Identification of oligoclonal CD4 T cells in diffuse large B cell lymphomas

Human B cell lymphomas often contain CD4 T cells. Here we show that, in diffuse large B cell lymphomas (DLCL), such T cells are oligoclonal. The CDR3 lengths and nucleotide sequences of oligoclonal TCRBV of CD4 T cells in an original and relapsed lymphoma from one patient were compared. Three BV23 sequences were identical (12/17 and 16/16 clones in primary and relapsed lymphomas, respectively), but were absent in CD4 T cells from another patient's DLCL. Two of the repetitive BV23 sequences were found in peripheral blood CD4 T cells (5/17 clones); gamma-irradiated DLCL from this patient stimulated syngeneic BV23 response in CD4 cells (92% of BV23 had the same CDR3 length). Skew in TCRBV representation was observed in CD4 T cells from all the DLCL. One DLCL, with overrepresentation of BV13S1 in CD4 cells, stimulated the same TCR in CD4 cells from three unrelated individuals. These findings support the conclusion that there is clonal selection of CD4 T cells in DLCL.