Immediate immunity: Barriers and Soluble effectors I

Question 1

what are the 3 barriers of the immediate immune system

Answer 1

mechanical
chemical
microbiological

Question 2

what are the 2 soluble effectors of the immediate immune system?

Answer 2

complement

antimicrobial peptides

Question 3

innate immunity is a system of what?

Answer 3

pattern recognition

Question 4

what are the four components of the innate immunity?

Answer 4

barriers
soluble effectors
cells
cytokines

Question 5

what are 4 pathogen associated molecular patterns (PAMPs)

Answer 5

LPS
flagellin
mannose sugars
unmethylated CpG DNA

Question 6

what are 3 damage-associated molecular patterns?

Answer 6

heat shock proteins
fibronectin
chromatin
**induces inflammation

Question 7

what is an example of pattern recognition receptors?

Answer 7

Toll like receptors aka TLRs

Question 8

what are the mechanical barriers?

Answer 8

epithelial cells joined by tight junctions

flow of fluid on surface

Question 9

what are the chemical barriers

Answer 9

fatty acids
low pH
surfacatant
enzymes in tears
alpha and beta defensins

Question 10

what are the microbiological barriers?

Answer 10

normal microbiota

Question 11

mechanical barriers prevent infiltration, how?

Answer 11

• physically block pathogens from entering
• barriers are not passive
• mucosal cells produce chemical barriers
• specialized immune tissues are integrated into barriers(eg: payers patches)

Question 12

what is the importance of lymphoid tissues that are integrated into barriers?

Answer 12

-where B and T cells are locally activated
example is payers patches in the ilium
-connected to the lymphatic system
-have less structure than lymph nodes

Question 13

every mucosal tissue has what two things?

Answer 13

• secretion-traps pathogens

- motility-removes pathogens from mucosal surface

Question 14

what are two ways that chemical barriers get ride of pathogens?

Answer 14

• isolation and physical removal

- targeted destruction(eg: lysozyme that cleaves peptidoglycan)

Question 15

what are chemical barriers made of and where is one place they can all be found?

Answer 15

peptides and proteins mostly with some lipids and carbohydrates
**all can be found in the mouth

Question 16

lysozyme

Answer 16

cleaves glycosidic bonds of peptidoglycan allowing the cell membrane to be exposed

Question 17

lactoferrin

Answer 17

• binds and sequesters iron, limiting growth of bacteria and fungi
• limits infectivity of some viruses
• disrupts microbial membranes

Question 18

defensins (alpha and beta)

Answer 18

disrupts membranes of bacteria, fungi, protozoan parasites, and viruses.

• also has toxic effects intracellularly
• kill cells and disable viruses
• *puts a hole in the cell membrane

Question 19

surfactant proteins

Answer 19

block bacterial surface components and promotes phagocytosis

Question 20

what type of defensin is released by a PNM

Answer 20

alpha

Question 21

what type of defensin is released by mucosal surfaces in the body?

Answer 21

beta

* constitutively

Question 22

what do defensins do

Answer 22

make holes in bacteria cell membranes because they are positively charged. remember cell membrane is negatively charged.

Question 23

do defensins affect eukaryotic cells?

Answer 23

no due to proteins and other lipids in the membrane

Question 24

what is another function of defensins other than make holes in bacterial cell membranes?

Answer 24

signaling molecules

eg: chemotaxis, opsonization

Question 25

defensins are prominent in the oral epithelium, where do they come from and where are they found?

Answer 25

• neutrophils secrete alpha into GCF
• startified oral epithelium constitutively release beta defensins
• *can control the type of bacteria present

Question 26

what type of bacteria form barriers in the gut?

Answer 26

mutualistic-both benefit

commensal-one benefits one doesn’t benefit or get harmed

Question 27

what are the functions of the microbiota of the gut?

Answer 27

• pathogen displacement
• nutrient competition
• receptor competition
• produce antimicrobials
• induce IgA
• aide in metabolism of food and synthesis of vitamins

Question 28

how does the mucosal flora interact with the immune system

Answer 28

• antimicrobial peptides shape the flora
• commensal outcompete pathogenic
• pattern recognition receptors(PPR) detect commensal bacteria and prevent inflamm
• commensals induce IgA and antimicrobial peptide release
• dendritic cells constantly browse mucosal flora

Question 29

T/F resident microbiota are resistant to defensins of the gut?

Answer 29

true

Question 30

what is the complement system?

Answer 30

plasma proteins that act in cascades to selectively kill extracelluar pathogens and diseased tissue, promote inflamm, clear tissue damage, regulate tissue homeostasis

Question 31

what are the three complement pathways?

Answer 31

classical
lectin
alternate

Question 32

what are the three outcomes of the complement?

Answer 32

• phagocytosis (opsinization)
• lysis (MAC)
• activating adaptive immune system

Question 33

how do barriers actively resolve pathogens?

Answer 33

antimicrobial peptides and removal of pathogens

Question 34

how do barriers passively resolve pathogens?

Answer 34

prevent entry of pathogens into host