RÉSUMÉ
Porcine transfer factor(TF-P) was prepared from porcine spleen by means of hom-ogenization and vaccum dialysis. Fractionized by Sephadex G-10 gel chromatography,TF-P could be separated into seven fractions but five fractions were obtained from human transfer factor(TF-h) .These fractions of TF-P and TF-h and different dilutionsof TF-P were tested for biological activity in vitro. By the use of ~3H-TdR uptake assay we found that, both of whole TF-P and TF-hpossessed suppresivs activity to PHA-induced human periperal blood lymphocyte tran-sformation. Whereas, Fraction Ⅲ of TF-P and Fraction Ⅲ and Ⅳ of TF-h containedcomponents responsible for augmentation of PHA-induced responses. When TF-P was diluted 10~(-2) to 10~(-5) and cultured with normal human peripheralblood lymphocytes, we found that the original suppression effects of whole TF-P toPHA-induced lymphocyte transformation were converted to normal. The optimum dil-ution of TF-P was 10~(-3), which were shown to augment responses. It shoud be notedthat the responsiveness of normal human lymphocytes to TF-P was dose dependent.