NKT Cell Activation During (Microbial) Infection

Invariant Natural Killer T (iNKT) cells constitute an innate-like lymphocyte population endowed with powerful immunomodulatory functions. Unlike conventional T cells, iNKT cells predominantly express a conserved semi-invariant T cell receptor (TCR), Vα14-Jα18/Vβ2, 7, 8 in mice and Vα24-Jα18/Vβ11 in humans. These canonical TCRs in both species do not recognize peptides, but glycosphingolipid (GSL) patterns presented by CD1d on antigen presenting cells (APCs). The natural mechanisms for iNKT cell activation were unclear prior to the recent identification of their endogenous and exogenous GSL ligands.