Interaction between Taenia taeniaeformis and the complement system
Hammerberg, B.; Williams, J.F.
Journal of Immunology 120(3): 1033-1038
1978
ISSN/ISBN: 0022-1767 PMID: 632577 Document Number: 132314
Cystic bladder fluid was collected from larvae in the livers of rats 3 to 5 months after infection with 500 Taenia taeniaeformis eggs. Larvae from some infected rats were dissected free and incubated in culture medium for 24 hours. After concentration by dialysis against Carbowax both culture medium and bladder fluid interacted with the complement system (C) in vitro and in vivo. This interaction resulted in the depletion of haemolytic C in normal serum of several species, the generation of anaphylatoxin-like activity in vitro, the conversion of C3, and changes in vascular permeability. The substances appeared to initiate C fixation non-immunologically. Intravenous administration of parasite factors in rats led to marked depression of circulating complement and the rats did not become refractory to this effect after repeated dosing over a 3-week period. Circulating haemolytic complement was not altered in infected rats over the first 8 weeks of infection. C-dependent inflammatory responses in the skin of rats were inhibited in animals given intravenous doses of parasite factors. Local consumption of complement around the cestode could contribute to its successful evasion of inflammation and immune rejection during infection.