title: Elevated neutrophil, macrophage and dendritic cell numbers characterize immune cell populations in mice chronically infected with Salmonella.
abstract: The present study characterizes immune cell populations in mice chronically infected with Salmonella. Mice were characterized as chronically infected based on persistently high titers of Salmonella-reactive immunoglobulins in the serum >6 months after a single oral dose of S. enterica serovar Typhimurium. These mice had a visibly enlarged spleen but not liver, while both organs harbored bacteria and had increased total cellularity up to 11 months post-infection. Flow cytometry analysis revealed significantly elevated numbers of neutrophils, dendritic cells (DC) and macrophages in the spleen of chronically infected mice. In contrast, no significant increase in the absolute number of T and B cells was apparent in the spleen and DX5+ cells, which includes NK cells, some NK T cells and possibly some activated T cells, appears to correlate with chronic Salmonella infection in the liver but not the spleen. In situ analyses revealed that CD8alpha+ DC and Gr-1+ cells (neutrophils) increased in the splenic red pulp of chronically infected mice. In addition, Gr-1+ cells, CD68+ cells and CD11c+ cells (DC), the latter lacking detectable staining for CD8alpha and CD4, accumulated around hepatic blood vessels and in the hepatic network in the liver of mice chronically harboring bacteria. These data provide insight into changes that occur within immune cell populations, most notably within splenic and hepatic phagocytic cell populations, that accompany chronic infection with the intracellular bacterium Salmonella.
authors.affiliation: Department of Cell and Molecular Biology, Section for Immunology, Lund University, 221 84 Lund, Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Johansson
authors.forename: Mikael
authors.initials: M
authors.lastname: Ingman
authors.forename: Mary
authors.initials: M
authors.lastname: Jo Wick
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D015214:Antigens, Differentiation, Myelomonocytic / Q000276:immunology; D039521:CD11c Antigen / Q000276:immunology; D002908:Chronic Disease; D003713:Dendritic Cells / Q000276:immunology*; D005260:Female; D005802:Genes, MHC Class II / Q000276:immunology; D007136:Immunoglobulins / Q000097:blood / Q000276:immunology; D008099:Liver / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009504:Neutrophils / Q000276:immunology*; D011817:Rabbits; D012481:Salmonella Infections, Animal / Q000276:immunology*; D012485:Salmonella typhi / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D039521:CD11c Antigen; D007136:Immunoglobulins; C067980:CD68 antigen, human; D000097382:CD68 Molecule