May play an important role in the persistence of mycobacteria in host cells. May regulate the innate immune response of macrophages by promoting the production of pro-inflammatory cytokines and inhibiting the production of anti-inflammatory cytokines. Promotes the death of macrophages during infection. Cell wall-associated. Expression in M.smegmatis enhances the ability to resist in vitro stress and early survival in macrophages. Macrophages infected with recombinant M.smegmatis produce significantly greater amounts of interleukin (IL)-1beta, IL-6, tumor necrosis factor (TNF)-alpha and an early decrease in IL-10 along with higher levels of host cell death. Belongs to the mycobacterial PPE family.