Lecture 1 Flashcards
(28 cards)
what does the immune system consist of?
- collection of cells, tissues and molecules for defense action
who invented the first vaccine?
Edward jenner in 1796 against small pox
between what does the i.s. differentiate?
between self and non-self
describe the healthy organism
balance between immune tolerance and response
if the immune response is insufficient
there can be chronic infections and cancer
what is innate immunity?
functions directly in response to infection
major components of the innate immune system are?
- epithelial barriers like the skin, GI tract, respiratory tract
- phagocytic leukocytes (neutrophils + macrophages)
- innate lymphoid cells like ILCs and NK cells
- circulating plasma proteins and complement system
what is an antigen?
a foreign substance
name a few functions of the innate immune system
- defensive functions early after infection
- tissue repair
- induce inflammation
- stimulate adaptive immune responses
- recognize microbial pathogens or damaged dying host cells
what are MAMPs and PAMPs
- pathogen-associated molecular patterns (PAMPs) and Microbe-associated molecular patterns (MAMPs)
How are MAMPs and PAMPs expressed?
different classes of microbes express different PAMPs and MAMPs
DAMPs are
damage-associated molecular patterns
- released from damaged or dying cells
How are DAMPs produced
may be produced due to damage caused by infections, toxins, burns and trauma
Describe pattern-recognition receptors PRR
- cellular receptors for pathogens and damage-associated molecules
where are PRR located?
- in the cytoplasm or on the surface
what are toll-like receptors?
- evolutionarily conserved family of pattern recognition receptors expressed on many cell types
- are mammalian homologues of toll
in humans there are how many different TLRs?
9
name the sequential steps of phagocytosis
- recruitment of the phagocytic cells to the sites of infection
- recognition of microbes and activation → binding of microbes to receptors
- ingestion of the microbes by phagocytosis
- destruction of ingested microbes
name the steps of recruitment of phagocytic cells to the sites of infection
- rolling
- integrin activation by chemokines
- stable adhesion
- migration through endothelium
which cells express receptors that specifically recognize microbes?
- neutrophils and macrophages
the binding of microbes to these receptors does what
- kill phagocytosed microbes by microbicidal molecules in phagolysosomes
name examples of microbicidal molecules in phagolysosomes
- lysosomal enzymes
- reactive oxygen species
- nitric oxide
neutrophils and macrophages could also
injure normal host tissues by the release of these molecuels
what is opsonization?
- process of attaching opsonins to microbial surfaces to target microbes for phagocytosis
