class switchings การใช้

• When the B cells get activated, class switching can occur.
• Class switching occurs by a mechanism called class switch recombination ( CSR ) binding.
• In B lymphocytes ( B cells ), interferon gamma stimulates antibody class switching.
• On the other hand, immunoglobulin class switching causes heavy chain rearrangement of the mature B cell ..
• In addition, cytokines are factors that have great effects on class switching of different classes of antibodies.
• Class switching occurs in the heavy chain gene locus by a mechanism called class switch recombination ( CSR ).
• Their interaction with B cells provides the appropriates signals needed for B cells differentiation and eventual class switching occurrence.
• IL-4 induces B-cell class switching to IgE, and up-regulates MHC class II production.
• One of the main physiological changes that occurs during an adaptive immune response is a process called immunoglobulin class switching.
• The class switching involves switch regions that made up of multiple copies of short repeatts ( GAGCT and TGGGG ).
• A defect in this gene results in an inability to undergo immunoglobulin class switching and is associated with hyper IgM syndrome.
• Most hypergammaglobulinemias are caused by an excess of immunoglobulin M ( IgM ), because this is the default immunoglobulin type prior to class switching.
• During class switching, the constant region of the immunoglobulin heavy chain changes but the variable regions, and therefore antigenic specificity, stay the same.
• Class switching only occurs after the B cell binds an antigen through its B cell receptor, and is activated through interaction with a T helper cell.
• T cell-derived cytokines bound by B cell cytokine receptors also promote B cell proliferation, immunoglobulin class switching, and somatic hypermutation as well as guide differentiation.
• They are essential in B cell antibody class switching, in the activation and growth of cytotoxic T cells, and in maximizing bactericidal activity of phagocytes such as macrophages.
• Class switch recombination is a biological mechanism that allows the class of antibody produced by an activated B cell to change during a process known as isotype or class switching.
• If these activated B cells encounter specific signaling molecules via their CD40 and cytokine receptors ( both modulated by T helper cells ), they undergo antibody class switching to produce IgG, IgA or IgE antibodies.
• Antibody genes also re-organize in a process called class switching that changes the one type of heavy chain Fc fragment to another, creating a different isotype of the antibody that retains the antigen-specific variable region.
• Once a BCR binds a TD antigen, the antigen is taken up into the B cell through receptor-mediated endocytosis, proliferation, immunoglobulin class switching, and somatic hypermutation as well as sustains T cell growth and differentiation.