Deng_2012_J.Cell.Biochem_113_1087

Mycobacterium tuberculosis is the most successful pathogen with multiple mechanisms to subvert host immune response resulting in insidious disease A unique Mycobacterium antigen family termed PPE Pro-Pro-Glu has long been widely speculated as molecular mantra to escape host immunity Members of this family are characterized by a conserved N terminal and a variable C terminal This family associated closely with ESAT-6(ESX secretion system and largely located in cell wall or cell membrane The expression of PPE protein is temporally regulated and highly expressed during M tuberculosis persistence Importantly the distribution of PPE family is so far limited to Mycobacterium genus prevalent among pathogenic Mycobacterium species It is tempting to explore this family due to its potential in the latency and reactivation of M tuberculosis The evolution structure and functions of most PPE proteins remain elusive The understanding of these questions will deepen our appreciation of the pathogenesis of M tuberculosis and accelerate novel anti-TB measures discovery.