Some T-cell leukemia lines express surface markers related to a restricted set of human V H determinants

Abstract

Serological studies were carried out to obtain information regarding the relationship of the V H-related determinants expressed by certain permanent in vitro T-cell leukemia lines and corresponding determinants expressed by characterized human serum immunoglobulins. A panel of conventional (goat and rabbit) antisera, produced against various Fab-related fragments of monoclonal human Waldenstrom macroglobulins and polyclonal IgG molecules, bound to certain in vitro T-cell leukemia lines, notably, 70-N2, MT-1, YT4E, and HUT78, as shown by microhemagglutination. Inhibition studies using characterized myeloma proteins to inhibit this agglutination indicated the expression of a restricted V H-related determinant by these T-cell lines. Parallel studies performed using conventional (rabbit) and murine monoclonal/hybridoma antibodies produced against the isolated 68,000-Da V H-related product synthesized by the 70-N2 line showed that the determinant expressed by this molecule was restricted in expression, comprising 2–3% of the normal, polyclonal human Fab pool, and that the determinants found on the other positive T-cell leukemias were cross-reactive rather than identical. The inhibition studies suggest that the determinant resides between residue 22 and the end of the V H region. These results further define the antigenic nature of the V H-related marker found on the surfaces of certain normal and neoplastic T-cell lines.