The overall purpose of this project is to investigate the role of liver macrophages, or Kupffer cells (KC), in resistance to intracellular pathogens. KC line the sinusoids of the liver, and consequently clear the blood of gastrointestinal and other blood borne pathogens. KC appear to have an important role in the early events in host resistance to many pathogens. For a number of years, we have studied a prototypic model of intracellular infection, murine listeriosis. Host defenses in this model depend on the interaction between T lymphocytes and macrophages. For the past three year grant period, we have developed and used T cell clones to investigate the role of T cells in immunity to Listeria. Most recently, we have developed techniques for isolating KC from livers. In an initial study, we found that KC can serve as efficient antigen-presenting cells to Listeria-specific T cell clones in vitro, thus demonstrating the potential of KC to initiate an immune response. In this proposal, we will study two major functions of KC and the capacity of T cells to regulate these functions during listerial infection. Initially, we will measure the production of cytokines, including interleukin-1, interleukin-6, and interferon, by KC during listeriosis. KC cytokine production will be determine in vivo by Northern blot analysis, in situ hybridization, and immunohistochemistry. These studies will be confirmed by in vitro analysis of cytokine production by isolated KC populations. The factors that regulate cytokine production by KC will be identified by both in vivo and in vitro studies. In addition, the antimicrobial potential of KC will be determined by analyzing in vivo growth curves of KC-associated Listeria. To confirm in vivo studies, we will measure the capacity of KC harvested from infected mice to kill Listeria in vitro. We will also use well established assays to investigate the capacity of KC to kill Listeria in vitro after stimulation with T cells and T cell products. By investigating secretory and antimicrobial activity of KC during listeriosis, we hope to define the importance of KC during murine listeriosis. These studies will be the first to study comprehensively the role of KC in the immune responses to infection. Immune mechanisms active in listeriosis have proven to have wide applicability to immune host resistance against many pathogens. The findings from our studies, therefore, will advance our understanding of immunity against infection in general, and may lead to newer approaches to enhance immune host defenses.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI024141-06
Application #
3136853
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Project Start
1987-09-01
Project End
1994-06-30
Budget Start
1993-07-01
Budget End
1994-06-30
Support Year
6
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of Pittsburgh
Department
Type
Schools of Medicine
DUNS #
053785812
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Jiang, X; Gregory, S H; Wing, E J (1995) Hepatocytes can serve as accessory cells in the response of immune T lymphocytes to heat-killed Listeria monocytogenes. Infect Immun 63:926-33
Cooper, M H; Gregory, S H; Starzl, T E et al. (1994) Rapamycin but not FK506 inhibits the proliferation of mononuclear phagocytes induced by colony-stimulating factors. Transplantation 57:433-9
Gregory, S H; Sagnimeni, A J; Wing, E J (1994) Arginine analogues suppress antigen-specific and -nonspecific T lymphocyte proliferation. Cell Immunol 153:527-32
Gregory, S H; Wing, E J (1993) IFN-gamma inhibits the replication of Listeria monocytogenes in hepatocytes. J Immunol 151:1401-9
Gregory, S H; Wing, E J (1993) Macrophage colony-stimulating factor and the enhanced migration of monocytes are essential in primary but not secondary host defenses to Listeria organisms. J Infect Dis 168:934-42
Gregory, S H; Wing, E J; Hoffman, R A et al. (1993) Reactive nitrogen intermediates suppress the primary immunologic response to Listeria. J Immunol 150:2901-9
Gregory, S H; Barczynski, L K; Wing, E J (1992) Effector function of hepatocytes and Kupffer cells in the resolution of systemic bacterial infections. J Leukoc Biol 51:421-4
Gregory, S H; Wing, E J; Tweardy, D J et al. (1992) Primary listerial infections are exacerbated in mice administered neutralizing antibody to macrophage colony-stimulating factor. J Immunol 149:188-93
Cooper, M H; Gregory, S H; Thomson, A W et al. (1991) Evaluation of the influence of FK 506, rapamycin, and cyclosporine on processing and presentation of particulate antigen by macrophages: assessment of a drug ""carry-over"" effect. Transplant Proc 23:2957-8
Magee, D M; Williams, D M; Wing, E J et al. (1991) Production of colony-stimulating factors during pneumonia caused by Chlamydia trachomatis. Infect Immun 59:2370-5

Showing the most recent 10 out of 18 publications