Untitled - D Ank Unlimited

antibody fragment 47 antibody titer
Membrane lg
Passive immunization.
Ag-Ab complex
(binds to antigen-specific
B cells)
Fc receptor
Antibodies
from mother
Umbilical
cord
that antigen. Several mechanisms may be responsible
for this including (1) removal of the initiating stimulus
by the antibody, (2) binding of antigen–IgG antibody
immune complexes to the Fcγ receptors of B cells, and
(3) inhibition of T cell responses by antigen–antibody
complexes. The use of Rh immune globulin to prevent
erythroblastosis fetalis in the infants of Rh– mothers is
an example of antibody feedback. Secreted IgG antibodies
may downregulate antibody production when antigen–antibody
complexes simultaneously engage B cell
membrane immunoglobulin and Fcγ receptors (FcγRII).
The cytoplasmic tails of Fcγ receptors transduce inhibitory
signals inside the B cells.
antibody fragment
A product of enzymatic treatment of an antibody immunoglobulin
molecule with an enzyme such as papain or
pepsin. For example, papain treatment leads to the production
of two Fab and one Fc fragments, whereas the use of
pepsin yields the F (ab′) 2 fragment. Refer to the individual
fragments for further information.
antibody half-life
The mean survival time of a particular antibody molecule
after its formation. Half-life is the time required
to rid an animal body of one half of a known amount
of antibody. Thus, antibody half-life differs according
to the immunoglobulin class to which the antibody
belongs.
Antibody feedback.
Membrane lg
Anti-lg antibody
(binds to all B cells)
Fc receptor
antibody humanization
The transference of the antigen-binding part of a murine
monoclonal antibody to a human antibody.
antibody-mediated suppression
The feedback inhibition that antibody molecules exert on
their own further synthesis.
antibody repertoire
All of the antibody specificities that an individual can
synthesize.
antibody screening
Candidates for organ transplants, especially renal
allografts, are monitored with relative frequency for
changes in their percent reactive antibody (PRA) levels.
Obviously, those with relatively high PRA values are considered
less favorable candidates for renal allotransplants
than those whose PRA values are low. PRA determinations
may vary according to the composition of the cell panel. If
the size of the panel is inadequate, it may affect the relative
frequency of common histocompatibility antigens found in
the population.
antibody-secreting cells
Differentiated B lymphocytes that synthesize the secretory
form of immunoglobulin. Antibody-secreting cells result
from antigen stimulation. They may be found in the lymph
nodes, spleen, and bone marrow.
antibody specificity
A property of antibodies determined by their relative
binding affinities, intrinsic capacities of the antibodycombining
sites expressed as equilibrium dissociation
(K d) or association (K a) for their interactions with different
antigens.
antibody synthesis
The 10 12 B lymphocytes that comprise the human immune
system synthesize 10 20 antibody (immunoglobulin) molecules
present inside and on the surfaces of these cells and
most of all in the serum. Other species have B cell and
immunoglobulin molecule numbers relative to their body
weights. B cells and immunoglobulin molecules are formed
and degraded throughout the human lifespan.
antibody titer
The amount or level of circulating antibody in a patient with
an infectious disease. For example, the reciprocal of the
highest dilution of serum (containing antibodies) that reacts
with antigen (e.g., agglutination) is the titer. Two separate
A