Toll-like receptor ligands enhance the protective effects of vaccination against porcine reproductive and respiratory syndrome virus in swine

作者：Zhang, Lili; Bai, Juan; Liu, Jie; Wang, Xiaoye; Li, Yufeng; Jiang, Ping^*

来源：Veterinary Microbiology, 2013, 164(3-4): 253-260.

DOI：10.1016/j.vetmic.2013.02.016

• PRRSV
• Killed virus (KV) vaccine
• TLR ligands
• Adjuvants

Porcine reproductive and respiratory syndrome virus (PRRSV) is mainly responsible for the heavy economic losses in pig industry in the world. Current vaccination strategies provide only a limited protection. Previous studies have demonstrated the immunostimulatory adjuvant effects of Toll-like receptor (TLR) ligands, synthetic double-stranded RNA polyriboinosinic polyribocytidylic [poly(I:C)], lipoteichoic acid (LTA) and CL097 in humans and animals. To study the effects of these compounds on the induction of PRRSV-specific immune responses, mice were immunized subcutaneously with killed virus (KV) antigens incorporating pairs of TLR ligands. It was found that poly(I:C) and CL097 induced the higher IFN-gamma levels and PRRSV-specific antibodies, comparing with that KV with or without LTA in mice. Piglets were vaccinated with the KV mixed with poly(I:C) or CL097 and the protective effects of the vaccination were evaluated. The results showed that PRRSV-specific antibodies and T lymphocyte proliferation levels in KV mixed with poly(I:C) or CL097 groups were higher than those in KV group. Following challenge with PRRSV, pigs inoculated with KV mixed with poly(I:C) or CL097 showed lighter clinical signs, lower viremia and less pathological lesion of lungs, as compared to those of KV and challenge control groups. It indicated that co-administration of poly(I:C) and CL097 with killed PRRSV vaccine conferred higher protection against PRRSV challenge. TLR3 and TLR7/8 ligands are promising adjuvant candidates for the development of novel vaccines against PRRSV.

• 出版日期2013-6-28
• 单位南京农业大学