title: Concomitant immunity in a rodent model of filariasis: the infection of Meriones unguiculatus with Acanthocheilonema viteae.
abstract: In an attempt to study the occurrence of concomitant immunity in filarial infections, jirds (Meriones unguiculatus) were experimentally infected with Acanthocheilonema viteae, and patent animals were superinfected with a defined dose of A. viteae stage 3 larvae (L3). Infected animals harbored significantly less worms deriving from the superinfection than the control group (P < 0.05, 56.2%, and 63.4% protection), as shown by analysis of female worms 6 wk after superinfection on the basis of their developmental status and their length. This protection was not due to contact with L3 antigens because a significant reduction of worm burdens deriving of a superinfection was also observed after subcutaneous implantation of a single female worm (P < 0.05, 40.2% and 64.9% protection). The induced protective responses target L3 and restrict their migration because an established infection resulted in a reduction of L3 recovery (95.6% and 94.3%, P < 0.001) from tissues of jirds at day 5 after superinfection. Other data show that L3 from a superinfection are trapped within eosinophil-rich granulomas, which is likely to create unfavorable conditions for the worms and to lead to later death. Taken together, established A. viteae-infections partially protect hosts against homologous superinfection by an immune-mediated mechanism and, thus, regulate the population density of the parasites within the host by concomitant immunity.
authors.affiliation: Department of Molecular Parasitology, Institute of Biology, Humboldt-University Berlin, Philippstr. 13, 10115 Berlin, Germany. parasito@rz.hu-berlin.de
authors.forename: Sethu
authors.initials: S
authors.lastname: Rajakumar
authors.forename: Wilfrid
authors.initials: W
authors.lastname: Bleiss
authors.forename: Susanne
authors.initials: S
authors.lastname: Hartmann
authors.forename: Peter
authors.initials: P
authors.lastname: Schierack
authors.forename: Anorte
authors.initials: A
authors.lastname: Marko
authors.forename: Richard
authors.initials: R
authors.lastname: Lucius
mesh_terms: D000818:Animals; D004153:Dipetalonema / Q000276:immunology* / Q000302:isolation & purification; D004154:Dipetalonema Infections / Q000276:immunology* / Q000469:parasitology / Q000635:transmission; D004195:Disease Models, Animal; D005260:Female; D005849:Gerbillinae / Q000276:immunology / Q000469:parasitology*; D007814:Larva / Q000276:immunology; D008297:Male; D011156:Population Density; D018709:Statistics, Nonparametric; D013997:Time Factors