Mycobacterium tuberculosis antigens MPT63 and MPT83 increase phagocytic activity of murine peritoneal macrophages

Macrophages (MΦ) are the most described and characterized target and host of mycobacteria. Like other cells of innate immunity MΦ have a wide range of receptor molecules which interact with different pathogen associated molecular patterns (PAMPs). Immunodominant proteins MPT63 and MPT83 that are synthesized in abundance by Mycobacterium bovis or Mycobacterium tuberculosis strains could be involved in development of tuberculosis infection. The aim of this study was to search for effects of these mycobacterial antigens on target cells. For this aim full-sized sequences of MPT83 (rMPT83full) and MPT63 antigens were cloned into plasmid pET24a(+). The increase of phagocytic activity of murine peritoneal macrophages was demonstrated, but not of macrophage-like cells from J774 cell line, which were treated by rMPT63 and rMPT83full proteins for 24 h. This effect of such antigens can be considered as a way to facilitate the consumption of mycobacterial cells by macrophages to avoid other effector mechanisms of innate and adaptive immunity.