Dominant negative biologics normalise the tumour necrosis factor (TNF-α) induced angiogenesis which exploits the Mycobacterium tuberculosis dissemination.

Background: Tumor necrosis factor (TNF) is known to promote T cell migration and increase the expression of vascular endothelial growth factor (VEGF) and chemokines. The administration of Xpro-1595, a dominant-negative TNF (DN-TNF) engineered to selectively inactivate soluble TNF (solTNF), has been extensively studied and proven effective in reducing TNF production without suppressing innate immunity during infection. The literature also supports the involvement of glutamic acid-leucine-arginine (ELR+) chemokines and VEGF in angiogenesis and the spread of infections.

Materials and methods: In this study, we administered Xpro-1595 to guinea pigs to selectively inhibit solTNF, aiming to assess its impact on Mycobacterium tuberculosis (M.tb) dissemination, bacterial growth attenuation, and immunological responses. We conducted immunohistochemical analyses, immunological assays, and colony enumeration to comprehensively study the effects of Xpro-1595 by comparing with anti-TB drugs treated M.tb infected guinea pigs. Throughout the infection and treatment period, we measured the levels of Interleukin-12 subunit alpha (IL-12), Interferon-gamma (IFN-γ), TNF, Tumor growth factor (TGF), and T lymphocytes using ELISA.

Results: Our findings revealed a reduction in M.tb dissemination and inflammation without compromising the immune response during Xpro-1595 treatment. Notably, Xpro-1595 therapy effectively regulated the expression of VEGFA and ELR + chemokines, which emerged as key factors contributing to infection dissemination. Furthermore, this treatment influenced the migration of CD4 T cells in the early stages of infection, subsequently leading to a reduced T cell response and controlled proinflammatory signalling, thus mitigating inflammation.

Conclusion: Our study underscores the pivotal role of solTNF in the dissemination of M.tb to other organs. This preliminary investigation sheds light on the involvement of solTNF in the mechanisms underlying M.tb dissemination, although further in-depth research is warranted to fully elucidate its role in this process.