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 enteric a serovar enteritidis was studied by immunizing chickens with liposome-asso ciated antigen. An ultrasonicated whole cell extract of the bacteria was us ed for immunizing antigen. Intraocular immunization induced serum IgA, IgG and IgM responses. Also, significant IgA and IEC antibodies were detected i n the intestinal tract. Immunization with antigen alone induced only IgG re sponse in the intestine. Salmonella enteritidis-specific antibody-secreting lymphocytes were detected in the spleen and lamina propria of the intestin al tract of immunized chickens. Immunoglobulin tig) fractions extracted fro m intestines of immunized chickens inhibited the adherence of S. enteritidi s to cultured HeLa cells. These results indicate that intraocular immunizat ion with liposome-associated S. enteritidis elicits specific antibody-produ cing lymphocytes in the intestinal tract, and that Ig secreted in the intes tine inhibits adherence of the bacteria to intestinal epithelial cells, sup pressing the spread of bacterial infection in the host. (C) 2001 Elsevier S cience Ltd. All rights reserved.