Blockade of Salmonella enteritidis passage across the basolateral barriers of human intestinal epithelial cells by specific antibody

Antibodies specific to Salmonella enteritidis (S.E.) were obtained from immunized egg yolk, and their protective effects against S.E. were studied by using monolayer-cultured human intestinal epithelial cells, Caco-2 and T84. The Salmonella adherence and entry to the cells were partially inhibited by the antibodies. The antibodies inhibited the decrease in transepithelial electrical resistance (TEER) of the intestinal epithelial monolayers and IL-8 secretion of the cells induced by S.E. invasion. Also, the antibodies blocked the penetration of bacteria through the cell layer although they did not inhibit the growth of bacteria in the cells. Confocal microscopic photographs revealed the bacteria in the infected monolayer cells were bound to antibodies. These results indicate that anti-S.E. antibodies may protect the cells from destruction induced by S.E. invasion in intestinal epithelial cells in addition to the partial inhibition of adhesion and invasion of S.E. at the cell surface. Passive antibodies against invasive bacteria would be useful to prevent the migration of S.E. to blood not only at the cell surface but also inside of intestinal epithelial cells.