Effect of HMCLs and fresh purified MM cells on IFN-γ secretion by T lymphocytes.

Soluble IFN-γ levels were detected by ELISA in aliquots of conditioned medium of activated CD3⁺ T lymphocytes cocultured with HMCL RPMI-8266 or U266 in a transwell system for 48 hours (A) and in aliquots of conditioned medium of activated (B) and nonactivated (panel C) autologous T lymphocytes cocultured with fresh MM cells; C indicates nonactivated CD3⁺ cells. Graphs represent the mean levels ± SE of 6 repeated experiments. *P < .05; **P < .01.