T-cell receptor gene rearrangement in B-cell non-Hodgkin's lymphoma: correlation with methylation and expression

Two of 19 B-cell non-Hodgkin's lymphoma (NHL) were found to have clonally rearranged T-cell receptor (TCR) beta chain genes with a germline TCR-gamma gene configuration. The inappropriate rearrangements had a similar structure to the TCR-beta rearrangements described in B-cell chronic lymphocytic leukemia. All cases analysed displayed a consistent germline transcription of TCR-beta and alpha chain genes which was independent of rearrangement. Consistent with this, all cases showed some degree of hypomethylation of the TCR-beta chain locus similar though distinguishable from the pattern seen in mature T cells, but quite different from that seen in normal mature B cells. Taken together, these data suggest that most NHL's arise from an immature B-lymphocyte precursor at a stage of differentiation where lineage commitment is incomplete.