Quantification and isotype analysis of the serum anti-amebic antibody response produced after mucosal and systemic immunization in male and female mice.

It has not been established whether seric antiamebic antibodies are produced after local presence of amebas, or only after they invade the tissues. Therefore, the purpose of this work was to determine if mucosal immunization with glutaraldehyde-fixed trophozoites (GFT) could induce seric anti-amebic antibody responses in mice. We determined by ELISA the quality and quantity of anti-E. histolytica seric antibody responses induced after either a single or multiple doses of GFT by intragastric, rectal and intraperitoneal routes. Seric anti-amebic antibody responses were elicited by both mucosal or systemic immunization although such responses induced via intragastric route were low. However, the responses achieved via rectal route were high, suggesting that the local presence of amebas without mucosal tissue damage is enough to stimulate seric anti-amebic response. The highest seric anti-amebic responses were obtained via intraperitoneal route. The antibody isotype of the induced responses was influenced by the immunization route. The major isotypes produced via intraperitoneal and rectal routes were IgM and IgG. The predominant isotype elicited by intragastric route was IgM whereas the IgA and IgG responses were small and of the same magnitude. The lowest IgA anti-amebic response was produced by intraperitoneal route. In addition, our data show that in general GFT immunization elicits higher anti-amebic antibody responses in female than in male mice.