Study of the effects of Escherichia coli lipopolysaccharide on innate immunity: The expression profile of TLR4 and CD14 genes in rat liver

Abstract

Background: Bacterial endotoxin [lipopolysaccharide (LPS)] is essential for bacterial virulence as it has a biphasic effect which is either harmful and leads to aseptic shock and death or assists the body defense mechanisms as it stimulates B-cells activation. Many studies have noted that LPS do their action through activation of CD14/ TLR4 pathways, which occur mainly in liver cells, including Kupffer cells, hepatocytes, and liver sinusoidal endothelial cells, which are responsible for cytokines releases and shows the good or bad LPS effect.

Aim: The current study aimed to disclose the expression changes in the profile of innate immunological receptors TLR4 and CD14 in rats’ livers after stimulation with LPS.

Methods: Ten groups of male Wistar albino rats were used to study the effects of two types of LPS [extracted LPS from the local strain of Escherichia coli (ELPS) and standard E. coli (SLPS)]; these were given by using different doses (5 mg/kg and 100 µg/kg); the LPS were injected either intravenously or intraperitoneally. The TLR4 and CD14 mRNA expression patterns were estimated using qPCR after 6, 12, and 24 hours postinjection.

Results: The results show that there is a negative effect of ELPS on liver CD14 and TLR4, regardless of the dose and route of administration. On the other hand, the SLPS has an upregulatory impact on the liver gene expression. Also, different times show no effect on the gene expression of the two genes.

Conclusion: This study concludes that both LPS types used were able to stimulate the CD14 and TLR4 gene expression in the liver in different doses and routes of injection. Also, this study showed the possibility of using ELPS as an immunomodulator in rats.