bodys lines of defense, which are specific?
Antigen (Ag) -
Antigen (Ag) - A substance that can induce an
immune response when introduced into an
animal.
Antibody (Ab)
Antibody (Ab) - A protein that is produced in
response an antigen. The antibody binds the
antigen that stimulated its production. All
antibodies are immunoglobulins.
Immunoglobulin (Ig) -
Immunoglobulin (Ig) - A glycoprotein composed
of heavy and light chains that functions as an
antibody.
Schematic Structure of a Typical Immunoglobulin (Antibody) Molecule
• IgM -
• IgM - first immunoglobulin to
appear in an immune response
IgG -
IgG - principal immunoglobulin of the secondary immune response.
Only immunoglobulin capable of crossing the placental barrier
IgA -
IgA - principal immunoglobulin in
external secretions of mucosal
surfaces, tears, saliva, and
colostrum
IgE -
IgE - plays an important role in
immediate hypersensitivity
reactions and parasitic infections
IgD
gD - thought to activate the B-
lymphocyte
lymphocyte
Primary and Secondary Lymphoid Organs
• All lymphocytes arise in the bone marrow
• Primary lymphoid organs
– Bone marrow
– Thymus
• Secondary lymphoid organs
– Lymph nodes
– Tonsils
– Spleen
– Mucosal-associated lymphoid tissue (MALT)
Subsets of
Lymphocytes
B and T
distinguishing b and t cells
There are two
types of
lymphocytes, B
cells and T cells
• They look alike in
their H&E
phenotype, but
they are
completely
different
B lymphocytes become? role?
plasma cells
secrete antibodies when
challenged by antigen
• Antibodies are essential
for humoral immunity
Agammaglobulinemia (Bruton Agammaglobulinemia)
inheritence?
more common in?
type of dx?
result?
deficeint in what immune function?
susceptiable to?
tx?
QB of IS?
Tcells (CD4)
types of t cells
T Lymphocytes
• CD4+ (T Helper Cell) - quarterback
• CD8+( Cytotoxic T Cell) - effector
role of t cells
• Cell-mediated defense against intracellular pathogens
– Viruses, fungi and one important bacterial disease (tuberculosis)
Natural Killer Cell
• A component of the innate immune system
• A type of cytotoxic lymphocyte
• Do not have markers for B or T cells
Function of the Thymus
• T cells become educated
• Learn self from non-self
• Self-reacting T cells are
deleted
Lymph Nodes and lymphocytes
• B lymphocytes leave the bone
marrow and populate lymph nodes
• T lymphocytes leave the thymus and populate lymph nodes
IS balance
• Self / non-self recognition
• General / specific
• Natural / adaptive
• Innate / acquired
• Humoral / cell-mediated
• Active / passive
• Primary / secondary
classifications of pathogens, examples and immunity responsible for defense
• Extracellular pathogens
– Most bacteria
– Humoral immunity
• Intracellular pathogens
– Viruses, fungi, some bacteria
– Cellular immunity