Exam 2 Week 3

Question 1

HIV: Matrix Protein + gene

Answer 1

p17 + gag

Question 2

HIV: Nucleocapsid (binds to viral RNA genome) + gene

Answer 2

p7 + gag

Question 3

HIV: tat = function

Answer 3

trans-activator of transcription: binds TAR elements and promotes transcriptional elongation

Question 4

HIV: LTR = function

Answer 4

Long Terminal Repeat: Initiation stie for transcription, contains site for binding transcriptional regulatory proteins.

Question 5

HIV: Rev = function

Answer 5

Regulator of viral gene expression: promotes transportation of unspliced mRNA from nucleus to cytoplasm

Question 6

HIV: nef = function

Answer 6

Negative Factor: downregulation of cellular CD4 and MHC 1 proteins.

Question 7

Definition of Aids

Answer 7

Lab confirmed HIV infection +

CD4+ T cell count

Question 8

HIV evasion: Host innate immune response (APOBEC3)

Answer 8

Causes G to A hypermutation and DNA degradation, inactivating APOBEC3.

Question 9

Reservoir for HIV in body

Answer 9

Dendritic Cells (APC for CD4+ T cells)

Question 10

HIV: Disregulation of cytokines

Answer 10

Increase secretion of Th2 (not useful for fighting HIV) and Pro-inflammatory cytokines.

Decrease secretion of Th1 and Tfh (which stimulate CD8+ and IgG)

Note: Il-2, Il-2 and Il-15 activate HIV infected cells.

Question 11

HIV: Preventative vs Therapeutic Vaccine

Answer 11

Preventative: identifies viral epitopes and inducts antibod + CMI (but not gp 120/41 because they mutate quick)

Therapeutic: Inducts CMI (CD8+ cytotoxic T cells)

Question 12

HIV: Pathologic features of lymph node

Answer 12

Hyperplasia and enlarged follicles.

Question 13

HIV: Neurologic Features

Answer 13

Microglial nodules with multinucleated giant cells in the subcortical cray matter of cerebrum - AIDS Encephalopathy

Question 14

Gaisbock Syndrome

Answer 14

Relative Polycythemia: Obese, hypertensive, middle-aged male smokers.

Question 15

Polycythemia: Normoxia

Answer 15

1) PHD Hydroxylates proline on HIF-1(alpha)
2) VHL (tumor suppressor) = targets HIF-1alpha for degradation via hydroxylated proline
3) Targeting via PHD and VHL is absolutely required.

Question 16

Polycythemia: Hypoxia

Answer 16

1) PHD does not hydroxylate proline on HIF-1(alpha) therefore VHL cannot bind and degrade it.
2) HIF-1(alpha) interacts with HIF-1(beta) and upregulates EPO.

Question 17

Immunosuppressive drugs: Cyclosporin

Answer 17

Inhibit T cell activation

Question 18

Immunosuppressive drugs: Azathioprines

Answer 18

Disrupts synthesis of RNA and DNA: Inhibit cell division

Question 19

Immunosuppressive drugs: Monoclonal antibodies

• Anti CD20
• Anti TNF alpha
• Anti CD3
• Anti CD25
• Anti CD52

Answer 19

• Anti CD20 = Inhibits B Cells
• Anti TNF alpha = Induce apoptosis of T cells
• Anti CD3 = Inhibits T cells
• Anti CD25 = Decreases Treg
• Anti CD52 = Binds to B and T lymphocytes

Question 20

Immunosuppressive drugs: Corticosteroids

Answer 20

Suppresses inflammation

Question 21

c5a peptidase (F(x) and bug)

Answer 21

• helps evade phagocytosis + complement

- Group A Strep and Group B Strep

Question 22

Lysozyme

- Bacteria with resistance

Answer 22

Gram (-) because of outer membrane

Question 23

Defensins

- Bacterial resistant factor and which bug

Answer 23

Polypeptide Capsule = Bacillus anthracis

Question 24

Evading Antigen Presentation on MHC Class 1

Answer 24

Intracellular!!! pathogens have adopted various methods in blocking antigen presentation

Question 25

Evading Antigen Presentation on MHC Class 2

Answer 25

Just Avoid phagocytosis thus preventing it from ever being presented.