SEPARATION OF MITOGENIC AND PYROGENIC ACTIVITIES FROM SO-CALLED ERYTHROGENIC TOXIN TYPE-B (STREPTOCOCCAL PROTEINASE)

It is well-established that three types of erythrogenic toxins (ETA, E TB, ETC) are produced by Streptococcus pyogenes (group A streptococci) strains. Culture filtrate concentrates from Streptococcus pyogenes st rains T19P (T29, ETA(+), ETB(+), ETC), 27337 (T12, B3264, ETA(-), ETB( +), ETC(+)), 27252 (T4, ETA(-), ETB(+), ETC(+)) und 27195 (T8, ETA(-), ETB(+), ETC(-)) were analyzed by preparative isoelectric focusing. Th ese concentrates and the purified erythrogenic toxin type B (ETB) isol ated by ion exchange chromatography had mitogenic and pyrogenic activi ty. Now, it has been found that the mitogenic activity and the pyrogen ic activity of this ETB can be separated by preparative isoelectric fo cusing in Sephadex gels. This means that ETB is not a superantigen as described in literature. The mitogenic and biological activity is caus ed by traces of ETA (strain T19P), ETC (strains 27252 and 27337) and/o r by unknown mitogen(s) (MX, strain 27195) which preferentially stimul ate V beta 8(+) T cells. The differentiation between ETA (stimulating V beta 12(+) but not V beta 8(+) or V beta 2(+)), ETC (stimulating V b eta 2(+) but not V beta 8(+)), and MX (stimulating V beta 8(+)) was do ne using established leukemic cell lines.