Immunology of AIDS Flashcards Preview

Unit 4: Blood and Lymph > Immunology of AIDS > Flashcards

Flashcards in Immunology of AIDS Deck (33)
1

What is unique about long term survivors?

some are homozygous for a mutation in the CCR5 receptor

2

What happens first when someone is infected with HIV?

high blood virus levels develop and peak around 6 weeks

3

____ are able to suppress viral replication but not eliminate the virus DNA from their nuclei.

Tfh cells

4

Once they get symptoms of _____ or _____, or their Th (CD4+) cells fall below 200/μL of blood, it’s AIDS.

opportunistic infections; Kaposi’s sarcoma

5

How does HIV bind to Th cells?

using its gp120 envelope glycoprotein to CD4

6

People are ‘______' if they have antibody to HIV.

seropositive

7

Once they get symptoms of opportunistic infections or Kaposi’s sarcoma, or their Th (CD4+) cells fall below ___ of blood, it’s AIDS.

200/μL

7

During the _____, the major site of HIV persistence is memory Tfh cells in the lymph nodes.

long seropositive period

8

What is the normal CD4/CD8 ratio?

1.5:3

9

There are two classes of RT inhibitors: ____, which are competitive inhibitors and chain-terminators; and _____ inhibitors, which bind a hydrophobic pocket on the enzyme that changes the conformationof the catalytic site.

nucleosides (NRTI); non-nucleoside (NNRTI)

10

What is ART?

standard antiretroviral therapy that combines two NRTIs and a third drug from a different class, usually an NNRTI

11

Why does HIV want to form a syncytium?

to spread without going extracellular

11

During the long seropositive period, the major site of HIV persistence is _____ cells in the lymph nodes.

memory Tfh

12

These are some long term survivors that became infected with HIV but did not progress to AIDS; some have HLA-B57.

elite controllers

13

Why do CD4 cell counts eventually fall?

the immune system can no longer keep up

15

These are viruses that cause slow disease progressions but are ultimately fatal.

lentiviruses

16

People are ‘seropositive’ if they have _____.

antibody to HIV

16

HIV-1 is the most _____ pathogenic virus we have encountered.

antigenically variable

17

What are elite controllers?

some long term survivors that became infected with HIV but did not progress to AIDS; some have HLA-B57

18

What is a lentivirus?.

viruses that cause slow disease progressions but are ultimately fatal

18

____ is the leading cause of death in people infected with HIV.

TB

19

Tfh cells are able to suppress viral replication but not _____.

eliminate the virus DNA from their nuclei

20

_____ is a tumor of the endothelial cells lining lymphatics.

Kaposi sarcoma

21

What is CCR5?

an HIV coreceptor

21

What is important about the HLA-B57 allele?

pts with it make effective CTL to HIV peptides presented in HLA-B57

23

What happens to HIV infected T cells?

1. die rapidly OR 2. become persistent viral producers OR 3. enter latency

25

HIV binds to cells via ____ on _____ called _____.

lectin; dendritic cells; DC-SIGN

27

What is the mean incubation period from HIV to AIDS?

9.5 years w/o treatment

28

HIV virus type?

a nontransforming retrovirus,

29

What happens after HIV uses its gp120 to bind to Th cells?

gp120 undergoes a conformational change, allowing it to bind to the CCR5 co-receptor

31

Antibody to HIV peaks around ____, and then ____.

9 weeks; virus levels fall to almost zero

32

Why does ELISA for HIV have to be followed up with a Western blot?

ELISA has a false-positive rate

33

What does gp120/gp41 do?

when inserted in the plasma membrane, it allows fusion of the infected cell to nearby cells, forming a syncytium