Vol II Ch. 3: Virus Offense meets host defense

Question 1

Anatomical and physiological barriers to infection

Answer 1

skin, ciliary clearance, low stomache pH, lysozyme in tears/saliva

Question 2

Cells of the innate immunity

Answer 2

NK cells, neutrophils, dendritic cells, macrophages

Question 3

Adaptive immunity components

Answer 3

Cyt. T cells, T cells, B cells, antibodies

Question 4

All cells have ___ _____ that respond to various stresses including infection.

Answer 4

genetic programs;

Question 5

Immune defenses refer to _____ defenses wherease ____ defenses begin with a single cell and tend to be local. what couples these responses together?

Answer 5

systemic; instrinsic; cytokines

Question 6

What is a PAMP?

Answer 6

Pathogen assosciated molecular pattern

Question 7

Recognition of foreign nucleic acids in mammalian cells is performed by: What does Pkr activation cause?

Answer 7

Pkr, TLR’s, and Rig-1; autophosphorylation, followed by phosphorylation of Elf2alpha (blocking protein syn.);

Rig-I and Pkr signal transduction activates Nf-kb, which leads to IFN (interferon) and inflammatory cytokine production

Question 8

What are all the methods of NF-kappaB activation by viral infection?

Answer 8

signal transduction activated by virus binding receptor, viral proteins can engage signal transduction, Pkr binding dsRNA; Rig1 binding ss RNA; Ca release caused by overproduction of viral proteins in the ER

Question 9

What is one of the first indications of an active infection?

Answer 9

cytokines in the blood

Question 10

What are the three groups of cytokines?

Answer 10

proinflammatory; anti-inflammatory, chemokines

Question 11

What cells do secreted cytokines engage?

Answer 11

dendritic cells, macrophages, and adjacent uninfected cells, which in turn synthesize their own cytokines

Question 12

A localized viral infection often produces global effects including:

Answer 12

fever, lethargy, lymphocyte mobilization (swollen glands) (caused by colony stimulating factors (CSFs)), proinflammator gamma cytokines

Question 13

IFN-alpha:

Answer 13

induces antiviral state, upregulates MHCI and MHCII

Question 14

IFN-Gamma:

Answer 14

Activates macrophages, induces antiviral state

Question 15

Tnf-Alpha

Answer 15

activates neutrophils, induces inflammatory response initiates fat and muscle catabolism

Question 16

IFN is produced when: Cells that bind and respond to IFN create an environment where many virus are unable to propagate.

Answer 16

TLR bind, Rig-I binds, Mda5 binds,

Question 17

Members of ______ ______ ____ family are required for sustained IFN transcription after induction. IFN can cause abrupt ____ of protein syn. What are some proteins that mediate this?

Answer 17

interferon regulatory protein; halting; Pkr, Ribonuclease L (10-1000X increase in conc.)

Question 18

IFN-B enhancer lies in ______ free reason of genome

Answer 18

nucleosome

Question 19

______ binds and alters DNA conformation to allow for precise binding of transcription factors

Answer 19

Hmg(B)

Question 20

Where are PAMP receptors

Answer 20

Cell surface, endosomes cytoplasm

Question 21

How is apoptosis a defense against viral infection?

Answer 21

if the cell is forced out of a quiescent state by viral regulation, this can induce apoptosis. Virus can encode gene products to modulate this though.

Question 22

What is the apoptotic pathway?

Answer 22

It begins when cell binds proapoptotic ligand (TNF-A), which changes receptor domain to recruit death-inducing signaling proteins. This attracts procaspase 8 which activates caspase 3, which is the final effector.