Recently, The Porcine Respiratory Syndrome Innovation Research Team, led by Prof. Zhiyong Ma, has revealed a new mechanism for the inhibition of antigen presentation by highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV). This study provides new insights for further understanding of the immunosuppression and immune escape mechanisms. Research results were published on Journal of Virology online.

Porcine reproductive and respiratory syndrome virus (PRRS) is one of the most important diseases which impair the global pig industry. PRRSV has a variety of strategies to evade and inhibit the immune clearance of the host.

The Porcine Respiratory Syndrome Research Team from Shanghai Veterinary Research Institute conducted an in-depth study of PRRSV-induced host immune suppression and immune escape mechanisms. Researchers started from SLA-I which is a critical molecules in the inhibition of host immune response caused by PRRSV (Figure 1), analyzed the host cell signaling pathway effected by PRRSV. It was found that PRRSV infection caused a down-regulation of B2M, whereas B2M regulated the expression of SLA-I molecules (Fig. 2). In addition, the key regions of B2M were analyzed by constructing different active regions of Nsp4. It was confirmed that Domain III was the key region for Nsp4 to inhibit B2M transcription (Fig. 3).