Comparative in vitro transcriptomic analyses of COVID-19 candidate therapy hydroxychloroquine suggest limited immunomodulatory evidence of SARS-CoV-2 host response genes.

Michael Jay Corley; Christopher Sugai; Michael Schotsaert; Robert E. Schwartz; Lishomwa C Ndhlovu

We examined differential gene expression from gene counts using edgeR [7] and corrected for multiple comparisons using the FDR method and observed 16 genes that significantly differed between 24 hour untreated and 24 hour hydroxychloroquine conditions at an adjusted P value of P < 0.05 (Fig.1a) . The most significant difference was observed for the IL1R2 gene linked to immune regulation [8] , which was downregulated with HCQ treatment. Transcription of IL1R2 has been reported to be significantly upregulated in monocytes from individuals with chronic graft-versus host disease [9] suggesting HCQ may exert antiinflammatory effects. Notably, we observed that the chemokine CCL22 gene was significantly down regulated after 24 hours of HCQ treatment as compared to the untreated condition (Fig.1a) . CCL22 codes for a CC cytokine that is involved in chemotactic activity for monocytes, dendritic cells, natural killer cells, and activated T cells. Other genes that were significantly differently expressed comparing the untreated and HCQ treated conditions included SEMA3G, FN1, MSMO1, ARHGEF28, SLC1A2, PHOSPHO1, ENC1, CPNE6, SCD, NDRG2, LDLR, A2M, AQP9, and CYP51A1. Pathway analyses of this gene set using the Enrichr gene enrichment analysis tool [10] showed that the top pathways involved lipid and lipoprotein metabolism, SREBF and miR-33 in cholesterol and lipid homeostasis, lipoprotein metabolism, and steroid biosynthesis (Supplemental Data 1). These in vitro data suggest that 24 hour in vitro treatment with HCQ minimally impacts immune gene transcription and support findings that HCQ has potential immunomodulatory and lipid metabolism effects [11] . Specifically, previous work from in vivo studies has reported that HCQ treatment significantly decreased serum TNF-A and increased IL-10 levels in women following treatment with 400mg/per day orally [12] and inhibited IL-1β production from stimulated human neutrophils [13] . In the context of COVID-19 infection, clinical reports indicate severe patients exhibit a well-known immune cytokine storm that leads to multi-organ failure [14, 15] . Ongoing clinical trials will see if in addition to hypothesized in vivo viral impacts of HCQ whether this drug also averts the likelihood for a cytokine storm.