Immune Defenses Against Disease

1
Immune Defenses Against Disease Chapter 17
with these considerations Pg 383 IgD is not
the principal B-cell receptor -- T-cells are
not specific for eukaryotic pathogens Pg 385
lymphokines (cytokines) are not charged --
Cytotoxic T-cells do not interact directly with
microbes Pg 387 the description of B-cell
activation is muddled, and fails to state that
B-cells must interact directly with antigens not
with MHC-presented antigens error is reflected
in Figure 17.9 Pg 390 skip paragraph on somatic
recombination -- M of IgM does not stand for
macroglobulin -- most IgA is secreted Pg 392
Discussion of agglutinins and precipitins is
muddled Pg 393 section on 4 types of active and
passive immunity is unnecessarily complicated,
and do not worry about specific names of the
processes Pg 395 Skip the paragraphs on cytoxic
hypersensitivities
2
What are the two main arms of the immune defense
system? 1. Innate defenses against infection
(antigen-nonspecific) Barriers to
infection anatomical chemical
(molecular) physiological Cellular
responses 2. Acquired defenses against
infection antigen-specific humoral
cell-mediated systems These systems interact in
many ways
3
Cells of the Immune System Innate granulocytes
macrophages Acquired lymphocytes Cytokin
es coordinate activities
4
Organs of the Immune system Primary Lymphoid
organs Bone marrow Thymus Secondary
lymphoid organs Spleen lymph
nodes etc. B-cells and T-cells circulate
5
What are the functions of the Humoral and
Cell-mediated systems? Humoral attack
pathogens, toxins B-cells ------gt
antibodies Cell-mediated 1) Hormonal
regulation (Cytokines) Helper-T cells (TH,
T4) 2) attack infected body cells
cancerous cells Cytotoxic Killer-T cells (Tc,
T8)
6
What is an antigen? Antigenic molecules Perceive
d as foreign Complex macromolecule Non-antig
enic molecules Epitopes
7
What is an antibody? Functional regions antigen
binding sites constant region --
triggers response hinge region
What are the 5 types of antibodies and their
functions? IgG primary serum Ig IgA
secretory Ig IgM B-cell receptor IgE
eukaryotic Ags IgD membrane associated
8
How does the Humoral System respond to an
infection? Clonal Selection Naïve
B-cells Activation (AG selection) TH cell
stimulation Plasma cells Antibody
factories Memory cells create acquired
defense (T-cell response is similar)
9
How does antibodies trigger an immune
response? Blocking of receptors Toxin
neutralization Antigen clearing Enhanced
phagocytosis Activation of complement
10
How does the Cell-mediated system respond to
infections? MHC proteins -- antigen
presentation Role of macrophages T-Helper
cells -- release cytokines -- interferons,
interleukins, etc Cytotoxic-T (T-Killer)
cells -- attack infected body cels --trigger
cell lysis, apoptosis
Killer-T cell activation
Killer-T cell video
11
Clinical Manifestation of Immunity Primary vs
Secondary responses Differences in lag
time Ab Titer memory cells
12
Immunization Passive Immunotherapy maternal
antibodies anti-toxins Active Immunotherapy
(i.e., vaccination) Types of vaccines dead
cells attenuated cells molecular components
Vaccine production
13
Autoimmune disorders Examples Type I
diabetes -- B-cells of pancreas Rheumatoid
arthritis -- cartilage of joints Myasthenia
Gravis -- acetylcholine receptors Multiple
sclerosis -- myelin sheath
14
Hypersensitivities Type-1 allergies --
involved antibodies B-cells ----gt IgE mast
cells histamine inflammation Type IV
contact dermatitis -- involves T-cells and
macrophages e.g., poison Ivy
IgE and Allergy