Molecular analysis of T cell receptor and CD3 genes in CD3- large granular lymphocytes (LGLs): evidence for the existence of CD3- LGLs committed to the T cell lineage.

Seven patients with CD3- lymphoproliferative disorder of granular lymphocytes (LDGL) were analyzed for rearrangement of the T cell receptor (TCR) delta and alpha as well as gamma and beta genes. Among those patients six showed the germline configuration of all known rearranging TCR genes. Two analyzed patients of them lacked CD3-gamma transcripts and expressed nonfunctional TCR-beta transcripts. Meanwhile, TCR-delta gene rearrangement accompanied by expression of full-length TCR-delta transcripts was observed in one patient with CD3- LDGL. In addition, the cells from this patient transcribed the CD3-gamma gene which is one of the earliest events restricted to cells committed to the T cell lineage. These findings indicate that CD3- LGLs include not only cells belonging to the NK cell lineage but also precursor cells committed to the T cell lineage.