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Antigenic variation may be classified into two types, antigenic drift that results from a change in few amino acids and antigenic shift which is the outcome of acquiring new structural proteins. A new vaccine is required every year because influenza virus has the ability to undergo antigenic drift.
This can allow the cell to skip the parts of the endogenous pathway that involve synthesis of antigens from the antigenic genes with cellular machinery upon infection, because the endogenous pathway can involve infection before being able to present antigens with MHC I, and cross-presentation saves them the effort needed for that and allows the ...
IgM is first expressed as a monomer on the surface of immature B cells. Upon antigenic stimulation, IgM+ B cells secrete pentameric IgM antibody formed by five Ig monomers which are linked via disulfide bonds. The pentamer also contains a polypeptide J-chain, which links two of the monomers and facilitates secretion at mucosal surfaces.
Antigen processing and presentation in MHC-I pathway Cytotoxic T cells (also known as T c , killer T cell, or cytotoxic T-lymphocyte (CTL)) express CD8 co-receptors and are a population of T cells that are specialized for inducing programmed cell death of other cells.
According to Burnet's hypothesis, among antibodies are molecules that can probably correspond with varying degrees of precision to all, or virtually all, the antigenic determinants that occur in biological material other than those characteristic of the body itself
The individual peptides are then complexed with major histocompatibility complex class II (MHC class II) molecules located in the lysosome – this method of "handling" the antigen is known as the exogenous or endocytic pathway of antigen processing in contrast to the endogenous or cytosolic pathway, [17] [18] [19] which complexes the abnormal ...
Mechanism of class-switch recombination that allows isotype switching in activated B cells. Immunoglobulin class switching, also known as isotype switching, isotypic commutation or class-switch recombination (CSR), is a biological mechanism that changes a B cell's production of immunoglobulin from one type to another, such as from the isotype IgM to the isotype IgG. [1]
Antigenic shift is contrasted with antigenic drift, which is the natural mutation over time of known strains of influenza (or other things, in a more general sense) which may lead to a loss of immunity, or in vaccine mismatch. Antigenic drift occurs in all types of influenza including influenza A, influenza B and influenza C.