Measurement of binding specificity between T cell lymphomas and murine leukemia viruses

A murine retrovirus induces proliferation of unique lymphoid cell lines expressing T-cell-receptor structures utilizing common variable region alpha and beta chain genes

A murine radiation leukemia virus (RadLV) has been shown to induce in vitro proliferation of an unusual subset of lymphoid cells from spleen. They have the unusual property of expressing CD3/T-cell receptor alpha and beta chains (TCR-alpha beta) in the absence of other T-cell markers such as Thy-1, CD4, and CD8. Cell lines induced in two mouse strains with RadLV produced by the C6VL/1 thymoma all specifically utilize common V alpha 3 and V beta 8.2 variable region genes in the formation of a TCR structure. Each of these cell lines has now been found to express both class I and class II major histocompatibility antigens and the beta 2 integrin specific for spleen dendritic cells. Analysis of functional properties of these cells has revealed a subset that can endocytose proteins and function alone as antigen-presenting cells. They have therefore been called D-T cells (i.e., dendritic cells expressing TCR-alpha beta). A retroviral-driven event has been implicated in the proliferation of dendritic-like cells expressing a common TCR epitope.

Preferential expression of a common T cell receptor structure by T cells induced to proliferate in vitro with a murine retrovirus

We have successfully isolated continuous T cell lines from murine spleen which have been induced to proliferate after in vitro exposure to the murine leukemia virus RadLV. Cell lines isolated from several strains of mice have an "immature" phenotype and are immortalized CD4- CD8- CD3+ cell lines. Cell lines of similar phenotype have now been derived from many individual mice, after spleens have been infected with two different RadLV viruses, a leukemogenic and a nonleukemogenic isolate. Among cell lines induced with RadLV/C6VL, an unusually high proportion of cells was found to bind the 124-40 anticlonotypic antibody specific for the alpha beta TCR expressed by C6VL/1 cells which produces RadLV/C6VL. This was not reflected in cell lines induced with the RadLV/V13 isolate nor in various lymphocyte subsets freshly isolated from normal mice, or induced to proliferate in culture. Cells expressing a common TCR structure would appear to be appropriate targets for in vitro proliferation and transformation induced by RadLV.