-
What is natural immunity?
Hard-wired protective devices that don't depend on previous exposure to antigens (AGs)
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3 forms of natural immunity
- Mechanical barriers
- Phagocytic cells
- Protective proteins (ex/ lysozyme)
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What is an AG (antigen)?
a substance we recognize as foreign to our selves and elicits an immune response
-
What is aquired immunity?
- specific responses to antigens
- (note: this is all he had, so I assume all that is required, but it is very very generalized)
-
What are cells of the immune system called?
Lymphocytes
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Two types of Lymphocytes?
T-lymphocytes and B-lymphocytes
-
Cells derived from the thymus
T-lymphocytes
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Immune cells derived from the bone marrow
B-lymphocytes
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Lymphocytes in gastrointestinal and bronchial mucosa
mucosa-associated lymphoid tissue (MALT)
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2 ways to differentiate between or identify lymphocytes
Specific stains and surface markers
-
two types of T-lymphocytes
T helper and T suppressor/cytotoxic cells
-
help B cells produce immunoglobulin
T-helper cells
-
suppress unwanted antibody production and mediate killing of virus-infected cells or tumor cells
T suppressor/cytotoxic cells
-
______ percent of circulating lymphocytes are "T"
70
-
All T cells have surface _________ which is attached to a membrane protein __________, making these two unique markers for T cells.
T-cell receptor (TCR) and CD3
-
The 15% of peripheral lymphocytes that have TCR but no CD3
NK cells
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T/F: NK cells can kill virus infected cells, tumor cells and foreign cells WITHOUT previous sensitization
True
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T-helper cells express _____ on their surfaces while T-suppressor/cytotoxic cells express ______
- CD4 for T-helpers
- CD8 for T-suppressors/cytotoxic
-
Normal ratio of T-helpers to T-suppressor/cytotoxic
2(Th):1 (Tc)
-
T helper to T suppressor/cytotoxic ratio in a person with HIV (ratio of CD4 to CD8)
less than 1.0
-
Two subsets of CD4 cells and what they produce
- T-helper 1: produce interleukin-2 and interferon
- T-helper 2: prdouce IL 4,5, and 13
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These cells differentiate into immunoglobulin producing cells that develop RER and eventually become plasma cells
B lymphocytes
-
3 characteristics of plasma cells
- eccentric nucleus, a prominent Golgi apparatus and stain Pyrinophilic because of the marked numbers of concentric arranged
- RER.
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5 classes of immunoglobin (IG)
IgG, IgA, IgM, IgD, IgE
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Each IG molecule is made up of two ______ and two _______.
heavy chains and light chains
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The end of the molecule that attaches to the antigen has two portions. What are they?
variable and invariable
-
5 molecules linked together (IG)
IgM
-
First class produced (IG)
IgM
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Good compliment binder (IG)
IgM
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Secretory, in GI,tears and respiratory tract (IG)
IgA
-
secreted into lumen (IG)
IgA
-
1/1000 people deficient (IG)
IgA
-
-
IG that passes via placenta into baby
IgG
-
IG in very small amounts in body
IgE
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IG attached to mast cells
IgE
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IG important in allegies and anaphylaxis reactions
IgE
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IG that is a precursor, found on B cells
IgD
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This complex, often called human leukocyte antigens is what identifies us as ourselves.
major histocompatibility complex (MHC)
-
MHC's are responsible for _____________as well as ____________ to responsible cells for immunological reactions
- transplantation reactions
- presentation of antigens
-
What are the two groups of MHCs?
type I and type II
-
2 characteristics of type I MHCs
- receptors for CD8
- link macrophages to cytotoxic/suppressor lymphocytes
-
2 characteristics of type II MHCs
- receptors for CD4
- interact with B helper cells presentation of Ag
-
When antigens (Ag) and antibodies (aby) come together, they form an _______________.
immune complex
-
Depending on __________, immune complexes may be soluble or insoluble.
ratio of Ag to aby
-
If an aby attaches to a RBC (no complement), the cell will
destroyed in the spleen (delayed reaction)
-
If an aby plus complement attaches to a RBC what happens?
the RBC will lyse and be immediately destroyed
-
RBCs lysing from aby + complement reactions is commonly seen in ___________ and leads to _________.
- incompatible blood transfusions
- shock-like state and death
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Type I hypersensitivity reaction
- An IgE mediated event. IgE molecule binds to a mast cell with the
- Fab fragment outward. When the antigen and the Fab fragment come together, the
- mast cell ruptures releasing histamine and other mediators of inflammation.
- Examples are hay fever, atopic dermatitis, bronchial asthma and anaphylactic
- shock.
-
Type II hypersensitivity reaction
- When ABy or complement are attached to a cell,
- this can serve as a signal that causes cells such as neutrophils,monocytes and
- NK cells to attach to either the ABY or complement and destroy the cell. This
- is called antibody-dependent cellular cytotoxic reaction (ADCC). Other
- examples of Type II hypersensitivity include ABY to TSH receptors on thyroid
- cells and ABY against the receptor of acetylcholine in Myasthenia gravis.
-
Type III hypersensitivity reaction
- These are diseases where AG/ABy complexes
- produce an inflammatory effect often mediated by complement. When there is AB-ABy equilibrium or mild ABY
- excess the immune complexes are small and precipitate throughout the body. Complement is activated and tissue damage
- occurs. When there is ABy excess large
- insoluble complexes occur that are easily broken down and phagocytosed with
- little tissue damage. Again when the AG/ABY complexes are small and precipitate in small vessels
- producing a lot of inflammation. These
- mechanisms are important in:
- Systemic
- lupus erythematosus (SLW)
- Poststreptococcal
- glomerulonephritis
-
Type IV hypersensitivity reaction
- Called
- cell mediated – A cellular reaction when T-Lymphocytes that are previously sensitized
- are exposed to the sensitizing antigen to release a series of small molecular
- weight compounds called cytokines. IFN-gamma
- acts to stimulate macrophages to release other products phagocytose invading
- organisms and fuse together to form granulomas.
- This is the basis of the TB skin test, where TB antigen is injected, if
- there are sensitized lymphocytes, they
- stimulate macrophages that enter
- the area. This is manifested by cell
- infiltration and firmness or induration of the skin. Contact dermatitis such as
- poison ivy is another example of this type of reaction. This is why poison ivy
- stays around for such a long time
-
4 types of transplantation
- 1. Autografts – within one person – hair transplants, veins, skin grafts
- 2. Isografts – genitically identical individuals of same species
- 3. Homografts or allografts – not genetically
- related individuials
- 4.Xenografts – between different
- species – UMMC developed Pig that we will accept
-
Rejection of a transplantation can be___________,__________, or ___________.
hyperacute, acute, or chronic
-
Graft vs Host reaction
- A serious complication when donor lymphocytes
- attack recipient cells.
-
Many new drugs have been developed to depress the _________ ___________ so that transplants can occur.
immune system
-
Is a blood transfusion a form of a transplantation?
Yes
-
Blood transfusion – This is form of
transplantation
- There
- are ABO RBC membrane antigens, which are encoded by three genes. There are 6 genotypes: AA, AB, AO, BO, BB and OO. The A and B gene
- are dominant over the O gene so there are only 4 blood groups A which can be
- (AA or AO) , B (BB or BO), AB and O. O
- is the universal donor and AB is the universal recipient. If a person is type A, then there will have
- naturally occurring B antibodies. If a
- person is type B, then they will have natural occurring anti-A.
- All
- blood is typed to prevent incompatibilities.
- Another group of RBC antigens are called Rh factors
- blood group. These are strong antigens
- and if incompatible can elicit a strong immunologic reaction resulting in the
- death of the RBC. When an Rh- mother has
- an Rh+ baby the fetal RBC's (Rh+)can leak into the circulation of the mother
- and she will form Rh+ antibodies. These antibodies in subsequent pregnancies
- can destroy the fetal RBC's. This disease can be prevented by giving the mother
- a drug called RhoGAM, which can destroy these fetal cells in her circulation
- before they induce an immunological response. RhoGAM is an antibody against RBC's that are
- Rh+.
-
What is an autoimmune disease?
- These are a category of diseases where the
- immunological system has an immune response against its own antigens. There may
- involve Type II,III or IV reactions
-
Which gender has a higher prevalence of autoimmune diseases?
women
-
Autoimmune brain disease?
multiple sclerosis
-
autoimmune thyroid disease
Hashimoto's disease
-
autoimmune blood disorder
autoimmune hemolytic anema
-
autoimmune kidney disease
glomerulonephritis
-
autoimmune skin disorder
pemphigus vulgaris
-
autoimmune muscle disorder
myasthenia gravis
-
Systemic Lupus Erythematosus
- These
- individuals produced antibodies to many intrinsic antigens, such as
- DNA, RNA (anti-nuclear antibodies) as well as
- some organ specific antibodies
- The form immune complexes composed of AG-ABy that are deposited in tissue, activate
- complement and causes inflammation and attraction of inflammatory cells. This
- can produce joint disease.
- These complexes are sometimes deposited within the glomeruli of kidneys causes renal
- disease
- Treatment is immunosupression.
-
Transient immunodeficiency
infants of about 6 months run out of maternal aby and are slow to produce their own
-
HIV virus
- 1.
- The HIV virus (a retrovirus) has infinity for CD4 helper lymphocytes and
- destroys them creating a host that is susceptible to certain infectious
- disease. Currently we can identify the viral load and by doing a CD4/CD8 ratio
- determine the state of health of the
- infected individual. When the CD4 cells falls below 200, the crisis phase beg
- 2. There may be a significant latent time
- for symptoms to occur and there are examples of infected people who have no
- evidence of disease.
- 3. Like many viruses many systems can be infected including CNS, Lungs,
- Intestine New tumor formation (Lymphoma or Kaposi's sarcoma)
4. .HIV research has developed a large number of effective anti-viral
-
Amyloidosis
- Diseases caused by the infiltration of organs with amyloid (a fine fibrillar material)
- Associated with production of light chains from malignant antibody producing cells
- Can be produced by chronic disease states in
- particular liver disease where the amyloid is derived from a serum protein
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