Cells of the Immune System Flashcards
what type receptors are involved in the innate system
primitive and broad
TLRS
what type of receptors are involved in the adaptive system
highly specific
TCRs and BCRs
differences between adaptive and innate immunty
adaptive:
- slow
- highly regulated
- amplified
- long duration
- long memory
what are the primary lymphoid organs
bone marrow and thymus
what are the secondary lymphoid organs
lymph nodes
spleen
what are the sites of haemopoiesis
primary lymphoid organs
bone marrow and thymus
how does the skin protect against infection
keratinized cells shedding dryness acidity antagonistic pathogens
how does the respiratory tract defend against infection
cilia
coughing and sneezing
colonised by staph and strep
washed by salivation into acidic stomach
what are neutrophil extracellular traps
networks of secreted extracellular fibres composed of DNA and granule contents
what do neutrophil extracellular traps release
antimicrobial proteins such as neutrophil elastase, cathepsin g and histones
what do neutrophil extracellular traps do
kill bacteria and act as physical barrier that prevents the spread of the pathogen
what do cell surface TLRs recognise
lipoproteins and peptidoglycan
what do NLR and RLRs detect?
bacteria and viruses in the cytoplasm
what do TLR4 recognise
LPS on gram neg bacteria
what do TLR5 recognise
flagellin on motile bacteria
what do NODs recognise
bacterial peptidoglycan
what connects the innate and adaptive immune response
APCs to T cells
what are the APCs
DC, macrophages, langerhans cells, B lymphocytes
what are the roles of DCs
recognise invading microbes by PPRs on DC
presentation of antigens to t cells
maintaining B cell memory
what is immune tolerance?
t cells that respond to DCs carrying self peptides are destroyed in the thymus by negative selection
do NK cells possess t cell receptor
no
what are naive b cells
have surface antibody as BCR
what are the 2 isotypes of BCRs
IgM and IgD
what form is IgA
Dimer
what is CD34 used for
enrichment of hematopoietic stem stem cell for bone marrow transplant
do TCRs recognise free antigens
no
what cells have CD4
helper t cells
what cells have CD8
cytotoxic t cells
what kind of cells do NK kill
virus cells and cancer cells
