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Published on: November 22, 2024
Differential expression of toll-like receptor mRNA in corneal epithelium of ruminants
Sakthivel Dhanasekaran1, Thandavan Arthanari Kannan, Gopal Dhinakar Raj
1Department of Animal Biotechnology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai 600 007, India.
Purpose:
The present study was carried out to identify and assess the expression levels of toll-like receptors (TLRs) 1-10 mRNA in corneal epithelial cells of buffalo, goat, sheep and bull.
Materials And Methods:
The globes from the respective species were collected and the corneal epithelium was denuded. The expression levels of the different TLR mRNAs were assessed by densitometry of the band intensities following reverse transcriptase polymerase chain reaction (RT-PCR).
Results:
In all species TLR5 and TLR7 were highly expressed with lower levels of TLR10. The TLR6 mRNA levels were the lowest in the cornea of bull. The TLR2 expression was high in sheep and bulls, while TLR4 mRNA was higher in sheep alone. The level of the other TLRs varied across other species.
Conclusion:
Based on these observations it may be inferred that these animals would be resistant to flagellin (TLR5) and single-stranded RNA viruses (TLR7), while sheep alone may show more resistance to lipo-polysaccharide (TLR4) and peptidoglycan (TLR2)-mediated injury of the cornea. This work reports for the first time the expression of TLR mRNAs in the corneal epithelial cells of farm animals. The relationship of the TLR mRNA levels to corneal disease susceptibilities and pathogenicity remains to be explored further.
Insights
Toll-like receptors (TLRs) mRNA expression varies in farm animal corneas. High TLR5 and TLR7 levels suggest resistance to flagellin and RNA viruses, with sheep showing unique TLR4 and TLR2 expression patterns.
Area of Science:
- Veterinary immunology
- Ocular immunology
- Molecular biology
Background:
- Toll-like receptors (TLRs) are crucial innate immune sensors.
- Understanding TLR expression in animal corneas is vital for ocular health.
- Farm animals possess unique immune responses to ocular pathogens.
Purpose of the Study:
- To identify and quantify toll-like receptors (TLRs) 1-10 mRNA in corneal epithelial cells.
- To compare TLR mRNA expression across buffalo, goat, sheep, and bull corneas.
- To establish a baseline for TLR expression in the cornea of these species.
Main Methods:
- Corneal epithelium was isolated from buffalo, goat, sheep, and bull globes.
- Reverse transcriptase polymerase chain reaction (RT-PCR) was employed to assess mRNA levels.
- Densitometry of band intensities quantified the expression of various TLR mRNAs.
Main Results:
- TLR5 and TLR7 mRNA showed high expression in all studied species.
- TLR10 mRNA levels were consistently low across all species.
- TLR6 was lowest in bulls; TLR2 was high in sheep and bulls; TLR4 was highest in sheep.
Conclusions:
- High TLR5 and TLR7 suggest resistance to flagellin and viral RNA.
- Sheep may exhibit greater resistance to LPS and peptidoglycan-induced corneal injury.
- This study provides the first report on TLR mRNA expression in farm animal corneas, necessitating further research into disease susceptibility.
