[Staphylococcus aureus (STA), a B- and T-cell mitogen].

Mitogenesis in peripheral blood lymphocyte and separated T and non-T cells cultures activated with formalin-fixed and heated staphylococcus aureus strain 520 (STA) was studied. The peak of DNA-synthesis in presence of STA is on day 7. The maximum of proliferation was found for T cell on day 7 and for non-T cells on day 3 after stimulation with STA. We found a strong correlation between the expression of CD25 antigen and the 3H-thymidine incorporation. It is concluded that B and T cell proliferation can be studied without purifying the cells using the different proliferation kinetics in presence of STA.