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chapter 35
Molecular Immunology
T A B L E
3 5 - 1
Components of the Immune System
Cellular (Leukocyte)
Components
Principal Functions
Characteristic
Receptors/Specific Recognition
Molecules (CD’s)
Related
Figure(s) or
Tables
Lymphoid Cells
B-cells (B lymphocytes)
Recognition of antigens,
Antigen receptors are surface
Figure 1
Mature in bone marrow,
become antibody-forming
IgM (monomeric IgM), IgD.
Figure 18
reside in lymph nodes,
plasma cells (synthesize Ig
As APCs B-cells bind
spleen, alimentary and
molecules), act as antigen
exogenous antigens and
respiratory tract mucosa
presenting cells (APCs), some
present processed antigen
T-cells (T lymphocytes)
B cells defferentiate into
memory cells for rapid
recognition of previously
encountered antigens
Regulation of T and B-cell
via MHC Class II to T cells.
Express CD3, CD19, CD20,
CD21 (complement receptor),
CD32 (FCyReceptor II),
CD35 (complement receptor),
CD40 and CD45 on surface
Recognize antigens on APCs
Mature in thymus,
immune response
via
TcRs
(T-cell receptors)
reside in thymus
Th (T helper cells)
T-cell subclass that release
antigen (epitope) specific
All T-cells express CD3 on
their surface
Recognize antigens (epitopes)
Figure 1
Thl
necessary cytokines for cell
stimulation and proliferation
Thl
- regulation of cellular
on APCs via TcRs, specifically
MHC Class II
receptors
Express CD3 and CD4, on
Th2
immunity via IL2 and IFN-7
Th2 - B-cell stimulation via
surface, CD4 used to identify
T-helper cells in cell sorting
T Suppressor cells
IL’s 4, 5,
6
and 10
Suppress B and T cell responses
procedures. Also express CD2,
CD28 and CD45R
TcR, CD3
CTLs (Cytotoxic T-
to antigen stimulation
Cytotoxic against tumor cells,
Express
CD
8
on surface
Possess TcR, IL-2R, (IL-2
Figure 3
lymphocytes)
and virus infected host cells.
receptor) recognize processed
Natural killer cells
Destroy infected cells through
perforin-dependent permeability
changes. Produce TNFaand
TNF/3. Promote apoptosis.
Granular lymphocytes that
antigens (epitopes) via
MHC Class I
receptors
on APCs. Express CD3
and
CD
8
,
(also CD2, CD28)
NO Ig, CD3 or TcRs
Figure 4
(NK cells)
recognize and destroy virus-
Express CD16 (FC
7
IIR), i.e.
infected and cancer cells and
use ADCC. Exclude destruction
of cells that express MHC-I.
Stimulated by IL-2, IFN-7,
TNF-ce. Create pores that
permit transfer of proteins
which promote apoptosis of
infected cells
surface receptors that bind via
Fc portion of IgGs
Express CD56 on surface.
CD16 and CD56 used for
identification in cell sorting
(c o n tin u e d )
