New aspects of the infection mechanisms of <em>B. anthracis</em>

Biological Threats Identification and Coutermeasure Center of the Military Institute of Hygiene and Epidemiology, Puławy, Poland
Ann Agric Environ Med 2012;19(4):613–618
Articles concerning new aspects of [i]B. anthracis[/i] mechanisms of infection were reviewed. It was found, that the hair follicle plays an important role in the spore germination process. The hair follicle represent an important portal of entry in the course of the cutaneous form of disease infections. After mouse exposition to aerosol of spores prepared from [i]B. anthracis[/i] strains, an increase in the level of TNF-α cytokines was observed. The TNF-α cytokines were produced after intrusion into the host by the microorganism. This process may play a signi cant role in the induced migration of infected cells APCs (Antigen Presenting Cells) via chemotactic signals to the lymph nodes. It was explained that IgG, which binds to the spore surface, activates the adaptive immune system response. As a result, the release C3b opsonin from the spore surface, and mediating of C3 protein fragments of [i]B. anthracis[/i] spores phagocytosis by human macrophages, was observed. The genes coding germination spores protein in mutant strains of [i]B. anthracis[/i] MIGD was a crucial discovery. According to this, it could be assumed that the activity of [i]B. anthracis[/i] spores germination process is dependent upon the sleB, cwlJ1 and cwlJ2 genes, which code the GSLEs lithic enzymes. It was also discovered that the speci c antibody for PA20, which binds to the PA20 antigenic determinant, are able to block further PA83 proteolytic ssion on the surface of cells. This process neutralized PA functions and weakened the activity of free PA20, which is produced during the PA83 enzyme ssion process. Interaction between PA63 monomer and LF may be helpful in the PA63 oligomerization and grouping process, and the creation of LF/PA63 complexes may be a part of an alternative process of assembling the anthrax toxin on the surface of cells. It was found that actin-dependent endocytosis plays an important role in the PA heptamerisation process and leads to blocking the toxin activity. Chaperones, a protein derived from host cells, may be helpful in ATP and cytosolic factors translocation, and in this way increase the translocation of diphteria toxin A domein (DTA) and substrate of fusion protein LF[sub]N[/sub]-DTA.
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