Influence of Age and Immunostimulation on the Level of Toll-Like Receptor Gene (, , and ) Expression in Foals.

The aim of this study was to investigate the molecular mechanisms leading to the identification of pathogens by congenital immune receptors in foals up to 60 days of age. The study was conducted on 16 foal Polish Pony Horses (Polish Konik) divided into two study groups: control ( = 9) and experimental ( = 7). Foals from the experimental group received an intramuscular duplicate injection of 5 mL of Biotropina (Biowet) at 35 and 40 days of age. The RNA isolated from venous blood was used to evaluate the expression of the, , and genes using RT-PCR. The results of the experiment demonstrated a statistically significant increase in the level of gene expression and a decrease in the level of gene expression with foal aging. The level of gene expression did not show age dependence. Immunostimulation with Biotropina had a significant impact on the level of the genes' expression for Toll-like receptors. It increased the level of expression and decreased expression. Thus, it was concluded that the expression of the and genes in peripheral blood cells is dependent on age. This experiment demonstrated a strong negative correlation between and gene expression.