Functional and dysfunctional human CD4 T cell and B cell responses to bacteria and viruses

项目摘要 在约50%的人中可以检测到预先存在的对SARS-CoV-2的T细胞记忆。我们首先报道了这一点， 这可能主要是由于来自普通感冒冠状病毒的交叉反应性记忆CD 4 + T细胞 (CCC)感染.虽然这一观察结果已在三大洲得到重现，但最大的未解问题是， 这些交叉反应性记忆T细胞（i）是否能提供某种形式的保护，抵御COVID-19疾病 严重程度，（ii）对COVID-19严重程度没有影响，或（iii）增加COVID-19疾病严重程度。这个问题 在科学，公共和政治领域进行了广泛的讨论，并可能对 了解COVID-19大流行。解决这个问题的直接实验是一项纵向研究， 有感染SARS-CoV-2风险的未感染个体，然后评估COVID-19疾病严重程度， 感染SARS-CoV-2的个体，在有或没有感染前 现有的T细胞记忆SARS-CoV-2。

PROJECT SUMMARY Pre-existing T cell memory to SARS-CoV-2 is detectable in ~50% of people. We first reported this, and we have since shown that this may largely be due to crossreactive memory CD4+ T cells from common cold coronavirus (CCC) infections. While this observation has been reproduced on three continents, the big unanswered question is whether these crossreactive memory T cells (i) confer some form of protection against COVID-19 disease severity, (ii) have no impact on COVID-19 severity, or (iii) increase COVID-19 disease severity. This issue has been widely discussed in scientific, public, and political spheres, and it potentially has major ramifications for understanding the COVID-19 pandemic. The direct experiment to address this topic is a longitudinal study of uninfected individuals at risk for acquisition of SARS-CoV-2, then assessing COVID-19 disease severity in individuals who contract SARS-CoV-2 infection, stratified between individuals who did or did not have pre- existing T cell memory to SARS-CoV-2.