Mouse Anti-Chicken TCRgd-FITC

The monoclonal antibody TCR-1 precipitates a heterodimer of Mr 90 kDa (two bands of Mr 50 kDa and 40 kDa upon reduction) on chicken peripheral blood T cells. Deglycosylation of the heterodimer yields two polypeptides of Mr 35 kDa and 32 kDa. Unlike human and mouse in which ?? cells comprise a minor subset of T lymphocytes in the circulation, the chicken has a relatively large subset of ?? T cells. The frequency of TCR?? cells is typically 20-25% of the total blood T cells but may reach approximately 50% in chickens of six- months of age. The majority of TCR??+ cells in the thymus and blood are CD4-CD8- although a small subset of them may express CD8 or CD4 coreceptors. However, when the TCR??+ cells migrate into the spleen and intestine most of them begin to express CD8. Although the biological function of ?? T cells is unclear, they are clearly capable of cytotoxic activity in vitro. The CD8+ ?? T cells may also be involved in down-regulation of the immune response. They cannot, however, induce a graft-vs-host (GVH) reactions.