PWM treatment increases the susceptibility of primary myeloma cells to cell-mediated cytolysis
| Target Cell . | Number of Effectors . | Percentage Lysis Without PWM . | Percentage Lysis With PWM . | Increase in CD9 . |
|---|---|---|---|---|
| MM1 | 4 | 1 ± 0.9 | 8 ± 3.4 | Yes |
| MM2 | 6 | 2 ± 2.7 | 11 ± 5.2 | Yes |
| MM3 | 5 | 1 ± 1.7 | 1 ± 1.4 | No |
| MM4 | 3 | 0 | 19 ± 3.0 | Yes |
| MM5 | 3 | 5 ± 3.5 | 40 ± 11.6 | Yes |
| MM6 | 2 | 3 ± 0.7 | 16 ± 0.7 | Yes |
| MM7 | 6 | 1 ± 2.0 | 27 ± 11.8 | Yes |
| CLL1 | 3 | 4 ± 2.8 | 22 ± 3.5 | Yes |
| Target Cell . | Number of Effectors . | Percentage Lysis Without PWM . | Percentage Lysis With PWM . | Increase in CD9 . |
|---|---|---|---|---|
| MM1 | 4 | 1 ± 0.9 | 8 ± 3.4 | Yes |
| MM2 | 6 | 2 ± 2.7 | 11 ± 5.2 | Yes |
| MM3 | 5 | 1 ± 1.7 | 1 ± 1.4 | No |
| MM4 | 3 | 0 | 19 ± 3.0 | Yes |
| MM5 | 3 | 5 ± 3.5 | 40 ± 11.6 | Yes |
| MM6 | 2 | 3 ± 0.7 | 16 ± 0.7 | Yes |
| MM7 | 6 | 1 ± 2.0 | 27 ± 11.8 | Yes |
| CLL1 | 3 | 4 ± 2.8 | 22 ± 3.5 | Yes |
Freshly isolated primary myeloma cells from 7 patients and tumor cells from 1 patient with CLL were cultured with or without 1% PWM for 3 days and then used as targets in 51Cr-release assays. Effector cells were IL-2–stimulated PBMCs from normal donors. E:T ratios were 30:1. The data represent the mean ± SD of the percentage of lysis values for the number of effectors tested with each tumor target. The ability of PWM to increase cell surface CD9 expression in the tumor cells by a minimum of 25% by fluorescence-activated cell sorter (FACS) analysis is indicated.