Intestinal mucosal immune response in chickens following intraocular immunization with liposome-associated Salmonella enterica serovar enteritidis antigen

Induction of intestinal mucosal immune responses against Salmonella enterica serovar enteritidis was studied by immunizing chickens with liposome-associated antigen. An ultrasonicated whole cell extract of the bacteria was used for immunizing antigen. Intraocular immunization induced serum IgA, IgG and IgM responses. Also, significant IgA and IgG antibodies were detected in the intestinal tract. Immunization with antigen alone induced only IgG response in the intestine. Salmonella enteritidis-specific antibody-secreting lymphocytes were detected in the spleen and lamina propria of the intestinal tract of immunized chickens. Immunoglobulin (Ig) fractions extracted from intestines of immunized chickens inhibited the adherence of S. enteritidis to cultured HeLa cells. These results indicate that intraocular immunization with liposome-associated S. enteritidis elicits specific antibody-producing lymphocytes in the intestinal tract, and that Ig secreted in the intestine inhibits adherence of the bacteria to intestinal epithelial cells, suppressing the spread of bacterial infection in the host.