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Impairment of natural killer cell activity in Chlamydia trachomatis infected individuals
Author(s) -
Mavoungou Elie,
PoatyMavoungou Virginie,
Touré Fousseyni S.,
Sall Aïcha,
Delicat André,
Yaba Philippe,
Mandeme Yvette,
Nabias René,
LansoudSoukate Joseph
Publication year - 1999
Publication title -
tropical medicine and international health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.056
H-Index - 114
eISSN - 1365-3156
pISSN - 1360-2276
DOI - 10.1046/j.1365-3156.1999.00479.x
Subject(s) - antibody dependent cell mediated cytotoxicity , chlamydia trachomatis , biology , natural killer cell , immunology , cell culture , tumor necrosis factor alpha , cytolysis , cytotoxicity , interferon gamma , cell , interferon , cytokine , lytic cycle , antibody , in vitro , virus , monoclonal antibody , biochemistry , genetics
Summary Natural killer (NK) cell activity is impaired in Chlamydia trachomatis ‐infected patients. The mechanisms behind the altered NK functions are not clear, but data concerning NK and antibody‐dependent cellular cytotoxicity (ADCC) activity have been reported. To investigate whether this impairment is related to a defect at the target cell binding and/or the postbinding level, we evaluated highly purified NK cells obtained from 125 C. trachomatis ‐infected patients and compared them with 101 normal controls for their ability to kill K‐562 and U‐937 cell lines using a 51 Cr release assay; release tumour necrosis factor‐alpha (TNF‐α) and interferon‐gamma (IFN‐γ); and kill anti‐IgM preincubated P‐815 cell line (ADCC activity). We found a decrease in the lytic capability of NK cells from C. trachomatis ‐infected patients against target cell lines; decreased ability to kill bound target cells; and low levels of released TNF‐α and INF‐γ after incubation with U‐937 cells. Taken together, these findings suggest that the impaired NK cell reaction during chlamydial infection is related to defects both at the target and postbinding levels. However, the precise mechanisms remain to be determined. The inability to restore normal NK activity after long‐term culture in the presence of high levels of recombinant IL‐2 support the hypothesis of an anergic process during chlamydial infection.