Dynamics of the IgG3 responses following immunisation of BALB/c mice with somatic and excretory/secretory antigens from various Trichinella species.

Comparison of the dynamics and antigen recognition profiles of IgG3 following immunisation with larval crude extracts (LCE) and excretory-secretory (ES) products from muscle larvae of different species of Trichinella (T. spiralis, T. nativa, T. britovi, T. nelsoni and genotype T6) was made in BALB/c mice. High levels of gG3 response were obtained in ELISA following immunisation with LCE from all species with maximum levels achieved between days 59 and 64 post-immunisation (p.i.) and maintained up to the limit of the observation (day 164). Antigen recognition profiles as measured by western-blot showed dense and numerous bands in the range 45-64 kDa that were consistent from week 5th with variation in epitope recognition among the different species. Following immunisation with ES antigens a significant decrease in IgG3 response was observed for all species especially for T. nativa in comparison to LCE. Antigen recognition on ES antigens showed three main bands in the range of 45-60 kDa for all species excepting T. nelsoni and T. britovi where an additional band was also present. These results clearly show that IgG3 epitopes are more abundant in somatic (LCE) than in ES products of Trichinella muscle larvae and that quantitative as well as qualitative variations exist among different species.