SS2 selectively kills T cells and not B cells.

Splenocytes were stimulated with conA to induce T-cell proliferation or with LPS to induce B-cell proliferation, and then cultured in triplicate with IT. Three days later thymidine incorporation was assayed. (A) SS2 added to T cells and to B cells as control; (B) monomeric IT added in an identical manner. Spontaneous counts were determined for LPS stimulation (mean 864 ± SD 345) and conA stimulation (mean 1 587 ± SD 630). Maximum counts for LPS (mean 11 501 ± SD 2 228) and conA (mean 19 364 ± SD 2 660) were determined. Data are expressed as percentage (%) control response (experimental counts-spontaneous counts per maximum counts-spontaneous counts) × 100.