Differential expression of interferon-lambda receptor 1 splice variants determines the magnitude of the antiviral response induced by interferon-lambda 3 in human immune cells

Abstract

Type III interferons (IFN-lambdas(λ)) are important cytokines that inhibit viruses and modulate immune responses by acting through a unique IFN-λR1/IL-10RB heterodimeric receptor. Until now, the primary antiviral function of IFN-λs has been proposed to be at anatomical barrier sites. Here, we examine the regulation of IFN-λR1 expression and measure the downstream effects of IFN-λ3 stimulation in primary human blood immune cells, compared with lung or liver epithelial cells. IFN-λ3 directly bound and upregulated IFN-stimulated gene (ISG) expression in freshly purified human B cells and CD8 + T cells, but not monocytes, neutrophils, natural killer cells, and CD4 + T cells. Despite similar IFNLR1 transcript levels in B cells and lung epithelial cells, lung epithelial cells bound more IFN-λ3, which resulted in a 50-fold greater ISG induction when compared to B cells. The reduced response of B cells could be explained by higher expression of the soluble variant of IFN-λR1 (sIFN-λR1), which significantly reduced ISG induction when added with IFN-λ3 to peripheral blood mononuclear cells or liver epithelial cells. T-cell receptor stimulation potently, and specifically, upregulated membrane-bound IFNLR1 expression in CD4 + T cells, leading to greater antiviral gene induction, and inhibition of human immunodeficiency virus type 1 infection. Collectively, our data demonstrate IFN-λ3 directly interacts with the human adaptive immune system, unlike what has been previously shown in published mouse models, and that type III IFNs could be potentially utilized to suppress both mucosal and blood-borne viral infections.

Interferons and viruses induce a novel truncated ACE2 isoform and not the full-length SARS-CoV-2 receptor

“…All cell lines were regularly tested for mycoplasma contamination using the MycoAlert Mycoplasma Detection kit (Lonza). The previously described 21 NHBE cells were isolated from normal lungs that were not used for transplantation. The lungs were obtained from de-identified donors via a tissue retrieval service (International Institute for the Advancement of Medicine, Edison, NJ) with ethical approval from the Conjoint Health Research Ethics Board of the University of Calgary and the Internal Ethics Board of the International Institute for the Advancement of Medicine.…”

“…Supplementary Table 5. IFN treatment of NHBE cells was previously described 21 . Briefly, cells were cultured in BEGM with supplements (Lonza), seeded in 6-well plates and utilized at ~70% confluency (typically after 10-11 days with a medium change every 2 days).…”

“…3b,c). To directly address whether IFN was responsible for the induced expression of dACE2, we performed expression analysis in primary normal human bronchial epithelial (NHBE) cells 21 and human intestinal (colon and ileum) organoid cultures 22 . In NHBE cells from five healthy donors, the baseline expression levels of dACE2 and ACE2 were comparable, but only dACE2 was significantly induced by treatment with IFN-α or IFN-λ3 ( Fig.…”

Interferons and viruses induce a novel primate-specific isoform dACE2 and not the SARS-CoV-2 receptor ACE2

“…In most cell lines tested, dACE2 but not ACE2 was strongly upregulated by SeV infection (Figure 2B, C). To directly address whether IFN was responsible for the induced expression of dACE2, we performed expression analysis in primary normal human bronchial epithelial (NHBE) cells 22 and human intestinal (colon and ileum) organoid cultures 23 . In NHBE cells from 5 healthy donors, baseline expression levels of dACE2 and ACE2 were comparable, but only dACE2 was significantly induced by treatment with IFN-α or IFN-λ3 ( Figure 2D, Table S2B).…”

“…All cell lines were regularly tested for mycoplasma contamination using the MycoAlert Mycoplasma Detection kit (Lonza). The previously described 22 approved by the Ethics Commission of the University Hospital Heidelberg. Organoids were generated from these tissues as previously described 23 .…”