流感病毒受体结合与抗原性改变的分子基础

Molecular Base of Influenza Virus Receptor Binding and Antigenicity Changes

流感病毒的血凝素(HA)与宿主细胞表面糖链末端唾液酸(SA)的结合对流感病毒感染宿主起着至关重要的作用。禽流感病毒对SAα2-3Galβ糖链以及人流感病毒对SAα2-6Galβ糖链的结合特异性使跨种属传播受阻,但不同的流感病毒在猪和陆地家禽等中间宿主体内发生基因重配作用后,可使部分禽流感病毒获得适应性感染人的能力,另一方面,流感病毒自身的基因突变,尤其是受体结合部位周围的特定位点,可导致流感病毒受体结合特异性发生转变,而病毒的变异伴随着自身糖修饰和抗原表位的改变,使机体对其免疫识别结合的能力也随之发生变化。这些分子水平的改变都将对病毒相关的宿主受体结合和免疫应答反应产生影响。

The binding of influenza hemagglutinin and sialic acid which′s at the terminal of glycan on host cells′ surface plays a significant role in the infection of influenza virus to the host.Avain influenza virus mainly binds to SA α2-3Galβ glycan,and human influenza virus mainly binds to SA α2-6Galβ glycan,this difference leads to a barrier of interspecies transmission,but intermediate host like pig and terrestrialbird et al.can provide a palce for diverse flu viruses to gene reassort,and help part virus get adaption to infect human,on the other hand,the gene mutation of virus itself,especially in receptor binding domain results in changes of receptor binding specificity,however,the mutantion in virus can also make the sugar modified and antigenic determinant altered,which could change the immune recognition and binding capacity of the virus.All these changes in molecular level can affect the virus receptor binding and immune response.