title: Normal macrophage functions, but impaired induction of gamma delta T cells, at the site of bacterial infection in CD45 exon 6-deficient mice.
abstract: We investigated the protective functions of macrophages and gamma delta T cells in adult CD45 exon 6-deficient (CD45 -/-) mice against an intraperitoneal (i.p.) infection with Listeria monocytogenes. gamma delta T cells are preferentially localized in the spleen, liver, and intraperitoneal cavity of the adult CD45-/- mice. Increased numbers of gamma delta T cells were observed after i.p. infection with L. monocytogenes in the peritoneal cavity of C57BL/6 (CD45 +/+) mice but not in CD45 -/- mice. The gamma delta T cells showed predominant usage of V delta 5 and V delta 6 rearranged to J delta 1 in the infected CD45 -/- mice which are the same as those used by resident gamma delta T cells of noninfected CD45 +/+ and CD45 -/- mice. Furthermore, we analyzed the protective abilities of the CD45 -/-, CD45 +/+, and gamma delta T cell-depleted mice at the early stage of the listerial infection. The numbers of bacteria in the spleens and livers of the CD45 -/- mice 5 days after the listerial infection were almost ten times larger than those in the CD45 -/- and gamma delta T cell-depleted CD45 +/+ mice. Macrophages showed normal antigen presentation, nitric oxide production and bactericidal activity for L. monocytogenes despite their lacking CD45 surface expression, suggesting that CD45-negative macrophages have a minimal influence on the increased bacterial multiplication in the CD45-/- mice. These results suggest that the gamma delta T cells are induced by the bacterial infection in a CD45-dependent manner, and that unresponsiveness of the gamma delta T cells results in only weak protection against L. monocytogenes in CD45 -/- mice.
authors.affiliation: Department of Immunology, Medical Institute of Bioregulation, Kyusyu University, Fukuoka, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Fujise
authors.forename: K
authors.initials: K
authors.lastname: Kishihara
authors.forename: K Y
authors.initials: KY
authors.lastname: Lee
authors.forename: G
authors.initials: G
authors.lastname: Matsuzaki
authors.forename: K
authors.initials: K
authors.lastname: Nomoto
mesh_terms: D000818:Animals; D005091:Exons / Q000235:genetics; D005260:Female; D016694:Gene Rearrangement, delta-Chain T-Cell Antigen Receptor; D015334:Gene Rearrangement, gamma-Chain T-Cell Antigen Receptor; D017493:Leukocyte Common Antigens / Q000235:genetics / Q000502:physiology*; D008089:Listeria monocytogenes / Q000302:isolation & purification; D008088:Listeriosis / Q000276:immunology*; D008099:Liver / Q000382:microbiology; D008262:Macrophage Activation; D017737:Macrophages, Peritoneal / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D009569:Nitric Oxide / Q000378:metabolism; D010538:Peritonitis / Q000276:immunology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis*; D017384:Sequence Deletion; D013154:Spleen / Q000382:microbiology; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta; D009569:Nitric Oxide; D017493:Leukocyte Common Antigens