LECTURE 4: Primer to Avian Immunology Flashcards
*study antigen presentation (slide 25) + primary & secondary exposure (slide 35)
What are antigens?
A molecule that stimulates an immune response
What are antibodies?
Immunoglobulins (glycoprotein) produced by B-cells to bind to antigens to aid in their destruction.
What are white blood cells?
specific types of immune cells
What are 5 types of WBCs?
- Macrophages
- Lymphocytes
- Eosinophils
- Basophils
- Heterophils (neutrophils in mammals)
What is innate immunity?
Nonspecific defense mechanisms that come into “play” immediately or
within hours of challenge
What are the physical barriers of innate immunity?
- Mucociliary apparatus of the trachea
- SKIN!
- The GI tract
What is adaptive immunity?
Antigen-specific immune response. More complex than innate immunity
How does the adaptive immune system work?
Antigen must be processed and recognized by the immune system. Body then creates antigen specific immune cells to fight them off. Memory cells are then created as a response.
The mucociliary apparatus is apart of what immune system and what is its job?
Innate Immunity
Move particles
What is the largest organ?
the skin
The superficial skin layer that is the first line of defense is called?
Epidermis
TRUE or FALSE? All bacteria is harmful to the host.
FALSE
The surface of the GI tract can be referred to as an ________.
ecosystem
What is the gut microbiome
Area of bacteria and films that able to colonize that area. unique to everyone
Why is the gut microbiome important for poultry research?
as fewer antibiotics are used and gut health is prioritized
What are barriers at the surface of the intestines?
- Mucus
- Enterocytes
- Beneficial bacteria
Why are tight junctions important?
Connects enterocytes together
Prevents molecules from getting through
What are the two parts of adaptive immunity?
- Humoral Immunity
- Cell Mediated Immunity
Antibodies are produced by what cells?
B cells
Bursa in birds
Antibodies respond to how many specific antigens?
ONE SPECIFIC ANTIGEN ONLY
How many antibodies does the body have to make if an antibody can only respond to one antigen?
Millions
Where are antibodies found?
circulating throughout the body
What is the purpose of antibodies?
Bind to antigens coating the surface of various pathogens (viruses, bacteria, parasites, fungi) and marks these tagged cells for destruction
by the immune system
Where the do the first dosage of antibodies come from for the chicks?
Yolk
What are the 2 pathways that antibodies are produced/aquired?
- Created by B-lymphocytes
- Produced by the hen: maternal antibodies (passive immunity) that are deposited into the yolk.
IgY
Main antibody in circulation and the
“work horse” of the antibodies
IgM
First initial antibodies produced but
have the shortest have life. First line of defense against septicemia
What is septicemia?
End of bacteria in the blood
IgA
SECRETORY antibodies that are
released into biological fluids (mucus really common)
What is the antigen binding sight?
Area where the body will recognize the antigen
IgY half life?
4 days
IgM half life?
2 days (SHORTEST)
B lymphocytes produced in the ________ in chicks?
Bursa of Fabricius
Bursa of Fabricius is only present until?
Maturity, b cells then produced else where post maturity
B-cells then develop where?
spleen and bone marrow
B-cells circulate where?
circulate in the blood
Plasma cells are?
B-cells that produce large numbers of antibodies
HOW ARE ANTIBODIES GENERATED
BY THE BIRD? (5 Steps)
- Bird is exposed to a pathogen (bacteria, virus, parasite, fungus)
- Antigen presenting cells (macrophages) “ingest” the pathogen.
- Macrophages “digest” the pathogen.
- Macrophages “present” antigen on their cell surface.
- Helper T-lymphocytes and B-cells can then interact with macrophage and induce the B-cell to begin producing antibodies.
Macrophages do what?
“Eat” bacteria and break it up
What is the MCH II molecule?
Hand that is raised involved with antigen presentation
What are the 5 types of T cells?
- CD4 Helper
- CD4 Suppressor T Cells
- CD8 Cytotoxic Killer Cells
- Natural Killer Cells (NK)
- Memory T Cells
*CD4 Helper T-cells do what?
Help activate B-cells to produce antibodies by interfacing with the
macrophage
CD4 Suppressor T-cells do what?
Needed to stop an immune response
CD8 cytotoxic killer cells do what?
Special T-cells that directly kill cells that present the antigen they were
made to “kill”
Natural Killer cells (NK) do what?
Important for viral clearance and killing cancer cells
*Memory T-cells do what?
Allows for a more rapid and robust immune response on subsequent
exposure to a given antigen (pathogen)
Cell mediated immunity is not well
developed in birds until when?
6 wks of age
Where do T cells come from?
Thymus
The thymus is only present until when?
Sexual maturity
What is passive immunity?
Antibodies going from hen to chick
Maternal antibodies are based on what?
the HEN IS VACCINATED FOR or has been EXPOSED to
What two immunoglobulins are passed from hen to chick? Why?
Only IgM and IgA
Relatively short time that these antibodies are protected
How long do maternal antibodies last?
21 days
How long does it take for these antibodies to be made after antigen exposure?
-IgM
-IgY
- After 2-3 days post antigen exposure
- After 10-15 days post antigen exposure
Every time you are vaccinated what happens to the titer levels?
Spike
Why do you eventually have a stop to the titer increase as you vaccinate so many times?
The body can make only so many antibodies
TRUE or FALSE? The way the body protects against a given
disease is always the same.
FALSE, not always the same
ILT immunity depends on
cell-mediated immunity
IBV immunity depends on
humoral immunity
Heterophils
What are they?
What are they for?
- Most common circulating white blood cell
- Find something eat it and destroy it
Eosinophils are important for?
Very important role in controlling parasites, and inducing allergies
Basophils play a role with?
Also have a role in allergic reactions
