Mucosal and Immune Responses and Immunization

Question 1

What is Waldeyer’s Ring?

Answer 1

Lymphoid tissues around entrance of gut and airway (tonsils, palatine and lingual, and adenoids)

Question 2

How are pathogens in the gut lumen sampled?

Answer 2

Peyer’s:

• M cell transports it across lymphoid tissue (no villi) via endocytosis and phagocytosis
• vesicle
• Peyer’s patches have B, T, and DCs

Produce effector T cells, plasma cells for the sampled bacteria

Question 3

IgA is secreted into the intestinal lumen via:

Answer 3

transcytosis via pIgR

Question 4

DCs can reach their little arms across the epithelial layer to sample antigen from the lumen directly.

Answer 4

It is adorable.

Question 5

IgG secreted by plasma cells in the lamina propria and IgG from the blood is transported to the gut lumen via ________

Answer 5

FcRn receptors, which are recycled

Question 6

How do you make an attenuated virus for a vaccine?

Answer 6

• Virus isolated from patient and grown in human-cultured cells
• Virus taken out after being grown and used to infect monkey cells
• Virus acquires mutations that allow it to grow well in monkey cells
• No longer grows well in human cells! (vaccine)

Question 7

What is an inactivated or killed vaccine?

Answer 7

Grow virus, treat with formalin, isolate

• Influenza, rabies

Question 8

What is a subunit vaccine?

Answer 8

Only the protein is used for the antigen that creates immunity

• Hep B surface antigen in the HBV vaccine

Question 9

What is active immunity?

Answer 9

Development of antibodies in response to injected foreign antigens (vaccines)

Question 10

What is passive immunity?

Answer 10

Antibodies removed from donor and transferred

• Ig transfer to patients with X-linked agammaglobulinemia
• anti-HBV Ig to infants born to HBV SAg(+) mothers (to avoid infection)

Question 11

List some live-attenuated vaccines that are only given to the immunocompetent (6)

Answer 11

• Yellow fever (avoid for HIV)
• Measles
• Mumps
• Rubella
• Polio (Sabin; Salk is killed)
• Varicella-zoster

Question 12

What kind of vaccines are Diphtheria and Tetanus?

Answer 12

Toxoid

Question 13

Why is the H. influenzae vaccine conjugated?

Answer 13

The polysaccharide capsule of H. flu alone can’t activate T-cells (MHC can’t present them); must be conjugated to a protein (the Diphtheria toxoid)

B-cells can’t make high-affinity Ab without T-cell activation

Question 14

List some vaccines recommended in childhood (13 - sorry)

Just be able to recognize them on the test I guess.

Answer 14

HepB - subunit
*Rotavirus - attentuated
DTaP - toxoid / killed
H. flu (Hib) - conjugated
*PCV13 (Strep pneumo) - conjugated
*Polio - killed
Influenza - attenuated
MMR - attentuated
*Varicella - attentuated
*HepA - subunit
Meningococcal - capsular polysaccharide (?)
*HPV - subunit
*PPSV23 (Strep pneumo, for high risk) - conjugated

*denotes he mentioned it on a separate slide as well again

Question 15

What is the BCG vaccine against Mycobacterium tuberculosis?

Answer 15

Derived from bovine strain; not used in US

Question 16

What kind of vaccine exists for Salmonella typhi?

Answer 16

Live-attentuated; made via mutagenesis and selection for LOSS OF LPS necessary for pathogenesis

(remove the thing that causes pathogenic effects)

Question 17

What is an adjuvant?

Vaccine = Antigen (protein) + Adjuvant

Answer 17

An “immune booster” - TLR ligands

• Microbial products
• Alum
• Oil emulsion

Avoid the antigenic part of the vaccine being ignored by the immune system. Lower amount of antigen needed. Induce immune responses in weaker people.

Question 18

What do adjuvants activate?

Answer 18

APCs, B-cells, T-cells, and tissue cells via TLRs

• Activate/mature APCs
• Increase expression of co-stimulatory molecules and MHC
• Induce chemokines to recruit phagocytes

Question 19

What do alum and oil do?

Answer 19

Sustained release of antigens (slow release)
- Enhance antigen uptake by APC

Examples: Alum (mineral salt), MF59 (oil-in-water emulsion) / AS03

Question 20

Most-immunization… (what happens to IgG and IgM)?

Answer 20

Amount of IgG rises higher than IgM

Affinity of IgG is greater than IgM (the most important factor)

Question 21

Vaccine injection creates more:

Oral/nasal vaccines create more:

Answer 21

• IgG

- IgA (more physiologically relevant…whatever that means?)

Question 22

Possible adverse event to HepB vaccine?

Answer 22

Anaphylaxis

Question 23

Possible adverse event to Measles vaccine?

Answer 23

• Thrombocytopenia

- Death from anaphylaxis, DIC in immunocompromised

Question 24

Possible adverse event to DTaP vaccine?

Answer 24

Chronic encephalopathy

Question 25

Possible adverse event to vaccines with tetanus toxoid?

Answer 25

• Guillain-Barre
• Brachial neuritis
• Death via anaphylaxis (a common theme, I see)

Question 26

Diseases with no vaccine (yet!):

Answer 26

• Malaria
• HIV/AIDS
• Hep C

*TB vaccine not used in US