Probably plays a key role in regulating innate and adaptive immune responses through human Toll-like receptor 2 (TLR2). Interacts with TLR2, leading to the subsequent activation of the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-kappa-B) signaling pathways. Stimulates macrophage activation by augmenting pro-inflammatory cytokine production (TNF-alpha, IL-6 and IL-12p40) and the expression of cell surface molecules (CD80, CD86, MHC class I and II). Also participates in adaptive immunity by directing Th1-polarised immune responses. Interacts with human TLR2. Candidate for development of a vaccine for the control of tuberculosis. Belongs to the mycobacterial PPE family.