Anatomy Of An Immune Response Flashcards
(34 cards)
What is ‘inflammation’
A response to noxious conditions (infection and tissue injury).
What can inflammation be induced by?
Immune recognition of infection, that is hypersensitive to environmental components or autoimmune, or tissue damage.
What is a Leukocyte
Collective name of WBC
What is a Cytokine
A protein messenger that leukocytes use to communicate.
What is an Antigen
A molecule to which the immune system can respond
What is an ‘Epitope’
The specific ‘bit’ of the antigen which the immune system recognises
What is a Macrophage
A sentinel cell found in all tissues to protect against bacteria and fungi
- ‘big eaters’
- phagocytotic
- cytokine production
What is a neutrophil
A blood cell that rapidly responds to infection.
- phagocytotic
- highly motile
What is a B cell
A lymphocyte which produces antibody to kill extracellular pathogens.
What is a CD4 T cell
A helper lymphocyte which helps B cells produce antibody.
What is a CD8 T cell
Cytotoxic lymphocyte which helps kill virus infected cells
What is a mast cell
Sentinel cell found in epithelial tissues to protect against parasites.
Distinct Components of immune system
- Evolutionary, spatially and temporally separate.
- Evidence for distinct importance.
- Effective defence against infection requires multiple avenues.
Immunological barriers - skin
- stratum corneum
- sweat (pH 6)
- secretions (dermicidin)
- fatty acids and normal flora
Immunological barriers- gut and airways
- mucus
- stomach acid (pH 2)
- secretions (antibodies)
-normal flora
IMMUNE RECEPTOR COMPARISON- pattern recognition receptors
- Germline encoded
- approx 50 different types
- leukocytes co- express many different ones
- recognise key pathogen components
IMMUNE RECEPTOR COMPARISON- Lymphocyte receptors
- random modular design during development
- 10^7 different types
- each lymphocyte has many copies of one receptor
- can recognise almost anything
Adaptive immune cells- lymphocytes- B cells
Develop in bone marrow and produce antibodies.
- secreted version of lymphocyte receptor
- binds to target antigen on pathogen
Adaptive immune cells- lymphocyte- T cells
Develop in bone marrow BUT mature in thymus
What are Dendritic cells
- innate immune cell
- derived from same blood monocyte precursor as macrophage
- tissue resident phagocyte (sampling antigens in environment)
- recognises pathogens using pattern recognition receptors
-mature to the response of ‘danger’
The Lymphoid system
- drainage system from tissues
- second circulatory system
- lymph nodes and spleen
- nexus points where dendritic cells meet B and T lymphocytes
Lymphocyte activation
- DONT react to purified antigens in solution alone
- antigens must be processed and T cells require antigens to be presented correctly
Lymphocyte activation - T cells
T- cells require antigens to be presented on a special scaffold on the surface of dendritic cells
Need to receive constant constimulation from mature dendritic cells
Lymphocyte activation- B cells
Receive costimulation from T cells or pattern recognition receptors
