Inflammatory antigens of Brugia malayi and their effect on rodent host Mastomys coucha

SUMMARY The study was aimed at identifying pro‐ and anti‐inflammatory cytokine releasing potential of Brugia malayi adult worm fractions and their role in filarial infection and pathogenesis. THP‐1 cells were incubated with soluble somatic Brugia malayi adult worm extract (BmAS) and its Sephadex G‐200 fractions BmAFI, BmAFII and BmAFIII and the effect of the fractions on parasitological, immunological and lymph node parameters was assessed in Mastomys coucha. BmAFII stimulated the pro‐inflammatory TNF‐α, IL‐1β and IL‐6 release; IL‐10 release was insignificant. Sensitization of animals with BmAFII and subsequent intraperitoneal implantation of worms enhanced CMI response. BmAFII also increased lymph node weight and cellularity, stimulated lymph node mast cells and eliminated intraperitoneally instilled worms. BmAFI stimulated several folds more release of IL‐10, whereas TNF‐α release was negligible. Sensitization with BmAFI elicited low CMI responses, moderately stimulated mast cells and facilitated survival of implanted adult parasites. Fifty percent of naive animals exposed to BmAFI showed oedematous lymph nodes and increased node weight. NCP‐bound molecules corresponding to BmAFI and II showed cytokine‐stimulating potential in vitro. It is concluded that BmAFII is protective and stimulates pro‐inflammatory cytokines, whereas BmAFI facilitates parasite survival and stimulates IL‐10.