Untitled - D Ank Unlimited

isotype switching 422 IVIG
5'
5'
V
D J S µ
V D J
isotype switching
The mechanism whereby a cell changes from synthesizing
a heavy polypeptide chain of one isotype to that of
another, as from μ chain to γ chain formation in B cells
that received switch signals from T cells. Refer also
to switch region and switch site. Antigenic specificity
remains the same during isotype switching that involves
joining a rearranged VDJ gene unit to a different heavy
chain constant region gene.
isotypic determinant
Immunoglobulin epitope present in all normal individuals
of a species. Isotypic determinants of immunoglobulin
heavy and light chains determine immunoglobulin class
and subclass and light-chain type.
isotypic exclusion
The use by a B cell or antibody of one light polypeptide
chain isotype, κ or λ.
isotypic specificities
Species-specific variability of antibody (human, mouse,
rabbit, etc.). Examples of isotypes include IgG, IgM, and κ
light chains.
isotypic variation
Differences among antigens found in members of a species
such as the epitopes that differentiate immunoglobulin
classes and subclasses and light chain types among immunoglobulin
chains.
S µ
S γ 3
C µ C δ S γ 3
5'
C γ 3
Recombination
S γ 1
Transcription and
processing
V D J
C γ 1
C γ 3
C γ 3
S α 1
3'
S γ 1
C α 1
C γ 1
Isotype switching from immunoglobulin M (IgM) to IgG.
3'
S α 1
C α 1
ITAM
Abbreviation for immunoreceptor tyrosine-based activation
motif.
ITIM
Abbreviation for immunoreceptor tyrosine-based inhibition
motif.
ITIM/ITAM immunoreceptors
ITAMs (immunoreceptor tyrosine-based activation motif;
consensus sequence YxxI/Lx 6-12 YxxlI/L) and ITIMs
(immunoreceptor tyrosine-based inhibition motif; S/I/V/
LxYxxI/V/L) are phosphorylation motifs found in a large
number of receptors or adaptor proteins. Phosphorylated
ITAMs serve as docking sites for tandem SH2 domains of
Syk family kinases, whereas phosphorylated ITIMs recruit
tyrosine phosphatases. Signaling through ITAM-bearing
receptors usually results in cell activation, while engagement
of ITIM-bearing receptors is usually inhibitory. Most
of these receptors are involved in tumor development and
regulation of the immune system, although they also function
in tissues such as bone and brain.
ITP
Abbreviation for idiopathic thrombocytopenic purpura.
IVIG
Abbreviation for intravenous immunoglobulin.
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