Interferon-Induced Transmembrane Protein: A Moonlighting Protein Against SARS-CoV-2 Infection or in Support of Invasive Ductal Breast Carcinoma?

Rinki Minakshi

doi:10.31557/apjcc.2020.5.s1.241-242

Abstract

The interferon-induced transmembrane proteins (IFITMs), widely acting against invading viruses are ubiquitously expressed on the cellular membranes, were previously known for their prominent role in tumorigenesis. Studies productively showed that the entry restriction on SARS-CoV spike glycoprotein agreeably involved the action of frontier IFITM1, 2 and 3. On the contrary, overexpression of IFITM3 has been reported in Invasive ductal breast carcinoma (IDC) tissue specimens where lentivirus-delivered shRNA resulted in targeted silencing of IFITM3 mRNA expression. Despite acting protective against virus infection, expression of IFITM favors cancer migration as seen in IDC. The existence of such a phenomenon wherein a choice is made by the selection pressure on IFITM allele frequency in human population between opposing roles of the protein, needs to be untangled.

Highlights

The innate immunity, being an autonomous cellular arsenal against invading viruses, has strategically evolved its surveillance power as well as effector functions
The interferon-induced transmembrane proteins (IFITMs), labelled as a moonlighting protein, are one such ubiquitously expressed IFN-stimulated genes (ISGs), on the cellular membranes, that were previously known for their prominent role in tumorigenesis
Studies productively showed that the entry restriction on SARS-CoV spike glycoprotein agreeably involved action of frontier IFITM1, 2 and 3 rather than concomitant ACE2 downregulation

Summary

Introduction

The innate immunity, being an autonomous cellular arsenal against invading viruses, has strategically evolved its surveillance power as well as effector functions. Cells show basal expression levels of IFITMs, which significantly see an upsurge in their levels during virus infection [3]. As witnessed in studies using siRNA, IFITM1, -2 and -3 have acted by inhibiting infection establishment in influenza A virus (IAV), West Nile virus, dengue virus, Marburg virus, Ebola virus, HIV-1 and SARS-CoV [4]. The mechanistic details of this inhibition are still in its juvenile stage, but studies have emphasized that IFITM proteins inhibit enveloped viruses [5].

Results

Conclusion