Surfactin inhibits immunostimulatory function of macrophages through blocking NK-kappaB, MAPK and Akt pathway.
Surfactin is one of the most powerful biosurfactants, and is known to have antibiotic, anti-tumor and anti-inflammatory functions. In this study, we investigated the effect of surfactin on antigen-presenting property of macrophages. Thioglycollate-elicited mouse peritoneal macrophages were tested for surface molecule expression, cytokine production, phagocytosis, capacity to induce T cell activation by mixed lymphocyte reaction, and underlying signaling pathways. Surfactin significantly suppressed lipopolysaccharide-induced expression of CD40, CD54, CD80, and MHC-II, but not of CD86 and MHC-I. Surfactin-treated macrophages also exhibited impaired phagocytosis and reduced IL-12 expression. And surfactin markedly inhibited the activation of CD4+ T cells. Impaired translocation and activation of NF-kappaB p65 were founded on macrophages exposed to surfactin. In addition, surfactin inhibited the phosphorylation and degradation of IkappaB-alpha, and suppressed the activation of IKK, Akt, JNK and p38 kinase. These results suggest that surfactin impair the antigen-presenting function of macrophages by inhibiting the expression of MHC-II and costimulatory molecules via suppression of NF-kappaB, p38, JNK and Akt. These novel findings provide new insight into the immunopharmacological role of surfactin in autoimmune disease and transplantation.
Park
Sun Young
SY
Department of Molecular Biology, College of Natural Sciences, Pusan National University, Jangjeon-dong, Keumjeong-gu, Pusan 609-735, Republic of Korea.
Kim
Younghee
Y