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Publication Abstract from PubMed

T cells are crucial players in cell-mediated immunity. The specificity of their receptor, the T cell receptor (TCR), is central for the immune system to distinguish foreign from host antigens. Superantigens are bacterial toxins capable of inducing a toxic immune response by cross-linking the TCR and the major histocompatibility complex (MHC) class II and circumventing the antigen specificity. Here, we present the structure of staphylococcal enterotoxin E (SEE) in complex with a human T cell receptor, as well as the unligated T cell receptor structure. There are clear structural changes in the TCR loops upon superantigen binding. In particular, the HV4 loop moves to circumvent steric clashes upon complex formation. In addition, a predicted ternary model of SEE in complex with both TCR and MHC class II displays intermolecular contacts between the TCR alpha-chain and the MHC, suggesting that the TCR alpha-chain is of importance for complex formation.

Structure of Staphylococcal Enterotoxin E in Complex with TCR Defines the Role of TCR Loop Positioning in Superantigen Recognition.,Rodstrom KE, Regenthal P, Lindkvist-Petersson K PLoS One. 2015 Jul 6;10(7):e0131988. doi: 10.1371/journal.pone.0131988., eCollection 2015. PMID:26147596^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.