The PE/PPE Multigene Family of Mycobacteria and TB Vaccines

Abstract

Volume 5 • Issue 3 • 1000231 Adv Tech Biol Med, an open access journal ISSN: 2379-1764 Mycobacteria including Mycobacteria tuberculosis (Mtb) contain a multi-gene family, named the PE/PPE family. Mycobacterial strains contain about 165 genes, consisting of two major subfamilies the PE (containing the PE_PGRS group) and PPE, of which many of the constituents are very homologous (>50%). Since their discovery, scientists speculated about the role the members in this family might play in Mtb pathogenesis, immunity, evolution, and antigenic variation. Brennan et al. [1] in Issue 6 of Infection and Immunity, summarizes what is known about PE/PPEs with a particular focus on how they could be used in new TB vaccines. In fact, two TB vaccines presently being studied in clinical trials, GSK’s M72 and IDRI’s ID93, each contain a PPE protein. Another TB vaccine, the live Mtb mutant strain MtbΔPPE/ PE25-PE19 developed by the laboratories at the University of Pisa and Institute Pasteur, is a mutant which is missing two PEs and three PPEs, is under preclinical development. Evidence indicates that this vaccine is safe and is protective due to cross reactivity among the PE and PPEs in animal models for TB.