Untitled - D Ank Unlimited

SOD 661 soluble complex
DD
TRADD
FADD
TNF-R1
Pro-caspase 8
TNF
George Davis Snell.
cIAP
RIP
TRAF2
Apoptosis
NF-κB
(a) TNF-RI-initiated apoptosis and activation activation of NF-κB. (b) SODD silencing
of TNF-RI signaling.
(a)
(b)
the development of congenic mice. He made many seminal
contributions to transplantation genetics and received the
Gairdner Award in 1976. (Refer to Histocompatibility [with
Dausset and Nathenson], 1976.)
SOD
Abbreviation for superoxide dismutase.
SODD (silencer of death domains)
The tumor necrosis factor (TNF) receptor superfamily
contains several members with homologous cytoplasmic
domains known as death domains (DDs). The intercellular
DDs are important in initiating apoptosis and other
signaling pathways following ligand binding by the
receptors. In the absence of ligand, DD-containing receptors
are maintained in an inactive state. TNF-RI contains
a cytoplasmic DD required for signaling pathways
DD
associated with apoptosis and NF-κB activation. Jiang
et al. identified a widely expressed 60-kDa protein they
named SODD (silencer of death domains) associated with
the DDs of TNF-RI and -DR3. Overexpression of SODD
suppresses TNF-induced cell death and NF-κB activation,
demonstrating SODD’s role as a negative regulatory
protein for these signaling pathways. TNF-induced
receptor trimerization aggregates the DDs of TNF-RI
and recruits the adapter protein TRADD. This in turn
promotes the recruitment of the DD-containing cytoplasmic
proteins FADD, TRAF2, and RIP to form an active
TNF-RI signaling complex. In contrast, SODD acts as a
silencer of TNF-RI signaling and does not interact with
TRADD, FADD, or RIP. It is associated with the DD of
TNF-RI and maintains TNF-RI in an inactive, monomeric
state. TNF-induced aggregation of TNF-RI promotes the
disruption of the SODD–TNF-RI complex. SODD does
not interact with the DDs of other TNF receptor superfamily
members such as Fas, DR4, DR5, and TNF-RII. SODD
association with TNF-RI may represent a general model
for the prevention of spontaneous TNF signaling by other
DD-containing receptors.
solid organ transplant
The surgical transfer of a kidney, heart, lung, liver or skin
from a donor to a recipient.
solid phase radioimmunoassay
The attachment of antigen (or antibody) to an insoluble
support that can be used to capture antibodies (or antigens)
in a specimen to be assayed. Antibodies in a serum sample
are exposed to excess antigen on an insoluble support and
sufficient time is allowed for antigen–antibody interaction.
This is followed by washing and the application of
radiolabeled anti-Fc antibodies specific for the Fc regions
of the captured antibodies. Quantification of the bound
antibody is determined from the amount of radioactivity
adhering to the insoluble support. Various materials may be
used as supports. These include Sepharose beads or tissueculture-plate
wells. An unrelated protein must be used to
coat the insoluble support prior to application of the specific
antibody to saturate areas of the insoluble support where
antigen SODD is not located.
solitary plasmacytoma of bone
A plasma cell dyscrasia characterized by a single plasma
cell neoplasm in the bone marrow.
solubilized water-in-oil adjuvant
A water-in-oil emulsion adjuvant composed of a smallvolume
aqueous phase compared to the volume of oil.
A mixture of aqueous and oil phases results in an emulsion
that is stabilized by the addition of emulsifying
agents.
soluble antigen
An antigen solubilized in an aqueous medium.
soluble complex
An immune (antigen–antibody) complex formed in excess
antigen and rendered soluble. Antigen excess prevents
lattice formation in vitro and in vivo. Soluble complexes
may produce tissue injury in vivo, which is more severe
if complement has been fixed. C5a attracts neutrophils,
and capillary permeability is increased. PMNs, platelets,
and fibrin are deposited on the endothelium, followed by
thrombosis and necrosis. Immune complexes induce type
III hypersensitivity reactions.
S