T-Cell Receptor and Immunoglobulin Genes Are Rearranged Together in Abelson Virus-Transformed Pre-B and Pre-T Cells

Abstract

We have assessed the state of rearrangement and expression of B- and T-cell antigen receptor genes in cells of Abelson murine leukemia virus-transformed thymomas and other tumors. We found that unrearranged TcRγ genes are expressed, as are unrearranged Cµ genes, in pre-T, pre-B, and myeloid cells. We also found TcRγ genes rearranged and expressed in putative pre-T cells and in cells apparently committed to the B-cell lineage. This is in contrast to the data from more mature T- and B-cell tumors. We conclude that in immature lymphoid cells both immunoglobulin and TcRγ genes are accessible for rearrangement. We discuss the implications of these observations for an understanding of the B-T lymphoid differentiation event.