Pathogenic and Apathogenic Strains of Lymphocytic Choriomeningitis Virus Have Distinct Entry and Innate Immune Activation Pathways

Journal Article · 18 April 2024 · Viruses

DOI: https://doi.org/10.3390/v16040635 · OSTI ID:2404604

Johnson, Dylan M.  ^[1]; Khakhum, Nittaya ^[2]; Wang, Min ^[3]; Warner, Nikole L. ^[3]; Jokinen, Jenny D. ^[3]; Comer, Jason E. ^[2]; Lukashevich, Igor S.  ^[3]

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1. Univ. of Louisville, KY (United States); Univ. of Texas Medical Branch, Galveston, TX (United States); Sandia National Laboratories (SNL-CA), Livermore, CA (United States)
2. Univ. of Texas Medical Branch, Galveston, TX (United States)
3. Univ. of Louisville, KY (United States)

Lymphocytic choriomeningitis virus (LCMV) and Lassa virus (LASV) share many genetic and biological features including subtle differences between pathogenic and apathogenic strains. Despite remarkable genetic similarity, the viscerotropic WE strain of LCMV causes a fatal LASV fever-like hepatitis in non-human primates (NHPs) while the mouse-adapted Armstrong (ARM) strain of LCMV is deeply attenuated in NHPs and can vaccinate against LCMV-WE challenge. Here, we demonstrate that internalization of WE is more sensitive to the depletion of membrane cholesterol than ARM infection while ARM infection is more reliant on endosomal acidification. LCMV-ARM induces robust NF-κB and interferon response factor (IRF) activation while LCMV-WE seems to avoid early innate sensing and failed to induce strong NF-κB and IRF responses in dual-reporter monocyte and epithelial cells. Toll-like receptor 2 (TLR-2) signaling appears to play a critical role in NF-κB activation and the silencing of TLR-2 shuts down IL-6 production in ARM but not in WE-infected cells. Pathogenic LCMV-WE infection is poorly recognized in early endosomes and failed to induce TLR-2/Mal-dependent pro-inflammatory cytokines. Following infection, Interleukin-1 receptor-associated kinase 1 (IRAK-1) expression is diminished in LCMV-ARM- but not LCMV-WE-infected cells, which indicates it is likely involved in the LCMV-ARM NF-κB activation. By confocal microscopy, ARM and WE strains have similar intracellular trafficking although LCMV-ARM infection appears to coincide with greater co-localization of early endosome marker EEA1 with TLR-2. Both strains co-localize with Rab-7, a late endosome marker, but the interaction with LCMV-WE seems to be more prolonged. These findings suggest that LCMV-ARM’s intracellular trafficking pathway may facilitate interaction with innate immune sensors, which promotes the induction of effective innate and adaptive immune responses.

• Research Organization: Sandia National Laboratories (SNL-CA), Livermore, CA (United States)
• Sponsoring Organization: National Institutes of Health (NIH); USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: NA0003525
• OSTI ID: 2404604
• Report Number(s): SAND--2024-09112J
• Journal Information: Viruses, Journal Name: Viruses Journal Issue: 4 Vol. 16; ISSN 1999-4915
• Publisher: MDPICopyright Statement
• Country of Publication: United States
• Language: English