Role of complement activation and antibody in the interaction between Mycobacterium tuberculosis and human macrophages.
نویسندگان
چکیده
Mycobacterium tuberculosis-specific antibodies possess immunomodulatory effects during tuberculosis infection. Prior sensitization to environmental mycobacteria is known to suppress immune responses against BCG and M. tuberculosis. Mycobacteria-induced antibodies can influence events such as complement activation and phagocytosis during infectious process. In the present study role of anti-M. tuberculosis IgG (anti-M. tb IgG) antibody during interaction between M. tuberculosis and human macrophages mediated through complement has been examined in vitro. Anti-M. tb IgG antibody significantly enhanced complement activation by M. tuberculosis. Phagocytosis of M. tuberculosis by macrophages increased significantly in the presence of complement and/or antibody. Moreover, antibody enhanced phagocytosis in the presence of complement. Addition of antibody alone or in combination with complement also augmented intracellular viability of bacilli within macrophages. Results of this study showed that anti-mycobacterial antibody enhances complement activation and anti-M. tb IgG antibody probably modulates effects of complement during early stages of tuberculosis infection.
منابع مشابه
Brucella melitensis and Mycobacterium tuberculosis depict overlapping gene expression patterns induced in infected THP-1 macrophages
Pathogens infecting mammalian cells have developed various strategies to suppress and evade their hosts’ defensive mechanisms. In this line, the intracellular bacteria that are able to survive and propagate within their host cells must have developed strategies to avert their host’s killing attitude. Studying the interface of host-pathogen confrontation can provide valuable information for defi...
متن کاملInhibition of Ca2+ Signaling by Mycobacterium tuberculosisIs Associated with Reduced Phagosome–Lysosome Fusion and Increased Survival within Human Macrophages
Complement receptor (CR)-mediated phagocytosis of Mycobacterium tuberculosis by macrophages results in intracellular survival, suggesting that M. tuberculosis interferes with macrophage microbicidal mechanisms. As increases in cytosolic Ca(2+) concentration (¿Ca(2+)(c)) promote phagocyte antimicrobial responses, we hypothesized that CR phagocytosis of M. tuberculosis is accompanied by altered C...
متن کاملSignaling by Mycobacterium tuberculosis Is Associated with Reduced Phagosome–Lysosome Fusion and Increased Survival within Human Macrophages
Complement receptor (CR)-mediated phagocytosis of Mycobacterium tuberculosis by macrophages results in intracellular survival, suggesting that M . tuberculosis interferes with macrophage microbicidal mechanisms. As increases in cytosolic Ca 2 1 concentration ([Ca 2 1 ] c ) promote phagocyte antimicrobial responses, we hypothesized that CR phagocytosis of M . tuberculosis is accompanied by alter...
متن کاملبررسی ارتباط پلیمورفیسمهای شایع ژن پذیرنده ویتامین (VDR) D با استعداد ابتلاء به سل ریوی
Background and Aim: In addition to exposure to Mycobacterium tuberculosis (MTB), development of tuberculosis is influenced by environmental and host genetic factors, and clinical disease only occurs in less than 10% of the infected individuals. Vitamin D metabolism leads to activation of macrophages and restricts the intracellular growth of mycobacterium. This effect may be influenced by poly...
متن کاملComplement protein C3 binding to Mycobacterium tuberculosis is initiated by the classical pathway in human bronchoalveolar lavage fluid.
In high concentrations of fresh nonimmune human serum, Mycobacterium tuberculosis activates the alternative pathway of complement and binds C3 protein, resulting in enhanced phagocytosis by complement receptors on human alveolar macrophages. Yet in the lung, the alternative pathway of complement is relatively inactive compared to the classical pathway. To begin to determine whether C3 opsonopha...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Indian journal of experimental biology
دوره 50 8 شماره
صفحات -
تاریخ انتشار 2012