Suppression of Staphylococcus aureus Cowan I-induced immunoglobulin synthesis in vitro: discrimination between the presence of suppressor T cell precursors and effectors.

In co-cultures with control cells lymphocytes obtained from some patients with hypogammaglobulinaemia can suppress PWM but not S. aureus Cowan I-induced polyclonal immunoglobulin production. When such co-cultures were stimulated at the same time with both mitogens, the response was greatly suppressed. This phenomenon was further studied in cultures of lymphocyte populations isolated from healthy donors. It was found that suppressor T lymphocytes activated by PWM in cultures co-stimulated with Con A, with high T:B cell ratio, or with an increased proportion of OKT8+ T cells can suppress the S. aureus-induced response. In contrast, under the same conditions S. aureus did not activate suppressor cells. Moreover, in cultures stimulated with this polyclonal B-cell activator OKT8+ lymphocytes could serve as helper cells.