HIV - Fenger Flashcards Preview

D&T 1 Exam 1 > HIV - Fenger > Flashcards

Flashcards in HIV - Fenger Deck (14):
1

Basic structure

+ RNA
Point mutations occur -- reverse transcriptase cannot repair
Errors change over time...specificity changes
2 identical copies of RNA connected by tRNA
Cylindrical core - p24 (reverse transcriptase)
Outer envelop (p17 protein)

2

Initial HIV infection

M Trophic HIV
Infects macrophage lineage and T cells

3

2ndary HIV infection

T Tropic HIV
CD4 T cells

4

HIV Env Proteins

gp 160 cleaved into gp120 (DISTAL) + gp41 (PROXIMAL)

120 and 41 = major antigens of the virus

41 - induces fusion

5

Accessory proteins are encoded for by what additional genes?

TAT
REV
VIF
NEF
VPU
VPR

6

TAT

Transcription transactivator
Both viral and cellular control regions of genes
LTRs with promoters and enhancers that bing reg proteins

7

REV

Regulates transport of viral mRNAs out of the nucleus and into the cytoplasm
Regulates splicing of viral RNAs

8

NEF

Diminshes expression of CD4 and MHC1
NEEDED TO ACHIEVE HIGH VIRUS LOAD
KEY component in allowing progression of HIV infection

9

ccr5

coreceptor -- present on peripheral T cells/macrophages

M Tropic HIV binds (initiating infection)

** individuals who lack CCR5 are resistant to HIV**

10

CXCR4

T tropic HIV binds

11

Screening for HIV

Ab in serum
Antigens
ELISA -- primary screening for HIV Ab

*If 2 ELISAs are confirmed, a WESTERN BLOT confirms

12

How does one determine HIV load in blood?

Reverse Transcriptase PCR

Reports RNA copies per ml
Indicator of extent of HIV replication

13

Western Blot

Based on MW
Nitrocellulose Sheets
Serum added -- specific Ab bound to individual HIV polypeptides

Results: Positive, serum antibodies MUST bind to gp120, gp41, p31 AND p24 = minumum requirement

14

Acute HIV Syndrome

Wide dissemination of virus
SPIKE in CD4 Count
Fever symptoms

Followed by clinical latency