Abstract Antigen–antibody complexes are formed when the body's immune system raises antibodies against antigenic determinants of host or foreign substances that recognise and bind to the antigen molecules. Normally, insoluble immune complexes that are formed are cleared by the phagocytic cells of the immune system, but when an excess of antigen–antibody are present, the immune complexes are often deposited in tissues, where they can elicit complement activation, localised inflammation resulting in the generation of tissue lesions in a variety of autoimmune diseases, exacerbating disease pathology. Conversely, exogenous antigen–antibody complexes can trigger specific cell‐mediated immunity when taken up, processed and presented with MHC class I molecules by dendritic cells. This results in direct priming of CD8+ cytotoxic T cells, by a process termed ‘cross‐presentation’. This can be of benefit in the induction of tumour protection and immunity against viral infections. Therefore, the generation of immune complexes can initiate both autoimmunity and protection against tumours and infectious agents. Key Concepts • IgG and IgM are the two major classes of antibodies involved in immune complex formation. Deposition of insoluble immune complexes in tissues can activate C, leading to assembly of the. C5b-9 complexes. The authors think that the abnormal C concentration could cause the impaired bactericidal activities of the patient serum. Kalmanson GM, Herbert E, Guze LB: Serum bactericidal activity in patients. Activate Immune Complex is an exclusive combination of extracts and vitamins that have all shown. ACTIVATE-C IMMUNE COMPLEX| 1. ACTIVATE-CIMMUNE COMPLEXTM FAQ'S. How do the ingredients help support your immune system? Activate-C is a natural blend of the ingredients you need most to help boost your immunity. This powerful supplement drink includes: • Vitamin C—(1,200 mg) long linked to boosting. • The Fab region of antibodies can bind to many antigens comprising proteins, carbohydrates, nucleic acids or lipids. • In the blood circulation, small antigen–antibody complexes form soluble lattices when either antibody or antigen is present in excess. • When antigens and specific antibody are present in equivalent concentrations, large insoluble complexes can form, initiating an inflammatory reaction. • Insoluble immune complexes often deposit in joints and filtration organs (e.g. Kidneys), leading to recruitment and activation of complement proteins and phagocytes. • The Fc portion of antibodies can bind to Fc receptors (FcRs) on cells and C1q, activating immune responses. • Tumour antigen–antibody complexes can activate dendritic cell maturation and promote the development of long‐lasting CD8 memory T cells against tumour antigens. • Viral antigens presented to T cells by dendritic cells results in rapid cellular immunity, while antigen–antibody complexes sustain the T‐cell effector memory. Keywords: antibodies; antigens; complement; cross‐presentation; immune complexes diseases. Types of antibody–antigen complexes formed. (a) Antibodies of the class IgM, IgA, IgG or IgE can bind to IgG and form small soluble or larger insoluble complexes that are deposited in various tissues of the body. IgM rheumatoid factors are the most frequently formed and react with modified Fc regions of IgG. (b) Post‐translational modification of host proteins during stress can potentially lead to overstimulation of the immune response resulting in proteolytic fragments of self‐antigen eliciting an autoimmune response. (c) Peptides can be generated from host anti‐sense DNA or peptides from microbes that arose from DNA sequences homologous to anti‐sense DNA. The complementary peptides initiate the production of antibodies, which in turn trigger release of autoantibodies against self‐antigens. (d) The majority of circulating antibodies recognise and bind to either soluble ‘non‐self’ or foreign antigens or attach to epitopes on the surface of microorganisms, enhancing complement fixation and lysis of microorganisms, followed by clearance by phagocytes.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
April 2018
Categories |