During thymocyte development, cell fate is determined by signals originating from the alphabeta T-cell receptor.

At the DN4 stage, Notch signaling still significantly contributes to the generation of alphabeta T cells.

Naive alphabeta T cells, NK cells, and DC also amplify secondary adaptive responses to previously encountered pathogens.

However, there were no significant differences in the numbers of either lamina propria or epithelial alphabeta T cells between different intestinal regions.

A novel lymphocyte lineage, V alpha 14 NKT cells, has recently been identified and appears to be distinct from conventional alphabeta T cells.

Moreover, genetic deficiency of gammadelta T cells resulted in impaired IFN-gamma production by tumor antigen-triggered alphabeta T cell upon immunization with tumor lysate.

These studies lead to a broader view of the natural function of alphabeta T cells, which involves recognition of both cellular proteins and lipids.

Gammadelta T cells have unique features and functions compared with alphabeta T cells and have been proposed to bridge the innate and adaptive immune responses.

Background: The concentration of T-cell receptor-rearrangement excision DNA circles (TREC) in peripheral-blood T cells is a marker of recent thymic emigrant alphabeta T cells.