Lipopolysaccharide induces the expression of inflammatory factors and reactive oxygen species production in human peripheral blood mononuclear cells

Alireza Bahiraee,1,* Reyhane ebrahimi,2 Solaleh emamgholipour,3

1. Department of Medical Genetics, Faculty of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
2. Department of Clinical Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
3. Department of Clinical Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran

Abstract

Introduction

The inflammatory role of lipopolysaccharide (lps) has been considered by many researchers. lps is a component within the cell wall of gram-negative bacteria and it has a stimulating effect on the release of inflammatory factors in various cell types. here, we study the priming effects of lps exposure on the gene expression of inflammatory factors including interleukin (il)-6, il-1β, and tnf-α and also reactive oxygen species (ros) production in human peripheral blood mononuclear cells (pbmcs).

Methods

First, peripheral blood was drawn from healthy volunteers and pbmcs were separated using ficoll–paque. then, pbmcs were suspended in roswell park memorial institute (rpmi) culture medium supplement with 5% (v/v) fetal bovine serum and 100 iu/ml penicillin in 6-well plates. next, pbmcs were treated with lps at a concentration of 100 ng/ml for 4 hours and total rna was isolated using geneall rna extraction kit. subsequently, cdna was synthesized by the quantitect reverse transcription kit. real-time measurements were performed after 4 hours incubation in order to investigate the gene expression of il-6, il-1β, and tnf-α using a sybr green assay. moreover, intracellular ros production stimulated by lps was measured by flow cytometry using 2′,7′-dichlorofluorescein diacetate (dcfh).

Results

The gene expression levels of il-6 and tnf-α were significantly higher in pbmcs treated with 100 ng/ml of lps compared with cells left untreated (p < 0.05). additionally, the gene expression of il-1β was higher too but it was not reported as significant. the ros production measured by flow cytometry was higher in pbmcs treated with 100 ng/ml of lps compared with control however it was not statistically significant.

Conclusion

Collectively, it seems likely that lps can mediate the induction of ils and also the intracellular ros production, then it may cause to antibacterial activities of pbmcs. hence, this material can be used as an inflammatory agent in circulating immune cells like pbmcs. moreover, developing effective treatments for its inflammatory responses-induced cellular injury and concurrent sepsis is very imperative.

Keywords

Inflammation, lipopolysaccharide (lps), interleukins, reactive oxygen species (ros)