Emmenegger Marc, Fiedler Sebastian, Brugger Silvio D, Devenish Sean R A, Morgunov Alexey S, Ilsley Alison, Ricci Francesco, Malik Anisa Y, Scheier Thomas, Batkitar Leyla, Madrigal Lidia, Rossi Marco, Meisl Georg, Lynn Andrew K, Saleh Lanja, von Eckardstein Arnold, Knowles Tuomas P J, Aguzzi Adriano
Institute of Neuropathology, University of Zurich, 8091 Zurich, Switzerland.
Fluidic Analytics, Unit A, The Paddocks Business Centre, Cherry Hinton Road, Cambridge CB1 8DH, UK.
iScience. 2022 Aug 19;25(8):104766. doi: 10.1016/j.isci.2022.104766. Epub 2022 Jul 16.
The B.1.1.529 (omicron) variant has rapidly supplanted most other SARS-CoV-2 variants. Using microfluidics-based antibody affinity profiling (MAAP), we have characterized affinity and IgG concentration in the plasma of 39 individuals with multiple trajectories of SARS-CoV-2 infection and/or vaccination. Antibody affinity was similar against the wild-type, delta, and omicron variants ( ranges: 122 ± 155, 159 ± 148, 211 ± 307 μM, respectively), indicating a surprisingly broad and mature cross-clade immune response. Postinfectious and vaccinated subjects showed different IgG profiles, with IgG3 (p-value = 0.002) against spike being more prominent in the former group. Lastly, we found that the ELISA titers correlated linearly with measured concentrations (R = 0.72) but not with affinity (R = 0.29). These findings suggest that the wild-type and delta spike induce a polyclonal immune response capable of binding the omicron spike with similar affinity. Changes in titers were primarily driven by antibody concentration, suggesting that B-cell expansion, rather than affinity maturation, dominated the response after infection or vaccination.
B.1.1.529（奥密克戎）变种已迅速取代了大多数其他严重急性呼吸综合征冠状病毒2（SARS-CoV-2）变种。我们使用基于微流控的抗体亲和力分析（MAAP），对39名有多种SARS-CoV-2感染和/或疫苗接种轨迹的个体血浆中的亲和力和IgG浓度进行了表征。针对野生型、德尔塔和奥密克戎变种的抗体亲和力相似（范围分别为：122±155、159±148、211±307μM），表明存在令人惊讶的广泛且成熟的跨分支免疫反应。感染后和接种疫苗的受试者表现出不同的IgG谱，其中针对刺突蛋白的IgG3（p值 = 0.002）在前一组中更为突出。最后，我们发现酶联免疫吸附测定（ELISA）滴度与测量浓度呈线性相关（R = 0.72），但与亲和力无关（R = 0.29）。这些发现表明，野生型和德尔塔刺突蛋白诱导了一种能够以相似亲和力结合奥密克戎刺突蛋白的多克隆免疫反应。滴度变化主要由抗体浓度驱动，这表明B细胞扩增而非亲和力成熟在感染或接种疫苗后的反应中占主导地位。
