EN
The antibody responses in resistant (BALB/c) and susceptible, C57BL/10 (BIO) mice to enteral-parenteral and enteral phases of infection with Trichinella spiralis were investigated by ELISA. Generally, IgG and IgA antibodies in both strains of mice remain at low levels during first two weeks of infection. An increase in IgA antibody at mucosal level and in serum was evident in B10 mice during the third week of infection. However, these data indicate genotype dependent IgA response both at mucosal level and in serum. Independently of the route of T. spiralis antigen exposure, B10 mice produced high level of IgA antibody in the second and third weeks of infection. Immunoblotting was used to analyse the components of the two antigen (AgL1 and AgAd) preparations recognized by IgG and IgA from sera, or IgA from intestinal lumen samples (ILS) of infected mice. In both strains of mice the antigen recognition profiles of the two analysed antigens were different for specific IgA in ILS and IgG or IgA in sera. Characteristically, in B10 mice infected by enteral-parenteral route specific IgA response to AgL1 was aggregated in low molecular weight (33-38 kDa) components, whilst enteral infection stimulated IgA responses at the mucosal level by higher molecular weight components (62-67 kDa).