Differentiation properties of avian tumor cell lines: analysis using chicken fetal antigen and other markers.

Three avian lymphoblastoid tumor cell lines were compared for the expression of the serologically complex cell surface antigen, chicken fetal antigen (CFA), and other properties associated with differentiation. Two Marek's disease cell lines (CU-12 and CU-36) and a cell line associated with lymphoid leukosis (CU-10) were all found to differ qualitatively in the expression of CFA. While both Marek's disease cell lines exhibited overall phenotypes similar to those of T-lymphocytes, the lymphoid leukosis cell line possessed characteristics in common with either immature lymphocytes or cells of the reticuloendothelial system. The specific patterns of CFA expression on these lymphoid tumor cells may be related to the particular level of differentiation blockage during tumorigenesis as has been proposed for erythroblastosis. The lymphoid leukosis cell line exhibited a pattern of CFA expression that would not distinguish between the possibility of differentiation blockage versus retrogenic expression. Since CFA is known to be associated with a series of cell surface glycoproteins, the exact relationship between individual molecules, the level of lymphoid differentiation, and changes associated with tumorigenesis may now be examined.