Effects of in vitro exposure to autologous blood and serum on expression of interleukin-8, interleukin-1β, and chemokine (C-X-C motif) ligand 2 in equine primary bronchial epithelial cell cultures.

The research article discusses an in vitro study on the effects of exposure to autologous horse blood, serum, endotoxin and hay dust on gene expression of certain cytokines in equine bronchial epithelial cell cultures. The study finds that these factors potentially contribute to the development of inflammatory airway disease in horses.

Objective of the Study

• The study was conducted to examine how equine bronchial epithelial cell (BEC) cultures respond in vitro to different treatments – autologous horse blood (AHB), autologous horse serum (AHS), lipopolysaccharide, and hay dust.

Methodology of the Study

• BEC cultures were derived from the bronchi of 6 healthy horses.
• The 5-day-old BEC cultures were then exposed to different treatment solutions – PBS solution, two concentrations of AHB, AHS, hay dust solution, and lipopolysaccharide solution – for a 24-hour period.
• Post-treatment, the expressions of the genes for interleukin (IL)-8, IL-1β, CXCL2 (a chemokine), and glyceraldehyde-3-phosphate dehydrogenase were measured using a kinetic PCR assay.

Results of the Study

• All treatments, barring AHS, resulted in the upregulation of the target genes compared to their expression in cultures treated with a PBS solution.
• AHB treatment caused a dose-dependent increase in the gene expression of the cytokines, most notably a greater than 1200-fold increase in IL-1β expression.
• Lipopolysaccharide and hay dust treatments also increased the expressions of the IL-8 and IL-1β genes by 20-fold.
• CXCL2 expression was elevated 7-fold and 8-fold by lipopolysaccharide and hay dust treatments respectively.

Conclusions

• The results suggest that these chemical expressions by equine BECs, particularly chemokines following exposure to blood, could have a role in the development of inflammatory airway disease in horses.