Ag85B-TB10.4 fusion protein (H4) (H4)

The H4-specific CD4+ T cells are the primary immunological effectors induced by the H4 (Ag85B-TB10.4) tuberculosis vaccine candidate. H4 is a recombinant fusion protein consisting of two major antigens from Mycobacterium tuberculosis: Ag85B (a mycolyltransferase) and TB10.4 (a member of the Esat-6 family). These T cells are characterized by a polyfunctional cytokine profile, typically producing interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and interleukin-2 (IL-2), which are critical for controlling intracellular mycobacterial infection. In clinical development, the H4 antigen is often formulated with adjuvants like IC31 to enhance the magnitude and durability of the CD4+ T cell response. While the T cells themselves are the biological readout of vaccine efficacy, the molecular target is the H4 fusion protein, which serves as the template for TCR recognition and immune memory induction.

Other names

H4 antigenAg85B-TB10.4H4 vaccine antigenMycobacterium tuberculosis fusion protein H4

Vaccine antigen that induces polyfunctional CD4+ T cell responses (IFN-gamma, TNF-alpha, IL-2) to provide protective immunity against Mycobacterium tuberculosis.