Pathogenicity of tick-derived lymphocytic choriomeningitis virus in BALB/c mice

Background Lymphocytic choriomeningitis virus (LCMV) is a zoonotic pathogen primarily transmitted by rodents. Recently, we identified LCMV in ticks in northeastern China; however, the pathogenicity of the virus in mice remains unknown. Results Here, we examined the tick-derived LCMV strain JX14 by inoculating BALB/c mice with 3.5×10 ⁵ PFU of virus. The mice infected with LCMV displayed clinical manifestations including unkempt fur, anorexia, depression, and oliguria, which subsequently resolved by 10 days post infection (dpi) leading to survival of the infection. Viral RNA was detectable in throat and anal swabs during the early phase of infection and exhibited proliferation in Vero cells. Viral RNA was detected in the blood and various organs, with detectable levels persisting for up to 6 months specifically in the heart. Pathological lesions were identified in most organs within 5 dpi except for the kidneys and testicles. Elevated production of pro-inflammatory cytokines, including interleukin (IL)-5, IL-6, keratinocyte chemoattractant (KC), and interferon gamma (IFN-γ), was observed during the early stages of infection. Conclusions This study provides crucial insights into the pathogenic characteristics of LCMV strain JX14, isolated from ticks in northeastern China, thereby offering a valuable in vivo research tool for investigating immunological responses induced by chronic viral infections.