BiP/GRP78 is a pro-viral factor for diverse dsDNA viruses that promotes the survival and proliferation of cells upon KSHV infection

PLoS Pathog. 2024 Oct 29;20(10):e1012660. doi: 10.1371/journal.ppat.1012660. eCollection 2024 Oct.

Abstract

The Endoplasmic Reticulum (ER)-resident HSP70 chaperone BiP (HSPA5) plays a crucial role in maintaining and restoring protein folding homeostasis in the ER. BiP's function is often dysregulated in cancer and virus-infected cells, conferring pro-oncogenic and pro-viral advantages. We explored BiP's functions during infection by the Kaposi's sarcoma-associated herpesvirus (KSHV), an oncogenic gamma-herpesvirus associated with cancers of immunocompromised patients. Our findings reveal that BiP protein levels are upregulated in infected epithelial cells during the lytic phase of KSHV infection. This upregulation occurs independently of the unfolded protein response (UPR), a major signaling pathway that regulates BiP availability. Genetic and pharmacological inhibition of BiP halts KSHV viral replication and reduces the proliferation and survival of KSHV-infected cells. Notably, inhibition of BiP limits the spread of other alpha- and beta-herpesviruses and poxviruses with minimal toxicity for normal cells. Our work suggests that BiP is a potential target for developing broad-spectrum antiviral therapies against double-stranded DNA viruses and a promising candidate for therapeutic intervention in KSHV-related malignancies.

MeSH terms

  • Cell Proliferation*
  • Cell Survival
  • DNA Viruses
  • Endoplasmic Reticulum Chaperone BiP*
  • Heat-Shock Proteins* / metabolism
  • Herpesviridae Infections / metabolism
  • Herpesviridae Infections / virology
  • Herpesvirus 8, Human* / physiology
  • Humans
  • Unfolded Protein Response
  • Virus Replication*

Substances

  • Endoplasmic Reticulum Chaperone BiP
  • HSPA5 protein, human
  • Heat-Shock Proteins

Grants and funding

This work was supported by a grant to CA from the University of California Research Initiatives (UCRI CTN-19-586108). GN was supported by the National Science Foundation (NSF) Bridge to Doctorate. HW, LD, VT-L, SK, CL, RW, CL, CG, FMC, JEE, and CA were supported by the Chan Zuckerberg Biohub intramural program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.