Low levels of residual oil fly ash (ROFA) impair innate immune response against environmental mycobacteria infection in vitro

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• 作者：Ver¨®nica C. Delfosse ; Andrea K. Gioffr¨¦ ; Deborah R. Tasat
• 关键词：Alveolar macrophages ; Environmental mycobacteria ; Mycobacterium phlei ; ROFA ; Innate immune response
• 刊名：Toxicology in Vitro
• 出版年：2012
• 出版时间：September, 2012
• 年：2012
• 卷：26
• 期：6
• 页码：1001-1006
• 全文大小：376 K

文摘

Epidemiological studies have shown that pollution derived from industrial and vehicular transportation provokes adverse health effects causing broad spectrum of ambient respiratory diseases. Therefore, air pollution should be taken into account when microbial diseases are evaluated. Environmental mycobacteria (EM) are opportunist pathogens in a variety of immunocompromised patients eliciting significant impact on human morbidity and mortality. The aim of this study was to evaluate the in vitro effects of residual oil fly ash (ROFA) on the alveolar macrophages (AMs) response to opportunistic bacteria.

AMs from young Wistar rats were obtained by bronchoalveolar lavage and co-cultured with Mycobacterium phlei (MOI 10). We exposed AM cultures to ROFA to characterize the effect of low ROFA concentrations (0, 2.5, and 5 ¦Ìg/ml) and evaluated the response of pre-exposed AM against the bacilli. Low ROFA concentrations induced superoxide anion and nitrites production (p < 0.001). Pre-exposure to ROFA (2.5 and 5 ¦Ìg/ml) caused a significant reduction on TNF¦Á (p < 0.001) and superoxide anion (p < 0.001) production but, did not modify the nitrite production when AM were co-cultured with M. phlei. In addition, ROFA significantly diminished AM killing ability in culture (p < 0.001). Hence, our results indicate that pre-exposure to low levels of ROFA modifies the innate pulmonary defence mechanisms against environmental mycobacteria.