The use of an ELISPOT assay to evaluate intestinal and systemic antibody responses to locally administered Entamoeba histolytica antigen in mice.

The local induction of humoral immune response to Entamoeba histolytica trophozoites in the gut has not been studied. This work reports some of our recent studies aimed to induce optimal immune responses against E. histolytica in mice and to describe a novel approach for monitoring mucosal immune responses induced in the gastrointestinal tract and expressed locally and systemically. We have compared the kinetics of both mucosal and systemic primary antibody responses to E. histolytica in the Peyer's patches (PP) and the spleen in Balb/c mice after a single dose of glutaraldehyde fixed amebas (GFA) by intragastric (IG), rectal (R), and intraperitoneal (IP) routes. The number of antibody-secreting cells directed to E. histolytica was assessed by the technique of ELISPOT on nitrocellulose filters. The antibody response to E. histolytica was detected in both PP and spleen with the three routes, indicating that either mucosal or systemic stimulation by GFA generates both types of response. We also determined the total antibody response in intestinal fluids and the antibody secretions from spleen and PP cells in vitro and found differences between male and female mice.