Enterotoxigenic Escherichia coli (ETEC)-induced diarrhoea is the second most commoncause of death in children in the developing countries. Heat labile toxin (LT) is responsible forETEC-induced diarrhoea. In the present study, a novel live ETEC vaccine based on subunitB of LT (LTB) expression in attenuated PhoPc Salmonella strain was developed. Herein, weaimed to compare the in-vitro activity of...

Enterotoxigenic Escherichia coli (ETEC)-induced diarrhoea is the second most commoncause of death in children in the developing countries. Heat labile toxin (LT) is responsible forETEC-induced diarrhoea. In the present study, a novel live ETEC vaccine based on subunitB of LT (LTB) expression in attenuated PhoPc Salmonella strain was developed. Herein, weaimed to compare the in-vitro activity of...

The PhoP-PhoR two-component signaling system from Mycobacterium tuberculosis is essential for the virulence of the tubercle bacillus. The response regulator, PhoP, regulates expression of over 110 genes. In order to elucidate the regulatory mechanism of PhoP, we determined the crystal structure of its DNA-binding domain (PhoPC). PhoPC exhibits a typical fold of the winged helix-turn-helix subfa...

The PhoP and PhoR proteins from Mycobacterium tuberculosis form a highly specific two-component system that controls expression of genes involved in complex lipid biosynthesis and regulation of unknown virulence determinants. The several functions of PhoP are apportioned between a C-terminal effector domain (PhoPC) and an N-terminal receiver domain (PhoPN), phosphorylation of which regulates ac...

Light microscopic studies of phagocytosis showed that Salmonella typhimurium entered mouse macrophages enclosed in spacious phagosomes (SP). Viewed by time-lapse video microscopy, bone marrow-derived macrophages exposed to S. typhimurium displayed generalized plasma membrane ruffling and macropinocytosis. Phagosomes containing Salmonella were morphologically indistinguishable from macropinosome...

Attenuated strains of Salmonella are attractive live vaccine candidates for eliciting mucosal as well as systemic immune responses. The ability to induce immune responses in the reproductive tract may be critical for the effectiveness of a prophylactic vaccine against genital human papillomaviruses (HPV), which are important etiologic agents in the development of cervical cancer. To examine the...

Oral tolerance to foods can be regulated by microorganisms in the gut lumen. We hypothesized that pretreatment with avirulent Salmonella typhimurium strains could prevent food allergy in mice. Mice were administered S. typhimurium PhoPc (STPhoPc) or S. typhimurium AroA prior to oral sensitization to beta-lactoglobulin in the presence of cholera toxin. An oral antigen challenge after sensitizati...

Live attenuated Salmonella are attractive vaccine candidates for mucosal application because they induce both mucosal immune responses and systematic immune responses. After breaking the epithelium barrier, Salmonella typhimurium is found within dendritic cells (DC) in the Peyer's patches. Although there are abundant data on the interaction of S. typhimurium with murine epithelial cells, macrop...

The defensin sensitivities of Salmonella typhimurium strains with mutations in the phoP/phoQ two-component virulence regulon were tested by using purified defensins NP-1 and NP-2. Strains with mutations in either gene of the regulatory pair (phoP [transcriptional activator] or phoQ [membrane sensor kinase]) had increased sensitivities to defensin. The predicted periplasmic domain of the PhoQ pr...

During intestinal disease induced by Salmonella typhimurium transepithelial migration of neutrophils (PMN) rapidly follows attachment of the bacteria to the epithelial apical membrane. Among the events stimulated by these interactions is the release of chemotaxins that guide PMN through the subepithelial matrix and subsequently through the epithelium itself (McCormick, B.A., S.P. Colgan, C. Del...