Immunomodulatory Roles of PE/PPE Proteins and Their Implications in Genomic Features of Mycobacterium tuberculosis

Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), remains a notorious cause of human death worldwide. A deeper understanding of the proline-glutamate (PE) and proline-proline-glutamate (PPE) families, which compromise 10% of the coding regions in the Mtb genome, has uncovered their unique roles in host-pathogen interactions. Further, comparative genomic analysis of different Mtb strains has proposed that Mtb has acquired diverse gene sets that play immunomodulatory roles in host-pathogen interactions. This review delineates the various immunomodulatory roles of PE/PPE antigens and discusses their implications in the development of the improved diagnostic tools and vaccines.