Thymocyte proliferation and maturation in response to staphylococcal lipoteichoic acid

Lipoteichoic acid (LTA) from Staphylococcus saprophyticus strain S1 could be shown to induce thymocyte proliferation and maturation in BALB/c-mice after systemic administration. The increase in thymocyte numbers per mg organ weight was statistically significant. Determination of thymic lymphatic subsets revealed a considerable up-regulation of mature cells expressing helper/inducer (L3T4) or cytotoxic/suppressor (Lyt-2) phenotypes. Thus administration of staphylococcal LTA obviously accelerated murine thymocyte proliferation and maturation. Counts of BALB/c-mouse peripheral blood lymphocytes (PBL) revealed no evident fluctuation within one week after LTA administration, however, statistically significant increases could be detected two weeks after treatment. The determination of activated PBL expressing IL-2 receptors suggested that injection of staphylococcal LTA apparently induced an immunostimulation since those cells were significantly enhanced within one week after LTA administration.