Induction of inflammatory response in human cell lines by arsenic-contaminated soil-isolated bacterium Micrococcus sp. KUMAs15

Abstract

Background: An arsenic-resistant microbial strain, Micrococcus sp. KUMAs15 isolated from West Bengal, India, has demonstrated high resistance to arsenic due to its arsenic accumulation and adsorption ability, establishing the strain as a potential arsenic bioremediation candidate for arsenic-contaminated niche. The successful field application of the microbe necessitates evaluation of probable immunotoxicological reactions on human cells. The present study determines expression profiles of pro-inflammatory and anti-inflammatory cytokines in cells exposed to KUMAs15. Results: The present study explored the alterations in expressions of the pro-inflammatory and anti-inflammatory cytokines in two human cell lines exposed to KUMAs15. The expression profile of the cytokine genes demonstrated that Micrococcus sp. KUMAs15 does not significantly induce inflammatory effects in these human cell lines. The upregulated expression of IL-8 and downregulated expression of IL-6 were observed in HaCaT. The HepG2 have shown downregulated IL-12 gene expression. These observations indicate the non-pathogenicity of KUMAs15 on the human cell lines. Conclusion: The observations from the study extend the applicability of the arsenic-resistant Micrococcus sp. KUMAs15 for environmental arsenic decontamination. The isolate KUMAs15 was observed to be non-pathogenic to the human cell lines, as the strain does not initiate inflammatory reactions in these cell lines.