Innate and adaptive immunity Flashcards
Compare and contrast adaptive and innate immunity (speed, memory, specificity)
Innate = immediate, no memory, not specific Adaptive = slow, memory, specific
Innate, natural or non-specific immunity is the first line of defence. Give examples of mechanical innate immunity?
Body surfaces = skin and fur
Cilia in respiratory tract
Flushing liquids (tears, urine)
Mucus as a barrier
Give examples of physiologically innate immunity
pH changes and extremes
Pyrexia kills some infectious agents
Give examples of the 4 cellular innate defences
Macrophages
Polymorphs
Mast cells
NK cells
What do macrophages do? Which other cells are phagocytic?
Ingest/phagocytose microorganisms
Polymorphs
What do mast cells do?
Have receptors for IgE antibodies
Increase vascular permeability
What do NK cells do?
Kill tumour cells, virally infected cells or antibody coated cells
What are examples of molecular innate defences?
Defensins Complement Acute phase proteins Interferons Lysozymes Myeloperoxidase system
What are defensins? Where are they particularly found?
Small proteins
Phagocytes and epithelial
What pathogens are defensins active against?
Bacteria, fungi, viruses
Bind to microbe membrane
Important in skin barrier to infections
What are lysozyme?
Family of enzymes that attack peptidoglycan cell walls of bacteria
Where are lysozymes found?
Cells - e.g. macropahges
Secreted in tears, saliva and mucus
Sebum from sebaceous glands
Where is sebum secreted from? What does sebum do?
Sebaceous glands
Waxy fatty acids hydrate and lubricate skin
Stop bacterial attachment
What is myeloperoxidase? Which cells is it found in?
Enzyme found in lysosomes (organelle containing lysozyme and others)
Granulocytes and macrophages
What does myeloperoxidase do?
Kill bacteria and pathogens by producing toxic substances