Humoral immune responses in mice infected with gamma-irradiated third-stage larvae of Angiostrongylus cantonensis.

Abstract

Humoral immune responses in C57BL/6 strain mice infected with 1.0 kGy gamma-irradiated third-stage larvae (L3) and with non-gamma-irradiated L3 of Angiostrongylus cantonensis were assessed in this study. The young-adult worm (L5) antigen-specific antibodies in sera of both groups of mice elevated gradually and reached a peak in the third week after infection. The IgM antibodies of mice 1-week after infection with gamma-irradiated L3 and with non-gamma-irradiated L3 recognized several L5 antigens of the same molecular weight. However, only partially identical profiles were observed in the reaction of L5 antigens with IgM and IgG antibodies from mice 3 weeks after infection with gamma-irradiated L3 and with non-gamma-irradiated L3 respectively by western blot analysis. With regard to antibody-dependent cell-mediated cytotoxicity, antibodies from 3-week infected mice significantly increased the adherence of mouse eosinophils and neutrophils to L3 of A. cantonensis. The immunoresponses of splenic cells from mice in the third week of infection to sheep red blood cells were suppressed because the number of plaque forming cells obviously decreased more than the uninfected control.