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== Function == | == Function == | ||
[[http://www.uniprot.org/uniprot/1A02_HUMAN 1A02_HUMAN]] Involved in the presentation of foreign antigens to the immune system. [[http://www.uniprot.org/uniprot/B2MG_HUMAN B2MG_HUMAN]] Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system. | [[http://www.uniprot.org/uniprot/1A02_HUMAN 1A02_HUMAN]] Involved in the presentation of foreign antigens to the immune system. [[http://www.uniprot.org/uniprot/B2MG_HUMAN B2MG_HUMAN]] Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system. | ||
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== Publication Abstract from PubMed == | |||
Human CD8+ cytotoxic T lymphocytes (CTLs) can mediate tumour regression in melanoma through the speci fi c recognition of human leukocyte antigen (HLA)-restricted peptides. Because of the relatively weak affinity of most anti-cancer T-cell receptors (TCR), there is growing emphasis on immunizing melanoma patients with altered peptide ligands in order to induce strong anti-tumour immunity capable of breaking tolerance towards these self-antigens. Previous studies have shown that these immunogenic designer peptides are not always effective and detailed structural analyses will be required in order to improve future success rates. The melanocyte differentiation protein, glycoprotein (gp)100, encodes a naturally processed epitope that is an attractive target for melanoma immunotherapies, in particular peptide-based vaccines. Previous studies have shown that substitutions at peptide residue Glu3 have a broad negative impact on polyclonal T-cell responses. Here, we describe the first atomic structure of a natural cognate TCR in complex with this gp100 epitope, and highlight the relatively high affinity of the interaction. Alanine scan mutagenesis performed across the gp100280-288 peptide showed that Glu3 was critically important for TCR binding. Unexpectedly, structural analysis demonstrated that the Glu3>Ala substitution resulted in a molecular switch that was transmitted to adjacent residues, abrogating TCR binding and T-cell recognition through knock-on effects. These findings help to clarify the mechanism of T-cell recognition of gp100 during melanoma responses and could direct the development of altered peptides for vaccination. | |||
A molecular switch abrogates gp100 TCR-targeting of a human melanoma antigen.,Bianchi V, Bulek A, Fuller A, Lloyd A, Attaf M, Rizkallah PJ, Dolton G, Sewell AK, Cole DK J Biol Chem. 2016 Feb 25. pii: jbc.M115.707414. PMID:26917722<ref>PMID:26917722</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
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== References == | == References == | ||
<references/> | <references/> | ||
Revision as of 23:01, 9 March 2016
HLA Class I antigenHLA Class I antigen
Structural highlights
Disease[B2MG_HUMAN] Defects in B2M are the cause of hypercatabolic hypoproteinemia (HYCATHYP) [MIM:241600]. Affected individuals show marked reduction in serum concentrations of immunoglobulin and albumin, probably due to rapid degradation.[1] Note=Beta-2-microglobulin may adopt the fibrillar configuration of amyloid in certain pathologic states. The capacity to assemble into amyloid fibrils is concentration dependent. Persistently high beta(2)-microglobulin serum levels lead to amyloidosis in patients on long-term hemodialysis.[2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] Function[1A02_HUMAN] Involved in the presentation of foreign antigens to the immune system. [B2MG_HUMAN] Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system. Publication Abstract from PubMedHuman CD8+ cytotoxic T lymphocytes (CTLs) can mediate tumour regression in melanoma through the speci fi c recognition of human leukocyte antigen (HLA)-restricted peptides. Because of the relatively weak affinity of most anti-cancer T-cell receptors (TCR), there is growing emphasis on immunizing melanoma patients with altered peptide ligands in order to induce strong anti-tumour immunity capable of breaking tolerance towards these self-antigens. Previous studies have shown that these immunogenic designer peptides are not always effective and detailed structural analyses will be required in order to improve future success rates. The melanocyte differentiation protein, glycoprotein (gp)100, encodes a naturally processed epitope that is an attractive target for melanoma immunotherapies, in particular peptide-based vaccines. Previous studies have shown that substitutions at peptide residue Glu3 have a broad negative impact on polyclonal T-cell responses. Here, we describe the first atomic structure of a natural cognate TCR in complex with this gp100 epitope, and highlight the relatively high affinity of the interaction. Alanine scan mutagenesis performed across the gp100280-288 peptide showed that Glu3 was critically important for TCR binding. Unexpectedly, structural analysis demonstrated that the Glu3>Ala substitution resulted in a molecular switch that was transmitted to adjacent residues, abrogating TCR binding and T-cell recognition through knock-on effects. These findings help to clarify the mechanism of T-cell recognition of gp100 during melanoma responses and could direct the development of altered peptides for vaccination. A molecular switch abrogates gp100 TCR-targeting of a human melanoma antigen.,Bianchi V, Bulek A, Fuller A, Lloyd A, Attaf M, Rizkallah PJ, Dolton G, Sewell AK, Cole DK J Biol Chem. 2016 Feb 25. pii: jbc.M115.707414. PMID:26917722[15] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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