Immunology Flashcards
What are the three types of phagocytic cells of the immune system?
- Macrophages (mature monos)
- Granulocytes (produced in vast quantities during immune response)
- Dendritic cells (antigen presenting)
What are cytokines?
Small proteins important in cell signaling that have a specific effect on the interactions and communications between cells
What are chemokines?
SIgnalling proteins that induce directional movement of neuts and monocytes from the bloodstream to the site of inefction
What are pathogen recognition receptors (PRR)?
- Proteins that are part of the innate immune system that recognize microorganisms
- They enable the phagocytic cells to recognize PAMPs
- They enable the immune innate system to differentiate between its self and non self because the body’s own cells lack PAMPs
What are PAMPs?
- Pathogen associated molecular patterns
- Molecular structures found in pathogens like bacteria and some viruses that trigger an inflammatory response in the body
What are toll-like receptors?
- PRRs
- A family of proteins that are a key part of the innate immune system and the first line of defense against microbes. TLRs can recognize invading pathogens and danger molecules released from damaged tissues and dying cells. They play a vital role in linking innate and adaptive immunity
What are DAMPs?
- Damage associated molecular patterns
- Endogenous danger molecules
- Molecules that are released from damaged or dying cells and can activate the innate immune system
What is the complement system?
- A group of proteins that is a component of innate immunity that circulate in inactive form, and once activated, stimulate phagocytosis to clear foreign material, and cause inflammation to attract additional phagocytes
Adaptive immunity
- Takes several days to mount a response
- More efficient than the innate system because of inherent recognition functions of lymphocytes
- Antibodies and activated lymphocytes persist after original pathogen eliminated which serves to prevent reinfection and allows for long lasting immunity because with recognition, faster responses can occur
What is a natural killer (NK) cell?
- A lymphocyte with a distinctive granular cytoplasm that is considered part of the innate immune system
- They can destroy potential threats without prior exposure to a particular pathogen
What are antigen specific lymphocytes?
The T and B lymphocytes are involved in the acquired or antigen-specific immune response given that they are the only cells in the organism able to recognize and respond specifically to each antigenic epitope
B cells….
- produce antiBodies used to attack invading Bacteria, viruses, toxins
T cells…
- destroy body’s own cells that have been Taken over by viruses or cancer
When does the adaptive immune response begin?
When an antigen reaches peripheral lymphoid tissues after traveling from the site of infection through afferent lymphatic vessels
How is avoidance of the body’s own cells accomplished?
Through target recognition cells (TCR) and major histocompatibility molecules (MCH)
What is an antibody?
- The secreted form of B cell receptors (BCR)
- They bind to pathogens and block their access into cells
What is humoral immunity?
Immunity generated by antibodies
What are the 5 main classes of antibodies?
- IgG
- IgM
- IgA
- IgD
- IgE
What does the IgG antibody do?
- The main and most abundant antibody in blood
- Powerful ability to bind to bacteria and toxins
- Important role in biological defense
What does the IgM antibody do?
- The 1st antibody produced by B cell upon pathogen invasion
- Key role in initial immune system defense
- In bloodstream
- Can undergo class switching process
What does the IgA antibody do?
- Defends mucous membranes from bacteria
- Found in secretions
What is the IgD antibody?
it is the first receptor expresseD by b cells
What does the IgE antibody do?
- Defends against parasites
- Involved in allergic reactions
What is autoimmunity?
- The process by which the immune system recognises self antigens as foreign and attacks and destroys body tissue
What type of autoimmunity is IMHA?
Type III
Which antibodies are involved in IMHA reactions?
- IgG
- IgM
- IgA
When does intravascular hemolysis in IMHA occur?
- When the autoantibody cascade is triggered
- Lysis occurs while they are still in circulation
When does extravascular hemolysis in IMHA occur?
- Occurs if the complement and membrane attack systems are NOT activated
- Lysis occurs outside of blood vessels via normal mechanisms, but in pathologic proportions which overwhelms the liver
What is microangiopathic hemolytic anemia?
- RBC are physically damaged during circulation due to vessel occlusion, abnormal vascular morphology, or fibrin shearing
- Clinical signs are a direct result of tissue hypoxia due to reduced CaO2
Why do reticulocytes predispose patients to thromboembolism?
Due to its associated proinflammatory process
What is the first line therapy for IMHA and why?
Glucocorticoids, due to their inhibition of macrophages of the MPS
Splenectomy is an option for IMHA patients with which type of hemolysis?
Extravascular
Why might heparin not be effective in IMHA patients?
Heparin requires antithrombin to be effective, and antithrombin is often decreased in IMHA dogs
What type of autoimmunity is ITP?
Type II
Why is vincristine used in ITP?
- It is immunomodulating
- It induces release of platelets from megakaryocytes through premature fragmentation and by impairing consumption of platelets by macrophages
What are the two components of acquired immunity?
- Humoral
- Cellular
Humoral immunity
- The function of activated B lymphs
- The major defense system against Bacterial infections
- “B moves are usually HUMORous due to their low Budget”
Cellular immunity
- Mediated by T lymphocytes
- Incl killer T lymphs, helper T cells, suppressor T cells
- “Cellular communications company T mobile”
What are the 3 classifications of anaphylactic reactions?
- Immunological IgE - mediated (think stings) (releases histamine)
- Immunological non IgE - mediated (think immunoglobin tx) (does not release histamine)
- Non immunological hypersensitivity reactions (think chemo or cold)
What are the shock organs of the dog?
Liver and GIT
What are two reliable biomarkers for anaphylaxis?
- Precipitous rise in ALT
- Gallbladder halo
