Filarial infection induces protection against P. berghei liver stages in mice.
Chronic helminth infections such as filariasis in human hosts can be life long, since parasites are equipped with a repertoire of immune evasion strategies. In many areas where helminths are prevalent, other infections such as malaria are co-endemic. It is still an ongoing debate, how one parasite alters immune responses against another. To dissect the relationships between two different parasites residing in the same host, we established a murine model of co-infection with the filarial nematode Litomosoides sigmodontis and the malaria parasite Plasmodium berghei (ANKA strain). We found that filarial infection of BALB/c mice leads to protection against a subsequent P. berghei sporozoite infection in one-third of co-infected mice, which did not develop blood-stage malaria. This finding did not correlate with adult worm loads, however it did correlate with the presence of microfilariae in blood. Interestingly, protection was abrogated in IL-10-deficient mice. Thus, murine filariasis, in particular when it is a patent infection, is able to modify the immunological balance to induce protection against an otherwise deadly Plasmodium infection and is therefore able to influence the course of malaria in favour of the host.
Fernández Ruiz
Daniel
D
Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Sigmund Freud Strasse 25, 53105 Bonn, Germany.
Dubben
Bettina
B
Saeftel
Michael
M
Endl
Elmar
E
Deininger
Susanne
S
Hoerauf
Achim
A
Specht
Sabine
S
D000818:Animals; D005368:Filariasis / Q000276:immunology*; D005370:Filarioidea / Q000276:immunology*; D016753:Interleukin-10 / Q000276:immunology; D008099:Liver / Q000469:parasitology*; D008288:Malaria / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D010962:Plasmodium berghei / Q000276:immunology*
D016753:Interleukin-10