Establishment of ELISpot technique for detection of cellular immunity against PRRSV

Abstract

The porcine reproductive and respiratory syndrome, has a high mortality and morbidity. The vaccination of PRRS is still an important means to control the epidemic disease. The purpose of this paper is to set up an effective method to evaluate cellular immunity against PRRSV. Because the GP5 protein of PRRSV is the largest structure protein and the M protein is the most conserved protein in PRRSV, we selected GP5 protein and M protein to be screened for finding the effective epitope in stimulating T cell response against PRRSV infection. The epitope of GP5 protein and M protein was predicted by using Net-MHC4 server polypeptide MHC I molecules with Artificial Neural Network (ANN). The ELISpot technology was established to detect IFN-γ secreting T lymphocyte, which provides an effective method for evaluation of the cellular immunity in PRRS. The results showed that the polypeptide pool, prepared by mixing multiple polypeptides from GP5 and M protein of PRRSV, was better than any single polypeptide in stimulating T lymphocyte to produce IFN-γ, and the total IFN-γ level in the supernatant of cell culture detected by ELISA was consistent with the result of ELISpot. The ELISpot technique to detect the T cell-mediated immunity of PRRS will pave the way to understand the pathogenesis of PRRS and evaluate the cellular immunity against PRRSV after PRRS vaccination.