8euq: Difference between revisions

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<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8euq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8euq OCA], [https://pdbe.org/8euq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8euq RCSB], [https://www.ebi.ac.uk/pdbsum/8euq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8euq ProSAT]</span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8euq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8euq OCA], [https://pdbe.org/8euq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8euq RCSB], [https://www.ebi.ac.uk/pdbsum/8euq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8euq ProSAT]</span></td></tr>
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== Function ==
<div style="background-color:#fffaf0;">
[https://www.uniprot.org/uniprot/DRA_HUMAN DRA_HUMAN] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading.
== Publication Abstract from PubMed ==
Subunit vaccines typically require co-administration with an adjuvant to elicit protective immunity, adding development hurdles that can impede rapid pandemic responses. To circumvent the need for adjuvant in a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) subunit vaccine, we engineer a thermostable immunotargeting vaccine (ITV) that leverages the pan-HLA-DR monoclonal antibody 44H10 to deliver the viral spike protein receptor-binding domain (RBD) to antigen-presenting cells. X-ray crystallography shows that 44H10 binds to a conserved epitope on HLA-DR, providing the basis for its broad HLA-DR reactivity. Adjuvant-free ITV immunization in rabbits and ferrets induces robust anti-RBD antibody responses that neutralize SARS-CoV-2 variants of concern and protect recipients from SARS-CoV-2 challenge. We demonstrate that the modular nature of the ITV scaffold with respect to helper T cell epitopes and diverse RBD antigens facilitates broad sarbecovirus neutralization. Our findings support anti-HLA-DR immunotargeting as an effective means to induce strong antibody responses to subunit antigens without requiring an adjuvant.
 
Modular adjuvant-free pan-HLA-DR-immunotargeting subunit vaccine against SARS-CoV-2 elicits broad sarbecovirus-neutralizing antibody responses.,Kassardjian A, Sun E, Sookhoo J, Muthuraman K, Boligan KF, Kucharska I, Rujas E, Jetha A, Branch DR, Babiuk S, Barber B, Julien JP Cell Rep. 2023 Apr 25;42(4):112391. doi: 10.1016/j.celrep.2023.112391. Epub 2023 , Apr 3. PMID:37053069<ref>PMID:37053069</ref>
 
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 8euq" style="background-color:#fffaf0;"></div>


==See Also==
==See Also==
*[[MHC 3D structures|MHC 3D structures]]
*[[MHC 3D structures|MHC 3D structures]]
*[[MHC II 3D structures|MHC II 3D structures]]
*[[MHC II 3D structures|MHC II 3D structures]]
== References ==
<references/>
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</StructureSection>
</StructureSection>

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