THE IMMUNOBIOLOGY OF T-CELLS WITH INVARIANT GAMMA-DELTA ANTIGEN RECEPTORS

T cells bearing specific gamma-delta TCR are the major lymphoid population in certain epithelial tissues. There are striking differences between these and peripheral T cells. The epithelial gamma-delta T cells exhibit highly restricted V gene use, preferential pairing of TCR chains, and lack of diversity at the junctions creating populations of cells with virtually identical TCR in particular epithelia. Generation of certain epithelial gamma-delta populations appears to be restricted to a discrete stage early in development. The restricted localization and expression of invariant antigen receptors may equip the epithelial gamma-delta T cells to perform specialized functions which differ from those of circulating alpha-beta and gamma-delta TCR+ cells. This review provides a summary of the characterization of gamma-delta T cells found in epithelial tissues and speculates on the in vivo role of these cells.