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Role of CD8 T cells in primary Chlamydia infection.
Magee DM; Williams DM; Smith JG; Bleicker CA; Grubbs BG; Schachter J;
April 30, 1995
Infect Immun. 1995 Feb;63(2):516-21. Unique Identifier : AIDSLINE

The role of CD4 and CD8 T cells in primary Chlamydia trachomatis pneumonia was investigated by using in vivo depletion techniques to eliminate T-cell populations. Reduction of either CD4 T cells or CD8 T cells caused a significant increase in organism burden in the lungs, as measured by both quantitative culture and detection of chlamydial antigen on day 14 postinfection. Chlamydia-specific antibody levels in plasma or antigen-induced gamma interferon (IFN-gamma) production by spleen cells was dramatically reduced by depletion of CD4 cells. The reduction in IFN-gamma achieved by depletion of CD8 cells did not reach statistical significance. In the survival studies, depletion of CD4 cells led to a significant increase in mortality. Although there was a trend toward higher mortality, depletion of CD8 cells did not significantly increase mortality. The role of CD8 T cells in host defense was clarified in studies using beta 2-microglobulin-deficient (major histocompatibility class I antigen-deficient, C1D) mice which are defective in CD8 T-cell function. In this model, a significant increase in organism burden was seen during infection in C1D mice compared with that C57BL/6 controls and a significant increase in mortality was observed as well. However, surviving C1D mice were able to clear the infection by day 34. C1D mice had increased numbers of CD4 T cells in both the spleen and the lungs during infection compared with those of C57BL/6 controls. IFN-gamma in C57BL/6 mice was produced by both CD4 and CD8 cells. Thus, there is a protective role for both CD4 and CD8 cells in host defense against Chlamydia infection, but the former appear to be dominant.

beta 2-Microglobulin/DEFICIENCY Animal Chlamydia trachomatis Chlamydia Infections/*IMMUNOLOGY CD4-Positive T-Lymphocytes/*IMMUNOLOGY CD8-Positive T-Lymphocytes/*IMMUNOLOGY Female Immunity, Cellular Interferon Type II/BIOSYNTHESIS Male Mice Mice, Inbred BALB C Mice, Inbred C57BL Mice, Knockout Mice, Nude Pneumonia/*IMMUNOLOGY Support, Non-U.S. Gov't Support, U.S. Gov't, Non-P.H.S. Support, U.S. Gov't, P.H.S. JOURNAL ARTICLE

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