4pv8

Crystal Structure of H2Kb-Q600F complex

spinqualitylabelsall models 4pv8, resolution 2.31Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4pv8 is a 6 chain structure with sequence from Lk3 transgenic mice. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ACT, PG4 NonStd Res: ABA Related: 2zsv, 4pv9 Gene: H2-K1, H2-K (LK3 transgenic mice), B2m (LK3 transgenic mice) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [HA1B_MOUSE] Involved in the presentation of foreign antigens to the immune system. [B2MG_MOUSE] Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system. Publication Abstract from PubMed Peptides that bind poorly to MHC class I molecules often elicit low-functional avidity T cell responses. Peptide modification by altering the anchor residue facilitates increased binding affinity and may elicit T cells with increased functional avidity toward the native epitope ("heteroclitic"). This augmented MHC binding is likely to increase the half-life and surface density of the heteroclitic complex, but precisely how this enhanced T cell response occurs in vivo is not known. Furthermore, the ideal heteroclitic epitope will elicit T cell responses that completely cross-react with the native epitope, maximizing protection and minimizing undesirable off-target effects. Such epitopes have been difficult to identify. In this study, using mice infected with a murine coronavirus that encodes epitopes that elicit high (S510, CSLWNGPHL)- and low (S598, RCQIFANI)-functional avidity responses, we show that increased expression of peptide S598 but not S510 generated T cells with enhanced functional avidity. Thus, immune responses can be augmented toward T cell epitopes with low functional avidity by increasing Ag density. We also identified a heteroclitic epitope (RCVIFANI) that elicited a T cell response with nearly complete cross-reactivity with native epitope and demonstrated increased MHC/peptide abundance compared with native S598. Structural and thermal melt analyses indicated that the Q600V substitution enhanced stability of the peptide/MHC complex without greatly altering the antigenic surface, resulting in highly cross-reactive T cell responses. Our data highlight that increased peptide/MHC complex display contributes to heteroclitic epitope efficacy and describe parameters for maximizing immune responses that cross-react with the native epitope. Structural and functional correlates of enhanced antiviral immunity generated by heteroclitic CD8 T cell epitopes.,Trujillo JA, Gras S, Twist KA, Croft NP, Channappanavar R, Rossjohn J, Purcell AW, Perlman S J Immunol. 2014 Jun 1;192(11):5245-56. doi: 10.4049/jimmunol.1400111. Epub 2014, May 2. PMID:24795457 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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