Abstract: At present, the pathogenesis of Mycobacterium tuberculosis (Mtb) and the defense mechanism of the host are not very clear. The study on the biological characteristics of Mtb protein antigen will contribute to understand these problems, and lay the foundation for the development of new tuberculosis vaccine, immune diagnostic reagents and drugs. The early secreted antigenic target 6 (ESAT-6) family proteins is a class of small molecular proteins with spiral structure, which exports the cell through the ESX secretion system. This family includes 23 members (EsxA-W), in which the genes coding two adjacent proteins in the genome form 11 gene pairs liking operon structure. These proteins involve in the interaction between the host and pathogen, are the immunodominant antigens in the recognition of human immune system, in which most of them are immunodominant T cell antigens, play a key role on the pathogenesis of Mtb and immune protection mechanism of the individual. There have been more reports on the EsxA and EsxB, but the researches on other members of the ESAT-6 family were less reported. Therefore, in this paper we briefly introduced the research progress of other ESAT-6 family members in order to lay the foundation for further research.

Key words: Antigens, bacterial, Bacterial proteins, DNA-binding proteins, Proto-oncogene proteins, Transcription factors, Mycobacterium tuberculosis