鸡TRIM25蛋白可促进宿主对禽流感病毒的天然免疫应答

Chicken TRIM25 protein promotes host antiviral innate immune response to avian influenza virus in chicken fibroblast cells

TRIM家族蛋白在抗病毒天然免疫中发挥着重要作用.然而,鸡TRIM25(chicken tripartite motif25,chTRIM25)蛋白对禽流感病毒复制的影响仍不明确.本文旨在克隆chTRIM25基因并初步分析其功能.首先应用RT-PCR方法,从鸡成纤维细胞(chicken embryo fibroblast, CEF)中扩增chTRIM25基因.序列分析发现, chTRIM25基因可读框全长1902 bp,编码633个氨基酸,预测其分子量为71.42 kD.结构预测发现, chTRIM25蛋白的21～66位氨基酸为RING结构域, 110～146位氨基酸为B-box1结构域, 160～189位氨基酸为B-box2结构域, 208～311位氨基酸则为卷曲螺旋结构域, 465～633位氨基酸则为B30.2结构域.同源性分析发现,鸡TRIM25与鸭和鹅TRIM25氨基酸序列同源性在74%～77%,具有较高的同源性;而鸡TRIM25与人和鼠TRIM25的氨基酸序列同源性在46%左右,同源性较低.荧光定量实验发现,在禽流感病毒感染CEF后, TRIM25及相关抗病毒相关因子的表达量上调;也发现,TRIM25可以促进流感病毒对天然免疫信号通路的激活.这为深入了解TRIM25基因在禽流感病毒感染宿主后激发的宿主抗病毒天然免疫应答提供实验基础.

TRIM family proteins play an important role in antiviral innate immunity.However,the function of chicken TRIM25(chTRIM25) protein remains unclear.In this study,we cloned the full-length of chTRIM25gene and analyzed its function.Sequence analysis revealed that chicken TRIM25 contained a 1902-bp open-reading frame that probably encodes a 633-amino acid protein with a molecular weight of 71.42kD.Structural analysis demonstrated that the chTRIM25 protein had a RING finger domain (amino acids 21-66),B-boxl (amino acids 110-146),B-box2(amino acids 160-189),a coiled-coil region (amino acids 208-311) and B30.2 domain (amino acids 465-633).The homology analysis showed that the amino acid sequence homology of chicken TRIM25 with duck and goose TRIM25 was from 74% to 77%,while the amino acid sequence homology of chicken TRIM25 with human and mouse TRIM25 was about 46%.We further found that chTRIM25 promoted type I interferon-mediated immune response to avian influenza virus in chicken fibroblast cells.This study will help us to further understand the host antiviral innate immune response to avian influenza virus in chickens.