title: Changes in peritoneal myeloid populations and their proinflammatory cytokine expression during infection with Listeria monocytogenes are altered in the absence of gamma/delta T cells.
abstract: Evidence that gamma/delta T cells play a broad, immunoregulatory role has been accumulating steadily. We show here that myeloid cells are disregulated after peritoneal infection with Listeria monocytogenes in mice lacking gamma/delta T cells. Inflammatory populations of neutrophils and monocytes recruited to the site of infection remained longer. Intracellular cytokine analysis showed that frequencies of myeloid cells producing interleukin-12 and tumor necrosis factor alpha were higher and remained elevated longer after infection in mice genetically deficient in gamma/delta T cells. In vivo dye-tracking studies indicated that the majority of inflammatory monocytes differentiated into resident tissue macrophages in situ. In vitro experiments confirmed that monocytes harvested from mice lacking gamma/delta T cells were defective in their maturation process. This evidence suggests that gamma/delta T cells promote differentiation in the monocyte/macrophage lineage. These cells are important for bactericidal activity, inflammatory cytokine production, clearance of inflammatory neutrophils, and ultimately, antigen presentation to T cells. Regulation of monocyte/macrophage differentiation may underlie a broad segment of the phenotypic alterations that have been reported in mice lacking gamma/delta T cells.
authors.affiliation: Emory University School of Medicine, 1510 Clifton Road, Atlanta, GA 30322, USA. ziegler@microbio.emory.edu
authors.forename: Marianne J
authors.initials: MJ
authors.lastname: Skeen
authors.forename: Molly M
authors.initials: MM
authors.lastname: Freeman
authors.forename: H Kirk
authors.initials: HK
authors.lastname: Ziegler
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000276:immunology; D002465:Cell Movement / Q000276:immunology; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis*; D005434:Flow Cytometry; D007424:Intracellular Fluid / Q000737:chemistry; D008089:Listeria monocytogenes / Q000276:immunology; D008088:Listeriosis / Q000276:immunology*; D008262:Macrophage Activation / Q000276:immunology; D051379:Mice; D022423:Myeloid Cells / Q000166:cytology / Q000276:immunology*; D010529:Peritoneal Cavity / Q000166:cytology* / Q000502:physiology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000172:deficiency*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D016207:Cytokines; D016692:Receptors, Antigen, T-Cell, gamma-delta