MIC finals Flashcards
fx of neutrophils
- usually 1st cell to respond
- ingest microbes via phagocytosis, discharge granules containing microbicidal substances
fx of mast cells
- allergic responses
- parasites (worms)
- inflammation
- release histamine
fx of basophils
- allergic responses
fx of eosinophils
- allergic responses
- parasites (worms)
- asthma
fx of NK cells
- do not attack microbes
- kill virally infected target cells and tumour cells
fx of macrophages
- ingest via phagocytosis
- APC
fx of dendritic cells
APC
fx of T cells
helper and cytotoxic T cells
- T cell R on their surface recognises Ag
- some can kill infected cells and cancer cells
fx of B cells
plasma cells secrete antibodies, which binds to Ag
pri lymph organs
foetal liver, thymus, bone marrow
sec lymph organs
lymph nodes, spleen
organisation of lymph nodes
immune cells enter through afferent lymphatics and High Endothelial Venules
immune cells exit via efferent lymphatics
what is lymphadenopathy
enlargement of lymph nodes
fx of spleen
- filters blood (remove old or damaged RBCs, foreign materials)
- contains red pulp (RBC destruction) and white pulp (B cells in white pulp produces antibodies)
progression from stem cell to dendritic cell
stem cell - myeloid progenitor - granulocyte - monocyte - dendritic cell (/ macrophages)
progression from stem cell to B cell
stem cell - lymphoid stem cell - lymphocyte - b cell progenitor - plasma cells/ memory cells
progression from stem cell to NK cell
stem cell - lymphoid stem cell - lymphocyte - NK cell
autocrine
cytokine producing the signal is also the cell that responds to it
paracrine
cytokine produced signals that affects cells in the near vicinity
endocrine
cytokine produce signals that affect cells that are far away
what are Pathogen Associated Molecular Patterns (PAMPs)?
found only on pathogens, the “red flag” to be recognised by body’s cells
what are Pattern Recognition Patterns (PRRs)?
found on body’s cells (either secreted, located on cell surface or intracellular); PAMPs bind to PRR
what are the receptors req’d for phagocytosis?
- membrane receptors
- opsonin receptors
what are 2 types of membrane receptors?
- mannose receptors: directly bind to polysaccharides
- schavenger receptors: directly recognise charged molecules in targets
which type of PRR is most associated w intracellular recognition of pathogens and can activate inflammatory responses?
nod-like R
intracellular PRRs pri fx to
respond to pathogens inside the cell
what happens when intracellular PRRs, such as nod-like R, detect a pathogen?
they trigger inflammatory responses, including cytokine release or apoptosis of infected cells
how do toll-like R contribute to the immune response?
by recognising PAMPs and triggering the production of cytokines and interferons
what is a potential result of a cell infected by a pathogen utilising intracellular PRRs?
release of chemokines and cytokines
what is a key role of secreted PRRs in the immune syst?
to induce the complement cascade by binding to pathogen surfaces
extracellular PRRs pri participate in
phagocytosing pathogens
what is the pri fx of mannose and scavenger R in the immune response?
to engulf and destroy pathogens through phagocytosis and release of lysosomal contents
which type of PRR on the cell surface is pri responsible for recognising pathogens associated molecular patterns and can activate the secretion of cytokines or interferons when a virus invades a cell?
toll-like R
what is the role of the complement cascade activated by secreted PRRs?
to opsonise pathogens for phagocytosis and induce cell lysis
what action is most closely associated w mannose R?
binding to carbohydrate structures on pathogens
which receptor class would pri be involved in recognising and responding to fungal cell wall components?
scavenger R
which receptor type is mainly secreted by the liver as a crucial part of the innate immune syst?
complement R
how do APCs present antigens onto MHC?
convert the antigen into peptides by proteolytic cleavage, binds to MHC which is then presented by APCs
what MHC class presents endogenous Ag?
MHC I to cytotoxic T cells
what MHC class presents exogenous Ag?
MHC II to helper T cells
