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Porcine CD14 gene silencing partially inhibited the bacterial immune response mediated by TLR4 signaling pathway
Chaohui Dai1, Haifei Wang1, Guoqiang Zhu2
1Key Laboratory for Animal Genetics, Breeding, Reproduction and Molecular Design of Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu 225009, China.
Abstract:
Cluster of differentiation antigen 14 (CD14) is the membrane receptor protein in Toll-like Receptor 4 (TLR4) signaling pathway, which plays an important regulation role in not only innate immune response but also adaptive immune response. In this study, the pig kidney epithelial cell (PK15) line with CD14 gene silencing mediated by lentivirus was established and cells of CD14-RNAi and NC group were exposed to three kinds of Escherichia coli (E. coli F18ab, E. coli F18ac and E. coli K88ac) and LPS. Then qPCR and western blot were used to detect expression levels of TLR4 signaling pathway-related genes. Finally, ELISA was used to detect the level of proinflammatory cytokines in the cell culture supernatant. The results showed that the expression level of TLR4 signaling pathway-related genes in the entire signal pathway had obvious increases when cells were exposed to the stimulation induced by E. coli and LPS. In addition, the expression levels of CD14-RNAi group were overall significantly lower than NC group (P<0.05 or P<0.01), which was the same with the release levels of proinflammatory cytokines. This study revealed that pig CD14 gene silencing partially inhibited immune response to E. coli F18 invasion mediated by TLR4 signaling pathway.
Insights
Pig CD14 gene silencing partially inhibited immune responses to E. coli invasion. This study investigated the Toll-like Receptor 4 (TLR4) pathway, finding reduced inflammatory cytokines and gene expression after CD14 silencing.
Area of Science:
- Immunology
- Molecular Biology
- Veterinary Science
Background:
- Cluster of differentiation antigen 14 (CD14) is a key receptor in the Toll-like Receptor 4 (TLR4) signaling pathway.
- CD14 plays a critical role in both innate and adaptive immune responses.
- Understanding CD14's function is crucial for addressing bacterial infections in livestock.
Purpose of the Study:
- To investigate the role of CD14 in the pig immune response to Escherichia coli (E. coli) infection.
- To determine the effect of CD14 gene silencing on the TLR4 signaling pathway and pro-inflammatory cytokine release.
Main Methods:
- Establishment of a pig kidney epithelial cell (PK15) line with CD14 gene silencing using lentivirus.
- Exposure of CD14-silenced and control cells to E. coli strains (F18ab, F18ac, K88ac) and lipopolysaccharide (LPS).
- Quantitative PCR (qPCR), Western blot, and ELISA were used to analyze gene expression and cytokine levels.
Main Results:
- E. coli and LPS stimulation significantly increased TLR4 signaling pathway-related gene expression.
- CD14 gene silencing markedly reduced the expression of these genes compared to the control group (P<0.05 or P<0.01).
- Pro-inflammatory cytokine release was significantly lower in the CD14-silenced cells.
Conclusions:
- Pig CD14 gene silencing partially inhibits the immune response to E. coli F18 invasion.
- CD14 plays a significant role in mediating the TLR4 signaling pathway activation during E. coli infection in pigs.
- Targeting CD14 could be a potential strategy for managing bacterial infections in swine.
