T cell receptor gamma variable 3 (TRGV3)

V region of the variable domain of T cell receptor (TR) gamma chain that engages in the antigen recognition (PubMed:24600447). Gamma-delta TRs recognize a variety of foreign and self non-peptide antigens frequently expressed in the epithelial boundaries between the host and external environment, such as endogenous lipids introduced by MH-like protein CD1D and phosphoantigens introduced by butyrophilin-like molecule BTN3A1.

Upon antigen recognition induces rapid, innate-like immune responses involved in pathogen clearance and tissue repair (PubMed:23348415, PubMed:28920588). Binding of gamma-delta TR complex to antigen triggers phosphorylation of immunoreceptor tyrosine-based activation motifs (ITAMs) in the CD3 chains from the LCK and FYN kinases, permitting the recruitment, phosphorylation, and activation of ZAP70 that facilitates phosphorylation of the scaffolding proteins LCP2 and LAT.