Blockade ofSalmonella enteritidisPassage across the Basolateral Barriers of Human Intestinal Epithelial Cells by Specific Antibody

Abstract

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 inhibitionof 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.

Identification of Antiadhesive Fraction(s) in Nonimmunized Egg Yolk Powder: In Vitro Study

“…Such observations agree with the reported results (23) even if in the present assay's nonspecific IgY was used. In the cited in vitro study of adhesion (23), the anti-S. enteritidis antibodies were unable to completely block the adhesion of Salmonella, and the antibody binding did not suppress the multiplication of bacteria inside the cells.…”

IgY: A promising antibody for use in immunodiagnostic and in immunotherapy

“…Four weeks after the bacterial challenge, hens were given daily a supplemented feed of 15% (w/w) of either non-immunized egg yolk powder or immunized egg yolk powder for 28 days. Oral administration of both powders resulted in a rapid decrease in the number of S. enteritidis in faeces and an elimination of the organism after 2 weeks of feeding (Brady et al, 2002;Sugita-Konishi et al, 2000).…”

Protection of epithelial cells from Salmonella enterica serovar Enteritidis invasion by antibodies against the SPI-1 type III secretion system

“…In one study, it was revealed that sera against Salmonella Enteritdis LPS, but not flagella, prevented entry of the bacterium in Hep-2 cells (Iankov et al 2002). The use of polarized Caco-2 and T84 cells demonstrated that invasion was inhibited by antisera to both Salmonella Enteritidis flagella and formalin-inactivated Salmonella Enteritidis (Sugita-Konishi et al 2000). Similarly, antibodies against Salmonella Typhimurium LPS have blocked S. Typhimurium invasion in MDCK cells (Michetti et al 1994;Forbes et al 2008).…”