1 - Intro Flashcards
What is the main function of the immune system?
Host protection
What is the goal of every immune response?
Eliminate or neutralize threat and secure host survival.
What is the goal of the immune system during infections?
Eradicate (or at least control) the foreign invader.
The immune system is composed of…
Tissues, cells, molecules, and processes.
Which veterinarian was a Nobel prize winner?
Peter Doherty
What was the goal of the first vet school?
Conservation of humanity
Who opened the first vet school?
Claude Bourgelat
What are the steps in a typical immune response?
- Immune surveillance
- Detection of threat
- Initiation of inflammation
- Innate immune system effector mechanisms
- Stimulation of adaptive immune effector mechanisms
- Lymphocyte clonal expansion
- Adaptive immune effector mechanisms
- Immunologic memory
Eradication of threat
What are the two arms of the vertebrate immune system?
- Innate
- Adaptive
What is the first line of defense?
Innate immune system
The innate immune system relies on…
Highly conserved receptor proteins that recognize conserved microbial/danger molecules (molecules present on many pathogens)
What happens when the innate immune system is activated?
The cells release cytokines which lead to inflammatory mechanisms.
What are the “professional phagocytes” of the innate immune system?
- Macrophages
- Neutrophils
- Dendritic cells
- Natural killer cells
What is the lifespan difference between neutrophils and lymphocytes?
Neutrophils = Short lifespan
Lymphocytes = Longer lifespan, better for long-term response
List the immune cells in order of most to least abundant in the blood.
- Neutrophil (50-70%)
- Lymphocytes (20-40%)
- Monocyte (2-8%)
- Eosinophil (1-4%)
- Basophil (0-1%)
The adaptive immune system generates a response that is…
Antigen specific.
What is an antigen?
Any molecule that can result in an immune response, usually proteins.
How is the adaptive immune response highly diverse?
It is capable of distinguishing among millions of antigens/epitopes.
What are the main cells of the adaptive immune system?
Lymphocytes: B and T cells.
Lymphocytes express…
Clonally distributed receptors for antigens or potential antigens.
Which immune system is more prone to mistakes?
Adaptive
How many specific antigen receptors are present on each clone?
Only 1.
How many different antigen receptors are expressed in a population of lymphocytes?
More than 5 x 10^7 different antigen receptors.
The adaptive immune system relies on the _____ and _____ of the clone/s that expresses the antigen receptor/s that can bind the specific relevant antigen/s
Relies on the IDENTIFICATION and EXPANSION of the clone/s that expresses the antigen receptor/s that can bind the specific relevant antigen/s
How does the adaptive immune response change over time?
It produces increased responses over time due to memory.
What is required for specialization in the adaptive immune system?
Specialization requires compartmentalization. Cells are “trained” in these tissues and clonal expansion also occurs here. Tissues include lymph nodes, spleen, tonsils, MALT.
What is MALT?
Mucosa-associated lymphoid tissue.
Vaccination prevents…
Fatality but does not prevent infection.
What was Edward Jenner’s contribution to vaccination?
- In 1769, smallpox was the most feared and greatest killer in England
- Jenner discovered cowpox could induce protection against fatal smallpox
How is the adaptive response different between a first and second exposure to an antigen?
The second response is faster, enhanced, and prolonged.
What are the diseases in dogs that are controlled by vaccines?
Distemper, infectious canine hepatitis, leptospirosis, parvovirus, kennel cough, rabies.
What are the diseases in cats that are controlled by vaccines?
Feline infectious enteritis (panleucopenia), feline leukemia, Chlamydia, rabies.
What are the diseases in horses that are controlled by vaccines?
Equine herpes virus 1, influenza, tetanus, viral arteritis, rabies, West Nile virus.
What are the diseases in rabbits that are controlled by vaccines?
Myxomatosis, viral haemorrhagic disease.
What are the diseases in pigeons that are controlled by vaccines?
Paramyxovirus, pigeon pox.
An issue with which aspect of the immune system is more severe?
A problem in innate immunity.
How do retroviruses affect the immune system?
It is an RNA virus so it integrates the host genome and is a lifelong infection. It results in a decline in CD4 T cells. This reduces the adaptive immune response but not the innate response. As a result, pathogens cannot be cleared.
Which animals have innate and adaptive immune systems?
Innate = All animals. Adaptive = Only vertebrates.
Which immune system is ready at all times?
Innate
Which immune system is rapidly deployed?
Innate
Which immune system requires a selection of lymphocytes?
Adaptive
Which immune system is responsible for a delayed response?
Adaptive
Which immune system involves gene rearrangement of receptors that are highly specific?
Adaptive
Which immune system involves germline encoded receptors that can recognize the presence of microbes or damage?
Innate
How does receptor selection vary between the innate and adaptive immune systems?
Innate receptors were selected over evolution and recognizes broad groups of related microbes or other threats. Adaptive receptors are selected in individual animals during maturation and recognizes specific single molecules.
What are the differences in the reaction to self-antigens for innate vs. adaptive immune responses?
Innate is rarely triggered by self antigens, adaptive may react to self antigens.
How does the innate immune response change over time?
It does not. There is no memory.
