Maurer Daniel P, Vu Mya, Ramos Ana S Ferreira, Dugan Haley L, Khalife Paul, Geoghegan James C, Walker Laura M, Bajic Goran, Schmidt Aaron G
bioRxiv. 2024 Nov 2:2024.10.22.619298. doi: 10.1101/2024.10.22.619298.
Monoclonal antibodies (mAbs) targeting the influenza hemagglutinin (HA) have the potential to be used as prophylactics or templates for next-generation vaccines that provide broad protection. Here, we isolated broad, subtype-neutralizing mAbs from human B cells targeting the H1 or H3 HA head as well as a unique mAb targeting the stem. The H1 mAbs target the previously defined lateral patch epitope on H1 HAs and recognize HAs from 1933 to 2021 in addition to a swine H1N1 virus with pandemic potential. Using directed evolution, we improved the neutralization potency of these H1 mAbs towards a contemporary H1 strain. Using deep mutational scanning of four antigenically distinct H1N1 viruses, we identified potential viral escape pathways. For the H3 mAbs we used cryo-EM to define the targeted epitopes: one mAb recognizes the side of the H3 head, accommodating the N133 glycan and a pocket underneath the receptor binding site. The other H3 mAb recognizes an epitope in the HA stem that overlaps with previously characterized mAbs, but with distinct antibody variable genes and mode of recognition. Collectively, these mAbs identify common sites recognized by broad, subtype-specific mAbs that may be elicited by next-generation vaccines.
靶向流感血凝素（HA）的单克隆抗体（mAb）有潜力用作预防性药物或下一代疫苗的模板，从而提供广泛的保护。在此，我们从人B细胞中分离出了广泛的、亚型中和性单克隆抗体，这些抗体靶向H1或H3 HA头部，以及一种靶向茎部的独特单克隆抗体。H1单克隆抗体靶向H1 HA上先前定义的侧向斑块表位，除了一种具有大流行潜力的猪H1N1病毒外，还能识别1933年至2021年的HA。通过定向进化，我们提高了这些H1单克隆抗体对当代H1毒株的中和效力。利用对四种抗原性不同的H1N1病毒进行深度突变扫描，我们确定了潜在的病毒逃逸途径。对于H3单克隆抗体，我们使用冷冻电镜来确定靶向表位：一种单克隆抗体识别H3头部的侧面，容纳N133聚糖和受体结合位点下方的一个口袋。另一种H3单克隆抗体识别HA茎部的一个表位，该表位与先前表征的单克隆抗体重叠，但具有不同的抗体可变基因和识别模式。总体而言，这些单克隆抗体确定了广泛的、亚型特异性单克隆抗体所识别的共同位点，这些位点可能由下一代疫苗引发。
