Class 5 - Innate Immunity Flashcards
List examples of the body’s first line of defense in innate immunity
skin, mucous membranes, bodily fluids
List examples of the body’s second line of defense in innate immunity
internal antimicrobial substances, NK cells, phagocytes, inflammation, fever
Name of the immune-functioning enzymes found in the lacrimal (tears) and salivary (saliva) gland secretions…
lysozymes (destroys microoganisms)
What are the 4 types of internal antimicrobial substances?
interferons
complement system
ion-binding proteins
antimicrobial peptides
Where do interferons come from? What do they do?
proteins secreted by lymphocytes, macrophages, fibroblasts that have been infected by a virus
they induce antiviral protein production to stop viral replication
What are 3 functions of the complement system?
cause microbe cytolysis
promote phagocytosis
contribute to inflammation
Give examples of iron-binding proteins and where they are found
transferrin (blood, tissue fluids)
lactoferrin (milk, saliva, mucous)
ferritin (liver, spleen, bone marrow)
hemoglobin (RBCs)
Which type of internal antimicrobial substance do microbes not develop resistance to?
AMPs (antimicrobial peptides) - broad spectrum antibiotic effects (attract dendritic and mast cells)
What are some examples of AMPs in the body?
dermacidin (sweat glands)
defensins + cathelicidins (neutrophils, macrophages, epithelia)
thrombocidin (platelets)
What do NK cells attack?
any abnormal or unusual cell of the body/foreign cells
Where are NK cells found?
in the blood (5-10% of lymphocytes)
spleen
lymph nodes
red bone marrow
Explain antibody dependent cell-mediated cytotoxicity
NK cells bind to the target cell via an antibody for the target cell (antibody dependent.)
They then release two toxic substances, perforin and granzymes, to destroy the target cell (cytotoxicity)
What effect does perforin have?
creates channels in membrane of a target cell so the cell swells with ECF and bursts (cytolysis)
What effect do granzymes have?
induce apoptosis in target cells (digest proteins)
True or false: NK cells destroy infectious microbes
false. NK cells kill the infected cell. the microbe inside is then released, to be destroyed by phagocytes.
Histiocytes, alveolar macrophages, microglial cells, and, Kupffer’s cells are all examples of…
fixed macrophages in specific tissues
What are the 5 phases of phagocytosis?
- chemotaxis (migration)
- adherence
- ingestion
- digestion
- elimination (killing)
What is a phagolysosome?
product of the merging of a phagosome and lysosome so the lysosome can digest the contents of the phagosome
What attracts macrophages? (chemotaxis)
WBC’s
damaged tissue cells
activated complement proteins
invading microbes
What are the 3 basic stages of inflammation?
- vasodilation/increased permeability
- emigration of phagocytes + demolition
- tissue repair/healing
What cells release histamine?
basophils
mast cells
platelets
What effect does histamine have?
dilation and increased permeability of blood vessels
What substance is formed in the blood, is responsible for much of the pain of inflammation, and produce chemotactic stimuli?
kinins
What substance intensifies the effects of histamine and kinins, and stimulates migration of phagocytes through capillary walls?
prostaglandins
What cells produce leukotrienes?
basophils, mast cells
What is the function of leukotrienes?
promote adherence of phagocytes to pathogens
chemotactic stimuli
True or false: both neutrophils and the complement system stimulate the release of histamine
true
How does fever help fight infection?
intensifies the effects of interferons
inhibits bacterial growth
speeds up repair reactions
innate immunity is designed to prevent_____ and ____
microbes from entering
help eliminate those that have gained access
adaptive immunity is a specific recognition of microbes once they have….
breach innate defenses (specific responses to specific microbes involving both B and T cells)
what does periodic shedding of the skin have to do with innate immunity?
periodic shedding removes bacteria from surface
cilia movement of mucous membranes, in the airways helps to do what?
expel trapped micro-organisms and foreign substances
