Belosevic M, Daniels CW. Phagocytosis of Giardia lamblia trophozoites by cytokine-activated macrophages.
Clin Exp Immunol 1992;
87:304-9. [PMID:
1735194 PMCID:
PMC1554267 DOI:
10.1111/j.1365-2249.1992.tb02992.x]
[Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Phagocytosis of Giardia lamblia trophozoites by cytokine-activated and non-activated bone marrow-derived macrophages was examined in vitro. Macrophages treated with recombinant interferon-gamma (IFN-gamma) and bacterial lipopolysaccharide (LPS) ingested a significantly higher number of in vitro-grown trophozoites than untreated macrophages. Maximal uptake of parasites occurred after 4 h and 6 h of incubation where 81.4% and 79.1% of macrophages were positive for trophozoites. Other cytokines tested, IL-2, IL-3, IL-4, IL-5, GM-CSF, CSF-1 and tumour necrosis factor-alpha (TNF-alpha) either alone or in combination with LPS, failed to activate macrophages to phagocytose G. lamblia. The induction of this activated macrophage anti-microbial function was achieved pharmacologically using phorbol myristate acetate (PMA) and ionophore A23187. The giardicidal activity of macrophages activated with IFN-gamma and LPS or that induced by PMA and A23187 was inhibited by H-7, indicating the role for protein kinase C in the intracellular events following activation.
Collapse