Evaluation of Cell-mediated Immune Response in PBMCs of Calves Vaccinated by Capri Pox Vaccines Using ELISA and Real-time RT-PCR

The analysis of antigen-specific cytokine expression has been considered to evaluate the immune responses and vaccines efficacy in recent years. The aim of this study was to compare the cell-mediated immune response characteristics of two Capri pox virus (CaPV) vaccines against lumpy skin disease in cattle.
Two Capri pox virus vaccines were administered to dairy cows of two farms and followed up to 5 weeks post vaccination. These vaccines were live attenuated Goat pox virus (GTP) Gorgan strain (n=20) and Sheep pox virus (SPP) Romanian strain (n=20). Cell-mediated immune response of vaccinated calves was evaluated using in vitro lymphocyte proliferation and IFN-g and IL-4 release assay after stimulation with recall vaccine strains, and in vivo cytokine expression in PBMCs by real-time PCR.
Lymphocyte proliferation in GTP- and SPP-vaccinated groups began to increase till reached to its peak at third week post vaccination and then decreased in the weeks thereafter. Stimulation index in stimulated PBMCs in GTP-vaccinated calves was higher than SPP-vaccinated calves in all weeks, which indicated higher levels of immunogenicity produced by the GTP-vaccine in cattle. Also, in both vaccinated groups the peak release of IFN-g and IL-4 proteins in cultured PBMCs in response to recall antigen was detected at week 3 post vaccination. Although the mean of the cytokine release in GTP-vaccinated calves was higher than SPP-vaccinated calves in all weeks of experiment, a significant difference was only observed at week 3 post vaccination (P The findings show that due to induction of high level cell-mediated immune response in live attenuated GTP vaccine compared to SPP vaccine, GTP vaccine has a good immunogenic response, and therefore can be a better choice for vaccination against lumpy skin disease.