Innate Immunity Part 1 Flashcards
What are the key properties of innate immunity?
Response time: mins/hrs
Specificity: low (general molecular patterns associated with pathogens
Diversity: limited to # of conserved germinated receptors
Memory responses: no memory (..)
Self/hon self discrimination: rarely falls
What are the response characteristics of innate immunity?
- First to act
- non adaptive
- same response (time, magnitude) to same pathogen everytime
What are the response characteristics of adaptive immunity?
- Starts fast / stronger bc of memory characteristic compared to first exposure
3 main innate immune defenses?
- Anatomical barriers
- Immune cells
- Proteins secreted by cells
What are properties of epithelial cells?
-tight junctions
-Regeneration
- desquamation
- secretions
What are tight junctions?
Molecular structures that Prevent pathogens from “squeezing” inside the tissue located between epithelial cells
What is regeneration?
Rapidly divide to replace dying cells
What is desquamation?
Shedding helps remove attached pathogens on epithelial cells
What is the 1st line of defense? What are its characteristics?
Skin
- has specialized stratified epithelial cells called keratinocytes which lose their nuclei and form a corneal layer ( a keratin “shield”)
What are the defense barrier mechanisms in the respiratory tract?
- Bronchial ciliated epithelium
- mucous gland
- goblet cell produces mucus components
- cilia mechanically keeps everything moving
What does the respiratory tract look like for someone with cystic fibrosis?
Cilia collapsed, mucus thick & dry, mutation to
Cftr, bacteria thrive
What is mucocillary clearance (mcc) ?
Mucus transport when healthy
Increased mucus and mucostasis when Cf
What are the barrier defense mechanisms fur the gastro-intestinal tract?
- Gut epithelium
- goblet cells for mucus
- paneth cells secrete enzymes to gut surface
What are the characteristics of leaky gut syndrome?
- Loss of barrier integrity = non-functioning tight junctions
- common in inflammatory bowel disease and ulcerative colitis
- causes inflammation
What are chemical defense mechanisms?
- Secreted by epithelial cells
- can be microbicidal (kill microbe)
- can be microbiostatic (prevent its growth)
What is the function of lysozyme?
- Glycosides that breaks down peptidoglycan effectively in gram positive bacteria because peptidoglycan is on the surface
What are defensins?
cationic antimicrobial peptides produced by immune or epithelial cells that disrupt cell membrane integrity
Where are microbiomes located?
on every surface (potential pathogen entry point) adapted depending on environment and person
What is the microbiome effected by?
environmental and genetic factors (mother’s microbiome, diet) and shifts rapidly during first months of life
What are the characteristics of Crohn’s disease?
- inflammatory bowel disease
- chronic inflammation of GI tract epithelial cells
- cause unknown
- dysregulated immune system
- altered microbiota
- environmental factors
- attacks it’s own microbiome
What do antibiotics do to gut microbiome?
usually has bacteria to keep pathogens away
- antibiotics wipes out healthy biome when can allow pathogens to colonize and produce toxins
What is microbial dysbiosis?
imbalance of the gut microbiota
What are opportunistic pathogens?
cause disease under special circumstances (immunocompromised, injuries, pregnant, etc.)
What are some examples of go pathogens breaching barriers?
- mucus binding proteins
- flagella
- secrete mucinases
- attach and internalize cells
