Immuno pathology Flashcards
The recognition or discrimination between the so-called ______ and _____ is the primary role of the immune system. This
recognition of ______ is important to protect against invading microorganisms, chemical agents, or other foreign substances.
“self” and “non-self”
non-self
Elimination of
foreign or non-self of the immune system involves a variety of mechanisms
such as:
1.Inactivation of biologic agents
2.Lysis of foreign cells
3.Agglutination of molecules
4.Precipitation of molecules or cells
5.Phagocytosis of foreign materials
Immune reactions are divided into two broad categories:
Humoral immunity
Cellular immunity
Humoral immunity
•
B-cell lymphocyte mediated via production of antibody
•
Often develops as a response to soluble antigens
•
B cells account for about 20% of circulating lymphocytes
•
Immunoglobulin gene rearrangements allow tremendous diversity of
responses to many antigens
In the diagram of an
immunoglobulin molecule, note
that there are two heavy (H)
chains and two light (L) chains
linked by disulfide bonds. Each
heavy and light chain has a
constant (C) and a variable (V)
region. It is the variable regions
in the Fab portion that react
with a specific antigen and give
rise to the diversity of
immunologic response.
Immunoglobulin can attach via
the Fc portion to a variety of
cells with Fc receptors.
Pg. 32
There are five immunoglobulin classes (isotypes) of antibody
molecules found in serum:
IgG, IgM, IgA, IgE, and IgD.
1. IgA (immunoglobulin A)
2. IgD (immunoglobulin D)
3. IgE (immunoglobulin E)
4. IgG (immunoglobulin G)
5. IgM (immunoglobulin M)
ACTION OF ANTIBODIES
• Agglutinin- antibodies that cause agglutination of cells
• Anti-toxin – neutralizes toxins or poisons
• Lysin – antibodies that cause lysis of cells
• Opsonin – antibodies that present or enhance phagocytosis
• Precipitins - antibodies that cause precipitation
• - antibodies that cause agglutination of cells
Agglutinin
neutralizes toxins or poisons
Anti-toxin
antibodies that cause lysis of cells
Lysin
antibodies that present or enhance phagocytosis
Opsonin
antibodies that cause precipitation
Precipitins
Cellular immunity
•
T-cell lymphocyte mediated
•
CD4+ helper lymphocytes: help B cells make antibody and also help to
generate cytotoxic T cells; participate in delayed hypersensitivity reactions;
account for 60% of peripheral T lymphocytes
•
CD8+ suppressor lymphocytes: are cytotoxic; represent about
30% of circulating T lymphocytes
•
T-cell receptors (TCR) are genetically programmed to recognize
specific antigens and can rearrange their alpha and beta genes to respond to
antigenic stimuli o Macrophages process antigen and present it with class
II HLA to the CD4+ cells o
Cytokines such as interleukin (IL) and
tumor necrosis factor (TNF) are elaborated by activated T cells to enhance
cellular immune reactions
Pg. 32
help B cells make antibody and also help to
generate cytotoxic T cells; participate in delayed hypersensitivity reactions;
account for 60% of peripheral T lymphocytes
CD4+ helper lymphocytes:
: are cytotoxic; represent about
30% of circulating T lymphocytes
CD8+ suppressor lymphocytes
are genetically programmed to recognize
specific antigens and can rearrange their alpha and beta genes to respond to
antigenic stimuli
T-cell receptors (TCR)