Comparison of the Effects of <i>Mycobacterium tuberculosis</i> H37Rv and <i>Brucella ovis</i> Infiltration on Tumor Necrosis Factor-Alpha and Interleukin-1 Beta Expression in Osteoblasts

<b><i>Objective:</i></b> This study aims to compare the expression levels of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) in osteoblasts infiltrated with <i>Mycobacterium tuberculosis</i> H37Rv (H37Rv) and <i>Brucella ovis</i> to understand the differential bone destruction in spinal tuberculosis (STB) versus <i>Brucella</i> spondylitis (BS). <b><i>Methods:</i></b> Primary osteoblasts were isolated and cultured from the cranial bones of 2-5 days old mice and characterized by alkaline phosphatase (ALP) staining and alizarin red staining (ARS). H37Rv and <i>B. ovis</i> were cultured to the logarithmic phase, and transfection solutions were prepared. Osteoblasts were infiltrated with these bacteria at various multiplicities of infection (MOI) and time points. Cell survival post-infiltration was assessed using CCK-8 to determine optimal infection conditions. Osteoblasts were divided into three groups: the H37Rv group (infiltrated with optimal MOI H37Rv), the <i>B. ovis</i> group (infiltrated with optimal MOI <i>B. ovis</i>), and a negative control group. TNF-α and IL-1β expression in the cytoplasm was observed using immunohistochemical staining, whereas their levels in cell supernatants were measured using enzyme-linked immunosorbent assay. Protein expression was analyzed by Western blot. Differences between groups were compared with using one-way analysis of variance and t-tests, with p < 0.05 indicating statistical significance. <b><i>Results:</i></b> Both H37Rv and <i>B. ovis</i> infiltrated osteoblasts, substantially increasing TNF-α and IL-1β expression. The H37Rv group showed substantially higher levels of TNF-α and IL-1β compared with the <i>B. ovis</i> group (p < 0.05). <b><i>Conclusion:</i></b> Infiltration of osteoblasts with H37Rv and <i>B. ovis</i> substantially increases TNF-α and IL-1β expression, with higher levels observed in H37Rv-infected osteoblasts. This overexpression may contribute to the more severe vertebral bone destruction seen in STB compared with BS.