Analysis of TCR and immunoglobulin gene rearrangements in EBV-transformed T cells. (A) EcoRI digested NC5 (lane 2) and TC (lane 3) DNA and control DNA from purified non-T, non-B human peripheral mononuclear cells (lane 1), monocytic cell line U937 (lane 4), EBV-LCL (lane 5), purified peripheral blood T cells (lane 7), and T-cell lymphoma Jurkat (lane 8) were analyzed with a 496-bp human Cβ1 cDNA probe. The sizes of the Cβ-germline restriction fragments obtained from non-T cells were 12 and 4.2 kb for Cβ1 and Cβ2, respectively (large arrows). The additional rearranged band (small arrows) of approximately 10 kb detected in EBV-transformed T cells (lanes 2 and 3) and in Jurkat cells (lane 8) showed the clonality of these cell populations, whereas in polyclonal purified T cells from peripheral blood, the mixture of all possible rearrangements is shown by a smear (lane 7). The molecular weight markers (MW II; Boehringer Mannheim) were loaded in lane 6. (B) The rearrangement of immunoglobulin heavy chains was analyzed by using primers specific for the VJ region of immunoglobulins amplifying a 105-bp fragment of DNA from an EBV-LCL (lane 5), the EBV-transformed T cell NC5 (lane 6), the EBV-transformed T cell TC (lane 7), or Jurkat cells (lane 8). To control for DNA integrity primers amplifying a 350-bp fragment inside an exon of the Cμ heavy chain region (lanes 1 to 4) or primers amplifying a 250-bp inside an exon of the Cβ chain of the TCR (lanes 8 to 12) were used on the DNA from an EBV-LCL (lanes 1 and 9), the EBV-transformed T cell NC5 (lanes 2 and 10), the EBV-transformed T cell TC (lanes 3 and 11), or Jurkat cells (lanes 4 and 12).