Abstract
Human γδT cells were discovered in 1986. Since then, many studies have been performed to clarify their physiological role and function. Recently, a new class of ligands, phospholigand, has been identified, which broadly stimulates Vγ9+Vδ2+T cells without antigen processing or MHC interaction. Probably through phos-pholigands, newborn or preimmune γδT cells can promptly respond to pathogens. Thus, γδT cells appear to represent a first line of defence against intracellular infectious agents. In addition, possible roles of γδT cells in autoimmune diseases, immunodeficiencies and malignancies are also reviewed.
