The tumor lines have the same immunoglobulin V_H rearrangement as tumor biopsy cells.

DNA was prepared from lung biopsy cells and from the spontaneous lines that grew from patient peripheral blood before and after CTL infusion. Controls were ML-1 and BJAB, which are B-cell lymphoma lines; the donor LCL; and a T-cell line KB (germline). DNAs were digested withBglII, separated on a 0.8% agarose gel, transferred to a nylon membrane, and probed with a J_H probe. Identical bands in the pre- and post-CTL LCLs and the tumor biopsy cells shows that all 3 are derived from the same cell. The additional band in the tumor biopsy cells probably represents the germline immunoglobulin DNA (arrow) in non-B cells in the tumor tissue.