Open AccessIdentification of a chemotactic, MCP‐1‐like protein from Mycobacterium avium
Author(s) -
Rao Savita P.,
Hayashi Tomoko,
Catanzaro Antonino
Publication year - 2002
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2002.tb00580.x
Subject(s) - chemotaxis , biology , microbiology and biotechnology , immune system , monocyte , mycobacterium , monoclonal antibody , macrophage , chemotaxis assay , western blot , in vitro , antibody , chemokine , immunology , bacteria , receptor , biochemistry , genetics , gene
Abstract In the immunocompetent host, Mycobacterium avium is responsible for chronic localized pulmonary disease, which is characterized by the presence of increased numbers of activated T cells and macrophages in the lungs. M. avium organisms as well as sonic extracts of M. avium were found to act as chemoattractants for THP‐1 cells as well as monocytes, monocyte‐derived macrophages and alveolar macrophages obtained from normal human donors in an in vitro chemotaxis assay, where a significantly higher number of cells were found in wells containing M. avium compared to control wells. Proteolytic treatment of M. avium sonicate resulted in significant loss (50%) of chemotactic activity. Monoclonal antibodies against recombinant human monocyte chemoattractant protein‐1 (MCP‐1) were found to cross‐react with a 34‐kDa protein of M. avium sonicate on Western blot and inhibit M. avium sonicate‐mediated chemotaxis of THP‐1 cells (47%). These data suggest the presence of an ‘MCP‐1 like’ molecule on M. avium . Recruitment of host immune regulatory cells to the site of infection by pathogens may be involved in generating a local immune response or may be a bacterial strategy for survival within the host by recruiting the cells that they infect, i.e. macrophages.