曹永長教授研究團(tuán)隊在H7N9流感病毒廣譜疫苗研究領(lǐng)域取得突破性進(jìn)展

中山大學(xué)生命科學(xué)學(xué)院有害生物控制與資源利用國家重點(diǎn)實(shí)驗室曹永長教授團(tuán)隊近期在國際抗病毒權(quán)威期刊《Antiviral Research》上發(fā)表了題目為“A recombinant H7N9 influenza vaccine with the H7 hemagglutinin transmembrane domain replaced by the H3 domain induces increased cross-reactive antibodies and improved interclade protection in mice”的研究論文，報道了一種對血凝素蛋白（Hemagglutinin，HA）進(jìn)行結(jié)構(gòu)設(shè)計的H7N9流感病毒全病毒滅活疫苗，并且證明這種全病毒滅活疫苗可以刺激機(jī)體產(chǎn)生H7N9亞型內(nèi)廣譜交叉免疫反應(yīng)和交叉保護(hù)。

自2013年3月，我國首次報道H7N9流感病毒感染人以來，H7N9流感病毒已經(jīng)經(jīng)歷了5波流行，感染病例1364例（截至2017年4月1日），死亡率達(dá)30%。H7N9流感病毒不僅具有潛在大流行的威脅，也對養(yǎng)禽業(yè)造成了巨大的損失。跟其他流感病毒一樣，H7N9流感病毒變異十分迅速，已經(jīng)形成了多個基因型，因此研制具有廣譜交叉保護(hù)效果的H7N9流感病毒疫苗十分必要。

該團(tuán)隊之前的研究證實(shí)H3亞型HA蛋白跨膜區(qū)（Transmembrane domain，TM）與HA蛋白穩(wěn)定性、HA蛋白交叉免疫原性關(guān)系密切，通過HA跨膜區(qū)置換策略可以提高三聚化H1、H5和H9亞型HA蛋白的亞型間交叉保護(hù)力。在H7N9廣譜疫苗的研究中，該團(tuán)隊將H7N9流感病毒HA蛋白TM置換為H3亞型HA TM，并通過反向遺傳技術(shù)拯救出包含TM置換的重組H7N9流感病毒。在小鼠動物模型中，重組病毒制備的全病毒滅活疫苗能夠誘導(dǎo)機(jī)體產(chǎn)生針對不同分支毒株抗原的更高的HI抗體、HA特異性IgG抗體、HA特異性IFN-γ細(xì)胞因子。并且該疫苗能夠?qū)π∈笸�源或異源H7N9病毒攻毒提供完全保護(hù)，經(jīng)過免疫的小鼠在攻毒后檢測不到肺病毒滴度、無明顯肺部病變和炎癥反應(yīng)。

博士研究生王洋為本文第一作者，曹永長教授為本文通訊作者。

曹永長教授團(tuán)隊長期進(jìn)行動物病毒學(xué)研究，先后獲得國家自然科學(xué)基金、863項目、國家重點(diǎn)研發(fā)計劃項目、廣東省自然科學(xué)基金等科研項目的資助，發(fā)表SCI論文30余篇。目前該團(tuán)隊致力于流感病毒防控、冠狀病毒（豬流行性腹瀉病毒PEDV、雞傳染性支氣管炎病毒IBV）遺傳演化和免疫逃逸機(jī)制研究，已獲得多項研究成果。

A recombinant H7N9 influenza vaccine with the H7 hemagglutinin transmembrane domain replaced by the H3 domain induces increased cross-reactive antibodies and improved interclade protection in mice

Abstract

Influenza A H7N9 virus is the latest emerging pandemic threat, and has rapidly diverged into three clades, demanding a H7N9 virus vaccine with broadened protection against unmatched strains. Hemagglutinin (HA)-based structural design approaches for stabilizing HA proteins have provided excitingly promising results. However, none of the HA-based structural design approaches has been applied to a recombinant replicative influenza virus. Here we report that our HA-based structural design approach is a first in the field to generate a recombinant replicative H7N9 virus (H7N9-53TM) showing broadened protection. The H7N9-53TM contains a replaced H3 HA transmembrane domain (TM) in its HA protein. In mice, the inactivated H7N9-53TM vaccine induced significantly higher HI titers, HA-specific IgG titers, and IFN-γ production than the corresponding H7N9-53WT inactivated virus vaccine containing wild-type HA. More excitingly, mice immunized with the H7N9-53TM showed full protection against homologous (H7N9-53) and interclade (H7N9-MCX) challenges with minimal weight loss, no detectable lung viral loads, and no apparent pulmonary lesions and inflammation, while mice immunized with the H7N9-53WT showed partial protection (only 60% against H7N9-MCX) with severe weight loss, detectable lung viral loads, and severe pulmonary lesions and inflammation. In summary, this study presents a better vaccine candidate (H7N9-53TM) against H7N9 pandemics. Furthermore, our HA-based structural design approach would be conceivably applicable to other subtype influenza viruses, especially the viruses from emerging pandemic and epidemic influenza viruses such as H5N1 and H1N1.

Highlights

The recombinant H7N9-53TM virus with the H7 hemagglutinin transmembrane domain (TM) replaced by the H3 TM was rescued.     

Inactivated H7N9-53TM vaccine induces increased cross-reactive antibodies and improved interclade protection.      

The H3 TM domain replacement technology might be applicable for other subtypes of influenza viruses.

文章鏈接：http://doi.org/10.1016/j.antiviral.2017.03.029

來源：中國病毒學(xué)論壇