immunology Flashcards
antimicrobial defense specific to airways
as part of fn of innate system
- mucus production which trap invading infective agents
- elimination of mucus by ciliary escalator
antimicrobial defense specific to GIT
as part of fn of innate system
- low pH which destroys a large proportion of infective agents
- contain commensals (i.e. normal gut flora) which confer competitive protection against infection
epithelial barrier
as part of fn of innate system
- serves as a physical and chemical barrier against entry of infective agents
- intraepithelial lymphocytes are responsible for eliminating intracellular pathogens (i.e. infected cells)
- antibiotics such as defensins act on bacteria (extracellular pathogen)
Type I Interferons
as part of fn of innate system
- consist of IF-α & IF-β
- induce adjacent cells to transit into anti-viral states
-> activate various signalling pathways that inhibit viral replication and destory viral genomes
What is the enzyme that drives the point mutation that underlie somatic hypermutation?
Activation Induced Deaminase (AID)
which antibodies are responsible for immune complex formation
IgM and IgG
Trap and remove pathogens
which antibodies are responsible for opsonisation
IgG
Promotes phagocytosis of pathogen
which antibodies are responsible for complement activation
IgM
Activation of the classical pathway involving C1q
which antibodies are responsible for neutralisation
IgG and IgA
Prevent pathogen or toxin interaction with targets
which antibodies are responsible for ADCC
IgG
Activate NK cell killing of targets
which antibodies are responsible for mast cell degranulation
IgE
Release of toxic granules against parasites
via IgE coating parasite -> mast cells bind to IgE via specialised Fc receptor (FcER1)
function of IgD
Not as impt
- mainly serves as BCR (membrane-bound form)
- same antigen specificity as the antibodies that will be secreted by that B cell
Where does somatic recombination happen for T cells and B cells
same place as (+) and (-) selection
process goes like this:
1. somatic recombination
2. selection
T cells: thymus
B cells: bone marrow
bcos T cell = Thymus cell
B cell = Bone marrow cell
what does the somatic recombination which happens before selection specficially entail
Somatic rear rangement of the gene fragments
which gene segments do light chain gene somatic recombination involve
V J C segment
What are the two subtypes of light chain on an antibody
- Kappa κ
- Lambda λ
Lambda has more functional V gene segments available (22) than Kappa (2)
-> much greater potential for diversity
