class switch recombination

(noun)

A biological mechanism that changes a B cell's production of antibody from one class to another; for example, from an isotype called IgM to an isotype called IgG.

Related Terms

Examples of class switch recombination in the following topics:

  • Isotype Class Switching

    • Immunoglobulin class switching (or isotype switching, or isotypic commutation, or class switch recombination (CSR)) is a biological mechanism that changes a B cell's production of antibody from one class to another; for example, from an isotype called IgM to an isotype called IgG.
    • Class switching occurs by a mechanism called class switch recombination (CSR) binding .
    • 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.
    • Mechanism of class switch recombination that allows isotype switching in activated B cells.
    • Describe the process of class switch recombination that results in changes in the antibody-heavy chain

  • Antibodies: Classes and Affinity Maturation

    • Antibodies undergo class switching, somatic hypermutation, and affinity maturation to improve their effectiveness to specific pathogens.
    • Isotype or class switching is a biological process occurring after activation of the B cell, allowing the cell to produce different classes of antibodies (IgA, IgE, or IgG) .
    • Class switching allows different daughter cells from the same activated B cell to produce antibodies of different isotypes.
    • Class switching occurs in the heavy chain gene locus by a mechanism called class switch recombination (CSR).
    • Mechanism of class switch recombination that allows isotype switching in activated B cells.

  • Antibody Genes and Diversity

    • The first stage is called somatic, or V(D)J, which stands for variable, diverse, and joining regions recombination.
    • The second stage of recombination occurs after the B cell is activated by an antigen.
    • Affinity maturation occurs after V(D)J recombination, and is dependent on help from helper T cells.
    • Antibody genes also re-organize in a process called class switching, which changes the base of the heavy chain to another.
    • Outline the two stages which result in antibody diversity: somatic (V(D)J) and recombination stages

  • Gene Inversion

    • Gene Inversion utilizes recombinases to invert DNA sequences, resulting in an ON to OFF switch in the gene located within this switch.
    • Recombining sequences in site-specific reactions are usually short and occur at a single target site within the recombining sequence.
    • Through the utilization of specific recombinases, a particular DNA sequence is inverted, resulting in an ON to OFF switch, and vice versa, of the gene located within or next to this switch.

  • Maturation of B Cells

    • In the heavy-chain 'V' region there are three segments; V, D, and J, that recombine randomly, in a process called VDJ recombination, to produce a unique variable domain in the immunoglobulin of each individual B cell.
    • The B cell may either become one of these cell types directly or it may undergo an intermediate differentiation step, the germinal center reaction, where the B cell will hypermutate the variable region of its immunoglobulin gene ("somatic hypermutation") and possibly undergo class switching.

  • Hosts for Cloning Vectors

    • E. coli and plasmid vectors are in common use because they are technically sophisticated, versatile, widely available, and offer rapid growth of recombinant organisms with minimal equipment.
    • For example, if the experimentalists wish to harvest a particular protein from the recombinant organism, then an expression vector is chosen that contains appropriate signals for transcription and translation in the desired host organism.
    • Whatever combination of host and vector are used, the vector almost always contains four DNA segments that are critically important to its function and experimental utility--(1) an origin of DNA replication is necessary for the vector (and recombinant sequences linked to it) to replicate inside the host organism, (2) one or more unique restriction endonuclease recognition sites that serves as sites where foreign DNA may be introduced, (3) a selectable genetic marker gene that can be used to enable the survival of cells that have taken up vector sequences, and (4) an additional gene that can be used for screening which cells contain foreign DNA.
    • Domain: Bacteria, Kingdom: Eubacteria, Phylum: Proteobacteria, Class: Gammaproteobacteria, Order: Enterobacteriales, Family: Enterobacteriaceae, Genus: Escherichia, Species: E. coli.

  • Medical Importance of Viruses

    • RNA viruses in particular must coordinate the switch between plus and minus strand synthesis and between replication and transcription while protecting their genomes from cellular nucleases.
    • Among these are the sudden emergence of the coronavirus that causes severe acute respiratory syndrome (SARS), the continued transmission of an avian influenza virus to humans ("bird flu"), and the isolation of poliovirus vaccine-wild type recombinants that have hampered poliovirus eradication efforts.

  • Mu: A Double-Stranded Transposable DNA Bacteriophage

    • Once the viral DNA is inserted into the bacteria, the Mu's transposase protein/enzyme in the cell recognizes the recombination sites at the ends of the viral DNA (gix-L and gix-R sites) and binds to them, allowing the process of replicating the viral DNA or embedding it into the host genome.
    • Its transposition mechanism is somewhat similar to a homologous recombination.
    • In this mechanism, the donor and receptor DNA sequences form a characteristic intermediate "theta" configuration, sometimes called a "Shapiro intermediate. " Replicative transposition is characteristic to retrotransposons and occurs from time to time in class II transposons.

  • Antibody Structure

    • Recombination and splicing may result in over 106 possible VJ combinations.
    • The numbers of repeated constant domains in Ig classes (discussed below) are the same for all antibodies corresponding to a specific class.
    • BCRs on naïve B cells are of the IgM class and, occasionally, the IgD class.
    • Similarly to IgM, BCRs containing the IgD class of antibodies are found on the surface of naïve B cells.
    • This class supports antigen recognition and subsequent maturation of B cells to plasma cells.

  • Pathogenicity Islands and Virulence Factors

    • Pathogenicity islands (PAIs) are a distinct class of genomic islands acquired by microorganisms through horizontal gene transfer.
    • Pathogenicity islands (PAIs) are a distinct class of genomic islands acquired by microorganisms through horizontal gene transfer.
    • Pathogenicity islands are discrete genetic units flanked by direct repeats, insertion sequences or tRNA genes, which act as sites for recombination into the DNA.