17 Infectious Diseases

Question 1

What percentage of deaths worldwide are associate with infectious disease?

Answer 1

25%

Question 2

What are viruses comprised of?

Answer 2

A nucleic acid genome (DNA/RNA) packaged in a protein coat (envelope, or capsid)

Question 3

How can viruses be neutralized by antibodie?

Answer 3

• binding to cell surface receptor
• block viral penetration
• facilitate opsonization

Question 4

How do viruses evade host defense mechanisms?

Answer 4

• can inhibit type I interferon expression
• can inhibit MHC I presentation
• escape complement-mediated destruction
• mutate to change their antigens

Question 5

True or false: Genetic variability generates new virus strains that can cause pandemics

Answer 5

TRUE

Question 6

In what two ways can antigenic change in viruses occur?

Answer 6

Antigenic drift: slowly but continuously

Antigenic shift: suddenly but episodically

Question 7

How does antigenic drift occur?

Answer 7

The accumulation of point mutations within regions of the envelope glycoprotein genes – RNA Pol. don’t have proofreading mechanisms

Question 8

How does antigenic shift occur?

Answer 8

Reassortment of influenza virus genes during mixed infections when there are two or more virus subtypes

Question 9

What are the four primary steps in bacterial infection?

Answer 9

1. Attachment to host cells
2. Proliferation
3. Invasion of host tissue
4. Toxin-induced damage

Question 10

What is the main protective response against extracellular bacteria?

Answer 10

humoral immune response

Question 11

What is the main protective response against intracellular bacteria?

Answer 11

cell-mediated immune response

Question 12

The majority of parasitic infection result in _______ rather than acute diseases

Answer 12

chronic

Question 13

Who cause parasitic diseases?

Answer 13

Protozoans and helminths (worms)

Question 14

What controls most of fungal infections?

Answer 14

Innate immunity

Question 15

Protective immunity can be achieved by active immunization as well as _______ immunization

Answer 15

passive

Question 16

What are the different vaccine development strategies? How?

Answer 16

Live, attenuated vaccines: weakened pathogens (often do not need boosters, but may have more side-effects)

Inactivated/killed vaccines: heated or chemically treated to inactivate (NO reversion to pathogenic form, but often require booster shots)

Subunit vaccines: use purified macromolecules derived from pathogen, similar to pros/cons of killed vaccines

Recombinant vector vaccines: Use an attenuated pathogen (all benefits of attenuated vaccines, stability issues)

Question 17

What are DNA vaccines?

Answer 17

Plasmids carrying pathogen genes injected into muscle tissue, host cells take up DNA, and express it internally. Too new to know cons, but very stable and customizable!

Question 18

What are mRNA vaccines?

Answer 18

Pathogen gene mRNA coated with lipid nanoparticles injected into muscle tissue

Question 19

Conjugate or ___________ vaccines can improve immunogenicity and outcome because some molecules aren’t strong enough Ag on their own to stimulate a good response.

Answer 19

multivalent

Question 20

What do you do if you want to induce CTL responses?

Answer 20

Deliver Ag into cells for presentation in MHC class I molecules which creates lipid carriers for delivery

Question 21

Adjuvants are included to _______ the immune response to a vaccine

Answer 21

enhance ; by promoting inflammation, more immune cells are recruited to the area to enhance effectiveness