Flashcards
Innate Immunity
Cards in this deck (42)
- 1Define innate immunityThis is your 1st line of defence, it is naturally present & not stimulated by the presence of antigens ∴ generally not specific
- 2What are the 3 phases of response following an initial infection?1. Immediate innate immune response
• pathogen recognition by pre-formed non-specific effectors
2. Early induced response
• recruitment of effector cells
3. Adaptive immune response
• >96hrs after initial infection
• requires transport of antigens to lymphoid organs, specific generation of immune cells & clonal expansion of effector cells - 3How can pathogens gain access to the body?Mucosal membranes
External epithelia - 4What forms of barriers does the body have to infection?Mechanical
Chemical
Microbiological - 5Mechanical barriers against infection• Tight junctions
• Air & fluid flow across membranes
• Cilia moving mucus - 6Chemical barriers against infection• Fatty acids on skin
• Enzymes e.g. lysozyme
• Low pH in stomach
• Antibacterial peptides e.g. defensives & cryptidins - 7Microbiological barriers against infectionNormal flora
• compete for nutrients and attachment (forming biofilms)
• produce antibacterial substances e.g. colicins - 8What bactericidal effects & agents are produced by phagocytes?• Acidification
• Toxic O2 derivatives: superoxide, H2O2 & hydroxyl radicals
• Nitric oxide
• Defensins & other cationic peptides
• Lysozyme & acid hydrolases
• Competitors: lactoferrin & Vit B12 binding protein - 9Where are all cellular elements of blood derived?Haematopoietic stem cell progenitor in the bone marrow
- 10What is a monocyte?A large phagocytic WBC which is a circulating precursor to macrophages
• it differentiates in tissues - 11—Monocyte
- 12Which phagocytic cell is the most numerous?Neutrophil
- 13How are neutrophils adapted to prevent parasitic growth inside the cells?They have a short life-span
- 14What is chronic granulomatous disease?A hereditary condition in which cells of the immune system, namely neutrophils, have a difficult time producing the toxic O2 derivatives required for phagocytosis
- 15What is alpha 1-antitrypsin deficiency?Excessive tissue damage due to neutrophil driven inflammation
- 16What do eosinophil granules contain?Histamine
Peroxide
RNAse & DNAse
Lipase
Plasminogen
Major basic protein - 17In what conditions would eosinophilia be observed?Parasitic infections of the gut
Some vascular diseases
Hodgkins disease & Addisons disease - 18What is often observed with glucocorticoid use?Eosinopenia - lower than expected number of eosinophils
- 19Eosinophilia-myalgia syndromeA potentially fatal neurological conditions linked to the ingestion of the dietary supplement L-tryptophan
- 20—Neutrophil
- 21—Eosinophil
- 22Name the granulocytesNeutrophils
Basophils
Eosinophils
Mast cells - 23What do basophils excrete upon activation?Histamine
Proteoglycans
Leukotrienes
Some cytokines - IL-4 - 24—Basophil
- 25What do the substances released from mast cells affect?Vascular system
- 26—Mast cell
- 27What do B-cell lymphocytes do?Produce antibodies
- 28What do T-cell lymphocytes do?Become cytotoxic T-cells or helper T-cells
- 29—Lymphocyte
- 30Function of dendritic cellsBridges the gap between the innate & adaptive immune response
Specialised in antigen presentation & uptake - 31Function of NK cellsProtection before the adaptive immune response begins
- 32What happens when a cell becomes infected?Cell releases 2 cytokines (IFN-alpha & IFN-beta)
• these tell nearby cells that something is wrong so they can adapt to become less susceptible to the infection
• they up-regulate MCH in nearby cells
• triggers NK cells to kill the virus infected cells - 33What is the role of MHC molecules on non-infected cells?To send inhibitory signals to the NK cells - not to kills them
- 34What is the complement system?A part of the innate immune system which floats in circulation pre-formed waiting for activation
- 35Name the 3 activation pathways of the complement cascade1. Classic Pathway
Antibodies binding to a bacteria
2. Lectin Pathway
Mannose-binding proteins binding to the pathogen surface
3. Alternative pathway
Pathogen surface itself triggers activation - 36What occurs at the end of the pathways?Recruitment of inflammatory cells
Opsonisation
Lysis & cell death - 37What is C3a & what is its function?Peptide mediators of inflammation
• float off & encourages other immune cells to come to the site of infection - 38What is C3b & what is its function?Opsonin
• encourages phagocytosis - 39Function of C5aAssists in the phagocytosis of C3b coated bacteria
- 40Describe the assembly of the MACMembrane Attack Complex
• C5b, C6 & C7 begin forming the MAC on the bacterial surface, eventually it punches holes in the membrane ∴ you get diuretic lysis of the bacteria - 41How is the complement system regulated?• C1s and C1r inhibitors which dislodge & stop their interaction
• Factor H & I which block the interaction of complement components - 42How is the MAC regulated?Expression, in most cells, of CD59 which blocks th C9 component ∴ stoping the barrel wall of MAC interacting with C5b
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- MD2002 Flashcards on Innate Immunity, created by Lareyna Mcmenemy on 02/05/2018.
- Created by
- Lareyna Mcmenemy · May 2018
- Updated
- May 3, 2018
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