Retroviruses

Question 1

Physical structure of virus

Answer 1

Enveloped and large

Question 2

Nucleic acid of virus

Answer 2

positive; RNA; diploid

Question 3

Special requirement of retrovirus RNA and enzyme needed

Answer 3

Must be converted into DNA by reverse transcriptase and integrated within host DNA

Question 4

3 genera that infect humans

Answer 4

1. Lentiviruses
2. Oncoviruses - HTLV
3. Spumavirus

Question 5

Lentivirus complications and symptoms

Answer 5

• associated with neurologic and immunosuppressive diseases

- cause persistent infections

Question 6

Transmission of lentivirus

Answer 6

body fluids

Question 7

Cell types infected by lentiviruses

Answer 7

CD4 + T cells

Question 8

Brief history of HIV/AIDs

Answer 8

1. gay related immune deficiency
2. acquired immune deficiency syndrome
3. believed to be native to monkeys of western Africa

Question 9

3 enzymes that reside in core

Answer 9

1. transcriptase
2. integrase
3. protease

Question 10

Regions of virus that contain GAG

Answer 10

• capsid and matrix

- group specific antigen

Question 11

Two glycoproteins that reside on surface

Answer 11

gp120; gp41

Question 12

Function of gp120

Answer 12

provides attachment points to the tcells

Question 13

Function of gp41

Answer 13

acts as a fusion protein

Question 14

Process of HIV entering into the cell

Answer 14

1. gp120 binding with CD4
2. Conformational change
3. CCR5 or CXCR4 recruitment
4. gp41 membrane insertion
5. membrane fusion

Question 15

Process of RNA entering nucleus

Answer 15

1. reverse transcriptase make viral DNA
2. inserted into host cell DNA via integrase
3. viral RNA made by host cell polyermase

Question 16

Process of making new HIV

Answer 16

1. viral RNA made by host cell polyermase
2. viral RNA serves as template for new RNA and as mRNA
3. mRNA make proteins
4. new virus made and bud from plasma membrane.

Question 17

4 stages of HIV infection

Answer 17

Primary; Asymptomatic; Symptomatic; AIDS

Question 18

Symptoms and duration of primary stage

Answer 18

• short flu like illness
• fever, fatigue, rash, headache, swollen lymph nodes, sore throat
• occurs 1-6 weeks after infection
• no symptoms possible

Question 19

Description of asymptomatic stage

Answer 19

• average of 10 year duration
• free of symptoms
• swollen glands potentially
• HIV in blood drops
• HIV antibodies detectable

Question 20

Description of symptomatic stage

Answer 20

• mild symptoms
• immune system deteriorates
• emergence of opportunistic infections and cancers

Question 21

Description of AIDS stage

Answer 21

• weakened immune system

- aids diagnoses

Question 22

Bacterial infections associated with AIDS

Answer 22

Tuberculosis; Strep pneumonia

Question 23

Viral infections associated with AIDS

Answer 23

Kaposi sarcoma; Herpes; Influenza

Question 24

Fungal infections associated with AIDS

Answer 24

Candida; Pneumocystis carinii; Cryptococcus

Question 25

Natural progression of opportunistic infections

Answer 25

Bacterial ; Herpes ; Candida ; PCP; CMV, MAC, Fungi

Question 26

AIDS definition

Answer 26

• CD4 count less than 200cells/m3
• CD4 percent below 14%
• PCP, toxoplasmosis, MAC, Karposi sarcoma

Question 27

Pathogenesis of AIDS

Answer 27

• profound immunosuppression of AIDS is due to depletion of T4 helper lymphocytes
• followed by high level of HIV in blood
• followed by low level, but incubation; massive turnover of CD4 cells
• immune system succumbs; AIDS develop when CD4 not replaced

Question 28

Control of HIV/AIDS

Answer 28

• block transmission
• nucleoside RT inhibitors
• nonnucleoside RT inhibitors
• protease inhibitors