Immunology Exam 2 Flashcards
What are killed vaccines (inactivated)?
The agent in the vaccine has been killed. They often contain an adjuvant to enhance the immune response
What does the EPA regulate?
Topical insecticides
What is vaccine potency?
The vaccine containes the required amount of antigens and adjuvants needed to induce immunity
Maternal Antibodies _____Antibody production in the newborn
inhibits
What type of vaccines usually have adjuvants?
Killed vaccines
What are some things that can happen to a vaccine or the way it was administered?
- Storage Temp
- exposure to light
- improper diluent used
- mixing of vaccines
- Vaccines administered concurrently
- Freeze thawing of reconstituent vaccine
- bacterial contamination of multi-dose vial -administered the wrong route
- Different strain
What is active immunity?
Immunity that is produced as a result of antigen stimulated immune response in the individual
What is an example of a type II hypersensitivity?
RBC (Transfusion reactions, Hemolytic disease of the newborn, anemia) other cells types like skin
What is a cytokine?
• Protein messenger molecules - low molecular-weight secreted proteins that regulate intensity and duration of innate and adaptive immune responses
Key Role of ILC3 and TH17
Extracellular bacteria and fungi
What are the disadvantages of MLV’st
- can revert to virulence
- May be virulent in a immunosupressed animal
- may be immunosupressive
- may cause abortion
- can be contaminated with other live viruses
- must be handled carefully to maintain viability
What is a colony Stimulating Factor?
stimulate colony formation in bone marrow, stimulate stem
cell differentiation
Define Antibody
An immunoglobulin protein molecule synthesized on exposure to antigen which can then bind to that antigen
What does it mean when we detect high levels of IgM in an antibody test?
Recent infection
How does allergen specific immunotherapy work?
expose the organism to small amounts of the antigen to cause a local degranulation reaction
What are the two types of passive immunity?
Maternal Transfer
By injection
When can you see systemic effects of proinflammatory cytokines?
in moderate amounts and act on hypothalamus
Where does antibody synthesis occur?
In plasma cells (thousands per minute)
What are the basic components of lateral flow immunodiagnostic test?
Ex: Heartworm test
as the heartworm antigen passes by it picks up the antibody labeled in red and then picks up the antibody with blue color. If there is antigen then the red and blue line show.
How is the innate immune response activated?
by danger signals from the pathogen or tissue damage
What factors influence vaccine efficacy in the presence of maternal antibody?
- Maternal antibody titer
- Immune mechanisms
- characteristic of the pathogen
- immune competence of the young animal
What charcteristics of the vaccine influences vaccine efficacy in the young animal?
MLV/vs. killed Adjuvant rte. of administration antigenic mass number of doses
What does lack of parasites contribute to?
Type I hypersensitity
What turns down the cytokine response?
Feedback inhibitory mechanisms
What are the factors that can decrease resistance and increase suceptibility to bacterial pneumonia?
- Genetics
- Distress
- Viruses
- Age
- Coccicia
- Poor nutrition
- Paracites
Explain how vaccines can fail due to an overwhelming challenge dose
- Poor sanitation in diarrheal viruses
2. Poor ventilation in respiratory viruses
What are the cellular components of the innate immune response?
cellular components (setinal cells, phagocytes and granulocytes, innate lymphoid cells
A person with very high levels of antibody to tetanus toxin is at risk for an adverse vaccine reaction following a tetanus toxoid booster. The reaction begins to manifest 6-8 hours after the booster and is characterized by acute inflammation at the site of the booster (can cause swelling and pain which resolves in a day or two). Give the immunologic basis for this reaction and include the cells and molecules involved. Do your best to include the type of hypersensitivity, inciting cause of inflammation, and the cells and molecules that result in inflammation.
Type of Hypersensitivity: Type III (Arthus Reaction)
Cells: Neutrophils and mast cells
Molecules: Complement fixation components, mediators released from the mast cells and oxygen radicals produced by the neutrophils causing damage
Complexes form and invade tissues
Timing 2-8 hrs.
What are the major sentinel cells?
Dendritic, macrophages, mast cells
- Give an explanation for a potential mechanism of action for hyposensitization therapy for Type I hypersensitivities.
Allergy Shots: getting injected with small amounts of the allergen they have made IgE to. Over time the goal is to get the immune system to switch away from IgE. They want the immune system to make TH1 cells and IgG.
What does the classical pathway require?
Antibody
What is autoimmune disease?
The adaptive immune system attacks self molecules or cells
What is the difference between a normal vaccine reaction and an immediate type hypersensitity reaction?
A immediate type reaction will be very rapid and may cause swelling of the muzzle, and face. I can also be systemic and mount an anaphalactic response
What are some clinical manifistations of Type III hypersensitivites
Serum sickness or Autoimmune disease
Define Hypersensitivity
An immune mediated damaging inflammatory response to a normally innocuous antigen
What is immunodeficiency?
Failure to protect from infections or cancer
When type of protective immunity is considered a circulating antibody?
IgG or IgM that provides protection
Why are proteins good antigens?
they are complex; they have positive/negative charges, hydrophobic areas, etc.
What antibodies are complement fixing?
IgM and IgG
How does • Production and secretion of interferon by one cell protects nearby cells ?
including activating proteins in the neighboring cells that inhibit viral replication
How are cells destroyed in a Type II hypersensitivity?
An antibody attacks a cell surface in the body: Phagocytosis of the cell (rbc) or if a tissue cell the neutrophils and macrophages can attack the cell on lacation. If we get enough antibodies complement system is activated.
Define passive immunity
Antibodies passed from one individual to another
What is perceived vaccine failure?
You think the vaccine failed but it really didn’t
What is a defensin?
A small cationic antimicrobial peptide that can insert and poke holes in bacteria
What are the types of cytokines?
Interleukins (IL1,IL2,IL3IL4) Interferons Chemokines Colony Stimulating Factors Growth Factors
Cellular response to cytokines is ______
tightly regulated
what questions should you ask in terms of protective immunity when vaccinating?
What are the important antigens you must have in your vaccine to induce protective immunity? and what type of antibodies
Are polysaccarides good antigens?
not as good as protein, because it is not complex, usually has repeating structures and no charge
In herd immunity what type of responses can you get?
- Most animals produce an adequate immune response
- Some animals produce an poor immune response and will be poorly protected
- A few animals produce a superior immune response
What is a membrane attack complex?
has a hydrophobic exterior and hydrophilic interior (poke a hole in the bacterial cell membrane)
How long do neutrophils live for?
1-2 days and then enter tissues and do not return to circulation
Antibiotic
A chemical compound obtained from microorganisms that can prevent growth or kill bacteria
What are antibodies?
large proteins with antigen binding sites and Fc portion that is responsible for the biological functions of antibody
What are new technology vaccines?
DNA Vx, RNA particle vaccines and Live vectored vaccines (Chimeric) Live gene deleted Non replicating recombinent antigen vx (virus like particle, Genetically engineered) nucleuic acid mediated
What part of immunity are basophils a part of?
innate
If you did a serology test for IgE antibodies would you see them in high numbers during a reaction?
No because they are not in the circulation and reside on mast cells.
How long before the adaptive immune response kicks in?
Several days to weeks
Where do lymphocytes circulate?
between the lymph and blood
How is active immunity activated via natural infection?
Exposed to pathogen and innate response is activated
B cells and T cells respond with antibodies, t cell cytokines and/or cytotoxic t cells
What are released when a vaccine is given?
Proinflammatory cytokines
What is a hypersensitivity reaction?
Immune mediated diseases such as allergies
This is when the adaptive immune system attacks molecules that are not dangerous
What is cytokine production induced by?
various signals
What are the Important Properties for Strong Antigens (immunogen)?
Foreigness
Size >10,000 MW
Molecular Complexity
Rigidity/Degradability
What is the duration of immunity of a vaccine dependent on?
- presence of the antibody
- Presence of effector and memory lymphocytes (B cells, TH1, TH2, TH17, CTL, or Gamma Delta T Cells)
- Health Status
- Characteristics of the pathogen (virulence and dose)
- Two dogs, Wrigley and Bush, are in for intradermal skin testing for allergies. Explain why Wrigley developed wheal and flare to ragweed and Bush did not and why they both developed wheal and flare to histamine.
This is an example of a type 1 hypersensitivity which is mediated by IgE. Therefore, Wrigley has been previously exposed to the antigen, resulting in the presence of the IgE ragweed antibodies on his mast cells in the dermis. This induced the response. Bush has not been previously exposed so he did not have the antibodies present to cause the reaction. Histamine is already present within the granules of mast cells and the cells of the body naturally have receptors for it to mediate mast cell action. Therefore, any dog would have a reaction to histamine injections because their receptors are not dependent on antibodies or previous encounters. Histamine is used in this situation as a positive control of the wheel and flare response.
Type 1 Interferons
Innate system cytokines
What are some examples of cytokines?
IL1, interferon alpha, interpheron gamma, GM-CSF (granulocyte-monocyte colony stimulating factors)
If we vaccinate all heathy animals we can then _____the effect unhealthy animals
minimize
What does it mean when we see high titers of IgG in a
The infection occurred a few weeks ago
What cell is responsible for the early phase immediate type (Type I) hypersensitivity reaction and what are its special features?
Mast Cells-it degranulates
what is important for a successful immune response?
Communication between adaptive and innate response
What are the cellular components of adaptive iimmunity?
Cytotoxic T cells
TH cell cytokines
Gamma Delta T Cells
- What is the difference between a COVID 19 PCR test, rapid antigen immunodiagnostic test, and an antibody test?
PCR-Looks for Portions of RNA from the virus
Rapid Antigen Test-Looks for a specific antigen (less sensitive)
Antibody Test-Tells us whether the patient already has antibodies for the infection
What are adjuvants?
Something that is added to vaccines to enhance immunity or alter the immune response to co-administered antigen
How is complement regulated?
The components of complement are short acting and are quickly hydrolyzed into inactive states. Many molecules can inactivate complement components
What are the key components in a type III hypersensitivity?
IgG and soluable antigens
What sytemic effects do you see with moderate amounts of pro-inflammatory cytokines?
Fever Sickness behavior action on the liver stimulates the bone marrow to produce more neutrophils neutrophilia Acute phase proteins
How is the Alternative pathway for complement initiation activated?
C3b binding on the cell wall of bacteria, fungi and some viruses
What are advantages to killed vaccine and bacterins?
- Safer
- No reversion to virulence
- no contamination with live viruses
- less likely to be immunosupressive
- less likely to cause abortion
- more stable in handling
If you know the pathogenic mechanism you can figure out the ________
defensive mechanism
What are the pathways for activation of complement?
Classical, Lectin and Alternative
What does the USDA regulate?
Vaccines and diagnostics
What is a true vaccine reaction?
Due to the vaccine or way it was administered
What are some antigen tests?
- Isolation and identification
- PCR
- ELISA
Why do some individuals develop type I hypersensitivity and others do not?
We don’t know the whole story but genetics is part of it along with environment (too clean)
How long does it take a mast cell to degranulate?
5 seconds to start and 1 minute for lots of granules
What is the biggest host factor that cause vaccines to fail?
Presence of the maternal antibody
Is the innate immune response antigen specific?
No
What are the major phagocytic cells?
Neutrophils, macrophages, dendritic cells
What defense mechanism do killed vaccines usually induce?
Neutralizing antibody and Th 1 cytokines
Key role of ILC2 and TH2
Helminthic parasites/allergy
Where can the veterinary vaccine regulations be found?
Virus-Serum-Toxin Act in title 9 of the code of federal regulations
What defensive mechanism would be activated when the pathogen is a parasite?
TH2 and IgE
What agency regulates pharmaceuticals and animal devices?
FDA
What are platelets important for?
Blood Clotting but no role in immune response
What do antibodies form against in SLE?
DNA
What does the USDA say that licensed biologicals must be?
Pure
Safe
Potent
Efficacious
Which types of vaccines induce the endogenous antigen pathway of presentation?
MLV
Live vectored
DNA vx
RNA particle vx
When selecting the optimal technology for new technology vaccines, what should you consider?
- Understand antigen processing and presentation
- pathogenic mechanisms
- defense mechanisms
- protective antigens
What is the function of cytokines?
Protein messenger molecules
Where are Mast cells located?
In tissues
What is hemolytic disease of the newborn?
The mother has developed rbc cell type of the father and newborn also has rbc type of father. When the newborn receive colostrum a reaction will occur
What are eosinophils important in?
Parasite defense and contribute to allergy symptoms
What type of protective immunity is usually activated for viruses?
cytotoxic T cells
At what point do MLV vaccines start to work in young animals
12 weeks but with a 2 weeks period of vuneralbility
What defensive mechanism would be activated when the pathogen is a virus that replicates very rapidly?
Type 1 and 2 interferons
What is the timing of a type IV hypersensitivity?
DTH 24-48 hrs.(TB testing)
What defensive mechanism would be activated when the pathogen infects epithelial cells?
Gamma delta T cells
What are the primary mediators in the type I hypersensitivity response?
Granule contents (Histamine, Proteases, and Chemostatic Factors)
If you are concerned about influenza, you may check a serum sample two to three weeks later, what will you be looking for?
o You would not expect to find IgM for influenza in the serum sample due to its short half-life of about 5 days. On the other hand, a serum sample collected those two to three weeks later could still indicate levels of IgG for influenza due to its half-life of around three weeks.
What does C3 break down to?
Spontaneously breaks down to C3a and C3b
T/F immunologic memory is faster than a primary response
True
Who would you call if you have issues with the safety of a vaccine?
USDA center for biologics or company veterinarian
How many cytokines exist?
over 60
What can the adaptive immune response develop?
Memory and tolerance
How long does it take for long lived plasma cells to be produced?
2 or 3 weeks
Name the proinflammatory cytokines.
IL-1,
TNF,
IL-6 and HMGB-1 (high mobility group box protein-1, also called “alarmin”, and is released from damaged tissue cells).
What defensive mechanism would be activated when the pathogen adheres to the mucosa?
A mucosal antibody (IgA)
What is the most important C component in the Alternative pathway and also has the highest concentration in the blood.
C3
What tests detect antibodies?
- Elisa
2. Neutralization /inhibition assays
What are the advantages of Live vaccines?
- More rapid protection
- Longer immunity
- One dose is sufficient
- No adjuvant required
- Better induction of cell mediated immunity (esp. cytotoxic T-cells)
- Better able to stimulate IgA
- May stimulate interferon
- Less expensive
Where are short lived plasma cells found?
lymphoid tissues
Where are endotoxins found?
Gram negative Bacteria
What are the secondary mediators in a Type I hypersensitivity response?
Membrane phospholipids that make arachadonic acid and PAF that release Leukotrienes and prostaglandin
T/F classical pathway occurs during primary response
False-antibody is not present
What is a plasma cell?
A fully differentiated B cell
If we given an animal a modified live vaccine at 6 weeks and the animal is receiving materal antibodies, will the vaccine work?
No because materal antibody titer is still too high
How does complement increase vascular permeability?
- endothelium allows neutrophils, macrophages and lymphocytes to easily exit the blood vessel and enter the tissues
- allows fluid containing antibody and components of complement to easiliy get to the site of infection
What is the • Interferon autocrine effect?
can result in infected cell increasing MHC1 presentation which will increase the likihood of a cytotoxic T cell recognizing the cell to kill
When is the innate response more effective?
In the presence of adaptive immunity
What are mucosal antibodies?
IgE on mast cells under the mucosal surface
IgA in the mucosal layer
Are mammalian DNA good Antigens?
not good , simple, flexible, easily degraded, not foreign
What do dendritic cells do?
phagocytose microbes and play a role in processing and presenting antigens to T cells
● Antibody molecules are different enough between animal species to be immunogenic, e.g. equine antibodies are immunogenic in humans. Think about the important characteristics of immunogens. What makes a good immunogen/antigen?
A good antigen is large (>10,000 MW), foreign, complex, rigid, and degradable.
What are primary lymphoid tissues?
Where T and B cells become educated to determine which antigen they will recognize
What does the Law mean by safety of vaccines?
Freedom from properties causing undue local or systemic reactions when used as recommended or suggested by the manufacturer
What type of vaccine can break through maternal antibodies sooner?
Intranasal
What are B lymphocytes are part of?
Adaptive immunity
- Humira (adalimumab) and Enbrel (etanercept) are commonly advertised on TV and in magazines for treatments for inflammatory diseases such as rheumatoid arthritis. What are the mechanisms of action of these two drugs?
Both of these drugs use similar mechanisms of action to accomplish the same goal. They both minimize free tumor necrosis factor (TNF) in the synovial fluid. TNF is responsible for the excessive inflammation in joints associated with rheumatoid arthritis. While both drugs bind TNF to inhibit its ability to bind cell receptors and exhibit action, Humira only targets the specific TNF-alpha. Enbrel will target TNF-alpha and -beta.
What are the two types of active immunity?
Natural infection
Vaccination
What function of the complement system does MAC function under?
Lysis of bacteria
What is a lectin?
A protein that binds to a carbohydrate
What do sentinel cells produce?
Pro-inflammatory cytokines
When does the innate immune response take affect?
immediately
- Provide some explanations for why vaccination for diseases such as measles have been so effective and induce immunity that lasts years, but vaccination for influenza is much less effective and yearly boosters are recommended.
-There are a variety of factors that contribute to immunity. For the individual receiving the vaccine, genetics, health status when receiving the vaccination, and health status when exposed all play a role in how the individual’s immune response. This also extends to the pathogen as well where virulence, dose, and antigenic drift and shift effect the outcome of immunity. One large difference between measles and influenza is that measles is given via a live-attenuated vaccine and demonstrates little mutation. It is considered a relatively stable virus which allows for longer immunity. On the other hand, influenza’s mutations due to antigenic drift and shift allows the virus to change immunity to the strain(s) of the virus that are present in the vaccine.
When is the adaptive immune response most effective?
when innate defense mechanisms are in play
- Explain why in an O negative (no A or B antigen on her RBCs and no Rh factor) human mother prevention of hemolytic disease of the newborn (fetus) in humans focuses only on the Rh antigen and not the antibodies the mother has to the A and B blood group antigens.
If the mother is exposed to Rh antigen the mother may make IgG antibodies that can cross over the placenta than it can damage the baby RBC’s. We do not have to worry about this in livestock animals because antibodies cannot cross the placenta but will be in the colostrum.