未感染個體對SARS-CoV-2具有低親和力的CD4+T細胞反應
作者：
小柯機器人發布時間：2020/11/29 22:02:20
德國基爾大學Alexander Scheffold研究小組發現，未感染個體對SARS-CoV-2具有低親和力的CD4+T細胞反應。相關論文於2020年11月26日在線發表在《免疫》雜誌上。
研究人員利用SARS-CoV-2-反應性CD4+T細胞富集來檢查了這些細胞的抗原親和力和克隆性，以及普通感冒冠狀病毒（CCCoV）交叉反應性的相對貢獻。 SARS-CoV-2-反應性CD4+記憶性T細胞幾乎存在於所有未暴露個體中，並顯示出低功能親和力和多種高度可變的交叉反應性，但不限於CCCoV。來自COVID-19患者的SARS-CoV-2反應性CD4+T細胞缺乏與CCCoV的交叉反應性，無論在所有分析的供體中對CCCoV的強烈記憶性T細胞反應如何。
在嚴重但非輕度的COVID-19中，儘管頻率增加，但SARS-CoV-2特異性T細胞仍顯示出較低的功能親和力和克隆性。這些發現將低親和力CD4+T細胞反應鑑定為嚴重COVID-19的標誌，並質疑了CCCoV反應性T細胞在SARS-CoV-2感染中的保護作用。
據悉，在未暴露的個體中可以發現對SARS-CoV-2有反應性的CD4+T細胞，這些細胞被認為是對CCCoV感染的反應而產生的。
附：英文原文
Title: Low avidity CD4+ T cell responses to SARS-CoV-2 in unexposed individuals and humans with severe COVID-19
Author: Petra Bacher, Elisa Rosati, Daniela Esser, Gabriela Rios Martini, Carina Saggau, Esther Schiminsky, Justina Dargvainiene, Ina Schder, Imke Wieters, Yascha Khodamoradi, Fabian Eberhardt, Maria J.G.T. Vehreschild, Holger Neb, Michael Sonntagbauer, Claudio Conrad, Florian Tran, Philip Rosenstiel, Robert Markewitz, Klaus-Peter Wandinger, Max Augustin, Jan Rybniker, Matthias Kochanek, Frank Leypoldt, Oliver A. Cornely, Philipp Koehler, Andre Franke, Alexander Scheffold
Issue&Volume: 2020-11-26
Abstract: CD4+ T cells reactive against SARS-CoV-2 can be found in unexposed individuals and these are suggested to arise in response to common cold corona viruses (CCCoVs) infection. Here, we utilized SARS-CoV-2-reactive CD4+ T cell enrichment to examine the antigen-avidity and clonality of these cells, as well as the relative contribution of CCCoV cross-reactivity. SARS-CoV-2-reactive CD4+ memory T-cells were present in virtually all unexposed individuals examined, displaying low functional avidity and multiple, highly variable cross-reactivities that were not restricted to CCCoVs. SARS-CoV-2 reactive CD4+ T cells from COVID-19 patients lacked cross-reactivity to CCCoVs, irrespective of strong memory T-cell responses against CCCoV in all donors analysed. In severe but not mild COVID-19, SARS-CoV-2-specific T-cells displayed low functional avidity and clonality, despite increased frequencies. Our findings identify low avidity CD4+T cell responses as a hallmark of severe COVID-19, and argue against a protective role for CCCoV reactive T cells in SARS-CoV-2 infection.
DOI: 10.1016/j.immuni.2020.11.016
Source: https://www.cell.com/immunity/fulltext/S1074-7613(20)30503-3