Cell surface antigens on avian erythroid cells. Their expression at various stages of cell differentiation.

Chicken erythroblasts transformed by a temperature-sensitive erythroblastosis virus (tsAEV) can terminally differentiate at the non-permissive temperature (42 degrees C). Morphological changes, as well as production of hemoglobin were shown to occur during maturation. The above system, as well as fractions of normal bone marrow cells were used to study the expression of cell surface antigens on erythroid cells. Four distinct reactivities were found with monoclonal antibodies (MAbs) and polyvalent sera: The MAb 4.5A5 was found to react with erythroblasts only. The MAb 4-M-12-26 reacted with tsAEV erythroblasts shifted to the non-permissive temperature (42 degrees C). The MAb 4.6C1 reacted weakly with erythroblasts and strongly with reticulocytes. The anti-Ery sera reacted with reticulocytes and erythrocytes. In addition the reactivity of MAb 4-M-12-26 was found only on virus-producing erythroblasts, though this MAb was found to react with myeloid cells which produce a helper virus of the same class.