Strain-Specific Immune Response Patterns to Borrelia burgdorferi Infection: A Comparative Transcriptomic Analysis in C3H and C57BL/6 Mice

Lyme arthritis is a significant pathological outcome of Borrelia burgdorferi infection, characterized by inflammatory joint responses that vary in severity depending on host genetic susceptibility. This study investigates the strain-specific immune mechanisms in Lyme arthritis using Borrelia burgdorferi strain B31. A total of 24 mice were used in this study, with 12 mice per strain (female C3H/HeNCr and C57BL/6NCr, 4-6 weeks). For each strain, 6 mice were sacrificed at day 14 post-infection or uninfection (control), and another 6 mice were sacrificed at day 56 post-infection or uninfection. For model establishment, experimental subjects received bilateral tibiotarsal joint injections (50 uL per site) containing 1*106 spirochetes in suspension, while control cohorts were administered equivalent volumes of PBS. For sampling, posterior tibiotarsal joint tissues were surgically isolated at the acute (14 days) and recovery (56 days) phases. The tissue excision involved removing the skin and meticulously separating the joint capsule to minimize bone marrow contamination, followed by total RNA extraction for transcriptomic sequencing. The primary significance of this research lies in elucidating the regulatory role of host genetic backgrounds in the temporal characteristics of immune responses, providing novel molecular insights into the differential susceptibility to Lyme arthritis and establishing a theoretical foundation for developing targeted therapeutic strategies.