Effect of the PA-MSHA vaccine on septic serum-induced inflammatory response.

Sepsis is defined as a complex clinical syndrome caused by a serious infection followed by an amplified and deregulated inflammatory response. The complex syndrome is associated with a high rate of morbidity and mortality, despite substantial clinical advances. A vaccine derived from the outer membrane proteins of the Gram-negative bacteria Pseudomonas aeruginosa (PA-MSHA) has been demonstrated to exhibit immune modulatory properties. In the present study, the effect of the PA-MSHA vaccine on the inflammatory response induced by serum from septic patients in peripheral blood mononuclear cells was determined. It was observed that PA-MSHA pretreatment inhibits the production of septic serum-induced tumor necrosis factor-α. In addition, PA-MSHA treatment increases interleukin-10 levels and promotes the generation of CD4+CD25+Foxp3+ T cells. Thus, the results of the current study provide mechanistic insight relevant to the potential application of PA-MSHA in the treatment of sepsis.