adaptive immune response Flashcards
summary of adaptive immune response
Response specific to antigen
Learnt behaviour
Memory to specific antigen
Quicker response
humoral adaptive immunity - b cell activation
B cells express membrane bound Ig (IgM or IgD monomer)
Each B cell can only make one Ab that will only bind one epitope on one Antigen
types of t cells
t -regs- suppress immune responses
t- helper - express CD4 To help activate B cells and cytotoxic T cells
Cytotoxic - express cd8- release perforin which causes cells to lyse
5 classes of immunoglobulins
IgG
IgA
IgM
IgD
IgE
main type of immonoglobilin and it’s characteristics
Igg
Highly specific
Important during secondary response
Basic structure of an antibody
Y shaped
Two chains - light and heavy
Functional region where it binds to receptors
Fab fragment bind to pathogens ( variable region )
What is CD20?
A protein found on B cells
Mature cell marker
Basic function of antibodies
Neutralise toxins
Opsonisation of pathogens
Destroy pathogens
Where are Mhc 1 expressed
On all nucleated cells
Where are mhc 2 expressed
Antigen presenting cells
What is igg important for
Secondary / memory response , crosses placenta
What is igm important for
Important in primary responses for complement system activation
What is iga important for
Protects mucosal surfaces
What is igE important for
bound to mast cells and basophils ,
Important in allergy and infection response
What do mhc class 1 display the antigen to
Cd8+ve cytotoxic T cells
What do MHC class 2 display antigens to
Cd4+ve helper T cells
Mechanism and example of type 1 hypersensitivity
Antigen reacts with igE bound to mast cells
Causes them to release histamine
Eg, anaphylaxis
Mechanism and example of type 2 hypersensitivity
IgG or Igm binds to antigen on cell surface
Eg, autoimmune haemolytic anaemia , rheumatic fever
Mechanism and example of type 3 hypersensitivity
Free antigen and antibody combine
Eg, systemic lupus
Mechanism and example of type 4 hypersensitivity
T cell mediated
Eg, tuberculosis , multiple sclerosis
What is extravasation
Leukocyte migration across the endothelium
Main ige receptor cell
MAST CELLS
where do t cell originate
haematopoetic stem cells
what do CD proteins do
help to differentiate major groups of effector t lymphocytes
what will cd8+ cells become
cytotoxic t cells
what will cd4+ cells become
t helper cells
what mhc class presents to cd8
class 1
what mhc class presents to cd4
class 2
when are t helper cells asctivated
when presented to mhc class 2 proteins
where does positive selection occur
cortex of thymus
purpose of positive selection
only allows selection for t cells that bind to self antigens
where does negative selection occur
medulla of thymus
A 3 year old girl is brought into A&E with a high grade fever and purpuric rash. She is
suspected to have bacterial meningitis and a lumbar puncture was performed.
Given the likely diagnosis, which cell type would you expect to predominate in the
CSF?
NEUTROPHILS
What IL is responsible for the proliferation and differentiation of b cells
Il 4
