Inhibition of chlamydia trachomatis growth by human interferon-.ALPHA.: mechanisms and synergistic effect with interferon-.GAMMA. and tumor necrosis factor-.ALPHA.

Abstract

We have evaluated the effect of natural human interferon (IFN)-α on the growth of chlamydia trachomatis in human epithelial cells in vitro and revealed that IFN-α has reduced both growth and infectivity of C. trachomatis. The effect of IFN-α was reversed by the addition of exogenous L-tryptophan and iron to the culture medium, suggesting that antichlamydial effect of IFN-α was caused by depletion of intracellular tryptophan and iron, both of which are essential for chlamydial growth. When IFN-α was combined with another antichlamydial cytokines, IFN-γ and tumor necrosis factor (TNF)-α, the effect was synergistically enhanced. Therefore, IFN-α would act coordinately with other cytokines such as IFN-γ and TNF-α, 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.

Complex Formation with Plasmid DNA Increases the Cytotoxicity of Cationic Liposomes

“…[41][42][43] Thus, it is possible that interactions with the lipoplex, but not pDNA or CL alone, modulates and triggers some gene expressions, which are involved in programmed cell death or cytokine generation of innate or adaptive immune reactions. Consequently, cells treated with lipoplex die via apoptosis.…”

Expresión de interferón gamma en la infección por el virus del papiloma humano y por Chlamydia trachomatis en muestras cervicales

“…No se han descrito estudios anteriores que permitan corroborar este resultado en la coinfección con estos patógenos, y una limitación importante de este estudio es el tamaño de la muestra. Nuestras observaciones concuerdan con estudios anteriores, llevados a cabo in vitro, que demostraron que el género Chlamydia induce la expresión de IFN-␥ 24 , causando la inhibición del crecimiento de C. trachomatis 25,26 ; otro estudio demostró aumento de expresión de IFN-␥ en pacientes con infección por VPH 13 . De las observaciones anteriores, se esperaría que la coinfección con VPH y con C. trachomatis tuviera un efecto aditivo sobre la expresión de IFN-␥, hipótesis confirmada con los resultados de este estudio.…”

Treating reactive arthritis: insights for the clinician

“…In the case of chlamydiae, specifically, these persistent bacterial organisms remain viable. Adding to these concerns, in vitro data has demonstrated that persistent chlamydial levels are inversely proportional to TNF-alpha levels [Ishihara et al 2005;Takano et al 2005;Perry et al 1997]. In keeping with the relative lack of prospective clinical trial data with ReA in general, there are few prospective data evaluating anti-TNF therapy in ReA.…”