In this paper, we show that a mouse monoclonal antibody, 111-427, specific for the V ß 5.3 chain of the human T-cell receptor (TCR) for antigen, also reacts with chicken
hematopoietic cells. Our data indicate that the majority of 111-427 positive cells among
peripheral blood leucocytes (PBL) are thrombocytes. This antibody also recognizes two
in vitro cell lines, III-C5, an IL-2-dependent T-cell-line and HD11, a macrophage cell line.
In addition, erythrocytes and a minor subpopulation of thymus and spleen cells are also
stained by the monoclonal antibody (mAb). No specific immunoprecipitation could be
detected from 125I radiolabeled cell lysates. By Western blotting techniques, the 111-
427 mAb identifies a single band of apparent molecular weight 91 kD, unaffected by
reduction, from III-C5 and HD11 cell lysates. This band is absent in negative cell control
lysates. On thrombocytes, the apparent molecular weight of the band is shifted to 87 kD.
These results indicate that the mAb does not recognize the chicken T-cell receptor for
antigen, but a cell surface marker shared primarily between thrombocytes and
erythrocytes. This new chicken cell marker is compared to other cell surface markers in
avian or mammalian species that present some analogies in their tissue distribution