Natural Killer Cells Mediate Protection against Yersinia pseudotuberculosis in the Mesenteric Lymph Nodes

• Published in: PloS one 2015-08, Vol.10 (8), p.e0136290-e0136290
• Main Authors: Rosenheinrich, Maik, Heine, Wiebke, Schmühl, Carina M, Pisano, Fabio, Dersch, Petra
• Format: Article
• Language: English
• Subjects: Activation; Animal sciences; Animals; Antibodies - pharmacology; Antigens, CD - genetics; Antigens, CD - immunology; B-Lymphocytes - immunology; B-Lymphocytes - microbiology; B-Lymphocytes - pathology; Bacteria; Bacterial infections; Biology; Care and treatment; Causes of; CD11b antigen; CD27 antigen; CD69 antigen; Crosstalk; Cytokines; Depletion; Female; Flow cytometry; Gene Expression; Genetic aspects; Health aspects; Immune clearance; Immune response; Immune system; Immunophenotyping; Infections; Inflammation; Interferon-gamma - genetics; Interferon-gamma - immunology; Interferon-gamma - secretion; Killer cells; Killer Cells, Natural - drug effects; Killer Cells, Natural - immunology; Killer Cells, Natural - microbiology; Killer Cells, Natural - pathology; Laboratory animals; Lymph nodes; Lymph Nodes - immunology; Lymph Nodes - microbiology; Lymph Nodes - pathology; Lymphatic system; Lymphocyte Count; Lymphocyte Depletion; Lymphocytes; Macrophages - immunology; Macrophages - microbiology; Macrophages - pathology; Mesentery - immunology; Mesentery - microbiology; Mesentery - pathology; Mice; Mice, Inbred C57BL; Natural killer cells; Neutrophils - immunology; Neutrophils - microbiology; Neutrophils - pathology; Pathogens; Physiological aspects; Proteins; Pseudotuberculosis; Salmonella; Salmonella Typhimurium; Spleen - immunology; Spleen - microbiology; Spleen - pathology; T-Lymphocytes, Cytotoxic - immunology; T-Lymphocytes, Cytotoxic - microbiology; T-Lymphocytes, Cytotoxic - pathology; Tumor Necrosis Factor-alpha - genetics; Tumor Necrosis Factor-alpha - immunology; Tumor Necrosis Factor-alpha - secretion; Tumor necrosis factor-α; Viral infections; Yersinia; Yersinia pestis; Yersinia pseudotuberculosis; Yersinia pseudotuberculosis - immunology; Yersinia pseudotuberculosis Infections - immunology; Yersinia pseudotuberculosis Infections - microbiology; Yersinia pseudotuberculosis Infections - pathology; Zoology
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0136290

Natural killer cells play a crucial role in the initial defense against bacterial pathogens. The crosstalk between host cells infected with intracellular pathogens and NK cells has been studied intensively, but not much attention has been given to characterize the role of NK cells in the response to extracellular bacterial pathogens such as yersiniae. In this study we used antibody-mediated NK cell depletion to address the importance of this immune cell type in controlling a Y. pseudotuberculosis infection. Analysis of the bacterial counts was used to follow the infection and flow cytometry was performed to characterize the composition and dynamic of immune cells. Depletion of NK cells led to higher bacterial loads within the mesenteric lymph nodes. We further show that in particular CD11b+ CD27+ NK cells which express higher levels of the activation marker CD69 increase within the mesenteric lymph nodes during a Y. pseudotuberculosis infection. Moreover, in response to the activation NK cells secrete higher levels of IFNy, which in turn triggers the production of the proinflammatory cytokine TNFα. These results suggest, that NK cells aid in the clearance of Y. pseudotuberculosis infections mainly by triggering the expression of proinflammatory cytokines manipulating the host immune response.