Innate (natural) Immunity Flashcards
3 types of epithelial barriers?
Mechanical - movement of mucous by cilia
Chemical, - skin (fatty acids), enzymes (lysozyme in saliva & tears), pepsin in gut
Microbiological - commensal bacteria (blocking of adhesion, production of anti-microbial substances)
Where do you find MALT (mucosal-associated lymphoid tissue)
find in gut, respiratory system, urogenital system, mammary glands
What does the mucosal system do? why is it important?
Principle site for infection and allergic reactions
Absorptive - food and oxygen defends against dangerous antigens
Barrier - against antigens penetrating
Respond - to antigen penetration
Where can you find organised cells (sites of antigen entry)?
Tonsils, peyers patches, mucosal surfaces,
what is the role of cells in the mucosal system (immune defence) ?
- slows down invasion of pathogens
- signal other area of immune system of danger
cells involved in immune defence:
- lymphocytes
- antigen present cells: langerhans, dendritic cells, macrophages
- neutrophils, NK
what is opsonisation?
Opsonisation is a process that helps your immune system identify and destroy pathogens. Opsonins coat cells or pathogens so cells of your immune system (phagocytes) can find them, attach to them and eliminate them by phagocytes.
Oposin: Molecules that bind to the surface of a foreign antigen
what is PRR and PAMP?
Pattern recognition receptors
Pathogen - associated molecular patterns
Macrophages express a range of PRR on cell surface in order to recognise PAMP.
Some PRR-PAMP engagement can lead to phagocytosis.
What do Toll like receptors do?
bind to PAMP - activate signal pathways and leads to inflammation
signal pathways activate transcription factors
what is salivary peroxide?
bacterial effects and desctruction of hydrogen peroxidase in mucosa that could cause tissue damage
what does lactoferrin do?
iron binding protein (anti-microbial) that blocks bacterial growth
what does histanins do?
anti -funal agents
host defenses for Extracellular:
- Interstitial spaces, lymph
- Epithelial surfaces
Intersitial: antibodies, complement, phagocytosis
epithelial surfaces: antibodies mucus, antimicrobial peptides
What do natural killer NK cells do?
- Granular lymphocytes defend against virus and tumours
- Natural killer cells (NK cells) are white blood cells that destroy infected and diseased cells, like
cancer cells. - They’re also a type of lymphocyte, like B-cells and T-cells.
- NK cells can destroy harmful cells in the early stages, preventing viruses and cancer cells from spreading
host defenses for Intracellular:
- cytoplasmic
- vesicular
Cytoplasmic: cytotoxic T cells, Natural killer cells
Vesicular: Phagocytosis in cell vesicle
