GRP78/Bip调控IBDV诱导淋巴细胞凋亡的分子机制

Infectious bursal disease（IBD）is an acute, highly contagious avian disease caused by infectious bursal disease virus (IBDV). IBDV leads to injury of bursa lymphocytes, which resulting in severe immunosuppression. Studies have shown that the unfolded protein response (UPR) of endoplasmic reticulum stress performs crucial role in the regulation of viral infection, which glucose-regulated protein 78 (GRP78/Bip) is a central regulator of UPR response. The main aim of the present research is to study the influence of GRP78/Bip for lymphocyte apoptosis infected by IBDV. GRP78/Bip will be highly and lowly expressed in primary lymphocytes incubated in vitro, which the lymphocytes infected by IBDV. SPF chicken is transfected by GRP78/Bip siRNA in vivo, which the level of GRP78/Bip is reduced and then the SPF chicken is infected by IBDV. The expression of GRP78/Bip and the changes of UPR signaling pathway as well as the lymphocyte apoptosis in vitro and in vivo are detected through molecular biology techniques and modern immunity technology after infection by IBDV. The role of GRP78/Bip is analyzed and the regulation mechanism is explored in lymphocytes apoptosis induced by IBDV, which can present scientific evidence and establish theory foundation through clarifying further GRP78/Bip molecule regulatory mechanism for lymphocytes infected by IBDV.

传染性法氏囊病（IBD）是由传染性法氏囊病病毒（IBDV）引起的一种鸡急性、高接触性传染病。IBDV可导致法氏囊淋巴细胞损伤，产生严重的免疫抑制。内质网应激未折叠蛋白反应（UPR）在调控病毒感染上具有重要作用，葡萄糖调节蛋白 78（GRP78/Bip）是UPR反应的中心调节子。本课题主要研究GRP78/Bip对IBDV感染淋巴细胞凋亡的影响，拟在离体培养原代淋巴细胞内高表达、低表达GRP78/Bip，IBDV感染；GRP78/Bip siRNA在体转染SPF鸡，下调其表达，IBDV感染；应用分子生物学技术与现代免疫技术研究IBDV感染在体、离体淋巴细胞内GRP78/Bip表达，UPR信号通路变化，淋巴细胞凋亡相关性，解析GRP78/Bip在IBDV诱导淋巴细胞凋亡中的作用，阐明GRP78/Bip调控IBDV感染宿主淋巴细胞抗病毒损伤分子机制，为该病的防制提供科学的依据并奠定理论基础。

传染性法氏囊病（IBD）是由传染性法氏囊病毒（IBDV）引起的一种雏禽鸡急性、高接触性传染病。IBDV导致法氏囊淋巴细胞损伤，产生严重的免疫抑制。.本课题通过荧光免疫实验、免疫组织化学实验对IBDV感染鸡不同时间点病毒的复制、增殖特点进行了研究，发现IBDV在感染雏鸡6-12小时后，胸腺皮质、髓质内淋巴细胞形态正常，未见IBDV病毒颗粒，法氏囊间质与淋巴滤泡内未见病毒颗粒。感染后24小时弥散性胸腺小体内的小囊、小泡内出现少量IBDV颗粒，从髓质向皮质边缘侵染，在整个感染期内持续存在，但淋巴小结中不存在病毒粒子；法氏囊滤泡内出现少量病毒粒子，72-120小时达到峰值。这种IBDV病毒破坏法氏囊B淋巴细胞，在胸腺弥散小体淋巴小结外周持续存在的特性，是造成雏鸡免疫抑制的主要因素。.此外，本课题通过小RNA干扰技术、western blot技术、实时荧光定量PCR技术、流式细胞术等对IBDV感染鸡不同时间点GRP78/Bip表达特点及信号通路进行了研究，结果表明GRP78/Bip表达在IBDV感染6-24后小时显著减少，在48-96小时显著增多；下调其表达，B淋巴细胞凋亡变化不明显，这揭示在IBDV淋巴细胞内复制、增殖过程中，GRP78/Bip对细胞凋亡调控仅具有辅助调控作用。