PEDV经母猪乳汁垂直传播给新生仔猪的机制研究

由猪流行性腹泻病毒（PEDV）引起的猪流行性腹泻（PED）主要发生在新生仔猪。PED具有多种传播途径，其中从母猪乳汁传递给新生仔猪的垂直传播也是大型猪场的重要传播途径。本项目前期工作表明PEDV可劫持淋巴细胞，作为病毒血症的携带者。进一步调查发现感染PEDV母猪初乳中淋巴细胞也携带PEDV。但迄今关于PEDV经母猪乳汁垂直传播新生仔猪的机理仍不清楚。本项目将对PEDV的垂直传播机制开展一系列研究：主要包括母猪感染PEDV后经小肠上皮细胞传播给淋巴细胞的机制，树突状细胞摄取PEDV再传播给淋巴细胞的机制，携带PEDV的淋巴细胞向乳腺中迁移以及进入腺泡腔中的机制，初乳中淋巴细胞将PEDV传播给新生仔猪肠上皮的机制等。重点探索携带PEDV的淋巴细胞迁移以及变形运动的机制。本项目科学问题来源于生产实践，研究结果通过揭示PEDV经乳汁垂直传播的机理，直接为流行性腹泻的预防和发生提供新的策略。

Porcine epidemic diarrhea (PED), caused by porcine epidemic diarrhea virus (PEDV), mainly affects neonatal piglets. PED spread widely by multiple routes, among which the vertical transmission from sow to newborn piglets via milk is also a major route of PEDV in large scale swine farms. Our previous study showed that PEDV could hijack lymphocytes to be carrier as viremia after infection. Further investigation revealed that PEDV also was detected in the lymphocytes from sow colostrum. A hypothesis was proposed that PEDV could vertical disseminate from sow to newborn piglets by breast milk. The mechanism by which PEDV vertical transmission to newborn piglets via milk will be systemically investigated in the project: 1)the mechanism by which intestinal epithelia transfer PDEV to lymphocytes in the sow; 2) the mechanism by which dendritic cells (DCs)uptake PDEV and then transfer PDEV to lymphocytes; 3) the mechanism by which PDEV-carrying lymphocytes migrate to mammary gland and then pass through acinus epithelium into the lumen(colostrum); 4)PDEV -carrying lymphocytes in the colostrum transfer virus to intestinal epithelia of newborn piglets. The mechanism by which PDEV-carrying lymphocytes migration and ameboid movement will be emphasized. The hypothesis of our study directly come from swine industry. Our results will provide strategies to prevent and control PED infection after a better understanding of the PDEV vertical transmission from sow to newborn piglets via milk.