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

Abstract

Background: 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. Materials and Methods: 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- and IL-4 release assay after stimulation with recall vaccine strains, and in vivo cytokine expression in PBMCs by real-time PCR. Results: 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 GTPvaccinated 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- 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<0.05). In contrast, the IFN- mRNA expression in PBMCs of vaccinated groups was induced early, peaked at week 1 post vaccination and decreased in the weeks thereafter, and this rate was higher in GTP-vaccinated calves compared with SPP-vaccinated calves in all weeks, but the significant difference was only found at week 3 post vaccination (P<0.05). However, the IL-4 mRNA expression showed delayed induction and peaked at week 3, and unlike the SPP group, it remained at this level in GTP group, until the end of experiment. Also this rate of expression in GTP-vaccinated calves was higher than SPP-vaccinated calves in all weeks and had a significant increase at week 5 post vaccination (P<0.05). Conclusion: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.

Review: Vaccines and Vaccination against Lumpy Skin Disease

“…All used adjuvants delivered a strong humoral immunity, but in the case of Adjuvant B, this robust humoral response was insufficient for complete clinical protection [ 68 ]. This supports the assumption that antibody-independent immune reactions are necessary to deliver full and sustainable protection [ 47 , 69 , 70 ]. Although both studies show promising results with inactivated LSDV vaccine prototype candidates, several questions remain unanswered.…”

Cross-Protection of an Inactivated and a Live-Attenuated Lumpy Skin Disease Virus Vaccine against Sheeppox Virus Infections in Sheep

“…Interestingly, these are the very sheep for which very low viremia was also detected. The observation that all vaccinated sheep were protected completely against the clinical signs of SPP after challenge infection with no correlation between protection and antibody titer supports previous reports that the immune status of LSDV-vaccinated or LSDV-infected animals cannot be related directly to the levels of neutralizing antibodies in the sera [3,55] and that cellular immunity also plays an important role in protection against CaPVs [56][57][58].…”

High Efficiency of Low Dose Preparations of an Inactivated Lumpy Skin Disease Virus Vaccine Candidate

“…These findings strengthen the possibility of commercial production of the inactivated vaccine candidate, since this titer can be easily achieved in the used non-bovine cell line, and no costly purification or concentration steps are needed. An evaluation of the cellular immune response analyzing interferon γ or interleukin 4 production and lymphocyte proliferation [ 34 , 35 , 36 , 55 ] could give further insight into the mechanisms of protection of our vaccine prototype and point out differences between different antigen amounts. In addition, an actual minimum protective dose as well as the duration of immunity after vaccination should be addressed in future studies to provide additional information about the protection efficacy of inactivated LSDV prototype vaccines in general and over time.…”