IgG Antibody responses in mice coinfected with Toxocara canis and other helminths or protozoan parasites

Abstract

SUMMARYThe immune response expressed by IgG antibodies in BALB/c mice experimentally infected with Toxocara canis, was studied with the aim of verifying the possible in vivo cross-reactivity between antigens of T. canis and other parasites (Ascaris suum, Taenia crassiceps, Schistosoma mansoni, Strongyloides venezuelensis and Toxoplasma gondii). Experiments included three groups of mice: one infected only by T. canis, another with one of the other species of parasites and a third concomitantly infected with T. canis and the other species in question. Animals were bled by orbital plexus at 23, 38 and 70 days post infection (p.i.). Sera were analyzed for anti-Toxocara antibodies by ELISA and Immunoblotting, using excretion-secretion antigens (ES), obtained from culture of thirdstage larvae of T. canis. For all experiments a control group comprised by ten non-infected mice was used. Only in the case of A. suum infection, in these experimental conditions, the occurrence of cross-reactivity with T. canis was observed. However, in the case of co-infection of T. canis -S. mansoni, T. canis -S. venezuelensis and T. canis -T. crassiceps the production of anti-Toxocara antibodies was found at levels significantly lower than those found in mice infected with T. canis only. Co-infection with S. mansoni or S. venezuelensis showed lower mortality rates compared to what occurred in the animals with single infections. Results obtained in mice infected with T. canis and T. gondii showed significant differences between the mean levels of the optical densities of animals infected with T. canis and concomitantly infected with the protozoan only in the 23 rd day p.i.

Behavioral changes in Rattus norvegicus coinfected by Toxocara canis and Toxoplasma gondii

“…rats infected with Toxocara canis or Toxoplasma gondii showed significant behavioral changes, similar to the findings of other reports 2,6,7,13 . However, when they were coinfected with both parasites, they showed a behavioral pattern similar to the control group without infection (G4), suggesting a modulation in the behavioral response.…”

“…Recently LESCANO et al 13 showed the occurrence of some delay in the humoral immune response in mice coinfected by Toxocara canis and Toxoplasma gondii when compared to animals infected only by Toxocara canis. On the other hand, in experimental models the interaction among Toxoplasma gondii and other parasites sometimes results in different frames than that observed in single infections 6,11 .…”

Kinetics and avidity of anti-Toxocara antibodies (IgG) in rabbits experimentally infected with Toxocara canis

“…This phenomenon has also been observed in murines, which are considered the experimental model for human toxocariasis. In mice, seroconversion was observed at 7 (OLLERO et al, 2008), 14 (KOLBEKOVÁ et al, 2011 and 23 DPI (LESCANO et al, 2012).…”

Experimental toxocariasis in BALB/c mice: relationship between parasite inoculum and the IgG immune response

“…In the case of T. canis , larvae that induce strong eosinophilic inflammation seem to be unaffected by this reaction, allowing the parasite to survive for several years in different host species (Lescano et al 2012). Mice, tolerating massive T. canis infections for long periods, are considered appropriate models for better understanding of host-parasite relationships in human toxocariasis.…”