Yu Xiaocong, Tsibane Tshidi, McGraw Patricia A, House Frances S, Keefer Christopher J, Hicar Mark D, Tumpey Terrence M, Pappas Claudia, Perrone Lucy A, Martinez Osvaldo, Stevens James, Wilson Ian A, Aguilar Patricia V, Altschuler Eric L, Basler Christopher F, Crowe James E
Departments of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA.
Nature. 2008 Sep 25;455(7212):532-6. doi: 10.1038/nature07231. Epub 2008 Aug 17.
Investigation of the human antibody response to influenza virus infection has been largely limited to serology, with relatively little analysis at the molecular level. The 1918 H1N1 influenza virus pandemic was the most severe of the modern era. Recent work has recovered the gene sequences of this unusual strain, so that the 1918 pandemic virus could be reconstituted to display its unique virulence phenotypes. However, little is known about adaptive immunity to this virus. We took advantage of the 1918 virus sequencing and the resultant production of recombinant 1918 haemagglutinin (HA) protein antigen to characterize at the clonal level neutralizing antibodies induced by natural exposure of survivors to the 1918 pandemic virus. Here we show that of the 32 individuals tested that were born in or before 1915, each showed seroreactivity with the 1918 virus, nearly 90 years after the pandemic. Seven of the eight donor samples tested had circulating B cells that secreted antibodies that bound the 1918 HA. We isolated B cells from subjects and generated five monoclonal antibodies that showed potent neutralizing activity against 1918 virus from three separate donors. These antibodies also cross-reacted with the genetically similar HA of a 1930 swine H1N1 influenza strain, but did not cross-react with HAs of more contemporary human influenza viruses. The antibody genes had an unusually high degree of somatic mutation. The antibodies bound to the 1918 HA protein with high affinity, had exceptional virus-neutralizing potency and protected mice from lethal infection. Isolation of viruses that escaped inhibition suggested that the antibodies recognize classical antigenic sites on the HA surface. Thus, these studies demonstrate that survivors of the 1918 influenza pandemic possess highly functional, virus-neutralizing antibodies to this uniquely virulent virus, and that humans can sustain circulating B memory cells to viruses for many decades after exposure-well into the tenth decade of life.
对人类针对流感病毒感染的抗体反应的研究在很大程度上局限于血清学，在分子水平上的分析相对较少。1918年的H1N1流感大流行是现代史上最严重的一次。最近的研究已经找回了这种不寻常毒株的基因序列，从而可以重建1918年的大流行病毒以展示其独特的毒力表型。然而，对于这种病毒的适应性免疫了解甚少。我们利用1918年病毒测序以及由此产生的重组1918血凝素（HA）蛋白抗原，在克隆水平上对幸存者自然接触1918年大流行病毒所诱导的中和抗体进行了表征。在这里我们表明，在测试的32名出生于1915年或之前的个体中，在大流行近90年后，每个人都显示出与1918年病毒的血清反应性。在测试的八个供体样本中，有七个样本的循环B细胞分泌的抗体能结合1918年的HA。我们从受试者中分离出B细胞，并产生了五种单克隆抗体，这些抗体对来自三个不同供体的1918年病毒显示出强大的中和活性。这些抗体还与1930年猪H1N1流感毒株的基因相似的HA发生交叉反应，但与更现代的人类流感病毒的HA没有交叉反应。抗体基因具有异常高的体细胞突变程度。这些抗体以高亲和力结合1918年的HA蛋白，具有非凡的病毒中和效力，并能保护小鼠免受致命感染。分离出逃避抑制的病毒表明，这些抗体识别HA表面的经典抗原位点。因此，这些研究表明，1918年流感大流行的幸存者拥有针对这种独特毒力病毒的高功能、病毒中和抗体，并且人类在接触病毒数十年后仍能维持针对病毒的循环B记忆细胞——直至生命的第十个十年。
