immune complex

(noun)

An immune complex is formed from the integral binding of an antibody to a soluble antigen. The bound antigen acting as a specific epitope, bound to an antibody is referred to as a singular immune complex.

Related Terms

Examples of immune complex in the following topics:

  • Immune Complex Autoimmune Reactions

    • An immune complex is formed from the integral binding of an antibody to a soluble antigen and can function as an epitope.
    • An immune complex is formed from the integral binding of an antibody to a soluble antigen.
    • The bound antigen acting as a specific epitope, bound to an antibody is referred to as a singular immune complex .
    • Type III hypersensitivity reactions are immune complex-mediated.
    • An immune complex is formed from the integral binding of an antibody to a soluble antigen.

  • Type III (Immune Complex) Reactions

    • When these antigens bind antibodies, immune complexes of different sizes form.
    • Large complexes can be cleared by macrophages but macrophages have difficulty in the disposal of small immune complexes.
    • These immune complexes insert themselves into small blood vessels, joints, and glomeruli, causing symptoms.
    • Often, immunofluorescence microscopy can be used to visualize the immune complexes.
    • An immune complex is formed from the integral binding of an antibody to a soluble antigen.

  • Immunoassays for Disease

    • Immunology is the study of molecules, cells, and organs that make up the immune system.
    • When a foreign agent penetrates the first line of resistance, an immune reaction is elicited and immune cells are recruited into the site of infection to clear microorganisms and damaged cells by phagocytosis.
    • If the inflammation remains aggravated, antibody-mediated immune reaction is activated and different types of immune cells are engaged to resolve the disease.
    • The immune system is composed of cellular and humoral elements.
    • Most assays rely on the formation of large immune complexes when an antibody binds to a specific antigen which can be detected in solution or in gels.

  • Type II (Cytotoxic) Reactions

    • In type II (cytotoxic) hypersensitivity, the antibodies produced by the immune response bind to antigens on the patient's own cell surfaces.
    • In type II hypersensitivity (or cytotoxic hypersensitivity), the antibodies produced by the immune response bind to antigens on the patient's own cell surfaces.
    • That is, mediators of acute inflammation are generated at the site and membrane attack complexes cause cell lysis and death.
    • The membrane attack complex (MAC; ) is typically formed on the surface of pathogenic bacterial cells as a result of the activation of the alternative pathway and the classical pathway of the complement system, and it is one of the effector proteins of the immune system.
    • The membrane-attack complex (MAC) forms transmembrane channels.

  • Superantigens

    • Superantigens (SAgs) are proteins that cause the T-cells of the immune system to over-react to infection.
    • The superantigens of each species are, like antigens, molecules the immune system recognizes as being foreign.
    • Superantigens cause symptoms of illness by tricking the T-cells of the immune system into over-reacting to these molecules.
    • Parts of a bacterium or a virus are usually recognized by the macrophage cells of the immune system.
    • Then the macrophage takes parts of the broken-down invader or other molecules that it ingested and posts the fragments on the outside of the cell using a major histocompatibility complex (MHC) to hold the fragment.

  • Type IV (Delayed Cell-Mediated) Reactions

    • Cell-mediated immunity is an immune response that does not involve antibodies, but rather involves the activation of phagocytes, natural killer cells (NK), antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen.
    • Historically, the immune system was separated into two branches: humoral immunity, for which the protective function of immunization could be found in the humor (cell-free bodily fluid or serum) and cellular immunity, for which the protective function of immunization was associated with cells.
    • Therefore in cell mediated immunity cytokines are not always present.
    • 3. stimulating cells to secrete a variety of cytokines that influence the function of other cells involved in adaptive immune responses and innate immune responses
    • CD4+ helper T cells recognize antigen in a complex with Class 2 major histocompatibility complex.

  • The Complement System

    • The serum complement system, which represents a chief component of innate immunity, not only participates in inflammation but also acts to enhance the adaptive immune response.
    • More recently, however, the role of the complement in the immune response has been expanded due to observations that link complement activation to adaptive immune responses.
    • Initiation of the classical pathway occurs when C1q, in complex with C1r and C1s serine proteases (the C1 complex), binds to the Fc region of complement-fixing antibodies (generally IgG1and IgM) attached to pathogenic surfaces.
    • The larger fragments associate to form C4bC2a on pathogenic surfaces, and the complex gains the ability to cleave C3 and is termed the C3 convertase.
    • It has become increasingly understood that complement functions in host defense extend beyond innate immune responses.

  • The Roles of Genetics and Gender in Autoimmune Disease

    • Any disease that results from such an aberrant immune response is termed an autoimmune disease.
    • The misconception that an individual's immune system is totally incapable of recognizing self antigens is not new.
    • These genes are related to immunoglobulins, T-cell receptors, and the major histocompatibility complexes (MHC).
    • HLA-DR is a MHC class II cell surface receptor encoded by the human leukocyte antigen complex on chromosome 6 region 6p21.31.
    • The complex of HLA-DR and its ligand, a peptide of 9 amino acids in length or longer, constitutes a ligand for the T-cell receptor (TCR).

  • Cells and Organs of the Immune System

    • The immune system includes primary lymphoid organs, secondary lymphatic tissues and various cells in the innate and adaptive immune systems.
    • Lymph nodes are garrisons of B, T and other immune cells.
    • Langerhans cells in the skin are part of the adaptive immune system.
    • T cells recognize a "non-self" target, such as a pathogen, only after antigens have been processed and presented in combination with a "self" receptor, called a major histocompatibility complex (MHC) molecule.
    • Recognize the cells and organs of the immune system and their functions

  • Cytotoxic Autoimmune Reactions

    • Autoimmunity is a result of the failure of an organism's immune system to recognize "self".
    • Any disease that results from such an aberrant immune response is termed an autoimmune disease.
    • Three main sets of genes are suspected in many autoimmune diseases: immunoglobulins, T-cell receptors and the major histocompatibility complexes (MHC).
    • HLA-DR is a MHC class II cell surface receptor encoded by the human leukocyte antigen complex on chromosome 6 region 6p21.31.
    • The complex of HLA-DR and its ligand, a peptide of 9 amino acids in length or longer, constitutes a ligand for the T-cell receptor (TCR).