Proteins of 30 and 36 kilodaltons, membrane constituents of the Staphylococcus aureus L form, induce production of tumor necrosis factor alpha and activate the human immunodeficiency virus type 1 long terminal repeat

We have previously demonstrated that the membrane of the Staphylococcus aureus L form induced tumor necrosis factor alpha (TNF-alpha) from murine macraphages. In this study, we purified two proteins which induce TNF-alpha production from a human monocytic cell line, THP-1, and murine macrophages. These molecules were purified from delipidated membranes by deoxycholic acid extraction, two-step anion-exchange chromatography, and preparative electrophoresis. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of the purified proteins showed for each a single band with a molecular mass of 30, and 36 kDa, These proteins were heat stable, Polymyxin B did not affect the production of TNF-alpha induced by these proteins, Furthermore, these proteins induced comparable levels of TNF-alpha in bath lipopolysaccharide-responsive and -nonresponsive mouse macrophages. Pretreatment of murine macrophages with gamma interferon enhanced 30- and 36-kDa protein-mediated TNF-alpha production, The 30-kDa protein showed lethal toxicity to D-galactosamine-treated mice. The 30- and 36-kDa proteins stimulated the human immunodeficiency virus type 1 long terminal repeat in a monocytic cell line but not a T-cell line, This effect appeared to be mediated through the induction of nuclear factor kappa B. These results indicate that the 30- and 36-kDa proteins, membrane constituents of the S. aureus L form, may play a role in S. aureus infection and/or in human immunodeficiency virus type 1-infected individuals.