4 - adaptive immunity Flashcards
what forms the basis for natural and artificial immunity
immune memory
what do vaccines initiate
primary immune response
edward jenner made what connection
1798
connection between protecting against smallpox using fluid from cowpox postules
noticed that milk maids had gained natural immunity q
t lymphocytes
kill virus-infected and cancer cells
activate other cells of immune system
b lymphocytes
secrete immunoglobulins
NK cells
dont need prior activation innate cells hunt to find foreign antigens lack antigen-specific receptors can kill virus-infected cells
antigen defn
molecule recognised by the variable antigen receptors on lymphocytes
naive lymphocytes in differentiation
sit in secondary lymphoid tissue
wait for information from dendritic cells
then migrate into peripheral tissue to carry out response
communication in lymhpatic system
via adhesive cell surface molecules
expressed by cytokines
how do lymphocytes enter lymphoid tissue
blood stream
CD stands for
cluster of differentiation
CD4
helper t cells co-receptor for MHC class II
CD8
cytotoxic t cells
co-receptor for MHC I
dendritic cells found
epithelial and mucosal surfaces
3 types/ locations of dendritic cells
langerhans
dermal
gut mucosa
Langerhans cells
subset of dendritic cells found in keratinised epidermis of skin
dermal dendritic cells
found in interstitial tissue
role of m cells in immunity
deliver antigen from gut lumen to underlying dc cells in tissue
what is an effector t cell
a differentiated and proliferated naive t cell
gets triggered to kill/activate cells displaying same MHC-antigen complex
how are t cells focused onto target cells
MHC cell surface proteins
they display fragments of antigen for recognition by t cell
importance of peter medawar 1944
clinical immunologist
burn victims of WWII allow opportunity to research into skin graft rejection
rejection relates to differences in MHC
importance of MHC
2 classes
monitor different internal compartments of cells
expressed by all body cells
MHC I
MHC II expressed on…
only on immune cells
MHC I
found on cell surface of all nucleated cells
upon activation, CD8 t cells produce…
perforins
granzymes
perforins
cytolytic proteins found in granules
form pores in target membranes
granzymes
proteases released by granules that induce apoptosis in target cells
helper t cells
recognise fragments that have been broken down and displayed by MHC II
stimulate macrophage to destroy internalised pathogen
B cells effect on antigens
internalise antigens bound to surface antibodies
deliver them to internal compartments to be digested
antigen presentation by MHC II
upon activation, B cells….
proliferate and differentiate into antibody-secreting plasma cell
cd4 t cell subsets
th1
th2
th1 function
promote cell mediated immune response
produce cytokines that activate macrophages
e.g. IFN-y, IL-10, TNF-a/B
th2 function
mediate humoral immunity
produce cytokines that activate B cells and lead to antibody production
CD28-CD80 is an example of..
a co-stimulatory pair
41BBLigand binds to…
41BB
required for full activation of CD8 T cell
