Targeting TMEM41B Lipid Remodeling: A Potential Broad-Spectrum Host-Directed Approach against Global Viral Threats

Developing broad-spectrum antivirals as an immediate therapeutic defense against both known and emerging viral threats is a critical priority for global pandemic preparedness. Targeting conserved host pathways hijacked by viruses rather than rapidly evolving viral proteins has the potential to generate pan-viral inhibitors that act across multiple viral families and maintain a higher barrier to resistance. Recent genome-wide CRISPR screens have identified the multifunctional host transmembrane protein 41B (TMEM41B) as an essential host dependency factor for multiple RNA viruses, including those classified as priority pathogens by the World Health Organization (WHO). TMEM41B is a conserved endoplasmic reticulum (ER)-associated scramblase and Ca2+ channel that mediates membrane remodeling, lipid mobilization, and autophagy, all of which facilitate the formation of virus-induced replication organelles. As many positive-sense RNA viruses rely on host membrane-restructuring mechanisms for viral replication, TMEM41B represents a promising host-directed strategic target (HDST) for the development of broad-spectrum antivirals. Notably, the macrolide antibiotic carrimycin has been reported to inhibit TMEM41B, highlighting its potential as a host-targeting antiviral agent. However, the therapeutic potential of TMEM41B inhibition and whether it could be safely targeted remain poorly understood. This article will investigate whether the inhibition of TMEM41B’s scramblase function could be an effective broad-spectrum approach against WHO priority viruses, particularly in coronaviruses and flaviviruses. It will also explore the use of carrimycin as an antiviral that targets TMEM41B, including its proposed mechanism of action and efficacy, to assess whether this host factor represents a safe and effective therapeutic target across multiple viral families. This paper aims to advance TMEM41B as a promising pan-viral HDST and contribute to the development of host-directed antiviral strategies capable of addressing current and future global viral threats.