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Blockade of macrophage migration inhibitory factor (MIF) in Schistosoma japonicum ‐infected mice results in an increased adult worm burden and reduced fecundity
Author(s) -
Stavitsky Abram B.,
Metz Christine,
Liu Shifan,
Xianli Jia,
Bucala Richard
Publication year - 2003
Publication title -
parasite immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 75
eISSN - 1365-3024
pISSN - 0141-9838
DOI - 10.1046/j.1365-3024.2003.00641.x
Subject(s) - macrophage migration inhibitory factor , biology , immune system , immunology , antibody , schistosoma japonicum , cytokine , schistosomiasis , splenocyte , schistosoma , tumor necrosis factor alpha , schistosoma mansoni , helminths
SUMMARY Macrophage migration inhibitory factor (MIF), a cytokine produced by many cell types, modulates cellular and humoral immune responses. In schistosomiasis, ova in the portal circulation induce a delayed type hypersensitivity (DTH) that results in formation of hepatic granulomas (HG) which secrete MIF activity. Therefore, we hypothesized that endogenous MIF modulates immune responses in schistosomiasis. To test this hypothesis, Schistosoma japonicum ‐infected mice were injected with rabbit IgG or neutralizing rabbit IgG antibody to MIF 4·5–6·5 week post infection when HG form and female worms are laying eggs. Compared with controls, 6·5–7‐week post‐infection, antibody‐treated mice had 1·7–3 times as many adult worms and half as many ova per worm pair in their livers. In contrast, antibody introduced before infection or 6–8 week post infection did not affect worm burden or fecundity. Thus, for the first time there is evidence that 4·5–6 week post‐infection endogenous MIF somehow mediates reduction of adult worm burden and promotes fecundity. Splenocytes and HG cells from antibody‐treated mice showed reduced intracellular expression of TNFα and/or IL‐10. We hypothesize that endogenous MIF enhances adult worm attrition by up‐regulating innate and adaptive immune responses by increasing expression of MHC‐II, co‐stimulatory, adhesion, receptor and cytokine molecules, and promotes fecundity by up‐regulating TNFα expression.