评估严重急性呼吸综合征冠状病毒2（SARS-CoV-2）刺突蛋白突变对抗体结合的影响：在多重Luminex检测中对武汉株和JN.1变体全长刺突蛋白的比较评估。

Assessing the Impact of SARS-CoV-2 Spike Mutations on Antibody Binding: A Comparative Assessment of the Wuhan and JN.1 Variants' Full-Length Spikes in a Multiplex Luminex Assay.

作者信息

Waweru Gerald, Nyakundi Ruth, Kutima Bernadette, Owuor Sharon, Konyino Gloria, Gitonga John, Lugano Doreen, Maina Angela, Musyoki Jennifer, Ochola Lucy, Omondi Martin, Kariuki Christopher K, Ogongo Paul, Mwachari Christina, Shee Faiz, Agoti Charles, Sande Charles, Uyoga Sophie, Kagucia Eunice, Agweyu Ambrose, Bejon Philip, Scott J Anthony G, Warimwe George M, Ochola-Oyier L Isabella, Nyagwange James

机构信息

KEMRI-Wellcome Trust Research Programme, Center for Geographic Medicine Research, Coast, Kilifi P.O. Box 230-80108, Kenya.

School of Pure and Applied Sciences, Department of Biological Sciences, Pwani University, Kilifi P.O. Box 195-80108, Kenya.

出版信息

Viruses. 2025 Sep 16;17(9):1248. doi: 10.3390/v17091248.

DOI:10.3390/v17091248

PMID:41012675

Abstract

UNLABELLED

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) continues to evolve, with mutations leading to the emergence of new variants. JN.1, a subvariant of omicron BA.2.86, has demonstrated marked immune escape and is now included in updated vaccine formulations. While reduced sensitivity has been reported for antibody assays using ancestral spike protein subunits to detect omicron-induced responses, the performance of full-length spike-based assays against omicron sublineages remains unclear. We aimed to compare the sensitivity of ELISA and Luminex assays using full-length spike proteins from the ancestral Wuhan strain and the JN.1 variant.

METHODS

Wuhan and JN.1 full-length spike protein constructs were designed and expressed in Expi293F mammalian cells. In-house ELISAs based on previously validated protocols were used to measure anti-spike IgG levels. Additionally, a Luminex-based assay for anti-spike antibody detection was developed and validated. Both assays were applied to the following sample groups: pre-pandemic samples (designated "gold standard negatives"); PCR confirmed 2020 positives ("gold standard wildtype positives"); PCR confirmed 2024 positives ("gold standard omicron positives"); 2022 vaccinated individuals with verbal confirmed infection ("gold standard hybrid positives"); and 2024 household samples ("unknowns").

RESULTS

Wuhan spike protein showed a sensitivity of 100% (95% CI: 0.88-1.0) in detecting omicron-specific antibodies using gold standard omicron positives with JN.1 spike protein as a reference assay. Overall, across all samples, in ELISA, the Wuhan antigen had a sensitivity of 0.93 (95% CI: 0.89-0.95) and a specificity of 0.98 (95% CI: 0.94-0.99). The JN.1 antigen showed a sensitivity of 0.91 (95% CI: 0.87-0.94) and a specificity of 0.97 (95% CI: 0.93-0.99). In Luminex, sensitivity was 0.95 (95% CI: 0.91-0.97) for Wuhan and 0.94 (95% CI: 0.91-0.96) for JN.1. Specificity for both antigens in Luminex was 0.98 (95% CI: 0.94-0.99).

CONCLUSIONS

Both ELISA and Luminex assays showed comparable sensitivity and specificity for both Wuhan and JN.1 antigens, indicating that mutations in the JN.1 variant do not significantly impact assay performance. This suggests preserved antigenic recognition across variants.

摘要

未标注

严重急性呼吸综合征冠状病毒2（SARS-CoV-2）持续进化，其突变导致新变种出现。奥密克戎BA.2.86的一个亚变种JN.1已表现出显著的免疫逃逸，现已被纳入更新的疫苗配方中。虽然使用原始刺突蛋白亚基的抗体检测方法检测奥密克戎诱导的反应时灵敏度有所降低，但基于全长刺突蛋白的检测方法针对奥密克戎亚谱系的性能仍不明确。我们旨在比较使用来自原始武汉毒株和JN.1变种的全长刺突蛋白的ELISA和Luminex检测方法的灵敏度。

方法

设计武汉和JN.1全长刺突蛋白构建体，并在Expi293F哺乳动物细胞中表达。基于先前验证方案建立的内部ELISA用于测量抗刺突IgG水平。此外，还开发并验证了一种基于Luminex的抗刺突抗体检测方法。两种检测方法均应用于以下样本组：大流行前样本（指定为“金标准阴性”）；PCR确诊的2020年阳性样本（“金标准野生型阳性”）；PCR确诊的2024年阳性样本（“金标准奥密克戎阳性”）；2022年有口头确认感染的接种疫苗个体（"金标准混合阳性"）；以及2024年家庭样本（“未知样本”）。

结果

以JN.1刺突蛋白作为参考检测方法，使用金标准奥密克戎阳性样本时，武汉刺突蛋白在检测奥密克戎特异性抗体方面的灵敏度为100%（95%CI：0.88 - 1.0）。总体而言，在所有样本中，ELISA检测中，武汉抗原的灵敏度为0.93（95%CI：0.89 - 0.95），特异性为0.98（95%CI：0.94 - 0.99）。JN.1抗原的灵敏度为0.91（95%CI：0.87 - 0.94），特异性为0.97（95%CI：0.93 - 0.99）。在Luminex检测中，武汉抗原的灵敏度为0.95（95%CI：0.91 - 0.97），JN.1抗原的灵敏度为0.94（95%CI：0.91 - 0.96）。两种抗原在Luminex检测中的特异性均为0.98（95%CI：0.94 - 0.99）。