Zakowska Dorota, Bartoszcze Michał, Niemcewicz Marcin, Bielawska-Drózd Agata, Kocik Janusz
Biological Threats Identification and Coutermeasure Center of the Military Institute of Hygiene and Epidemiology, Puławy, Poland.
Ann Agric Environ Med. 2012;19(4):613-8.
Articles concerning new aspects of B. anthracis 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 B. anthracis 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 significant 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 B. anthracis spores phagocytosis by human macrophages, was observed. The genes coding germination spores protein in mutant strains of B. anthracis MIGD was a crucial discovery. According to this, it could be assumed that the activity of B. anthracis spores germination process is dependent upon the sleB, cwlJ1 and cwlJ2 genes, which code the GSLEs lithic enzymes. It was also discovered that the specific antibody for PA20, which binds to the PA20 antigenic determinant, are able to block further PA83 proteolytic fission on the surface of cells. This process neutralized PA functions and weakened the activity of free PA20, which is produced during the PA83 enzyme fission 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(N)-DTA.
对有关炭疽杆菌感染机制新方面的文章进行了综述。发现毛囊在孢子萌发过程中起重要作用。毛囊是皮肤型疾病感染过程中的一个重要入口。小鼠暴露于由炭疽杆菌菌株制备的孢子气溶胶后，观察到肿瘤坏死因子-α（TNF-α）细胞因子水平升高。TNF-α细胞因子是微生物侵入宿主后产生的。这一过程可能在通过趋化信号诱导感染细胞抗原呈递细胞（APC）迁移至淋巴结中起重要作用。据解释，与孢子表面结合的免疫球蛋白G（IgG）激活适应性免疫系统反应。结果，观察到孢子表面释放补体C3b调理素，并介导人巨噬细胞对炭疽杆菌孢子C3蛋白片段的吞噬作用。在炭疽杆菌MIGD突变菌株中编码萌发孢子蛋白的基因是一项关键发现。据此，可以假设炭疽杆菌孢子萌发过程的活性取决于编码GSLEs裂解酶的sleB、cwlJ1和cwlJ2基因。还发现，与PA20抗原决定簇结合的PA20特异性抗体能够阻断细胞表面进一步的PA83蛋白水解裂变。这一过程使PA功能失活，并削弱了PA83酶裂变过程中产生的游离PA20的活性。PA63单体与致死因子（LF）之间的相互作用可能有助于PA63寡聚化和聚集过程，并且LF/PA63复合物的形成可能是炭疽毒素在细胞表面组装的替代过程的一部分。发现肌动蛋白依赖性内吞作用在PA七聚化过程中起重要作用，并导致毒素活性受阻。伴侣蛋白是一种源自宿主细胞的蛋白质，可能有助于三磷酸腺苷（ATP）和胞质因子转运，从而增加白喉毒素A结构域（DTA）和融合蛋白LF（N）-DTA底物的转运。
