This is an application for competitive renewal of an ongoing study concerning the nature and mechanism of cell mediated immunity (CMI) to L. pneumophila infection. We wish to further characterize CMI in comparison to other aspects of immunity to L. pneumophila such as humoral immunity in the guinea pig model we have utilized in this laboratory for a number of years as well as a new mouse model which we are developing. We will continue both our in vivo and in vitro studies. In guinea pigs, cell transfer studies will be continued to determined the role of various immune cells and antibodies in resistance and/or recovery from infection by these organisms. The fractionation and identification of cells responsible for transferring resistance to Legionella infection will be examined in some detail. In addition, the mouse model system we have developed will permit the use of both highly resistant and susceptible (strain A/J) mouse strains. Furthermore, resistant mice can be made more susceptible, either by intratracheal infection or treatment with cyclophosphamide. We propose to further identify cells responsible for transfer of resistance and the cell types which respond to the Legionella antigens in vitro by the blast cell transformation assay and by production of soluble mediators of immunity. By use of specific antibody we will purify appropriate cell populations. The role of these cells in resistance to infection will be determined. We will also examine the roles played by IL-1, IL-2 and gamma interferon, as well as TNF, in resistance of experimental animals, especially mice, to Legionella infection. We will continue to examine in detail endocytosis of Legionella in vitro by macrophages, including those obtained from susceptible guinea pigs, mice, and human monocytes and explore the possibility that clathrin mediated endocytosis is involved in Legionella ingestion and intracellular persistence. By these studies we will define various cell classes in the immune response system important in restricting the growth of L. pneumophila, both at the whole animal and at the cellular level. Intact bacterial antigen as well as various purified preparations, including outer membrane protein antigen and lipopolysaccharide, will be used in these experiments. We believe these studies will permit us to determine in detail the nature and mechanisms of cellular immunity and resistance to these important opportunistic intracellular pathogens.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI016618-09
Application #
3126743
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Project Start
1981-04-01
Project End
1993-11-30
Budget Start
1990-12-01
Budget End
1991-11-30
Support Year
9
Fiscal Year
1991
Total Cost
Indirect Cost
Name
University of South Florida
Department
Type
Schools of Medicine
DUNS #
City
Tampa
State
FL
Country
United States
Zip Code
33612
McHugh, S; Yamamoto, Y; Klein, T W et al. (2000) Differential expression of IL-1 and TNF receptors in murine macrophages infected with virulent vs. avirulent Legionella pneumophila. Can J Microbiol 46:885-91
McHugh, S L; Yamamoto, Y; Klein, T W et al. (2000) Murine macrophages differentially produce proinflammatory cytokines after infection with virulent vs. avirulent Legionella pneumophila. J Leukoc Biol 67:863-8
Friedman, H; Yamamoto, Y; Newton, C et al. (1998) Immunologic response and pathophysiology of Legionella infection. Semin Respir Infect 13:100-8
Smith, M S; Yamamoto, Y; Newton, C et al. (1997) Psychoactive cannabinoids increase mortality and alter acute phase cytokine responses in mice sublethally infected with Legionella pneumophila. Proc Soc Exp Biol Med 214:69-75
Yamamoto, Y; Klein, T W; Tomioka, M et al. (1997) Differential effects of granulocyte/macrophage colony-stimulating factor (GM-CSF) in enhancing macrophage resistance to Legionella pneumophila vs Candida albicans. Cell Immunol 176:75-81
Yamamoto, Y; Klein, T W; Friedman, H (1996) Induction of cytokine granulocyte-macrophage colony-stimulating factor and chemokine macrophage inflammatory protein 2 mRNAs in macrophages by Legionella pneumophila or Salmonella typhimurium attachment requires different ligand-receptor systems. Infect Immun 64:3062-8
Yamamoto, Y; Klein, T W; Friedman, H (1996) Immunoregulatory role of nitric oxide in Legionella pneumophila-infected macrophages. Cell Immunol 171:231-9
Retzlaff, C; Yamamoto, Y; Okubo, S et al. (1996) Legionella pneumophila heat-shock protein-induced increase of interleukin-1 beta mRNA involves protein kinase C signalling in macrophages. Immunology 89:281-8
Gebran, S J; Yamamoto, Y; Newton, C et al. (1995) LPS inhibits the intracellular growth of Legionella pneumophila in thioglycolate elicited murine peritoneal macrophages by iron-dependent, tryptophan-independent, oxygen-independent, and arginine-independent mechanisms. J Leukoc Biol 57:80-7
Yamamoto, Y; Retzlaff, C; He, P et al. (1995) Quantitative reverse transcription-PCR analysis of Legionella pneumophila-induced cytokine mRNA in different macrophage populations by high-performance liquid chromatography. Clin Diagn Lab Immunol 2:18-24

Showing the most recent 10 out of 45 publications