Immunity to Bacteria & Fungi (19)

Question 1

T/F: Most of the microbes neither invade animals nor cause disease

Answer 1

TRUE - many bacteria are essential for the animal’s well-being

Question 2

What is the hygiene hypothesis?

Answer 2

lack of early childhood exposure to infectious agents, symbiotic microorganisms, and parasites increases susceptibility to allergic diseases by suppressing the natural development of the immune system

Question 3

Development of disease is related to many factors:

Answer 3

response (resistance to host)
presence of damaged tissues
location of the bacteria within the body
virulence (dangerousness of bacteria)

Question 4

What is the early innate response to bacteria?

Answer 4

recognition of bacteria through TLRs and other receptors induce inflammation, cytokine release, and complement activation

Question 5

What is the sustained adaptive response to bacteria?

Answer 5

if the innate response is insufficient in clearing bacteria, dendritic cells and macrophages ingest invading bacteria
initiate adaptive immunity by producing cytokines and triggering both T and B cell responses

Question 6

What is the bacteria in horses that causes pneumonia at high rates?

Answer 6

Rhodococcus equi

Question 7

In R. equi infection, dendritic cells and _____ secrete IL-_____, which promotes TH_____ cell differentiation

Answer 7

macrophages
23
TH17

Question 8

What does TH17 confer protection against?

Answer 8

extracellular bacteria and fungi by triggering inflammation

Question 9

NK cells do not express _______ receptors. How do they recognize altered self cells?

Answer 9

antigen-specific receptors
have receptors to ligands displayed by distressed cells

Question 10

Some bacteria causes up-regulation of NK___ ligands on infected cells

Answer 10

NKG2D

Question 11

What is innate immunity strategies towards bacteria?

Answer 11

complement
iron sequestering
anti-microbial peptides

Question 12

What was treatment for tuberculosis in the old days?

Answer 12

mycobacterium binds to TLR 2/1
activates vitamin D receptor
increases vitamin D hydroxylase
increases calthelicidins
kills bacteria

Question 13

What are the adaptive immunity mechanisms for killing bacteria?

Answer 13

neutralization of toxins or enzymes by antibody
killing of bacteria by classical complement pathway

opsonization of bacteria by antibodies and complement, resulting in their phagocytosis and destruction

destruction of intracellular bacteria by activated macrophages
killing of bacteria by cytotoxic T cells and NK cells

Question 14

What are some examples of toxigenic bacteria?

Answer 14

clostridium tetani
bacillus anthracis

Question 15

Describe immunity to toxigenic bacteria

Answer 15

immune system has to stop invading bacteria but also neutralize the toxin

neutralization occurs when antibody prevents the toxin from binding to its receptor on target cells

neutralization process involves the competition between receptor and antibodies for the toxin
neutrotoxin

Question 16

What is invasive bacteria?

Answer 16

bacteria getting into bloodstream from tissues

Question 17

How do you protect against invasive bacteria?

Answer 17

usually mediated by antibodies directed against surface antigens

antibodies are not only effective opsonins themselves but also increase binding of C3b by activating the classical complement pathway

Question 18

Antibodies generated against capsular antigens neutralize the ______ property of bacterial capsules, thus permitting their destruction of phagocytic cells

Answer 18

antiphagocytic

Question 19

Antibodies generated against E. coli pilus antigen _____ to the intestinal wall

Answer 19

interfere with iron binding
bacteria can’t scavenge iron and so they die

Question 20

Ig__ and Ig___ antibodies against Lyme disease damage surface proteins on the bacteria and are bactericidal in the absence of complement

Answer 20

IgM
IgG

Question 21

What are heat-shock proteins?

Answer 21

when exposed to fever from the host, bacteria express certain proteins when under heat stress
HSP 90, HSP 70, HSP 60

Question 22

HSPs are highly _____ because they:

Answer 22

highly antigenic

are produced in abundance during infection
readily processed by APCs
induce many cells of the immune system, such as gamma delta cells, NK cells

Question 23

List some intracellular bacteria that can grow inside macrophages

Answer 23

brucella abortus
R. equi

Question 24

Protection against intracellular bacteria is mediated by _______

Answer 24

macrophages activated through the M1 pathway

Question 25

What has been shown to be important in resistance to Listeria monocfytogenes, and more?

Answer 25

M1 polarization

Question 26

Both _____ & _____ are involved in immunity to Listeria

Answer 26

CD4+/CD8+

Question 27

If vaccinated, one has antibodies and _______. Intracellular bacteria is killed as cell is destroyed

Answer 27

cytotoxicity

Question 28

Immune responses influences the ____ and _____ of an infection

Answer 28

course
severity

Question 29

[Cell/Humoral]- mediated responses are required to control intracellular bacteria because ____

Answer 29

Cell
only activated macrophages can prevent their growth

Question 30

Macrophage activation required that TH___ cells produce _____

Answer 30

TH1 cells
IFN-gamma

Question 31

If an animal mounts an inappropriate TH2 response, cell-mediated immunity [fails to/does] develop

Answer 31

fails to
M2 macrophages are generated
chronic progressive disease may result

Question 32

What is MAP, or Johne’s disease?

Answer 32

agent of Johne’s disease in cattle and other ruminants
infects and grows within lining of intestine
passed lactogenically
100% mortality rate
no vaccine efficient

Question 33

Section of terminal ileum from a case of multibacillary Johne’s disease shows abundant _____ organisms within large infiltrating macrophages

Answer 33

acid-fast

Question 34

What are the 3 major types of fungal infections?

Answer 34

primary infections by fungi that affect the skin or other surfaces
respiratory infections
secondary infections by opportunistic fungi

Question 35

In the adaptive immune response to fungal infections, neutrophils are activated by _____

Answer 35

IL-23/IL-17 axis

Question 36

In the adaptive immune response to fungal infections, both TH__ and TH___ are important in cellular immunity to fungi by enhancing _____ reactions

Answer 36

TH1
TH17
pro-inflammatory reactions

Question 37

T/F: Antibodies alone cannot opsonize bacteria

Answer 37

FALSE - can do it alone and can neutralize bacterial toxins

Question 38

______ activation of macrophages is required to kill intracellular bacteria

Answer 38

T-cell mediated activation