特異性：Chicken TCR alpha beta (V beta 1) MAb TCR2 precipitates a CD3-associated heterodimer of Mr 90-kDa (two bands of Mr 40-kDa and 50- kDa upon reduction) on chicken peripheral blood T cells.1 Deglycosylation of the heterodimer yields two polypeptides of Mr 34-kDa and 29-kDa from TCR2 precipitates. In the chicken, two distinct subpopulations of alpha beta T cells appear in the thymus subsequent to the appearance of gamma delta T cells. These subpopulations, originally denoted as TCR2 and TCR3,1-3 arise sequentially in the thymus during ontogeny and are now known to represent two distinct V beta families, V beta 1 and V beta 2, respectively.4 The TCR2 MAb reacts with approximately 40% of thymocytes, 40-50% of blood mononuclear cells and 40% of splenocytes in the chicken. Two-color immunofluorescence has revealed that most of the TCR2+ thymocytes express both CD4 and CD8 antigens. The TCR2+ cells in blood were found to express either CD4 (74+/-2%) or CD8 (26+/-4%). TCR2+ cells in the spleen also express either CD4 (37+/-1%) or CD8 (64+/-4%). Surprisingly, a relatively large subpopulation of CD8+ cells in the spleen are negative for TCR2.1-3 This observation led to the demonstration that 71+/-6% of the TCR1(gamma delta)+ cells in the spleen express the CD8 marker.1-4
