Abstract: The ospF gene of Shigella flexneri encodes a phosphatase, which is a member of a new class of phosphatases. The OspF phosphatase inhibits the activity of several proteins either by direct protein modification or transcription downregulation. These proteins include MAP kinase, IL-8, CCL20, IL-12, AP1, CREB, RPA p32, and BCL2 related proteins. Methods for treating diseases using OspF phosphatase, methods for identifying agents that modulate OspF phosphatase's activity, methods for identifying agents that mimic OspF phosphatase's activity, and immunogenic compositions comprising OspF phosphatase are provided. A strain of Shigella flexneri containing an inactivated ospF gene is also provided.

Abstract: The ospF gene of Shigella flexneri encodes a phosphatase, which is a member of a new class of phosphatases. The OspF phosphatase inhibits the activity of several proteins either by direct protein modification or transcription downregulation. These proteins include MAP kinase, IL-8, CCL20, IL-12, AP1, CREB, RPA p32, and BCL2 related proteins. Methods for treating diseases using OspF phosphatase, methods for identifying agents that modulate OspF phosphatase's activity, methods for identifying agents that mimic OspF phosphatase's activity, and immunogenic compositions comprising OspF phosphatase are provided. A strain of Shigella flexneri containing an inactivated ospF gene is also provided.

Abstract: The present invention relates to compositions and methods for blocking entry of Shigella into a cell of an animal, to therefore providing protection against, or reduce the severity of Shigella infections. More particularly it relates to the use of the IpaD protein obtained from natural sources and/or through synthesis or recombinant technology, and conjugates thereof to induce neutralizing antibodies having protective activity against several serotypes of Shigella, in particular S. flexneri. The composition of the invention is useful to prevent and/or treat shigellosis caused by a bacterium of the Shigella family.

Abstract: The ospF gene of Shigella flexneri encodes a phosphatase, which is a member of a new class of phosphatases. The OspF phosphatase inhibits the activity of several proteins either by direct protein modification or transcription downregulation. These proteins include MAP kinase, IL-8, CCL20, IL-12, AP1, CREB, RPA p32, and BCL2 related proteins. Methods for treating diseases using OspF phosphatase, methods for identifying agents that modulate OspF phosphatase's activity, methods for identifying agents that mimic OspF phosphatase's activity, and immunogenic compositions comprising OspF phosphatase are provided. A strain of Shigella flexneri containing an inactivated ospF gene is also provided.

Abstract: Chlamydia spp. are strictly intracellular pathogens that grow inside a vacuole, called an inclusion. They possess genes encoding proteins homologous to components of type III secretion machineries which, in other bacterial pathogens, are involved in delivery of bacterial proteins within or through the membrane of eukaryotic host cells. Inc proteins are chlamydial proteins that are associated with the membrane of the inclusion and are characterized by the presence of a large hydrophobic domain in their amino acid sequence. To investigate whether some Chlamydia proteins, especially Inc proteins and other proteins exhibiting a similar hydropathic profile, might be secreted, the inventors used an heterologous secretion system, namely a type III system. Chimeras were constructed by fusing the N-terminal part of these proteins with a reporter, the Cya protein of Bordetella pertussis, and expressed in various strains of Shigella flexneri.

Abstract: This invention relates to mutant strains of gram-negative bacteria that constitutively secrete proteins via the type III secretion machinery and to methods of identifying molecules that are able to activate or inhibit secretion in wild-type strains of gram-negative bacteria by exposing gram-negative bacterial cells to a sample molecule, wherein the bacterial cells contain a reporter gene transcriptionally fused to a promoter of a gene activated or regulated by the type III secretion machinery and detecting the presence or activity of the product of the reporter gene.

Abstract: Chlamydia spp. are strictly intracellular pathogens that grow inside a vacuole, called an inclusion. They possess genes encoding proteins homologous to components of type III secretion machineries which, in other bacterial pathogens, are involved in delivery of bacterial proteins within or through the membrane of eukaryotic host cells. Inc proteins are chlamydial proteins that are associated with the membrane of the inclusion and are characterized by the presence of a large hydrophobic domain in their amino acid sequence. To investigate whether some Chlamydia proteins, especially Inc proteins and other proteins exhibiting a similar hydropathic profile, might be secreted, the inventors used an heterologous secretion system, namely a type III system. Chimeras were constructed by fusing the N-terminal part of these proteins with a reporter, the Cya protein of Bordetella pertussis, and expressed in various strains of Shigella flexneri.

Abstract: This invention relates to mutant strains of gram-negative bacteria that constitutively secrete proteins via the type III secretion machinery. It also relates to methods of identifying molecules that are able to activate or inhibit secretion in wild-type strains of gram-negative bacteria by exposing gram-negative bacterial cells to a sample molecule, wherein said bacterial cells contain a reporter gene transcriptionally fused to a promoter of a gene activated or regulated by the type III secretion machinery, and detecting the presence or activity of the product of the reporter gene.