In vitro differentiation of a null-acute leukemia: T-lymphoid surface antigen expression associated with...

We describe a human acute unclassified leukemia with a unique t(4;17) translocation that coexpresses T-lymphoid and myeloid surface antigens after in vitro culture in the presence of the tumor promoter, TPA. Under these conditions, the joining regions of the immunoglobulin heavy chain and T-cell receptor gamma and beta chain complexes remained in germ line configuration. A T-cell receptor beta chain variable gene probe, however, revealed the presence of rearrangements in the V beta M3-2 gene region after bilineage differentiation. These results may be pertinent to the interrelationship of T-cell receptor gene rearrangements and the control of T-cell antigen surface expression.