Host genetics and resistance to acute Trypanosoma cruzi infection in mice. I. Antibody isotype profiles

Abstract

Some strains of inbred mice survive acute infection with Trypanosoma cruzi while others die within a few weeks after infection. Mice which express B10 background genes and either the H-2q or H-2d haplotypes are resistant and survive. However, mice which share the B10 genetic background but express H-2k alleles die, usually within 4 weeks following infection. These data confirm that at least 1 gene in the major histocompatibility complex can determine whether an animal lives or dies during the acute phase. Expression of the H-2q haplotype on the B10 genetic background or in DBA/1 mice is associated with resistance, but H-2q mice expressing the C3H background are susceptible. Therefore, at least 1 gene in the genetic background also influences resistance. Our data suggest that genes associated with resistance must be present in both the MHC and the genetic background or the animal will die. The isotypes and specificities of parasite reactive antibodies found in the serum of different inbred mouse strains were assessed during acute infection. Levels of IgM were higher in sera from mice which express the resistant B10 background than in sera from mice expressing the susceptible C3H background. Conversely, mice which share the C3H background genes produced high levels of anti-parasite IgG2a when compared to B10 congenic strains. Antigen specificity, however, may be influenced by both background and MHC genes, as congenic strains expressing different MHC haplotypes recognized different constellations of T. cruzi antigens.(ABSTRACT TRUNCATED AT 250 WORDS)

Curcumin Enhances the Anti-Trypanosoma cruzi Activity of Benznidazole-Based Chemotherapy in Acute Experimental Chagas Disease

“…Although the production of IgG2a is predominant in the humoral response against T. cruzi, similar lytic activities of IgG2a and IgG1 have been previously reported; these antibodies have been shown to be the major effector molecules that control parasitemia (37,42). However, high IgG1 levels are not always beneficial to the host, since IgG1 can block the activities of different isotypes of anti-T. cruzi antibodies through cross-linking with irrelevant antigens in the defense against the parasite, thus deflecting humoral immunity toward a nonspecific and ineffective response (37,43). According to previous investigations (26,44), the attenuation of the humoral response observed in this study is consistent with the best parasitological control and reduction of the parasite load induced by the cruzi and treated with benznidazole and curcumin.…”

Cytokine responses in mice infected with Clonorchis sinensis

“…However, to determine whether IL-12 has a direct role in the productive immunity in C. sinensis-infected mice, future studies are needed. Several studies have suggested that both the levels and kinetics of cytokine production could be genetically regulated, and that at least one gene within the major histocompatibility complex (MHC) influences resistance and susceptibility in Trypanosoma cruzi-infected mice (Powell and Wassom 1993). A recent study reported that SC from C3H mice that express the resistant H2q haplotype produced significantly higher levels of IFN-c than did cells from B10 mice that share the susceptible H2k haplotype in T. cruzi-infected mice (Eksi et al 1996).…”

Anti-Trypanosoma cruziImmunoglobulin G1 Can Be a Useful Tool for Diagnosis and Prognosis of Human Chagas' Disease

“…Several studies have demonstrated that different clinical manifestations are associated with a distinct and complex hostparasite relationship with direct involvement of the immune system (23). The long-lasting nature of the asymptomatic chronic phase strongly suggests an effective participation of modulatory events that would allow the establishment and maintenance of the IND clinical form.…”