title: Th1-type immune response to infection by pYV-cured phoP-phoQ null mutant of Yersinia pseudotuberculosis is defective in mouse model.
abstract: The PhoP-PhoQ two-component system of Yersinia pseudotuberculosis, a Gram-negative enteric pathogen which causes a variety of gastrointestinal and extraintestinal infections in humans, has been shown to be necessary for virulence. A phoP-phoQ null mutant of a strain of Y. pseudotuberculosis cured of its native plasmid pYV was obtained and studied for generation of immune response in mouse model following intravenous inoculation. The phoP-phoQ null mutant elicited much weaker IgG antibody response to whole cell sonicated (WCS) antigen, in particular that of IgG2a isotype. Interferon-gamma levels were also significantly reduced in cultured splenocytes of mice immunized with phoP-phoQ null mutant. The null mutant was found to be about 72-fold less virulent than the parent isogenic strain of Y. pseudotuberculosis. Average counts in spleen of mice inoculated with the null mutant were observed to reduce by at least four logs when compared with the counts in the spleen of mice inoculated with parent isogenic strain. We can thus suggest that the Th1-type immune response of the phoP-phoQ null mutant of Y. pseudotuberculosis is diminished in mice.
authors.affiliation: Division of Microbiology, Defence R&D Establishment, Jhansi Road, Gwalior, 474 002, India. subodh_kumar@email.com
authors.forename: Subodh
authors.initials: S
authors.lastname: Kumar
authors.forename: K
authors.initials: K
authors.lastname: Balakrishna
authors.forename: G S
authors.initials: GS
authors.lastname: Agarwal
authors.forename: S
authors.initials: S
authors.lastname: Merwyn
authors.forename: G P
authors.initials: GP
authors.lastname: Rai
authors.forename: H V
authors.initials: HV
authors.lastname: Batra
authors.forename: A A
authors.initials: AA
authors.lastname: Sardesai
authors.forename: J
authors.initials: J
authors.lastname: Gowrishankar
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D016207:Cytokines / Q000032:analysis; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D051379:Mice; D009154:Mutation; D010957:Plasmids / Q000235:genetics*; D018417:Th1 Cells / Q000276:immunology*; D014774:Virulence; D015011:Yersinia pseudotuberculosis / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity*; D015012:Yersinia pseudotuberculosis Infections / Q000276:immunology* / Q000382:microbiology
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D016207:Cytokines; D007074:Immunoglobulin G; C079792:PhoQ protein, Bacteria; C061064:PhoP protein, Bacteria