TLR-2 DEPENDENT AND ITS ASSOCIATED CYTOKINES EXPRESSION PROFILE IN PRIMO AND REVACCINATED DAIRY CATTLE IMMUNIZED WITH AN INACTIVATED FOOT-AND-MOUTH DISEASE VACCINE

The only way to control foot-and-mouth disease (FMD) is through vaccination. The purpose of this study was to determine the TLR2 dependent and its associated cytokine expression profile in cattle. 18 animals were divided into three groups: control-naive calves (06), Gr1-primo-vaccinated calves (06), and Gr2-revaccinated adult animals (06). Gr1 and Gr2 animals were vaccinated intramuscularly with 2 ml of trivalent FMDV inactivated vaccine. On the 0th, 14th, and 21st days post vaccination (DPV), whole blood (4 ml) was collected, followed by RNA extraction and cytokine estimation by RT-qPCR. The abundance of these target genes’ mRNA was calibrated against a housekeeping gene (18-S) and expressed as a fold increase over the 0th DPV control. In the control, there was no significant difference in the expression of IL-6, IL-10, IL-12, IL-17, and IL-21. IL-10, IL-17, and IL-21 were significantly upregulated in Gr-1 on the 14th DPV, whereas IL-6, IL-17, and IL-21 were significantly up regulated on the 21st DPV. On the 14th DPV, significant up regulation of IL-21 was observed in Gr-2, while significant up regulation of IL-6, IL-17, and IL-21 was observed on the 21st DPV. The current research sheds new light on the differential expression of these TLR2 dependent and its associated cytokines following vaccine administration. The presence of good antibody titre could be indicated by the up regulation of IL-6, IL-17, and IL-21 following FMD vaccination. This could lead to the use of cytokine agonists as adjuvant during vaccine formulation to modulate immune response following vaccine inoculation.