1.1: Innate Immunity

Question 1

Are antibiotics a treatment for a yeast infection? Explain why you answered yes or no.

Answer 1

• antibiotics are NOT a treatment
  –doesn’t kill Candida albicans because this is a yeast, not a bacteria.
  –instead, antibiotics would kill Lactobacillus acidophilus (good bacteria), worsening the infection
• actual treatment:
  –probiotic
  –anti-fungal

Question 2

How can anticholinergic drugs compromise the immune system?

Answer 2

decreases saliva (so less lysozymes or IgA)
decreases stomach acid (chemical barrier)
= more prone to bacterial infections

Question 3

How do gastric juices help contribute to innate immunity? Is this a physical or chemical barrier?

Answer 3

low pH (few pathogens can survive acidic conditions)
chemical barrier

Question 4

How do the following defenses function as chemcials or produce chemicals that act in innate immunity?

sebum
lysozyme
saliva
tears
urine
gastric juice
vaginal secretions
Lactobacillus acidophilus

Answer 4

sebum
-low pH & bacteriostatic
lysozyme
-antimicrobial protein (enzyme)
-cleaves peptidoglycan (in other words, cuts cell walls)
tears & saliva
-contain lysozymes
urine & gastric juice (stomach acid)
-low pH (acidic)
vaginal secretions
-low pH (acidic)
Lactobacilus acidophilus
-produces lactic acid = creates low pH environment in vagina

Question 5

How do vaginal secretions kill bacteria? Is this a chemical or physical barrier in innate immunity?

Answer 5

low pH = kills bacteria
chemical barrier

Question 6

How does breast milk contribute to immune protection in an infant?
(State what is breast milk that provides immunity and the function).

Answer 6

breast milk contains IgA (an antibody)
Function: IgA
-prevents bacteria attaching to mucus membranes
-Adaptive immunity

Question 7

How does gastric juice kill bacteria? Is this a chemical or physical barrier in innate immunity?

Answer 7

gastric juice (a low pH)= kills bacteria
chemical barrier

Question 8

How does hair function as part of innate immunity? Is this a physical or chemical barrier?

Answer 8

line ears to prevent bacteria entering.
physical barrier

Question 9

How does peristalsis contribute to innate immunity? Is this a physical or chemical barrier?

Answer 9

movement in intestines moves things forwards
physical barrier

Question 10

How does the epiglottis function as part of innate immunity? Is this a physical or chemical barrier?

Answer 10

prevents bacteria from entering lungs
physical barrier

Question 11

How does urine function as part of innate immunity? Is this a physical or chemical barrier?

Answer 11

a physical and chemical barrier
physical: helps “wash out” bacteria in bladder, ureters, and urethra
chemical: low pH and bacteriostatic

Question 12

How does vomiting, coughing, and sneezing contribute to the first line of defense (innate immunity)? Is this a physical or chemical barrier?

Answer 12

expell pathogens out of the body
physical barrier

Question 13

Is adaptive immunity specific or non-specific? What line of defense makes up adaptive immunity? What cell types are found in adaptive?

Answer 13

adaptive immunity
-specific (“lock and key”)
-3rd line of defense
-Cell Types:
–lymphocytes
>B cells
>T cells (cytotoxic & helper)
–memory cells
–antibodies (immunoglobulins)

Question 14

Is innate immunity specific or nonspecific? What are the lines of defense that make up innate immunity and barriers for each line?

Answer 14

Innate Immunity
nonspecific
1st line of defense: physical barriers and chemical barriers
2nd line of defense: inflammation and complement system

Question 15

Out of all of the white blood cells, which type makes up the adaptive immunity? Do these WBCs look for general patterns or specific antigens?

Answer 15

adaptive immunity
made of lymphocytes (B cells, Helper T cells, Cytotoxic T cells)
specific defenses against pathogens

Question 16

What 3 things do tears and saliva have in common?

Answer 16

contain lysozymes (innate immunity)
IgA antibodies (adaptive immunity)
chemical barrier
So, tears & saliva contains aspects of both innate & adaptive immunity

Question 17

What are cilia and how does it function as part of the innate immunity?

Answer 17

Cilium (singular)- a hairlike structure found in large numbers on cells OR on microrganisms; allows movement via beating (wavelike) motion
part of mucucilliary escalator system which helps remove pathogens & debri in lungs
physical barrier

Question 18

What are defensins, what do they do, and what cells are they produced by?

Answer 18

amphipathic proteins (with a net (+) charge) that are attracted to (-) charges on phospholipid (cell) membranes of bacteria
function: punch holes in bacterial cell membranes (=kills bacteria)
produced by…
white blood cells
epithelial cells (in GI tract)
mammary glands
mucous membranes

Question 19

What are two examples of antimicrobial protiens in the body?

Answer 19

defensins
lysozymes

Note: since these are antimicrobial proteins, both are chemcial barriers

Question 20

What does the lacrimal apparatus produce and what does it protect? How does the lacrimal apparatus contribute to innate immunity?

Answer 20

protects the surface of the eyes by producing tears= flush out microbes
tears= have lysozymes (cut peptidoglycan = in cell wall)

Question 21

What effect can prolonged antibiotic treatment do in the vagina and gut?

Answer 21

vagina: Candida Albicans (yeast- a type of fungus) can take over, causing a yeast infection.
gut (large intestine): C. Diff can overrun the intestines, causing pseudomembranous colitis (death of part of the gut).
These disease take over because Lactobacillus acidophillus (normal flora in vagina) and E. Coli (normal flora in gut) have been decreased from antibiotic use, allowing oportunisitic pathogens to take over and cause an infection.

Question 22

What effect can prolonged treatment of antibiotics have on normal flora?

Answer 22

kill normal flora in the gut, skin, vagina, and other locations, allowing opportunisitc pathogens to take over.
Note: in chapter 3, you’ll learn how antibiotics kill the normal flora in the gut that make vitamin K. The lack of vitamin K will decrease clotting.

Question 23

What effect does smoking have on the mucociliary escalator system?

Answer 23

Smoking can paralyze this system and destroy it
how: smoking can reduce the speed at which cilia beat and even kill cilia, weakening this innate immunity defense (since we are not propelling pathogens out to be expelled from the body.)

Question 24

What is a bacteriocin? What are 3 examples?

Answer 24

a toxic protein produced by one bacteria that inhibits other bacteria of a similar strain
examples:
E. coli produces bacteriocins that inhibit salmonella, shigella, and C. diff (gut)
Pseudomonas aeruginosa produces pseudomonic acid to inhibit staphylococcus and streptococcus bacteria
Lactobacillus acidophilus creates bacteriocins to inhibit Candida albicans

Question 25

What is a lysozyme, what do lysozymes do, and where do we find them?

Answer 25

lysozyme
an enzyme
Function: cut bacterial cells walls (by cutting peptidoglycan)
Location: in secretions (tears, saliva, sweat, mucus)

Question 26

What is a mucous membrane and where can mucuous membranes be found in the body? What types of epithelial cells are part of mucous membranes in the respiratory tract and what barrier is this part of?

Answer 26

the soft tissue that lines the tube-like openings of the respiratory, gastrointestinal, and reproductive tract.
In the respiratory tract, mucous membranes contain various types of epithelial cells like ciliated columnar cells and goblet cells.
part of the Mucociliary Escalator System
physical barrier

Question 27

What is E. Coli, where is it found, what does it produce, and what bacteria does it inhibit?

Answer 27

Escherichia coli (E. coli)
normal flora
in gut (intestines)
helps produce vitamin K
produces bacteriocins that inhibit Salmonella, Shigella, & C. Diff
if C. Diff takes over= pseudomembranous colitis (condition that kills gut)

Question 28

What is lactobacillus acidophilus, where is it found, what does it produce, and what does it inhibit?

Answer 28

Lactobacillus acidophilus
normal flora
in vagina
uses glycogen as fuel and produces lactic acid
This lactic acid → creates low pH in vagina which…
inhibts Candida albicans (a yeast (type of fungus)) from taking over & causing a yeast infection.

Question 29

What is normal flora and what does it prevent the growth of? What line of defense and type of immunity is normal flora found in?

Answer 29

Good bacteria that prevents growth of bad bacteria
part of first line of defense (innate immune system)

Question 30

What is perspiration and how does it function as part of innate immunity? Is this a physical or chemical barrier?

Answer 30

persperation = sweat
produced by sweat glands in skin
creates a hypertonic environment that kills microbes
contains lysozymes
chemical barrier

Question 31

What is Pseudomonas aeriginosa, where is it found, what does it produce, and what bacteria does it inhbit? What is mupirocin?

Answer 31

Pseudomonas aeriginosa
normal flora
on skin
produces pseudomonic acid = kills staphylococcus (“staph”) & streptococcus (“strept”) bacteria
= prevents staph and strept infections
synthetic (drug) form of pseudomonic acid: mupirocin

Question 32

What is sebum, why is sebum a good chemical barrier in the innate immune system, and where is it produced?

Answer 32

sebum= oil on skin that fights infections via…
low pH
bacteriostatic (inhibits bacteria from reproducing)
produced by sabacceous glands

Question 33

What is the difference between lysozymes and lysosomes?

Answer 33

lysozymes
enzymes in tears & saliva
cut peptidoglycan (makes up bacterial cell walls)
lysosomes
a vesical filled with digestive enzymes
seen in macrophages & thyroid (to free thyroid hormones T3/T4)
lysosome + phagosome = phagolysosome

Question 34

What is the difference between pseudomembranous colitis vs Pseudomonas aeruginosa?

Answer 34

Pseudomembranous colitis
= death of bowels (colon).
happens when there’s extensive use of antibiotics
antibiotics kills E. coli normal flora in gut → allowing C diff. bacteria to grow = causes pseudomembranous colitis
Pseudomonas aeruginosa
normal flora on human skin
produces pseudomonic acid = fights staph infections

Question 35

What is the function of the lacrimal apparatus in innate immunity?

Answer 35

produces tears

Question 36

What is the Mucociliary Escalator System? How does it function as part of innate immunity? Is this a physical or chemical barrier?

Answer 36

a mucous membrane that uses mucous and cilia to protect the respiratory tract (lungs)
goblet cells (in mucus membranes) secrete mucus that traps inhaled pathogens
pathogens get “stuck” in mucus
the mucous lies ontop of ciliated epithelial cells (that line the airways)
cilia propels the pathogen-filled mucus (via beating motion) upward toward the → trachea = allowing pathogens to be expelled via coughing, sneezing, or even swallowing (bacteria can be destroyed by stomach acid if swallowed)
physical barrier

Question 37

What properties make skin a good physical barrier?

Answer 37

Epidermis…
Keratin
waterproof layer that makes skin resistant to bacteria
sebum (oil)
low pH & bacteriostatic
closely packed cells (tight junctions)
high salt content (hyperosmotic environment)
antibacterial proteins (defensins)
continual shedding of skin cells (high turnover rate)

Question 38

What type of cells produce mucous?

Answer 38

Goblets cells

Question 39

Why do antibiotics kill good bacteria (normal flora) and bad bacteria?

Answer 39

because antibiotics don’t differentiate between normal flora and harmful bacteria. Antibiotics just kill all bacteria.

Question 40

Why is humidity important for the mucociliary escalator system?

Answer 40

Humidity is important for this system to work optimally.
low humidity causes…
the pericilliary fluid layer to decrease
cilia to beat more slowly
→ causing decreased clearance of pathogen filled mucus
= increasing infection risk.
So, we need humidity!