Macrophage migration inhibitory factor (MIF): a Janus-faced cytokine in viral pathogenesis and host defense

Macrophage migration inhibitory factor (MIF) is one of several pivotal cytokines that contribute to orchestrate immune regulation, inflammation, and cell survival, acting as both a mediator of host defense and a factor that viruses can exploit. This comprehensive review delineates MIF's multifaceted roles across diverse viral families-including Retroviridae, Herpesviridae, Hepadnaviridae, Orthomyxoviridae, Flaviviridae, Paramyxoviridae, and Picornaviridae-highlighting the mechanisms by which viruses manipulate MIF signaling to promote replication, evade immune responses, and induce tissue damage. Viral strategies often involve upregulating MIF expression or leveraging its receptor pathways, such as CD74, CXCR2, and CXCR4, to enhance viral persistence, disrupt barrier integrity, and skew immune polarization toward pro-viral or immunosuppressive states. Conversely, MIF-driven inflammation can worsen pathogenic processes, including cytokine storms, neuroinvasion, and fibrosis, contributing to disease severity. Notably, pharmacologic inhibition of MIF has shown promise in preclinical models, reducing viral replication and mitigating tissue damage, thereby positioning MIF as one of the compelling targets for host-directed antiviral therapies. Understanding the complex, context-dependent functions of MIF in viral infections provides transformative insights for innovative treatment strategies that aim to disrupt virus-host interactions, control inflammation, and improve clinical outcomes in infectious diseases. Future research exploring MIF's molecular interactions, genetic variations, and therapeutic modulation will be crucial for harnessing its potential for personalized, effective antiviral interventions.