The mitogenic properties of lipoteichoic acid from Staphylococcus aureus

Lipoteichoic acid (LTA) isolated from Staphylococcus aureus Cowan I induced an in vitro blastogenic response in isolated mononuclear cells (MNC). Seventeen of 20 normal donors responded strongly, with peak response after 3-5 days of incubation. Significant stimulation was also obtained with human cord blood MNC from 3 donors, further indicating that the stimulation was due to a general mitogenic effect. The mitogenicity of deacylated LTA (dLTA) was similar to that of LTA. Binding of LTA to isolated MNC was demonstrated by an indirect immunofluorescent technique staining with specific rabbit anti-LTA antibodies and by rosette inhibition experiments. Results obtained in cell fraction experiments indicated that LTA had a monocyte dependent mitogenic effect on T lymphocytes.