Myeloma cell lines display enhanced susceptibility to lysis mediated by IL-2–activated PBMCs after PWM treatment; nonmyeloma cell lines are not significantly affected by PWM treatment.

(A) Myeloma cell lines MER, COL, RAM, ARK, ARD-2, and RLO were cultured with or without 1% PWM for 3 days and then used as targets in standard 4-hour ⁵¹Cr release assays. The E:T ratio was 30:1. The data represent mean values ± SEM of 3 individual experiments. (B) T-cell lines MOLT-4, Jurkat, 8402, HSB2, and CEM, as well as the erythroleukemia cell line K562, were used as targets in standard 4-hour⁵¹Cr release assays. Cells were treated with or without 1% PWM for 3 days. The E:T ratio was 30:1. The data represent mean values ± SEM of 3 individual experiments. Asterisk indicatesP < .0001; plus sign, P < .01.