Innate Immunity: Immediate Innate Flashcards
1
Q
roles of the innate immune system
A
- keep pathogen load under check until adaptive immune system kicks in
- prevent the establishment of infection
2
Q
why does the innate immune system fail
A
- overwhelming pathogen load
- evasive mechanisms
3
Q
3 barriers
A
- anatomical (skin & mucous membranes)
- physiological (enzymes, temperature, pH, …)
- microbiological (natural flora)
4
Q
anatomical barriers
A
- skin is constantly shedding
- tight junctions
- mucus
- cilia movement
5
Q
physiological barriers
A
- preformed soluble mediators present in the blood, extracellular spaces, lymph, secretions, …
- acidic pH
- fatty acids in sebum
- lysozymes
- lactoferrins
- surfactant proteins
- complement proteins
- antimicrobial peptides
6
Q
lysozyme
A
- cleaves glycosidic bonds of bacterial peptidoglycan
- found in mucosal/glandular secretions
7
Q
lactoferrin
A
- binds iron which limits the growth of most pathogens
- found in mucosal/glandular secretions
8
Q
surfactant proteins
A
- block bacterial surface components and promote phagocytosis
- found in respiratory secretions and other epithelia
9
Q
antimicrobial peptides
A
- create holes in pathogen cell membranes
- found in skin and mucosal epithelia
- secreted by epithelial cells and stored in neutrophil granules
- ex: panted cells in the intestines
- cytosine rich, cationic, and amphipathic
10
Q
microbiological barrier
A
- competitive exclusion by natural flora
- production of toxins
- alteration of environment
- vagina
11
Q
why are antimicrobial peptides generally cationic and amphipathic
A
- cationic + charge binds to bacterial cell wall - charge
- non polar body inserts itself into membrane and creates a pore
12
Q
innate immunity is all EXTRAcellular except what cell
A
NK cells
