ICS - Immunology Flashcards
Name the 2 types of immunity
Innate and Adaptive
What is innate immunity?
- nonspecific
- resistance doesn’t improve by repeat infection
- rapid response
- instinctive
- doesn’t depend on lymphocytes
- phagocytes and natural killer (NK) cells
- lysosome, complement, interferon (produced by virally infected cells: protect uninfected cells and activate macrophages and NK cells)
KILLING: COMPLEMENT SYSTEM
neutrophil and macrophage mostly
physical barriers: skin, mucus, cilia
chemical barriers: lysozyme in tears, stomach acid
What is adaptive immunity?
-specific acquired immunity
- required lymphocytes
- antibodies involved
- resistance is improved by repeat infection
- slower response (days-weeks)
- b lymphocytes and t lymphocytes
Name the components of the immune system
-neutrophils
- macrophages
- monocytes
- eosinophils
- basophils
- mast cells -
-nk cells
- t lymphocytes
- b lymphocytes
Give some information on neutrophils
- make up 65% of blood
- 6-12 hr lifespan
- important role in innate immunity - phagocytosis
- 2 main intracellular granules: primary lysosomes (combine with phagosomes containing microbes to digest them). secondary granules: lactoferrin and lysozyme.
- can kill microbes by secreting toxic substances (superoxide’s)
- Have Fc and complement receptors
Give some information on monocytes
- make up 5% of blood
- lifespan: months
- important role innate (phagocytosis) and adaptive (Antigen presentation) immunity
-differentiate into macrophages in the tissues - main role to remove anything foreign (microbes) or dead
- have lysosomes containing peroxidase that can kill microbes
- Have Fc, complement, pattern recognition receptors (PRR), toll-like receptors and mannose receptors - can bind to all kinds of microbes
Give some information of macrophages
- lifespan: months/years
- examples include: Kupffer cells (liver) and microglia (brain)
- Play important role in innate (phagocytosis) and adaptive (antigen presentation) immunity.
- 1st line of non-self-recognition.
- role: remove foreign (microbes) and self (dead/tumour cells)
- Have lysosomes containing peroxidase (free radicals)
- Have Fc, complement, toll-like and mannose receptors - can bind to all kinds of microbes
Give some information of Eosinophil:
5% of blood
8-12 days lifespan
granules stain for acidic dytes eg : eosin (red/pink)
associated with parasitic infections and allergic reactions
granules contain major basic protein (MBP) - potent toxin for helminth worms
MBP activates neutrophils and induces histamine release from mast cells and provokes bronchospasm (allergy)
Give some information of Basophil:
2% of blood
2 days lifespan
granules stain for basic dyes e.g.: haematoxylin - blue/violet
very similar to mast cells
high affinity IgE receptors
binding of IgE to receptor results in de-granulation, releasing histamine - main cause of allergic reactions
mainly involved in immunity to parasitic infections and allergic reactions.
note: mast cells are fixed in tissue whereas basophils are able to circulate in blood around the body.
explain the complement system
3 pathways: direct, alternate, lectin
destroy foreign antigens
Give some information on mast cells:
only in tissues
similar to basophils
express high affinity IgE receptors
Binding of IgE to receptor results in degranulation, releasing histamine - main cause of allergic reactions.
mainly involved in immunity to parasitic infections and allergic reactions.
Give some information on T Lymphocytes
10% of blood
lifespan hrs - years
ADAPTIVE IMMUNITY
originate from bone marrow but mature in thymus
recognise peptide antigen displayed by Antigen Presenting Cells (APC)
Bind antigen through specific T cell receptors (TCR)
produce cytokines
specifically kill infected host cells.
Give some information on B lymphocytes
15% of blood
hrs -yrs. lifespan
ADAPTIVE IMMUNITY
ORIGINATE AND MATURE IN BONE MARROW
