The main project purpose is to investigate the fundamental physiological state of Mycobacterium tuberculosis during the infection and the mycobacterial response within the infected host tissue, human lung. High-throughput proteomic analysis of M. tuberculosis cells will be involved to solve this problem. The description of pattern of proteins expressed in M. tuberculosis cells extracted directly from clinical material of patients with tuberculosis defines the main novelty of the given project. Undoubtedly, the intermediate project results describing the features of M. tuberculosis strains proteome in vitro will also be essential for the global scientific community.