[The effects of serum from tumor-bearing mice on mitogen-induced blastogenesis of normal spleen cells].

: In order to detect the serum immunosuppressive factors of tumor bearer, the effects of normal C3H/He mice serum (NMS), serum from methylcholanthrene induced fibrosarcoma bearing mice (F4w serum) and sera fractionated by high performance liquid chromatography (HPLC) using anion exchange column were examined on mitogen-induced blastogenesis of normal murine spleen cells (Nspc). The addition of 5% of NMS suppressed the blastogenesis of Nspc. Less than 0.6% of F4w serum suppressed the blastogenesis. NMS was applied to HPLC and was separated to four peaks (A,B,C,D). In HPLC pattern of F4w serum, peak B was higher than that of NMS and new peak (E) was observed next to peak D. Peak D of NMS suppressed the blastogenesis. Not peak D but peak E of F4w serum suppressed the blastogenesis. The properties of those blastogenesis-suppressive fractions were discussed.