Screening for regulators of SARS CoV-2 infection and inflammation

先天免疫系统的细胞，如树突状细胞和巨噬细胞，不断巡逻宿主粘膜表面和周围组织，寻找感染或损伤的迹象。由于许多感染SARS-CoV-2病毒的人清除了病毒而没有出现症状，因此先天免疫反应方面可能是击败这种病毒及其变种的关键。 在之前的工作中，我们研究了生物活性小分子如何在先天性免疫细胞中传递调制效应，在某些情况下，提供延长的长期记忆。在对具有生物活性的小分子进行肿瘤坏死因子诱导调节的筛选中，我们鉴定了几种具有诱导人巨噬细胞训练作用的化合物。在这些化合物中，Syk激酶抑制剂(SYKi IV)的筛选可促进对内毒素的增强反应，与先前报道的β-葡聚糖类似。此外，我们发现，Syk激酶抑制剂训练的巨噬细胞具有增强的细胞因子输出，并对多种SARS CoV-2变异株、OC43冠状病毒和流感病毒感染具有抵抗力。 在2023财年，我们在NIH临床中心与Jeffrey Strich建立了合作关系，因为他有一组COVID患者接受了Syk抑制剂福斯塔替尼的治疗。我们假设服用福斯塔替尼的患者可能接受了先天免疫训练，以增强他们对病毒感染的反应。因此，福斯塔替尼治疗组显示出改善的COVID结果，但尚不清楚他们免疫细胞图谱的哪些方面可以支持这种影响。 我们正在使用COVID资金的剩余部分与人类免疫学中心(CHI)共同开展一项CITE-SEQ/ATAC-SEQ联合研究，使用患者队列中的PBMC，我们用脂多糖进行了体外治疗。这将使我们能够确定福斯塔替尼训练的细胞是否有增强的炎症输出，以及各种免疫细胞亚群的转录谱(通过CITE-SEQ确定)如何与染色质可及性(从ATAC序列谱确定)相关。福斯塔替尼治疗组和对照组的进一步比较将使我们能够评估Syk激酶抑制所带来的潜在的先天免疫训练效果。

Cells of the innate immune system, such as dendritic cells and macrophages, constantly patrol host mucosal surfaces and peripheral tissues for signs of infection or injury. Since many people infected with SARS-CoV-2 clear the virus without developing symptoms, aspects of the innate immune response may hold the key to defeating this virus and its variants. In prior work, we investigated how biologically active small molecules can impart modulatory effects in innate immune cells, in some cases, providing extended long-term memory. In a screen of biologically active small molecules for regulators of TNF induction, we identified several compounds with the ability to induce training effects on human macrophages. Among these compounds, a Syk kinase inhibitor (SYKi IV) screen hit promoted an enhanced response to LPS similar to that previously reported for beta-glucan. Moreover, we found that Syk kinase inhibitor-trained macrophages exhibit enhanced cytokine output and resistance to multiple SARS CoV-2 variants, OC43 coronavirus and influenza viral infection. In FY2023, we established a collaboration with Jeffrey Strich in the NIH Clinical Center, as he had a cohort of COVID patients who were treated with the Syk inhibitor fostamatinib. We hypothesized that the patients on fostamatinib may undergo innate immune training that could enhance their response to the viral infection. Accordingly, the fostamatinib treated group showed improved COVID outcomes but it was unclear what aspect of their immune cell profile could underlie this effect. We are using the remainder of our COVID funding to run a combined CITE-seq/ATAC-seq study with the Center for Human Immunology (CHI) using PBMCs from the patient cohort, which we treated ex vivo with LPS. This will allow us to determine if the fostamatinib-trained cells have an enhanced inflammatory output and also how the transcriptional profile of the various immune cell subsets (determined via CITE-seq) correlates with the chromatin-accessibility (from the ATAC seq profiles). Further comparison of the fostamatinib-treated and control groups will allow us to assess potential innate immune training effects imparted by Syk kinase inhibition.