Macrophage-Induced Exacerbation of Nasopharyngeal Inflammatory Lymphocytes in COVID-19 Disease

Abstract

The nasal microenvironment plays a crucial role in the transmission, modulation, and clinical progression of COVID-19; however, the immune responses at the site of viral entry remain poorly understood. We deciphered the link between nasopharyngeal (NP) immune and inflammatory response that triggers cytokine/chemokine storms in the nasal route of COVID-19-positive patients. We used RT-PCR, multiplex ELISA, flow cytometry, and LC-MS/MS to decipher nasopharyngeal immune perturbations associated with severe COVID-19. In addition, we performed in vitro assays using cultured human monocytes-derived macrophages trained both in the presence and absence of SARS-CoV-2 trimeric spike protein(s) and co-cultured with and without autologous human peripheral blood mononuclear cells (hPBMCs)/total T-cells/CD8 T-cells. In vitro immune perturbations were examined by flow cytometry and LC-MS/MS assays. Our findings confirm that macrophages orchestrate NP immune inflammatory responses and highlight the cytokine/chemokine storms associated with the increased CD8+T-cells along with Tregs, Th1, and Th17.1 T-helper cells. We observed a correlation between in vitro and nasal findings that trained macrophages, profoundly M2c, differentially promote the inflammatory surfactome on CD8 T-cells, including ITGAM, LGALS3, CD38, TKT, LRPAP1, and SSBP1. The findings of this study conclude that inflammatory lymphocyte perturbations within the nasopharynx of COVID-19 patients may enforce immune homeostasis during SARS-CoV-2-infection and contribute to COVID-19 pathology. This study explored the therapeutic target proteins that could facilitate the development of new medications, which could allow for immediate treatment of possible emerging viral infections.

Keywords

• SARS-CoV-2
• COVID-19
• nasopharyngeal swabs
• immunology
• T-helper cells
• Th17.1