Mitogenic responsiveness of mouse, rat and human lymphocytes to Staphylococcus aureus cell wall, teichoic acid, and...

The mitogenic activity of Staphylococcus aureus peptidoglycan (PG), teichoic acid (TA) and cell wall (CW, a PG-TA complex) for mouse, rat and human lymphocytes was determined by measuring DNA synthesis. At optimal concentrations PG was the most potent mitogen, inducing maximum stimulation of mouse spleen lymphocytes on day 2 of culture, rat spleen lymphocytes on day 3, rat lymph node cells on day 2, human peripheral blood lymphocytes on day 5, and human cord blood lymphocytes on day 4. CW was less mitogenic than PG for mouse splenocytes and human peripheral and cord blood lymphocytes, with maximum stimulation occurring on days 2, 6 and 5, respectively. CW was not mitogenic for rat lymphocytes, and TA was not mitogenic for mouse, rat and human lymphocytes. At high concentrations CW and TA were cytotoxic, as indicated by markedly reduced thymidine uptake and low viability. PG was not toxic to lymphocytes. Our results suggest that TA when bound to PG can at high concentrations mask the mitogenic activity of PG and render CW cytotoxic.