BALB/c mice fail to develop an antibody response after immunization with low doses of a polysaccharide antigen (PS) isolated from the extracellular, gram-negative bacterium Pseudomonas aeruginosa. These mice do generate a protective T cell mediated immune response. Development of an in vitro system in which T cells kill these bacteria has permitted a detailed analysis of the cellular basis for this killing. Studies using this in vitro system have demonstrated that T cells kill the bacteria directly through secretion of a bactericidal lymphokine. The in vitro assay has also be used to evaluate the T cell killing capability of different inbred mouse strains. It has been found that C.B20 mice, which differ from the BALB/c strain at only one genetic locus, are unable to generate T cell killing in vitro. Preliminary results indicate that the difference in in vitro T cell killing between BALB/c and C.B20 mice correlates directly with the ability to these two strains to survive in vivo bacterial challenge. The significance of the C.B20 T cell bacterial killing defect will be evaluated in two different models of P. aeruginosa infection, the burned mouse model and the leukopenic mouse model. The effect on survival of reconstituting the C.B20 T cell response with adoptive transfer of cells from BALB/c mice will also be studied. These studies should establish the in vivo significance of this T cell killing mechanism. A human in vitro assay of T cell mediated bacterial killing has also been developed. This assay will be used to characterize the cellular mechanisms involved in human T cell killing. In addition, we will analyze the adequacy of T cell killing in humans, such as cystic fibrosis patients, who, like the C.B20 mouse, appear to be particularly susceptible to P. aeruginosa infection. Establishing the importance of T cell immunity in the pathogenesis of P. aeruginosa infection represents an important first step in efforts to intervene immunologically to prevent this infection in the susceptible host.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI022456-01
Application #
3133537
Study Section
Bacteriology and Mycology Subcommittee 1 (BM)
Project Start
1985-09-30
Project End
1988-08-31
Budget Start
1985-09-30
Budget End
1986-08-31
Support Year
1
Fiscal Year
1985
Total Cost
Indirect Cost
Name
Barnes-Jewish Hospital
Department
Type
DUNS #
City
Saint Louis
State
MO
Country
United States
Zip Code
63110
Pier, G B; Takeda, S; Grout, M et al. (1993) Immune complexes from immunized mice and infected cystic fibrosis patients mediate murine and human T cell killing of hybridomas producing protective, opsonic antibody to Pseudomonas aeruginosa. J Clin Invest 91:1079-87
Markham, R B; Pier, G B; Schreiber, J R (1991) The role of cytophilic IgG3 antibody in T cell-mediated resistance to infection with the extracellular bacterium, Pseudomonas aeruginosa. J Immunol 146:316-20
Powderly, W G; Schreiber, J R; Pier, G B et al. (1988) T cells recognizing polysaccharide-specific B cells function as contrasuppressor cells in the generation of T cell immunity to Pseudomonas aeruginosa. J Immunol 140:2746-52
Markham, R B; Pier, G B; Powderly, W G (1988) Suppressor T cells regulating the cell-mediated immune response to Pseudomonas aeruginosa can be generated by immunization with anti-bacterial T cells. J Immunol 141:3975-9
Markham, R B; Powderly, W G (1988) Exposure of mice to live Pseudomonas aeruginosa generates protective cell-mediated immunity in the absence of an antibody response. J Immunol 140:2039-45
Powderly, W G; Pier, G B; Markham, R B (1987) In vitro T cell-mediated killing of Pseudomonas aeruginosa. V. Generation of bactericidal T cells in nonresponder mice. J Immunol 138:2272-7
Powderly, W G; Pier, G B; Markham, R B (1986) T lymphocyte-mediated protection against Pseudomonas aeruginosa infection in granulocytopenic mice. J Clin Invest 78:375-80
Powderly, W G; Pier, G B; Markham, R B (1986) In vitro T cell-mediated killing of Pseudomonas aeruginosa. IV. Nonresponsiveness in polysaccharide-immunized BALB/c mice is attributable to vinblastine-sensitive suppressor T cells. J Immunol 137:2025-30