Understanding the complexity of [gamma][delta] T-cell subsets in mouse and human

Summary [gamma][delta] T cells are increasingly recognized as having important functional roles in a range of disease scenarios such as infection, allergy, autoimmunity and cancer. With this has come realization that [gamma][delta] cells are not a homogeneous population of cells with a single physiological role. Instead, ever increasing complexity in both phenotype and function is being ascribed to [gamma][delta] cell subsets from various tissues and locations, and in both mouse and human. Here, we review this complexity by describing how diverse [gamma][delta] cell subsets are generated in the murine thymus, and how these events relate to subsequent [gamma][delta] subset function in the periphery. We then review the two major [gamma][delta] cell populations in human, highlighting the several similarities of V[delta]1+ cells to certain murine [gamma][delta] subsets, and describing the remarkable functional plasticity of human V[delta]2+ cells. A better understanding of this spectrum of [gamma][delta] cell phenotypes should facilitate more targeted approaches to utilise their tremendous functional potential in the clinic. [PUBLICATION ABSTRACT]