英国伯明翰大学Paul Moss、伦敦大学Shamez Ladhani等研究人员合作发现，SARS-CoV-2特异性T细胞免疫可在感染6个月后仍维持。2021年3月5日，《自然—免疫学》杂志在线发表了这项成果。

研究人员分析了感染后6个月内100名志愿者中SARS-CoV-2特异性T细胞应答的大小和表型。通过ELISPOT和/或细胞内细胞因子染色分析，并以具有强白介素（IL）-2表达的主要CD4⁺T细胞应答为特征，研究人员发现T细胞应答均存在。在经历症状性感染的志愿者中，T细胞反应中值高出50％，这表明原发性感染的严重程度为细胞免疫建立了“设定点”。T细胞对突刺和核蛋白/膜蛋白的反应与峰值抗体水平相关。

此外，较高水平的核蛋白特异性T细胞与核蛋白特异性抗体水平的保持相关，尽管未观察到与刺突特异性应答有关的这种相关性。总之，这些数据表明，感染后6个月内SARS-CoV-2特异性T细胞应答仍存在。 

据悉，对SARS-CoV-2的免疫反应对于控制疾病至关重要，但人们担心免疫力的下降可能会导致再次感染。

附：英文原文

Title: Robust SARS-CoV-2-specific T cell immunity is maintained at 6 months following primary infection

Author: Jianmin Zuo, Alexander C. Dowell, Hayden Pearce, Kriti Verma, Heather M. Long, Jusnara Begum, Felicity Aiano, Zahin Amin-Chowdhury, Bassam Hallis, Lorrain Stapley, Ray Borrow, Ezra Linley, Shazaad Ahmad, Ben Parker, Alex Horsley, Gayatri Amirthalingam, Kevin Brown, Mary E. Ramsay, Shamez Ladhani, Paul Moss

Issue&Volume: 2021-03-05

Abstract: The immune response to SARS-CoV-2 is critical in controlling disease, but there is concern that waning immunity may predispose to reinfection. We analyzed the magnitude and phenotype of the SARS-CoV-2-specific T cell response in 100 donors at 6 months following infection. T cell responses were present by ELISPOT and/or intracellular cytokine staining analysis in all donors and characterized by predominant CD4+ T cell responses with strong interleukin (IL)-2 cytokine expression. Median T cell responses were 50% higher in donors who had experienced a symptomatic infection, indicating that the severity of primary infection establishes a ‘set point’ for cellular immunity. T cell responses to spike and nucleoprotein/membrane proteins were correlated with peak antibody levels. Furthermore, higher levels of nucleoprotein-specific T cells were associated with preservation of nucleoprotein-specific antibody level although no such correlation was observed in relation to spike-specific responses. In conclusion, our data are reassuring that functional SARS-CoV-2-specific T cell responses are retained at 6 months following infection.

DOI: 10.1038/s41590-021-00902-8

Source: https://www.nature.com/articles/s41590-021-00902-8