Mycobacterium tuberculosis fusion protein (Mtb fusion protein)

Mycobacterium tuberculosis (Mtb) fusion proteins are engineered recombinant antigens composed of multiple immunodominant sequences from the Mtb bacterium, designed to elicit a protective cellular immune response (Van Der Meeren et al., 2018, NEJM). These proteins typically combine antigens from different phases of the bacterial life cycle, such as Ag85B (secreted during active growth), ESAT-6 (early virulence factor), and latency-associated proteins like Rv2660c, to provide broad coverage against both active and latent infection (Lin et al., 2012, Nature Communications). Functioning as the active components of subunit vaccines, these fusion proteins are processed by antigen-presenting cells to activate CD4+ and CD8+ T cells, leading to the production of protective Th1-type cytokines such as interferon-gamma and tumor necrosis factor-alpha (Aagaard et al., 2011, Nature Communications). Prominent examples in clinical development include M72 (a fusion of Rv1196 and Rv0125) and ID93 (a fusion of Rv2608, Rv3619, Rv3620, and Rv1813), which are used in conjunction with novel adjuvants to enhance immunogenicity (Coler et al., 2013, Science Translational Medicine). These fusion proteins represent a critical strategy in global health for improving upon the limitations of the current Bacille Calmette-Guérin (BCG) vaccine, specifically targeting the prevention of pulmonary tuberculosis in adolescents and adults (WHO Global Tuberculosis Report, 2023). Their role in disease management includes both pre-exposure prophylaxis and post-exposure therapeutic vaccination to prevent the reactivation of latent tuberculosis.

Other names

Mtb recombinant fusion proteinTuberculosis vaccine antigenM72H56ID93H1Ag85B-ESAT-6Rv1196-Rv0125 fusionMtb32A-Mtb39A

Vaccine-mediated induction of antigen-specific cell-mediated immunity through the presentation of multiple Mtb epitopes by MHC molecules to prime and expand memory T-cell populations.