3pab

Crystal Structure of H2-Kb in complex with a mutant of the chicken ovalbumin epitope OVA-E1

spinqualitylabelsall models 3pab, resolution 2.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3pab is a 6 chain structure with sequence from Gallus gallus and Mus musculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.2Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function 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 High-avidity interactions between TCRs and peptide + class I MHC (pMHCI) epitopes drive CTL activation and expansion. Intriguing questions remain concerning the constraints determining optimal TCR/pMHCI binding. The present analysis uses the TCR transgenic OT-I model to assess how varying profiles of TCR/pMHCI avidity influence naive CTL proliferation and the acquisition of effector function following exposure to the cognate H-2K(b)/OVA(257-264) (SIINFEKL) epitope and to mutants provided as peptide or in engineered influenza A viruses. Stimulating naive OT-I CD8(+) T cells in vitro with SIINFEKL induced full CTL proliferation and differentiation that was largely independent of any need for costimulation. By contrast, in vitro activation with the low-affinity EIINFEKL or SIIGFEKL ligands depended on the provision of IL-2 and other costimulatory signals. Importantly, although they did generate potent endogenous responses, infection of mice with influenza A viruses expressing these same OVA(257) variants failed to induce the activation of adoptively transferred naive OT-I CTLps, an effect that was only partially overcome by priming with a lipopeptide vaccine. Subsequent structural and biophysical analysis of H2-K(b)OVA(257), H2-K(b)E1, and H2-K(b)G4 established that these variations introduce small changes at the pMHCI interface and decrease epitope stability in ways that would likely impact cell surface presentation and recognition. Overall, it seems that there is an activation threshold for naive CTLps, that minimal alterations in peptide sequence can have profound effects, and that the antigenic requirements for the in vitro and in vivo induction of CTL proliferation and effector function differ substantially. Affinity Thresholds for Naive CD8+ CTL Activation by Peptides and Engineered Influenza A Viruses.,Denton AE, Wesselingh R, Gras S, Guillonneau C, Olson MR, Mintern JD, Zeng W, Jackson DC, Rossjohn J, Hodgkin PD, Doherty PC, Turner SJ J Immunol. 2011 Oct 28. PMID:22039305 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Beta-2 microglobulin 3D structures

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