Journal article

Publication year: 2004

Pages: 45-52

Journal: Medical Microbiology and Immunology

Volume number: 193

Issue number: 1

ISSN: 0300-8584

DOI Link: https://doi.org/10.1007/s00430-003-0182-1

Publisher: Springer

Abstract: 
Chlamydia trachomatis-infected macrophages induce T cell apoptosis. This ability might promote intracellular survival of Chlamydia and perpetuate chronic chlamydial infection. The purpose of this study was to examine the molecular mechanisms by which C. trachomatis-infected macrophages induce T cell apoptosis. Monocytes and T cells were isolated from the peripheral blood of healthy donors. Macrophages were infected with C. trachomatis, and autologous T cells were stimulated by mitogen. After 6 days, both populations were cultured together using a two-chamber transwell membrane system to differentiate between mechanisms involving either cell-to-cell contact or secretion of apoptotic factors. Apoptotic T cells were identified by propidium iodide through-flow cytometry, and tumor necrosis factor-alpha (TNF-alpha) concentrations were measured by enzyme-linked immunosorbent assay. Antagonists of TNF-alpha, the Fas (CD95) molecule, TNF-related apoptosis-inducing ligand (TRAIL), and catalase were added to differentiate between the pathways of apoptosis. C. trachomatis-infected macrophages significantly induced T cell apoptosis by cell-to-cell contact (mean +/- standard deviation, 30+/-4%; P<0.001) and by humoral mechanisms (mean +/- standard deviation, 22+/-3%, P<0.001). Humoral apoptosis was mediated by secretion of TNF-alpha from infected macrophages. Inhibition of secretory TNF-alpha by the monoclonal anti-TNF-alpha antibody adalimumab (D2E7) blocked T cell death in vitro. In contrast, T cell apoptosis mediated by cell-to-cell contact was not inhibited by the different anti-apoptotic reagents. In summary, TNF-alpha derived from infected macrophages is an important apoptosis factor for T cell apoptosis induced by C. trachomatis-infected cells.

Harvard Citation style: Jendro, M., Fingerle, F., Deutsch, T., Liese, A., Köhler, L., Kuipers, J., et al. (2004) Chlamydia trachomatis-infected macrophages induce apoptosis of activated T cells by secretion of tumor necrosis factor-alpha in vitro., Medical Microbiology and Immunology, 193(1), pp. 45-52. https://doi.org/10.1007/s00430-003-0182-1

APA Citation style: Jendro, M., Fingerle, F., Deutsch, T., Liese, A., Köhler, L., Kuipers, J., Raum, E., Martin, M., & Zeidler, H. (2004). Chlamydia trachomatis-infected macrophages induce apoptosis of activated T cells by secretion of tumor necrosis factor-alpha in vitro.. Medical Microbiology and Immunology. 193(1), 45-52. https://doi.org/10.1007/s00430-003-0182-1