T4L7 - Innate immunity Flashcards
Function [3]
AIR
Promote acute inflammation
Prevent infection
Rapid response
Pattern like receptor
Toll-like receptors (TLRs) are an example of a pattern recognition receptor. Drosophila with TLR mutations were susceptible to fungal infection
Mechanical
Epithelial cells joined by tight junctions
Skin/Gut: Longitudinal air flow
Lungs: Movement of mucus by cilia
Chemical
Skin: Fatty acids
Gut: Low pH abd enzymes (pepsin)
Eyes/Nose: Salivary enzymes
Antigen receptors
Detect non-specifically using pathogen-associated molecular patterns
Pattern recognition receptors
MBL binding
Mannose and fucose residues with correct spacing
Phagocytosis
Neutrophil and macrophages = highly phagocytic
Ingested material killed by low pH, enzymes and respiratory burst -> produce free radical
NK cells
Recognise antibody-coated bacteria by Fc receptor - target organism and kill non-phagocytic
Antibody-dependent cellular cytotoxicity
Eosinophils
Parasitic
Granules contain toxic enzyme
Perform ADCC
Allergic inflammation use
Complement
A series of enzymes that are produced in the liver and circulate in the bloodstream
Opsonisation by complement
• Complement plays a role in opsonisation, along with antibody
• Activated complement component C3b sticks to pathogens
Binds to phagocyte C3b receptors
Alpha interferon
Production activated by viral infection
Works locally on cells
Stop cells dividing, stop protein synthesis and stimulate anti-viral production
Hydrocortisone [3]
Natural glucocorticoid secreted by adrenal cortex
Act via intracellular glucocorticoid receptor - influence gene expression
Anti-inflammatory agent and immunosuppressant
Hydrocortisone side effects
Hyperglycaemia
Osteoporosis
Cataracts, weight gain, body shape change, mood, acne
Steroid
Steroid receptors in cytoplasm complexed with heat-shock protein Hsp90
Steroids cross cell membrane and bind to receptors - release Hsp 90
Steroid-receptor complex cross nuclear membrane
Steroid receptor bind to gene reg sequence and activate transcription
