Immunological cross reactivity between Schistosoma mansoni and cholera toxin

Abstract

Intranasal administration of schistosome antigens in combination with appropriate adjuvant may be an effective route for immunization against schistosomes, since the lungs represent an important site of elimination of schistosomulae. Our previous studies have shown that in mice intranasal administration of cholera toxin (CT) before infection with Schistosoma mansoni results in an enhancement of the worm burden in comparison to nontreated infected animals. In the present study, it was shown that mice treated intranasally with CT displayed high numbers of schistosome-reactive IgM-secreting cells in the spleen as well as high levels of schistosome-reactive serum IgM antibodies, whereas no significant immunological response against two other antigens, ovalbumin (OVA) or keyhole limpet haemocyanin (KLH) was noted. Sera from mice treated intranasally with CT recognized a 22 kDA antigen on SWAP blots. This band was not demonstrable after absorption of the sera with SWAP. These findings indicate a possible cross reactivity between cholera toxin and schistosome antigens. Further analysis by Western blot revealed that a 22 kDa antigen was detected on CT blots by sera from mice and humans infected with S. mansoni. This band was not demonstrable after absorption of the mouse or the human sera with CT. The 22 kDa cross reactive antigen was heat-stable. The antibodies against the 22 kDa antigen were only found within the IgM class but not within other Ig isotypes. Our findings also indicate that the 22 kDa antigen detected by anti-S. mansoni antibodies represents the A1 fragment of the cholera toxin.

Serological Responses among Individuals in Areas Where Both Schistosomiasis and Malaria Are Endemic: Cross‐Reactivity betweenSchistosoma mansoniandPlasmodium falciparum

“…The widespread occurrence of cross-reactive antibodies to P. falciparum and S. mansoni infections has not, to our knowledge, been reported elsewhere, although Moser et al [37] showed that patients with malaria were able to recognize the S. mansoni heat shock protein 70 and although both malaria and schistosomiasis are known to induce antibodies to cross-reactive epitopes present on other pathogens. For example, antibodies from S. mansoni-infected patients who did not have fascioliasis recognized Fasciola hepatica antigens [38], whereas antibodies from individuals infected with S. mansoni who did not have cholera recognized cholera toxin [39]. Similar observations were described for reactions in serum from S. mansoni-infected patients to Trichinella spiralis [40], hookworm, and Ascaris lumbricoides [41].…”

Analysis of Immune Responses against T- and B-Cell Epitopes fromPlasmodium falciparumLiver-Stage Antigen 1 in Rodent Malaria Models and Malaria-Exposed Human Subjects in India

“…These results suggest that peptides LS1.1 and LS1.2 may represent sequences that are similar to those in the putative P. berghei LSA-1 or even perhaps in some other P. berghei antigens. However, how these peptides with no apparent sequence homology can cross-react both at the T-cell and B-cell levels is well established (1,21,39).…”

Interaction of Cholera Toxin with Three Life‐cycle Stages of Schistosoma mansoni: Adult Worm, Egg and Cercaria

“…Furthermore, sera from mice and humans infected with S. mansoni recognized a 22‐kDa antigen of CT by Western blot. These findings are indicative of an immunological cross‐reactivity between S. mansoni and CT [13].…”

“…In previous studies, we found that intranasal administration of CT in mice followed by challenge infection with S. mansoni cercariae induced a significant increase in worm burden when compared with PBS‐treated control mice [12]. It was also shown that administration of CT to uninfected mice induced high levels of schistosome‐reactive IgM antibodies [13], recognizing a 22‐kDa antigen on blots of separated soluble adult worm antigen (SWAP). Furthermore, sera from mice and humans infected with S. mansoni recognized a 22‐kDa antigen of CT by Western blot.…”