591 results about "Single chain" patented technology

This disclosure relates methods for expanding γδ T cells. More specifically, the disclosure relates to methods of expanding γδ T cells that have an eliminated or reduced expression of endogenous MHC Class I molecules, by expressing a single-chain fusion HLA Class I protein. In some embodiments, the endogenous B2M gene of the γδ T cells is disrupted. In some embodiments, the single-chain fusion HLA Class I protein includes at least a portion of B2M protein and at least a portion of HLA-E heavy chain.

The invention relates to the technical field of gene engineering, in particular to application of wheat TaLNUE protein in regulation and control of low nitrogen stress tolerance of plants. According to the invention, a single-chain guide RNA of a target wheat TaLNUE gene is designed, an expression vector of the TaLNUE gene is knocked out, and the expression vector is transformed into wild type wheat, so that transgenic wheat with the function inhibited by the TaLNUE gene is obtained. Researches find that the spike length and the spikelet number of wheat under low nitrogen stress can be increased by inhibiting the expression of the wheat TaLNUE protein, so that the single plant yield and the total yield of the wheat under low nitrogen stress are increased, and the nitrogen absorption efficiency and the nitrogen utilization efficiency of the wheat under low nitrogen stress are improved. According to the technical scheme, a feasible method is provided for improving the wheat yield under low nitrogen stress by utilizing a genetic engineering technology.

The present invention is directed to a monoclonal anti-human CS1 clone 7A8D5 antibody or a single-chain variable fragment (scFv), comprising VH having the amino acid of SEQ ID NO: 4 and VL having the amino acid of SEQ ID NO: 5. The present invention is also directed to a chimeric antigen receptor fusion protein comprising from N-terminus to C-terminus: (i) CS1 scFv of the present invention, (ii) a transmembrane domain, (iii) at least one co-stimulatory domains, and (iv) an activating domain.

The present invention provides a combined chimeric antigen receptor targeting CD19 and CD20 and application thereof. Specifically, the present invention provides a combined chimeric antigen receptor targeting CD19 and CD20, which comprises a scFv targeting CD19 and CD20, a hinge region, a transmembrane region, and an intracellular signaling domain. The present invention provides a nucleic acid molecule encoding the chimeric antigen receptor and a corresponding expression vector, a CAR-T cell, and applications thereof. The experimental results show that the chimeric antigen receptor provided by the present invention shows extremely high killing ability against tumor cells. The chimeric antigen receptor of the present invention targets CD19 and / or CD20 positive cells and can be used to treat CD19 and / or CD20 positive B-cell lymphoma, leukemia and other diseases.

The invention belongs to the technical field of immunodetection, and discloses an avian single-chain antibody for detecting a liver cancer marker GPC3, a kit and a detection method. The poultry-derived single-chain antibody has the characteristics of small volume, high specificity, high stability and good sensitivity, and can be used in an immunoassay method for detecting a liver cancer marker GPC3; according to the method, a chicken-derived single-chain antibody is coated on a solid-phase carrier, a rabbit-derived polyclonal antibody is taken as a detection carrier, the antibodies are combined with a GPC3 antigen to form a sandwich structure, and the double-antibody sandwich immunoassay method of the GPC3 is established by using the method, and has the advantages of high specificity, good sensitivity, high sensitivity and high sensitivity. The invention provides a rapid, accurate and reliable detection method for detecting GPC3 in serum.

The invention belongs to the technical field of immunodetection, and discloses a preparation and characterization method of a rabbit-derived single-chain antibody for detecting a liver cancer marker GPC3. The rabbit-derived single-chain antibody has the characteristics of small volume, high specificity, high stability and good sensitivity, and can be used in an immunoassay method for detecting a liver cancer marker GPC3; according to the method, a specific rabbit single-chain antibody is obtained through screening, expression and purification by using a phage display technology, a GPC3 antigen is coated on a solid-phase carrier, the rabbit single-chain antibody is used as a detection carrier, the binding force of the single-chain antibody and the antigen is identified, and the method is high in specificity, good in sensitivity and high in specificity. A novel single-chain antibody with high specificity and high sensitivity is provided for detection of GPC3 in serum.

The invention provides a glass nanopore probe based on an aptamer and application of the glass nanopore probe in dopamine detection, and belongs to the technical field of electrochemical sensing and scanning probe microscopy. The sensor comprises: a glass nanopore probe, the inner wall of which is modified with a gold layer; a cDNA (complementary deoxyribonucleic acid) single chain is fixed on the gold layer through a gold-sulfur bond; a part of the sequence of the dopamine aptamer is hybridized and combined with the cDNA single chain; wherein the combination of the dopamine and the dopamine aptamer causes the change of an ion current rectification signal of the glass nanopore probe, so that the detection of the dopamine is realized based on the change of the ion current rectification signal of the glass nanopore probe. The invention provides a valuable scheme for developing an aptamer nanopore scanning electrochemical sensor for single cell analysis and researching neurotransmitter-related diseases.

A protein cryoelectron microscope structure assembling method based on point cloud registration belongs to the field of bioinformatics, and comprises the following steps: firstly, obtaining a cryoelectron microscope experimental density map after redundancy elimination and a corresponding protein structure, generating a simulation density map, carrying out uniform sampling and density vector calculation, and converting into point cloud data; training and evaluating a registration network based on the point cloud data; secondly, predicting a single-chain structure of a to-be-assembled protein compound by utilizing AlphaFold3, processing in the same way according to the training data, firstly registering the longest chain, performing local optimization by using an LBFGS optimization algorithm, and if a correlation coefficient is lower than a threshold value and the chain comprises a plurality of structural domains, improving the precision by splitting the structural domains and performing independent registration; finally, the remaining chains are gradually fitted to the density map according to the chain length sequence. According to the method, point cloud registration and local optimization are combined, and the protein structure assembling precision and speed under the low-resolution density map condition are remarkably improved.

The invention provides an anti-PD-1 antibody, a CAR-T cell, and a preparation method and application thereof. The anti-PD-1 antibody comprises LCDR-1-3 as shown in SEQ ID NO: 1-3 and HCDR-1-3 as shown in SEQ ID NO: 4-6, respectively. The CAR-T cell expresses a novel element for efficiently blocking the PD-1, and the element is a single-chain antibody for targeting the PD-1 in a cell membrane anchoring manner. And the chimeric antigen receptor and the cell membrane anchored anti-PD-1 scFv are connected by a 2A cleavage protein. The membrane anchor type anti-PD-1 scFv expressed by the CAR-T cell can almost completely block the expression of PD-1 on the surface of a T cell membrane, and further block a signal channel combined with PD-1 / PD-L1, so that the capability of T cell depletion caused by antagonism tumor of the CAR-T cell is enhanced, and the purpose of enhancing the anti-tumor effect of the CAR-T cell is achieved.

The invention provides a single-chain and double-protein-expressed circular RNA construct and a preparation method and application thereof, and the single-chain and double-protein-expressed circular RNA construct comprises 5'and 3 'introns used for realizing RNA self-splicing and cyclization as a first kind of introns; the 5'and 3 'homologous arms are used as pairing sites in RNA molecules; the exon 1 and the exon 2, which are connected after being spliced, can be spliced and connected together under the action of the first type of introns to form a complete and continuous open reading frame; an interval sequence for providing spatial and adjustment sequence structures; the IRES is used for starting translation; a glycine-serine linker as a flexible linker; a green fluorescent protein for gene expression monitoring; a luciferase for producing light by a catalytic chemical reaction. All the advantages of the double-IRES system for generating natural complete protein are reserved, and the core defect of low efficiency can be thoroughly overcome.

The present invention is directed to a humanized BCMA single-chain variable fragment (scFv), comprising VH having the amino acid sequence of SEQ ID NO: 4 and VL having the amino acid sequence of SEQ ID NO: 5. The present invention is also directed to a BCMA chimeric antigen receptor fusion protein comprising from N-terminus to C-terminus: (i) a single-chain variable fragment (scFv) of the present invention, (ii) a transmembrane domain, (iii) at least one co-stimulatory domains, and (iv) an activating domain. This humanized BCMA-CAR-T cells have specific killing activity with secretion of cytokine IFN-gamma in CAR-T cells in vitro and in vivo.

The invention relates to screening methods. In particular, it relates to a method of identifying a functional TCR from a library of particles, which displays a plurality of different T cell receptors (TCRs). The method may comprise a) exposing the library of particles to a target antigen to identify TCRs that bind to the target antigen, b) transfecting a plurality of T cells with nucleic acid encoding TCRs identified in step (a), c) exposing the plurality of transfected cells to the target antigen, and d) selecting cells having TCR activity in the presence of the target antigen. Transfection of the T cells is such that each T cell comprises a nucleic acid encoding a single TCR from the library of particles, the nucleic acid is integrated into the genome of the T cell at a single identical pre-defined locus, and the TCR is in a single chain format and comprises an alpha chain variable domain, a beta cain variable domain and a constant domain. The T cells do not express endogenous TCR. A T-cell comprising a recombinase mediated landing pad, wherein the T cell constitutively expresses TCR constant domain and does not express endogenous TCR, is also claimed.

The invention discloses a single-chain antibody for recognizing an extracellular domain of a PPRV H protein and application of the single-chain antibody, and belongs to the technical field of genetic engineering. The amino acid sequence of a heavy chain variable region of the single-chain antibody is as shown in SEQ ID NO.5, and the amino acid sequence of a light chain variable region of the single-chain antibody is as shown in SEQ ID NO.9. The invention provides a single-chain antibody for recognizing a PPRV H protein extracellular region (185-609aa), a mouse is immunized through a PPRV H protein extracellular region protein, and VH and VL genes of the immunized monoclonal antibody are connected in series by using a monoclonal antibody preparation technology and a DNA molecular technology to prepare the single-chain antibody. A neutralization test verifies that the single-chain antibody can neutralize PPRV viruses and can be used for clinical detection of peste des petits ruminants.

The application discloses an anti-LMBV single-chain antibody and application thereof in preparation of a quantum dot fluorescent immunochromatography test strip, and belongs to the technical field of biological detection. The single-chain antibody comprises Ab-K1 and Ab-K2, the amino acid sequence of the Ab-K1 is shown as SEQ ID NO. 11, and the amino acid sequence of the Ab-K2 is shown as SEQ ID NO. 12. The single-chain antibody used in the application can accurately recognize and combine with iridovirus in a sample to be detected, so that the accuracy of detection is ensured. Meanwhile, the antibody labeled with fluorescent quantum dots has good fluorescent characteristics, so that the fluorescent signal is easy to observe and detect, and the specific surface area is relatively large, so that the antibody can be combined with more virus molecules, so that the sensitivity of detection is improved, the accuracy and sensitivity of detection are improved, the operation steps are simplified, and powerful technical support is provided for detection and prevention and control of iridovirus.

The invention discloses liver-responsive synthetic macrophages and a construction method and tumor immunotherapy application thereof, and belongs to the technical field of biological medicines. The system is an IBMDM cell line of a stable expression alpha SLC17A2-P65 / shSIRP alpha-synM system, and comprises an extracellular domain and an intracellular domain, the extracellular domain is composed of a single-chain antibody scFv for recognizing an antigen SLC17A2 and a transcription factor GAL4-VP16 (GV), and the intracellular domain is composed of a UAS promoter sequence recognized by the GV and P65 / shSIRP alpha. When the antibody responds to the liver, GV is released through the self-cleavage effect of synNotch, and the GV recognizes a UAS promoter sequence after entering a nucleus to activate downstream gene expression. The invention also provides a construction method of the system. The construction method comprises the following three steps: constructing a vector plasmid, packaging lentivirus and constructing a target cell line. The system can be applied to screening anti-liver cancer immunotherapy drugs, and a new research tool is provided for liver cancer treatment.

The utility model provides a watch chain easy to disassemble and assemble, which comprises a plurality of mutually connected single chains, two adjacent single chains are respectively a first single chain and a second single chain, the first single chain and the second single chain are respectively provided with a concave part, the concave part of the first single chain and / or the second single chain is provided with an opening, and the opening is communicated with the opening. During assembly, the concave parts of the first single chain and the second single chain are pressed correspondingly, so that the opening is opened, and the first single chain is connected with the second single chain. According to the utility model, the two adjacent single chains can be quickly disassembled and assembled through the opening, so that the length of the watch chain can be adjusted, the single chains can be simply disassembled and assembled, and the single chains cannot be damaged in the disassembly and assembly process.

The invention discloses an African swine fever mRNA vaccine composition capable of synergistically activating and enhancing humoral immunity and cellular immunity and application of the African swine fever mRNA vaccine composition, and belongs to the technical field of biological medicines. Specifically, a plurality of key antigen proteins of the African swine fever virus are used as target spots and are connected in series through connexons to form single-chain mRNA, so that multiple immunogens can be translated from the same transcript, and multiple antibodies are induced to be generated at the same time; a conservative recombinant T cell immunogen capable of activating cellular immune response is introduced, so that the cellular immune response can be enhanced, the ADE risk can be reduced, and the cross protection capability can also be improved; in addition, a molecular adjuvant IL-12 is added into the mRNA vaccine to enhance the immune response of the African swine fever vaccine, so that stronger immune protection efficacy is induced.

The application discloses an electrochemical sensor for detecting IBD protein markers and a preparation method thereof. The electrochemical sensor is composed of a CNT-embedded semi-cured PDMS flexible substrate, deposited gold nanoparticles and a nucleic acid sensing layer. The nucleic acid sensing layer comprises a tumor necrosis factor-alpha sensor, an interleukin 6 sensor, an interleukin 8 sensor, a transforming growth factor beta 1 sensor, a reference electrode and a counter electrode. The tumor necrosis factor-alpha sensor, the interleukin 6 sensor, the interleukin 8 sensor and the transforming growth factor beta 1 sensor all adopt single-stranded aptamers modified by a signal molecule methylene blue, and the nucleotide sequences corresponding to the single-stranded aptamers are SEQ ID NO. 1-4. The application can improve the modulus matching of the sensor and human tissue and excellent biocompatibility, realize accurate detection of low-concentration biomarkers and stable signal output of the sensor under a strain working condition.

The application discloses an oligonucleotide hydrogel and a preparation method and application thereof, and comprises the following steps: sequentially adding oligonucleotide and PBS buffer into a metal salt solution to obtain a mixed solution; placing the mixed solution in a shaking table and oscillating and incubating; after incubation, centrifuging, discarding the supernatant and reserving the precipitate; resuspending the precipitate by adding deionized water, centrifuging, discarding the supernatant and washing to obtain the hydrogel; the application only needs single-stranded oligonucleotide, has no special requirements on the sequence composition and structure of the oligonucleotide, does not need special design, can be assembled with divalent and trivalent metal ions, has a simple process, is easy to operate, and can wrap biological enzymes in the hydrogel, realizes enzyme immobilization and recycling.

The efficacy and indication of donanemab do not depend on the Fc region and are subject to transit across cell walls. They can be expanded by using their scFvs conjugated with N-methyl lobe of transferrin protein connected with an environment-sensitive cleavable linker to prevent exocytosis of the scFv yielding high exposure inside body cells such as in the brain, eye, and cancer cells that overexpress transferrin receptors.

This invention relates to a method for quantifying mRNA capping efficiency, the method comprising mixing a sample, an enzyme mixture, and an isotope standard solution in a buffer solution to produce an incubation mixture, the enzyme mixture comprising a nonspecific single-stranded nuclease and an acid phosphatase, and the isotope standard comprising isotopically labeled m7G and isotopically labeled 2'-O-methylated nucleoside; incubating the mixture; and analyzing the mixture using liquid chromatography-mass spectrometry to determine at least one of capping efficiency and 2-O-methyltransferase efficiency.

The present disclosure provides conjugates comprising a targeting moiety, such as an antibody, Fab fragment or single chain variable fragment (ScFv), and a lipid nanoparticle (LNP) encapsulating a therapeutic agent (i.e., payload) wherein the targeting moiety, such as an antibody, Fab fragment or ScFv, is conjugated to the lipid nanoparticle via a linker, and wherein the linker comprises an enzyme recognition sequence and a click product formed by a click reaction between a first click handle on the targeting moiety such as an antibody, Fab fragment or ScFv and a second click handle on the LNP.

The application discloses a TDN fluorescent molecular probe and a preparation method and application thereof, the TDN fluorescent molecular probe is constructed by self-assembly of S1 chains, S2 chains, S3 chains, S4 chains and S5 chains, a fluorescent group is modified at the 3' end of the S1 chain, and a quenching group is modified at the 5' end of the S2 chain adjacent to the S1 chain. The TDN structure is combined with the fluorescent in situ hybridization technology, so that the TDN structure has a certain stability after being hybridized with a target probe. One structural single chain in the framework of the TDN structure is replaced by a dynamic detection chain, and a fluorescent group / quenching group is modified at the corresponding chain end, so that the TDN structure has an 'on-off' function, and the TDN fluorescent molecular probe is constructed. After being synthesized by heat annealing, the TDN structure is formed, and the fluorescent group is affected by the quenching group in the structure.

Disclosed herein are monospecific and multispecific single chain antibodies having specificity for one or more of CD47, PD-L1, HSA, CD33, LAG3, and CD16.

The invention relates to the technical field of biological medicine, and discloses an anti-human 5T4 single-chain antibody, the antibody has the capability of specifically binding to human 5T4 protein, the human 5T4 protein corresponds to TPBG / WAIF1, and the GenBank login number is NP001018111.1; the antibody also has the capability of specifically binding and expressing human 5T4 protein tumor cells, and the human 5T4 protein tumor cells are breast cancer cells MCF-7, prostate cancer cells PC3 or gastric cancer cells MGC-803. By combining single B cell culture with a magnetic bead sorting technology, natural pairing of a heavy chain and a light chain of an antibody can be reserved, and the defect that pairing is damaged by a traditional hybridoma technology is overcome; meanwhile, false positive clones are effectively eliminated through double positive screening of detecting protein binding activity through ELISA and detecting cell binding activity through FACS, the finally obtained targeting 5T4 monoclonal antibody can be specifically combined with human 5T4 protein and tumor cells expressing the protein, and a high-quality targeting molecular basis is provided for research and development of subsequent antibody drugs and CAR-T cell treatment products.

An antigen (Ag) that elicits a polyclonal T cell receptor like antibody response from endogenous B cells. The Ag comprises a single chain peptide MHCI (pMHCI) complex, that directs B cell responses to the displayed peptide without reactivity to the rest of the pMHCI molecule. Also, methods of using the Ag to induce polyclonal T cell receptor like (TCRL) antibodies (Abs) and using the Ag to deliver the single chain peptide to a target cell.

The application provides an anti-Spike protein antibody of a novel coronavirus and an application thereof. By means of genetic engineering and phage surface display library technology, specific antibodies against the S protein of the novel coronavirus are screened from a single-chain antibody library of non-immune full human sequences. The antibodies have an affinity to the S protein of the virus between 1nM and 50nM, the antibodies have an inhibiting effect on the combination of the S protein of the novel coronavirus and human receptor ACE2, and the anti-S protein antibodies of the application have a good ability to combine with the S protein and a potential neutralizing inhibiting effect. The application provides specific antibody candidate molecules for the development of diagnostic reagents, preventive and therapeutic antibody drugs against the novel coronavirus (2019-nCoV) and the treatment of other diseases such as pneumonia caused by the coronavirus.

The present disclosure relates to oligonucleotides, compositions, and methods useful for reducing GYS2 expression, particularly in hepatocytes. The disclosed oligonucleotides for reducing GYS2 expression can be double-stranded or single-stranded, and can be modified to improve properties such as stronger resistance to nucleases and lower immunogenicity. The disclosed oligonucleotides for reducing GYS2 expression can also include targeting ligands to target specific cells or organs, such as hepatocytes of the liver, and can be useful for treating glycogen storage diseases (e.g., GSDIa, GSDIII, GSDIV, GSDVI, and GSDIX) and related conditions.

The invention discloses a paralichthys olivaceus rhabdovirus recombinant single-chain variable region antibody and application thereof, and belongs to the field of molecular immunology. The recombinant single-chain variable region antibody comprises a heavy chain variable region and a light chain variable region, the amino acid sequence of the heavy chain variable region is shown as SEQ ID NO: 4, and the amino acid sequence of the light chain variable region is shown as SEQ ID NO: 5. According to the present invention, paralichthys olivaceus rhabdovirus G protein gene is cloned, accurate screening is performed to obtain the B cell antigen epitope of the G protein, the hybridoma cell is prepared by using the epitope sequence as the antigen, and the specific single-chain antibody is efficiently produced by using the Escherichia coli expression system; the recombinant single-chain antibody can specifically recognize and combine with HIRRV, target a virus key functional region, effectively neutralize virus infection, reduce non-specific immunoreaction, and significantly improve the accuracy of rapid diagnosis, detection and treatment. The compound can be used as a paralichthys olivaceus rhabdovirus infection detection or diagnosis reagent and a paralichthys olivaceus rhabdovirus targeted blocking drug.

A fusion protein comprising at least one first polypeptide moiety and at least one second polypeptide moiety wherein the first polypeptide moiety is a single-chain polypeptide capable of binding to a target entity and the second polypeptide moiety is a stabilizing polypeptide and comprises a single-chain alpha-helix-containing domain, wherein the second polypeptide moiety has no binding affinity for the target entity. The presence of the second polypeptide moiety may improve at least one property of the fusion protein as compared to the property of the first polypeptide moiety alone, where the improved property is selected from the group consisting of: alkaline stability, recombinant protein expression, and coupling to a vector.