 2009). GO and KEGG pathway categories were selected for both up- and downregulation with an FDR < 0.01. Venn diagrams were generated using Biovenn (BioVenn - a web application for the comparison and visualization of biological lists using area-proportional Venn diagrams, T. Hulsen, J. de Vlieg and W. Alkema, BMC Genomics 2008, 9(1):488).Differentially upregulated genes involved in immune response in SNI-aged versus sham-young mice, collected from GO and KEGG pathways, were analyzed using protein-protein networks established by STRING (Szklarczyk et al., STRING v11: protein-protein association networks with increased coverage, supporting functional discovery in genome-wide experimental datasets, Nucleic Acids Res. 2019). Stringency criteria were selected using the highest confidence level among active interaction sources from experiments and databases, and a required minimum interaction score. Networks were visualized using Cytoscape (Shannon et al., Cytoscape: a software environment for integrated models of biomolecular interaction networks, Genome Research 2003 Nov;13(11):2498-504).

[0142] CXCL13 ELISA assay Three days after sham or sciatic nerve injury, sciatic DRGs were collected from two young or aged mice per sample and homogenized in 150 μL of assay diluent A provided by the mouse CXCL13 ELISA kit (ThermoFisher) containing protease inhibitors (Roche). After homogenization, Triton X-100 was added to a final concentration of 1%. Samples were frozen in liquid nitrogen, thawed, and centrifuged at 10,000 × g for 5 minutes to remove debris. Protein concentration was quantified using a BCA protein assay kit (ThermoFisher), and 100 μL of cell lysate was used for CXCL13 ELISA assays using the mouse CXCL13 ELISA kit according to the manufacturer's protocol. CXCL13 ELISA measurements were obtained by measuring absorbance in an ELISA plate reader set at 450 nm and subtracting the value at 550 nm to correct for optical imperfections in the microplate. The CXCL13 concentration in the cell lysates was calculated according to the standard curve.

[0143] immunohistochemistry Mice were deeply anesthetized with a ketamine / xylazine mixture (maximum 80 mg / kg body weight ketamine and 10 mg / kg body weight xylazine) via intraperitoneal (i.p.) injection and transcardially perfused with 20 ml of ice-cold PBS followed by 4% PFA at a flow rate of 5 ml / min. DRGs, sciatic nerves, or hairless skin from the hind limbs were excised, postfixed in 4% PFA on ice for 2 days, transferred to 30% sucrose (Sigma) for 3 days, and then embedded in OCT compound (Tissue-Tek). DRGs, sciatic nerves, and interdigital footpads were sectioned perpendicular to the skin surface at 10 μm, 12 μm, and 30 μm, respectively, using a cryostat (Leica). The sections were treated with a blocking solution containing 10% normal goat serum or normal donkey serum (Abcam) and 0.3% Triton X-100 in PBS at room temperature for 1 hour and then stained with primary antibodies overnight at 4°C.The primary antibodies were anti-Tuj1 (1:500, Novus, NB100-1612), anti-CXCL13 (10 μg / ml, R&D SYSTEMS, AF470), anti-neurofilament 200 (1:100, Sigma, N4142), anti-CGRP (1:200, Abcam, ab36001), and Alexa Fluor 100 (1:100, Sigma, N4142). 488 conjugate GS-IB4 (1:100, ThermoFisher, 121411), anti-SCG10 (1:500, NOVUS, NBP1-49461), anti-CD8 (1:100, ThermoFisher, 14-0081-82), anti-CD3 (1:100, Abcam, ab16669) , anti-CXCR5 (1:100, Abcam, ab133706), anti-CD68 (1:200, Abcam, ab125212), anti-B220 (1:100, Biolegend, 103228), anti-MHC-I (1:100, Abcam, ab15681), anti-active caspase 3 (1:200, Cell Cell Signaling, #9664), anti-phospho-AKT (1:200, Cell Signaling, #4060), anti-phospho-S6 (1:200, Cell Signaling, #5364), anti-perforin (1:100, NOVUS, NBP1-97512), anti-granzyme B (1:100, Abcam, ab4059), anti-PGP9.5 (1:200, Proteintech, 14730-1-AP), anti-phospho-NFκB2 (1:100, Abcam, ab194919), anti-luciferase (1:200, Fitzgerald, 70R-12141), and anti-GFP (1:500, Abcam, ab13970). After washing the sections three times with 1x PBS, secondary antibody incubation was performed for 2 hours at room temperature using Alexa Fluor 488 goat anti-chicken, Alexa Fluor 488 donkey anti-chicken, Alexa Fluor 488 goat anti-rat, Alexa Fluor 488 goat anti-rabbit, Alexa Fluor 568 donkey anti-goat, or Alexa Fluor 568 goat anti-rabbit (1:1000, ThermoFisher). Next, the sections were stained with DAPI (Molecular Probes, 1:5000) for 15 minutes at room temperature and mounted with Antifade mounting medium (Vectashield, H-1000).DRGs were imaged with a Nikon Eclipse TE2000 microscope using 20x magnification. The sciatic nerve (20x magnification) and epidermis (40x magnification with an oil lens) were imaged with a Leica TCS SP8 confocal laser scanning microscope.

[0144] Quantification of immunostaining Arbitrary fluorescence intensity was measured using ImageJ software (National Institutes of Health, USA). After subtracting background intensity, relative fold changes were calculated by normalizing fluorescence intensity to the control group. Cells positive for cleaved caspase 3, perforin, and granzyme B expression exhibited fluorescence intensity at least twofold higher than background. Longitudinal sections of sciatic nerves stained with SCG10 were analyzed for axonal regeneration. Arbitrary SCG10 intensity was measured along the nerve, and the percentage of intensity was quantified every 0.5 mm from the proximal site of the crush injury. The regeneration index was also assessed by calculating the distance from the proximal injury site at which the intensity decreased to 50%. For epidermal reinnervation, the number of intraepidermal nerve fibers (IENFs) per unit volume, as indicated by PGP9.5 staining, was measured from sagittal sections of skin.

[0145] Flow cytometry For in vivo cell characterization, young or old untreated or sciatic nerve-injured animals were intravenously (iv) injected with 3 μg of anti-CD45-APC (I3 / 2.3, Biolegend) for 3 minutes. After deep anesthesia, peripheral blood or DRGs were collected in 10 ml PBS containing 2 mM EDTA and RPMI-1640 medium (ThermoFisher), respectively. Blood cells were collected by centrifugation at 300 g for 5 minutes at room temperature, and red blood cells were lysed using 1× RBC lysis buffer (Biolegend). Cells were washed three times with PBS, filtered through a 70 μm cell strainer (Corning) to remove clumps, and resuspended in fresh FACS buffer (PBS containing 0.5% BSA and 2 mM EDTA) for staining. DRGs were washed once with 1x PBS and dissociated in digestion buffer (RPMI-1640 containing 0.5 mg / ml CLSPA (Worthington, #LS005273) and 7.5 μg / ml DNase I (Roche, #10104159001)) at 37°C for 30 minutes. After digestion, DRG tissue was dispersed and filtered through a 70 μm cell strainer to collect a single-cell suspension. The resulting solution was washed with wash buffer (RPMI-1640 containing 5% FBS). After centrifugation, the pellet was resuspended in DNase solution (250 μg / ml DNase I, 1x DNase buffer (RPMI-1640 solution containing 1.21 g / L Tris Base, 0.5 g / L MgCl2, and 0.073 g / L CaCl2)) at RT for 30 minutes. Cells were washed with FACS buffer for staining.

[0146] Cells isolated from blood and DRG samples were treated with TruStain FcX anti-mouse CD16 / 32 antibody (Biolegend) at 1.0 μg per 10 cells in a 100 μl volume for 10 minutes on ice to block Fc receptors, and then stained in FACS buffer containing Brilliant Stain buffer (BD Horizon). The following anti-mouse antibodies were used against the antigens: Pacific Blue-conjugated anti-CD45 (30-F11, Biolegend, 2 μg / ml), FITC-conjugated anti-CD62L (MEL-14, Biolegend, 5 μg / ml), Brilliant Violet 605-conjugated anti-CD19 (6D5, Biolegend, 1 μg / ml), Brilliant Violet 711-conjugated anti-CD8 (53-6.7, Biolegend, 2 μg / ml), and Brilliant Violet 711-conjugated anti-CD8 (53-6.7, Biolegend, 2 μg / ml). The following antibodies were used: 785-conjugated anti-TCRβ (H57-597, Biolegend, 2 μg / ml), APC-conjugated anti-CD4 (RM4.5, BD, 2 μg / ml), APC / CY7-conjugated anti-CD44 (IM7, Biolegend, 2 μg / ml), PE / CY7-conjugated anti-CD69 (H1.2F3, ThermoFisher, 2 μg / ml), biotin-conjugated anti-CXCR5 (SPRCL5, ThermoFisher, 5 μg / ml), FITC-conjugated anti-CD11b (M1 / 70, ThermoFisher, 2.5 μg / ml), and APC-conjugated anti-F4 / 80 (T45-2342, BD, 2 μg / ml). To exclude dead cells from the staining, we also used the LIVE / DEAD Fixable Aqua Dead Cell Stain Kit (ThermoFisher). Cells were stained with the antibody cocktail for 20 minutes at 4°C in the dark, washed, and then stained with 2 μg / ml PE-streptavidin (Biolegend) for 20 minutes at 4°C. Fluorescence Minus One (FMO) and PE-streptavidin staining controls were used for gating. To minimize anti-CXCR5 shedding before cell acquisition, stained cells were immediately fixed with IC fixation buffer (ThermoFisher) for 20 minutes at room temperature.Cells were washed with PBS and resuspended in FACS buffer. 20 μl of Precision Count Beads (Biolegend, 424902) were added to each sample before cell acquisition using a flow cytometer LSR II (BD Biosciences).

[0147] Cell depletion experiments To deplete CD8 T cells in vivo, 22- to 24-month-old mice were injected with 200 μg of InVivoMAb rat IgG2b isotype control (LTF-2, BioXcell, BE0090) or InVivoMAb anti-mouse CD8α (YTS 169.4, BioXcell, BE0117) three times every other day for 1 week before sciatic nerve crush injury. After sciatic nerve crush, one additional injection was administered when the animals had fully recovered from anesthesia. Three days after nerve injury, DRGs and nerves were dissected and subsequently subjected to FACS, immunostaining, or regeneration assays. CD4 T cell depletion was performed using the same protocol used for CD8 T cell depletion, using InVivoMAb anti-mouse CD4 (YTS 191, BioXcell, BE0119) and rat IgG2b isotype control. B cell depletion was performed according to a previously described strategy (Keren et al., 2011). Aged mice were intraperitoneally injected with an antibody cocktail consisting of 150 μg of InvivoMAb anti-mouse CD19 (1D3, BioXcell, BE0150), 150 μg of InvivoMAb anti-mouse B220 (RA3.3A1 / 6.1, BioXcell, BE0067), and 150 μg of InvivoMAb anti-mouse CD22 (Cy34.1, BioXcell, BE0011). Forty-eight hours later, the secondary antibody InvivoMAb anti-rat kappa (MAR18.5, BioXcell, BE0122) was injected into the mice at a dose of 150 μg per mouse. All injections were performed twice a week before sciatic nerve injury and once the day after injury. Control IgG of the same isotype as the antibodies used was injected using rat IgG2a (2A3, BioXcell, BE0089), polyclonal rat IgG (BioXcell, BE0094), mouse IgG1 (MOPC-21, BioXcell, BE0083), and mouse IgG2a (C1.18.4, BioXcell, BE0085).

[0148] CXCL13 neutralization For ex vivo DRG culture, young and old mice were treated with 30 mg / kg of control IgG or anti-CXCL13 antibody (anti-CXCL13 monoclonal antibody (mAb 5378-41) and control IgG2a (mAb 2510)) ip three times a week, followed by DRG dissection and primary cell culture. Isolated DRG cells were incubated at 37°C in 5% CO for 24 hours before neurite outgrowth measurement. For in vivo CXCL13 neutralization, young or old mice were injected ip with 30 mg / kg of control IgG or anti-CXCL13 antibody 4 hours after sciatic nerve crush and daily until sacrifice on day 3. For chronic nerve regeneration studies, 30 mg / kg of control IgG or anti-CXCL13 antibody was injected ip three times a week from 4 hours after injury until sacrifice.

[0149] Behavioral assessment Mice that underwent sciatic nerve crush injury and chronic administration of control IgG or anti-CXCL13 antibody were used for behavioral assessment. The sciatic nerve and left hind limb were injured and assessed. Researchers participating in the behavioral assessment were blinded to the groups and treatments.

[0150] Mechanical Sensitivity Test Mice were placed in the test chamber for 30 min for acclimation before behavioral assessment began. Mechanical sensitivity was determined by probing the plantar surface of the left hindpaw with a calibrated von Frey filament ranging from 0.4 g to 4 g. The interval between trials was at least 30 s to allow sufficient time for sensory receptors to return to baseline. Rapid hindpaw withdrawal was considered a positive response. Five trials were performed for each mouse, and the latency values ​​from three positive withdrawal responses were averaged. The threshold was set at the lowest level of monofilament force.

[0151] Heat Sensitivity Test For thermal sensitivity, the Hargreaves test was performed as previously described (Chen et al., (2014). Nature Communications 5, 5331; Hargreaves et al., (1988). Pain 32, 77-88). Briefly, mice were placed on a glass floor and isolated in a plastic chamber. Mice were allowed 30 min for acclimatization. A heat stimulus (infrared radiation source, intensity = 50) was carefully placed under the plantar surface of the hind paw for less than 10 s. Hind paw withdrawal times were automatically recorded. Five trials were performed for each paw, and the longest and shortest withdrawal times were included to calculate the average.

[0152] sticky substance removal A small adhesive stimulus (a 1 / 4-inch round adhesive label) was placed on the left hind paw of the mouse, and the latency to first touch with both forepaws or the mouth, as well as the latency to complete removal of the adhesive, was recorded. Each mouse underwent 10 minutes of training daily for one week prior to nerve injury. Each mouse underwent three trials. All tests were conducted blindly in the animal's home cage.

[0153] statistical analysis Unless otherwise stated, data were statistically analyzed using Graphpad Prism 8.0 (Graphpad Software Inc., La Jolla, CA) and expressed as mean ± SEM. Statistical comparisons between two groups were analyzed using an unpaired Student's t-test. Multiple groups were analyzed using one-way analysis of variance (ANOVA) with post-hoc Tukey correction or two-way analysis of variance with Tukey or Sidak's test. Statistical significance was considered p<0.05.

[0154] Example 2. Effect of aging on gene expression after nerve injury: Neuronal CXCL13 is elevated in aged DRG The effect of aging on gene expression in dorsal root ganglia (DRGs) was assessed by RNA sequencing (RNA-seq) from sciatic DRGs obtained from 8-10 week-old (young) and 20-22 week-old (old) mice before (sham) and after nerve injury. The sciatic nerves of x young and x old mice were subjected to crush injury by applying pressure to the nerve with forceps. Each mouse underwent either injury or sham treatment at approximately the same time points on the sciatic nerve, as described above. 24 hours later, DRGs near the site of sciatic nerve injury (SNI) or sham injury were removed, and RNA was extracted and sequenced. Changes in gene expression from DRGs were assessed in aged sham, young after SNI, and old mice compared with baseline expression in young sham animals. Significantly differentially expressed (DE) genes (FDR < 0.05) were analyzed by Gene Ontology (GO) and KEGG for functional classification. GO classes typically upregulated after SNI in young animals, involved in neurogenesis, neurotransmitter, ion transport, G-coupled signaling, and signal transduction, were not differentially enriched in aged DRGs, including after SNI (data not shown). However, the most striking finding from GO analysis was that aged DRGs showed highly significant enrichment for adaptive immune responses, including T cell signaling and partial B cell signaling, both before and after SNI. KEGG analysis further highlighted the presence of significant age- and injury-related changes in immune responses and signaling, as well as cytokine / chemokine signaling. The majority of DE genes in aged DRGs after injury (66.6% upregulated, 65% downregulated) were age-dependent.

[0155] Because significant age-dependent regulation of immune responses is known, we analyzed transcripts involved in immune responses. Analysis showed that CXCL13 was by far the most significantly upregulated gene associated with aging, both before and after sciatic nerve injury. Expression of the CXCL13 chemokine receptor CXCR5 was also significantly enhanced in aged DRG (Figure 1A), suggesting the existence of a CXCL13 / CXCR5 signaling axis. Measurement of the expression and localization of the neuron-specific growth-associated protein SCG10 in DRG 3 days after sciatic nerve crush, as well as the intensity of staining near the crush site, demonstrated reduced regeneration in aged compared with young animals (Figure 1B, C). Anti-CXCL13 immunostaining demonstrated a significant increase in CXCL13 expression in aged sciatic DRG neurons both before and 3 days after sciatic nerve injury (Figures 1D, 1E, and 1F).

[0156] Example 3. CD8 expressing the CXCL13 receptor CXCR5 + T cells are elevated in aged DRG To determine whether in vivo neuronal expression of CXCL13 attracts CXCR5+ T cells, we overexpressed CXCL13 in DRG neurons by infecting the sciatic nerves of young mice with AAV-GFP or AAV-CXCL13-GFP. Six weeks after infection, interferon-γ (IFNγ) and mannitol were systemically delivered to induce MHC-I presentation and favor blood-barrier permeability, respectively. Immediately following the infection, sciatic nerve crush injury was performed, and CXCR5+ T cells were measured by FACS in sciatic DRG neurons 3 days after injury (data not shown). Interestingly, CXCR5+ CD8+ T cells were found to be significantly increased in CXCL13-overexpressing DRG compared with GFP controls (Figure 2A and B).

[0157] Because CXCL13 is a chemoattractant for CXCR5-positive B and T cells, we assessed the localization and immunophenotype of CD8+ T cells within the DRG. Immunostaining showed that the number of CXCR5+CD8+ T cells was significantly higher in aged compared with young sciatic DRG (Figure 2C), and that the frequency of CXCR5+CD8+ T cells as a percentage of total CD8+ T cells increased in aged compared with young DRG 3 days after sciatic nerve injury (Figure 2D). These data indicate that aging is associated with both enhanced neuronal expression of CXCL13 and an increased number of CXCR5+CD8+ T cells localized within the DRG after sciatic nerve injury. These data demonstrate that the tissue microenvironment of aged DRG differs significantly from that of young DRG after nerve injury.

[0158] Example 4. CD8+ T cells are selectively associated with age-dependent decline in regenerative capacity after sciatic nerve injury; neuronal MHC-1 is induced in aged DRG and plays a key role in age-dependent decline in regenerative capacity after sciatic nerve injury We analyzed whether CD8 T cells impair axon regeneration in aged sciatic DRG neurons. CD8 T cell depletion was performed using an anti-CD8 monoclonal antibody injected systemically i.p. into aged mice 1 week before sciatic nerve crush injury, while control animals received normal isotype-matched IgG. Analysis of SCG10-positive sciatic nerve axons demonstrated that anti-CD8 monoclonal antibodies significantly promoted nerve regeneration (Figure 3A-B), resulting in a significant reduction in CD8 T cells within the DRG, as demonstrated by immunofluorescence analysis (Figure 3C). In stark contrast, in the same experimental injury model, depletion of CD4 T cells with anti-CD4 monoclonal antibodies or depletion of B cells with monoclonal anti-CD19 / anti-B220 / anti-CD22 antibodies did not alter the age-dependent decline in regenerative capacity after sciatic nerve injury (not shown).

[0159] These data directly and selectively implicate CD8+ T cells in the decline in regenerative capacity after SNI in aged animals.

[0160] RNA-seq data revealed age-dependent enrichment of major histocompatibility complex class I (MHC-I). MHC-I is expressed by antigen-presenting cells (APCs) to present antigenic peptides on the cell membrane after engaging with the T cell receptor (TCR) to activate CD8 T cells (Zinkernagel, (2002). European Journal of Immunology 32, 2385-2392). Immunostaining for MHC-I in DRG showed increased expression of MHC-I in aged DRG neurons before and after sciatic nerve injury (Figure 4A). However, SNI was associated with a significant increase in the percentage of DRG neurons capable of antigen presentation, as suggested by MHC-I localization on the neuronal cell surface (Figure 4B).

[0161] The next step was to determine whether MHC-I-dependent peptide presentation plays a key role in the decline of axon regeneration in aging after sciatic nerve injury. To this end, we used an AAV-based approach to express a virally encoded peptide sequence, GAr, in the sciatic DRG of aged mice, which inhibits MHC-I antigen presentation and evades CD8 T cell immune responses (Zaldumbide and Hoeben, (2008). Biotechnology Letters 32, 749-754). GAr was linked to a reverse tetracycline transactivator (rtTA) that responds to tetracycline / doxycycline-inducible expression of a luciferase reporter (Figure 4C, D) (Burnside et al., (2018). Brain 141, 2362-2381; Hoyng et al., (2014). Gene therapy 21, 549-557; Zaldumbide et al., (2010). Biotechnology Letters 32, 749-754). Specifically, the sciatic nerve was injected bilaterally with a mixture of equal amounts of AAV-luciferase and AAV-GAr-rtTA or control AAV-rtTA for 5 weeks, followed by i.p. administration of doxycycline for 1 week. Next, a sciatic nerve crush injury was performed, and the animals were sacrificed 3 days later. Expression of MHC-I and cleaved caspase 3 was significantly reduced in luciferase-positive DRG neurons after AAV-GAr-rtTA compared with control AAV-rtTA (Figure 4E). Sciatic nerve cord regeneration, measured by SCG10 immunostaining, was significantly enhanced upon AAV-GAr-rtTA infection (Figure 4F, G).

[0162] Taken together, these data suggest that CD8+ T cells and neuronal MHC-I play important roles in the age-dependent decline in regenerative capacity after SNI.

[0163] Example 5. CXCL13 neutralization reverses age-dependent decline in regenerative capacity and promotes neurological functional recovery after sciatic nerve injury We investigated whether neutralization of CXCL13 promotes axonal regeneration, epidermal innervation, and functional recovery in aged animals using the strategy outlined in the schematic diagram in Figure 5A. In the first experiment, a monoclonal antibody against CXCL13 or control IgG was injected intraperitoneally into young or aged mice daily for 3 days after sciatic nerve crush injury, as described above. Axonal regeneration was measured by anti-SCG10 immunostaining, as described above. Anti-CXCL13 antibody prevented the age-dependent regenerative impairment and had no effect on axonal regeneration in young mice (Figure 5B-C). CXCL13 neutralization significantly reduced the number of CXCR5+ T and B cells in aged DRG (Figure 5D). In another experiment, we tested the effect of long-term delivery of anti-CXCL13 antibody on functional recovery. As previously described, monoclonal antibodies against CXCL13 or control IgG were delivered to young or old animals three times a week for over 5 weeks, starting 4 hours after injury. Multimodal sensory assessment was performed, measuring responses to mechanical stimuli using the von Frey method, responses to touch using the tape removal test, and responses to thermal nociception using the Hargreaves method (Figure 5A). Data analysis showed that recovery in old mice was significantly slower than in young mice, and importantly, CXCL13 neutralization induced a significant acceleration of recovery in old mice in all sensory modalities selectively investigated in old mice (Figure 5E–J). Whether CXCL13 neutralization resulted in improved epidermal innervation was measured by PGP9.5 immunostaining from the hairless interdigital area of ​​the hind paw 18 days after sciatic nerve injury in both young and old mice after delivery of anti-CXCL13 or control IgG. CXCL13 neutralization was found to promote significant epidermal innervation in aged mice (Fig. 5K, L).

[0164] These data indicate that CXCL13 antagonism results in functional recovery in both thermosensitivity and mechanosensation.

[0165] Taken together, these data indicate that CXCL13 neutralization promotes axonal regeneration, epidermal reinnervation, and functional recovery in aged animals.

Claims

1. A pharmaceutical composition for treating peripheral nerve injury in a subject with age-dependent decline in regenerative capacity, the pharmaceutical composition comprising an isolated antibody or its antigen-binding fragment that specifically binds to CXCL13 and inhibits the interaction of CXCL13 with its receptor.

2. The pharmaceutical composition of claim 1, wherein binding of the isolated antibody or its antigen-binding fragment to CXCL13 inhibits recruitment of CXCR5+CD8+ T cells to the dorsal root ganglia (DRG) of injured peripheral nerves.

3. 3. The pharmaceutical composition of claim 1 or 2, wherein the isolated antibody or antigen-binding fragment thereof is a human antibody or a humanized antibody or antigen-binding fragment thereof.

4. the isolated antibody or antigen-binding fragment thereof a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 27, 30, and 33, respectively; or VH comprising the amino acid sequence set forth in SEQ ID NO:10; and VL comprising the amino acid sequence set forth in SEQ ID NO:

11.

4. The pharmaceutical composition of any one of claims 1 to 3, comprising:

5. 5. The pharmaceutical composition of any one of claims 1 to 4, wherein the peripheral nerve injury is selected from the group consisting of sciatic nerve injury, peroneal nerve injury, spinal accessory nerve injury, and brachial plexus injury.

6. 6. The pharmaceutical composition of any one of claims 1 to 5, wherein administration of said pharmaceutical composition to said subject results in complete or partial regeneration of a damaged nerve, reinnervation of epidermal tissue, or complete or partial restoration of neurological function of a damaged nerve, or a combination thereof.

7. Use of an effective amount of an isolated antibody or its antigen-binding fragment that specifically binds to CXCL13 and inhibits the interaction of CXCL13 with its receptor for the manufacture of a medicament for treating peripheral nerve damage in a subject with age-dependent decline in regenerative capacity and peripheral nerve damage.

8. 8. The use of claim 7, wherein the peripheral nerve injury is the result of compression, stretching, or severing of a peripheral nerve.

9. 9. The use of claim 7 or 8, wherein the peripheral nerve injury is an injury to the sciatic nerve, brachial plexus, peroneal nerve, or spinal accessory nerve.

10. 10. The use of claim 9, wherein the peripheral nerve injury is a sciatic nerve injury.

11. The use according to any one of claims 7 to 10, wherein the receptor is CXCR5.

12. The isolated antibody or antigen-binding fragment thereof comprises: a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 27, 30, and 33, respectively; or VH comprising the amino acid sequence set forth in SEQ ID NO:10; and VL comprising the amino acid sequence set forth in SEQ ID NO:

11. The use according to any one of claims 7 to 11, comprising:

13. A pharmaceutical composition for treating age-dependent decline in regenerative capacity in a subject with peripheral nerve injury, comprising an isolated antibody or its antigen-binding fragment that specifically binds to CXCL13 and inhibits the interaction of CXCL13 with its receptor.

14. the isolated antibody or antigen-binding fragment thereof a VH comprising the amino acid sequences of heavy chain complementarity determining region 1 (VH-CDR1), VH-CDR2, and VH-CDR3 set forth in SEQ ID NOs: 18, 21, and 24, respectively; and a VL comprising the amino acid sequences of light chain complementarity determining region 1 (VL-CDR1), VL-CDR2, and VL-CDR3 set forth in SEQ ID NOs: 27, 30, and 33, respectively; or VH comprising the amino acid sequence set forth in SEQ ID NO:10; and VL comprising the amino acid sequence set forth in SEQ ID NO:

11.

14. The pharmaceutical composition of claim 13, comprising:

15. 14. The pharmaceutical composition of claim 13, wherein the peripheral nerve injury is a sciatic nerve injury, a brachial plexus injury, a spinal accessory nerve injury, or a peroneal nerve injury.

16. 16. The pharmaceutical composition of claim 15, wherein the peripheral nerve injury is a sciatic nerve injury.

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