Inhibition of chlamydia trachomatis growth by human interferon-alpha: mechanisms and synergistic effect with interferon-gamma and tumor necrosis factor-alpha.
We have evaluated the effect of natural human interferon (IFN)-alpha on the growth of chlamydia trachomatis in human epithelial cells in vitro and revealed that IFN-alpha has reduced both growth and infectivity of C. trachomatis. The effect of IFN-alpha was reversed by the addition of exogenous L-tryptophan and iron to the culture medium, suggesting that antichlamydial effect of IFN-alpha was caused by depletion of intracellular tryptophan and iron, both of which are essential for chlamydial growth. When IFN-alpha was combined with another antichlamydial cytokines, IFN-gamma and tumor necrosis factor (TNF)-alpha, the effect was synergistically enhanced. Therefore, IFN-alpha would act coordinately with other cytokines such as IFN-gamma and TNF-alpha, and play an important role in host defense against infection and in the establishment of persistent chlamydial infection of host, in which the organism remains viable, but in a culture-negative state.
Ishihara
Tatsuya
T
Fujisaki Institute, Hayashibara Biochemical Laboratories Inc, 675-1 Fujisaki, Okayama 702-8006, Japan.
Aga
Miho
M
Hino
Keiko
K
Ushio
Chie
C
Taniguchi
Mutsuko
M
Iwaki
Kanso
K
Ikeda
Masao
M
Kurimoto
Masashi
M
D000970:Antineoplastic Agents / Q000276:immunology / Q000494:pharmacology*; D002690:Chlamydia Infections / Q000276:immunology / Q000378:metabolism*; D002692:Chlamydia trachomatis / Q000254:growth & development* / Q000276:immunology; D004357:Drug Synergism; D006367:HeLa Cells; D006801:Humans; D016898:Interferon-alpha / Q000276:immunology / Q000494:pharmacology*; D007371:Interferon-gamma / Q000276:immunology / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology / Q000494:pharmacology*
D000970:Antineoplastic Agents; D016898:Interferon-alpha; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma