Immunology Flashcards
What are the 2 types of immune response in mammals?
Acquired and innate
What are the 2 types of acquired immunity?
T and B cell
What are the 3 types of innate immunity?
- Complement cascade
- Phagocytes
- Physical barriers
Name the innate immunity mammalian leukocytes (5)
- Neutrophil
- Eosinophil
- Basophil
- NK cells
- Mast cells
Name the antigen presenting cells (4)
- Monocyte
- Macrophage
- B lymphocytes
- Dendritic cells
What is the relationship between plasma cells and B cells?
Plasma cells are differentiated B cells
What is the relationship between monocytes and macrophages?
Macrophages differentiate from monocytes once they are in tissues. Monocytes are found in blood
What are the 3 pathways of complement activation?
- Classical
- Lectin
- Alternative
What are the outcomes of complement activation?
- Altered membranes allowing bacterial lysis and opsonisation
- Opsonisation facilitates phagocytosis of the pathogen
- Inflammation leading to, and caused by, mast cell degranulation and neutrophil chemotaxis, which also causes pathogen destruction
How does the complement activation lead to inflammation?
Stimulation of histamine release from mast cells (mast cell degranulation)
How does the complement system lead to direct bacterial lysis?
Pore formation in cell membranes by Membrane Attack Complexes (formed by complement components)
What is the activating signal for the classical complement pathway?
Antigen:Antibody complex
Which complement proteins are anaphylatoxins?
C3a, C4a, C5a
What effects to anaphylatoxins have on the body?
- Contraction of smooth muscle
- Increased vasodilation in local blood vessels increasing movement within tissues and lymph flow
- Activates mast cells or neutrophils
- Increases fluid in tissue and speeds up lymph flow
- Increases chemotaxis
Outline the development of acute inflammation at mucosal surfaces
- Epithelium damaged due to breach by pathogen
- Leads to cytokine production and chemokine release from epithelial cells (ECs)
- Stimulates resident cells e.g. mast cells
- Recruits innate immune cells
- Histamine and other vasoactive substances increase vascular permeability from mast cells
What is the effect of neutrohphils on inflammation?
Increases inflammation, are pro-inflammatory
What are the results of acute inflammation?
- Increased vascular permeability
- Recruitment of cells and diapedesis
Where are acute phase proteins/reactants produced?
In the liver
What stimulates the production of acute phase proteins/reactants?
Cytokines secreted during inflammation IL-6 and IL-1, TNFalpha)
What acute phase proteins are secreted in response to IL-6?
C-reactive protein (CRP) and fibrinogen
What acute phase proteins are secreted in response to IL-1 and/or TNFalpha?
Serum amyloid A protein
What is the clinical significance of acute phase proteins?
- Can be markers for systemic inflammatory response
- Determine severity of disease
- Can be used to monitor the response to treatment
Name the pro-inflammatory cytokines
- TNFalpha
- IL-1
- IL-6
- CXC-8/IL-8
Name the anti-inflammatory cytokines
- IL-4
- IL-10
What are the effects of pro-inflammatory cytokines
Recruit cells to area for inflammatory response
What are the effects of anti-inflammatory cytokines?
- Promote production of antibody
- Mops up pathogen and reduces inflammatory response
- Adaptive response present, more specific and will resolve disease faster
What factors determine the immunity to pathogens?
- Intracellular vs extracellular pathogen
- Innate and adaptive immune responses
- Ig isotype location and function
- Complement, opsonisation, phagocytosis and removal of pathogen
Give the events leading to immunological memory
- Pathogen/antigen invasion
- Ag capture and processing, Ag recognition
- Selection of lymphocytes specific for that antigen
- Cell activation
- Proliferation of antigen specific lymphocytes to form a clone
- Differentiation into a function (effector) state or memory state
What is the function of antigen tolerance?
Prevents damage to self and regulates immune response to environmental antigens and fetus during pregnancy
What are the types of antigen tolerance?
- Central
- Peripheral
Where and when does central antigen tolerance develop?
- Education of T lymphocytes in thymus
- B lymphocytes in bone marrow
- Occurs during maturation
Where and when does peripheral antigen tolerance develop?
- T and B cells in secondary lymphoid tissue
- Occurs after birth
What is hypersensitivity?
Sensitisation as a result of repeated exposure of genetically susceptible individuals to the same antigen
What are the types of hypersensitivity?
- Type I: antibody mediated, immediate
- Type II: antibody mediated, cytotoxic activity, days
- Type III: immune complex mediated, 24h
- Type IV: cell mediated, delayed type (DTH), 24-72h
Give examples Type I hypersensitivities
- Localised: atopic dermatitis, flea allergy dermatitis, sweet itch, allergic rhinitis, asthma, food
- Systemic: bee stings, penicillin
Give examples of Type II hypersensitivityes
- Incompatible blood transfusion e.g. in cats
- Autoimmune disease: haemolytic anaemia, thrombocytopaenia, neutropaenia, myasthenia gravis
Give examples of Type III hypersentivities
- Allergy to fungal spores in cattle
- Recurrent airway obstruction in horses
- Blue eye in dogs
- Leishmaniosis in dogs