L4b: RETROVIRUSES

• lentiviruses

• spumavirus

• oncovirus

3 groups of RETROVIRUSES

Oncoviruses

a group of retroviruses that only infects humans

Lentus

latin term that means slow

Lentiviruses

group of retroviruses that takes time for its manifestation/onset to appear

spherical, icosahedral capsin, enveloped with glycoprotein spikes, ssRNA

shape, capsid, and genome of HIV I

Tree-layered structure

unique layered structure of HIV 1

pol, env, gag

Genes shared with other Retroviruses

pol gene

gene that codes for the viral core of HIV I

protease, reverse transcriptase, and integrase

3 enzymes coded by pol genes

GP120 and GP41

env gene codes for what two envelope protiens?

rev, tat, vif,

unique control genes of HIV I; for enhanced viral replication

nef gene

unique repressor gene of HIV I

env: gp120, gp 41

gag (3 polypeptides): p24

2 most important polypeptide of HIV1

fusion

HIV1 penetrates cell by?

CD4 (T-helper)

HIV1 binds to what receptor

budding

HIV1 is released from the plasma membrane by?

GP120

viral attachment protein of HIV1

nucleus

what part of the cell does HIV1 replicate

1981

what year was AIDS first noticed

1950

what year AIDS occurred as early

1. Asymptomatic

2. ARC (AIDS-related complex)

3. Full-blown AIDS

3 stages of AIDS

Slim disease

AIDS is also known as

10-11 yrs

years from asymptomatic to full-blown AIDS

a. p24

b. gp41

c. gp120

d. gp160

Diagnostically Important HIV Antigens:

p24

checked in the serum for early detection of HIV infection; monitored in HIV px for drug efficacy

gp160

gp41 and gp120 makes up what antigen

blood transfusion; sexual intercourse, intravenous drugs, perianal infection

transmission of HIV1

CD4, monocytes, macrophages, regional lymph nodes, cells of macrophage derivation in the brain

Target cells of HIV1

- steady decline of CD4 positive T- cells

- depression of the T4-T8 ratio to below 0.9

- functional impairment of monocytes and macrophages

- decreased NK cell activity

- anergy to recall antigens in skin test

Immunologic markers of HIV1

- Candidiasis of the respiratory tree

- Cryptococcal meningitis

- Cryptosporidiosis with persistent diarrhea

- Cytomegalovirus infection of organs other than liver, spleen, and lymph nodes

- persistent herpes simplex virus infection

- Kaposi’s sarcoma or lymphoma of the brain under 60 years old

- Lymphoid interstitial pneumonia and/or pulmonary lymphoid hyperplasia in children under 13 years

- Mycobacterium avium, M.kansii or Pneumocystis carinii pneumonia

- Progressive multifocal leuko encephalopathy

- Toxoplasmosis of the brain in patients over 1 month

give 2 opportunistic diseases caused by HIV1

ELISA

most common lab test for HIV1

→ Immunofluorescence

→ Western Blotting

→ ELISA – antibody to gag protein

CONFIRMATORY TESTING FOR HIV1

Virus Antigen Capture Tests

detect free viral p24 in blood

Isolation

method using lymphocytes cell lines but not routinely performed

RT-PCR

quantitate viral load; monitor disease progression and response to therapy; diagnose pediatric HIV-1 infection

HIV2

4th human retrovirus isolated from mildly immunosuppressed patients in West Africa

Human T-cell Lymphotropic Virus 1 (HTLV-1)

1 st human retrovirus from leukocytes of patient with leukemia

Adult T-cell Leukemia Lymphoma (ATLL)

presents as lymphoma of the skin, lymph nodes or both in adults

HTVL1 Associated Myelopathy Tropical Spastic Paraparesis (HAM-TSP)

HTLV-1 paralytic disease in the Carribeans; affecting the long motor neurons of spinal cord

Tax protein

P53 tumor suppressor protein

a. mother-to-child via breastfeeding

b. blood transfusion

c. blood contaminated needles

d. sexual intercourse

transmission of HTL