Resistance to COVID-19 infection has been observed in health care workers and has been attributed to the presence of memory T cells that target the RNA polymerase in the RTC (replication transcription complex), thereby preventing infection. This makes RNA polymerase an important target for making a pan-coronavirus vaccine that will be effective against SARS-CoV-2 and its other variants of concern (VoC’s), but also against the family of Coronaviruses in general.
Covid-19 流感大流行 is now almost 2 years old and has caused havoc among the world by disrupting world economy and halting the normal way of living. Millions have died and many more have been infected with the disease leading to high levels of morbidity. However, there have been instances where people have cleared the infection from the system so quickly that they didn’t test positive for the 病毒 or developed antibodies against it. This resistance has been attributed to the memory T cells-possibly those that are produced after exposure of the human system to such 病毒.
Swalding 等人最近在《自然》杂志上发表的一项研究中，来自 60 名高风险的医护人员的血液样本 Covid-19 due to their exposure, were examined and found out to be negative for the 病毒 and for the antibodies against the virus1. It is hypothesised that pre-existing memory T-cells, with cross-protective potential against SARS-CoV-2, expand in vivo to provide rapid viral clearance, thus aborting infection. These T cells are directed against the RNA聚合酶 在 RTC（复制转录复合物）中，而不是病毒的任何其他结构蛋白。 这些记忆 T 细胞可能是通过接触其他呼吸道或相关冠状病毒在医护人员中产生的，尽管没有直接证据表明这一点。 也有可能是其他环境因素导致了这些 T 细胞的产生。 此外，这些血清阴性个体还表现出 IFI27 的增加，这是一种指示 SARS-CoV-2 感染流产的蛋白质。 IFI27 是一种干扰素 α 诱导蛋白，在暴露于包括 SARS-CoV-2 在内的多种呼吸道病毒时会过度表达。 这也可能是导致个体病毒清除、预先暴露于其他呼吸道病毒、然后感染 SARS-CoV-2 的原因。
The fact that the memory T cells are directed against the RNA polymerase (being the most conserved among the human 冠状病毒 that cause common cold and SARS-CoV-2), makes this enzyme an important target to develop a pan-冠状病毒 vaccine that would not only be directed against SARS-CoV-2 and its other variants of concern (VoC’s) that have evolved as a result of mutations in the spike protein leading to more severe disease, but also against the family of Coronaviruses in general.
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Sumber:
Swadling, L., Diniz, MO, Schmidt, NM 等。 预先存在的聚合酶特异性 T 细胞在流产的血清阴性 SARS-CoV-2 中扩增。 自然 (2021)。 https://doi.org/10.1038/s41586-021-04186-8
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