Immune System

Question 1

What does Treg (CD25+, CD4+ T, FoxP3+ cell) secrete?

Answer 1

Secrete IL-10 and TGF-beta which will suppress auto reactive T cells and th1 cells.

Question 2

Macrophages can secrete which 3 cytokines

Answer 2

IL-6, IL-1 and TNF-a

Question 3

What’s the major group of WBCs in our body?

Answer 3

Neutrophils, aka polys

Question 4

Mast cells and basophils are both involved in allergic responses. Where are they found?

Answer 4

Mast cells are found in connective tissues throughout the body. Basophils are found in blood.

Question 5

Natural killer cells are large granular lymphocytes and can kill

Answer 5

Virus-infected cells and some tumor cells

Question 6

In general, innate immune cells have receptors that can recognize microbial products. For example, dendritic cells and macrophages have what receptors to recognize LPS, a thymus independent antigen, on gram negative bacteria?

Answer 6

Toll-like receptor (TLR), specifically TLR-4

Question 7

What are 3 main points of adaptive immunity?

Answer 7

1. Requires sensitization by antigen
2. Response is antigen specific
3. Results in immunologic memory

Question 8

Which two Ig classes can form polymeric immunoglobulins?

Answer 8

Pentameric IgM (monomeric IgM cannot produce antibodies) and dimeric IgA (both dimeric and monomeric IgA can make antibodies)

Question 9

Adjuvant

Answer 9

added to vaccine to make it more immunogenic (aluminum salt alum)

Question 10

passive immunity

Answer 10

use immune serum (Ab) to give an immediate resistance to an infection

Question 11

active immunity

Answer 11

use of antigens to induce immune response to a pathogen

Question 12

live attenuated

Answer 12

a weakened virus that can replicate to a limited extent

Question 13

herd immunity (coccon effect)

Answer 13

when enough ppl are immunized such that spread of an infection is slow or halted.

Question 14

What was the old vaccine that was given to protect against diptheria, pertussis, and tetanus. Why was it replaced?

Answer 14

The old vaccine called DPT was changed because it used the whole, killed pertussis which was too great of an adjuvant and caused swelling and fever.

Question 15

How is the current diptheria, pertussis and tetanus vaccine different from the old?

Answer 15

DTaP vaccine uses acellular components of pertussis instead of the whole, killed pertussis. It is a pertussis toxoid with added aluminum salt as an adjuvant.

Question 16

What is the booster given to protect against diptheria, pertussis and tetanus

Answer 16

Tdap =”d” and “p” are lower case because they are in reduced concentrations in the booster form. There are also just boosts for diptheria and tetanus (Dt or Td).

Question 17

Polio vaccine aka IPV (inactivated polio vaccine) has done a great job at almost eradicating polio. Some vaccines were contaminated with?

Answer 17

Simian40 virus known to be a cancer-causing virus.

Question 18

Why is the MMR (measles, mumps, and rubella) given at 12-15 months and not right at birth?

Answer 18

MMR is a live attenuated virus that requires the infant’s immune system to fight it to gain immunological memory. Up until 1 y.o, the infant has maternal antibodies that will fight off the MMR vaccine and not allow the infant’s own immune system to do so.

Question 19

How will mothers with rubella impact their unborn children?

Answer 19

Rubella may be the leading cause of birth defects. Congential rubella syndrome is very serious.

Question 20

Vaccine no longer has this product that anti-vaccine ppl used to say was a cause of autism

Answer 20

thimersol (mercury)

Question 21

Cervarix protects against which strains of HPV?

Answer 21

HPV types 16 & 18

Question 22

Gardasil protects against which strains of HPV

Answer 22

HPV types 16, 18, 6, and 11

Question 23

Rabies is a deadly viral disease. What happens when someone without previous exposure is exposed to rabies? What’s the plan of treatment?

Answer 23

Give antiserum near wound and vaccine at a different site. The vaccine requires follow up doses on day 3, 7, and 14

Question 24

Rabies is a deadly viral disease. What happens when someone with previous exposure is exposed to rabies again? What’s the plan of treatment?

Answer 24

Give booster

Question 25

The rabies vaccine used to be a purified chick embryo cell vaccine, but now it is

Answer 25

human diploid cell rabies vaccine (HDCV)

Question 26

Il-12 secreted by macrophages activate…

Answer 26

NK cells

Question 27

Il-1 which is secreted by macrophages can increase vascular permeability by activating vascular endothelium and increase access of effector cells. Which cytokine is produced by Il-1?

Answer 27

Il-6 causing fever and induces acute phase protein

Question 28

When macrophages sense microbial products, they secrete

Answer 28

Il-6, TNF-a, Il-1, CXCL 8, Il-12

Question 29

Superantigen toxins (i.e. staph) cause symptoms similar to Gram negative sepsis because both will cause release of which cytokines

Answer 29

high fever, DIC due to release of TNF-a and IL-1

Question 30

Tregs play a role in controlling which 5 diseases:

Answer 30

• colitis
• diabetes
• SLE
• graft rejection
• graft vs host

Question 31

What factors dictate if Ag will favor immune response or tolerance?

Answer 31

• chemical nature of Ag (more complex Ag will favor immune response while less complex/soluble/aggregate free Ag will favor tolerance)
• amt of Ag (there’s an optimal dose; too large or too small a dose will favor immune tolerance)
• route of entry (subcutaneous and intramuscular injections favor immune response while oral and IV favor immune tolerance)
• genetics (some vaccines are more effective in one group than others)
• age of person; older ppl will be more likely to mount a response than young children who favor immune tolerance
• immune status of host

Question 32

T/F: Most bacteria will die inside a phagocyte

Answer 32

True (it’s taffet’s rule #1); neutrophils and macrophages have lots of receptors for different bacteria.

Question 33

What is the primary adaptive response to extracellular bacteria?

Answer 33

Antibody!

• prevents bacterial attachment to epithelium (IgA)
• Ab can trigger complement
• bind to M proteins or capsules (acting as opsonin)
• neutralize toxins
• neutralize spreading factors

Question 34

Role of activated macrophages in dealing with intracellular bacteria

Answer 34

Activated macrophages (with TH1 Cell help) are non-specific but can kill better and can kill intracellular bacteria (listeria), but only active for a short period of time.

Question 35

In most cases, which immune cell plays the major role against viruses and parasites?

Answer 35

T cell mediated immunity (but other cells play a role too)