Exam 3 - AIDS Flashcards
What does AIDS stand for?
Acquired Immunodeficiency Syndrome
What does HIV stand for?
Human Immunodeficiency Virus
Name the two aggressive cancers are associated with AIDS.
1) Kaposi’s Sarcoma
2) B cell lymphoma
AIDS is characterized by susceptibility to infection with _____ _____.
AIDS is characterized by susceptibility to infection with OPPORTUNISTIC PATHOGENS.
What is another name for CD4+ cells?
Helper T Cells
T/F: HIV kills CD4+ cells.
TRUE
T/F: AIDS is accompanied by a profound increase in the number of CD4+ cells.
FALSE
-AIDS is accompanied by a profound DECREASE in the number of CD4+ cells.
What are the 2 types of HIV?
1) HIV-1
2) HIV-2
Which type of HIV is endemic in West Africa?
HIV-2
What type of HIV causes AIDS worldwide?
HIV-1
T/F: HIV infection, with some exceptions, does not produce enough immune response to eliminate it.
TRUE
HIV continues to replicate _____ and damages existing ____ _ ___.
HIV continues to replicate RAPIDLY and damages existing CD4+ T Cells.
How is HIV carried through the body?
In infected CD4+ T cells, or as free virus in body fluids (plasma, serum)
What does an acute infection with HIV cause?
Flu-like illness with the presence of virus in the peripheral blood and depletion of circulating CD4+ cells
Which MHC class of molecules kills helper T cells in AIDS?
MHC Class I molecules
T/F: Initially, all AIDS pts produce a humoral response followed by a cell-mediated immune response resulting in the production of HIV-specific CD8+ T cells.
TRUE
What is another name for CD8+ T cells?
Cytolytic T cells
What 2 ways does killing occur in AIDS?
1) Virus itself killing CD4+ cells
2) Human immune response generating cytolytic T cells, which are specific for the virus - killing CD4+ cells because they are infected with HIV virus
T/F: Most patients infected with HIV do not ever develop AIDS.
FALSE
-Most pts infected with HIV are eventually expected to develop AIDS
What is the term for the period after HIV infection and before the development of the disease?
- Clinical latency
- Asymptomatic period
What is the average latency period without therapeutic intervention?
- Between 3-15 years
- He said in class usually ~2-5 years
The asymptomatic period is not silent and there is a gradual decline of __ __ ___.
The asymptomatic period is not silent and there is a gradual decline of CD4+ T cells.
What is the normal ratio of CD4+ to CD8+ cells?
2:1
What is the ratio of CD4+ to CD8+ in HIV infected patients that develop AIDS?
0.5:1
At what ratio of CD4+ to CD8+ do AIDS infected patients develop opportunistic infections?
0.5:1
The structure of HIV is composed of __ proteins and __ genes.
The structure of HIV is composed of 19 proteins and 9 genes.
What type of virus is HIV?
Enveloped Retrovirus
How many copies of an RNA genome does each HIV virus particle have?
TWO
What transcribes RNA into DNA to integrate it into the host cell chromosome?
REVERSE TRANSCRIPTASE
What is the viral core of HIV composed of?
Protein p24
What 2 enzymes are contained in p24 in the viral core of HIV?
1) Reverse transcriptase
2) Integrase
3) Protease
What 3 enzymes (“RIP”) are required for viral replication?
1) R - Reverse transcriptase
2) I - Integrase
3) P - Protease
How many genes is HIV composed of?
NINE
How many of the nine genes that HIV is composed of are structural genes?
THREE
What are the 3 structural genes (“PEG”) that HIV is composed of?
1) P - pol
2) E - env
3) G - gag
What does gag encode?
Gag encodes major structural proteins of the HIV virus
What does pol encode?
Pol encodes the reverse transcriptase, the proteases, and the viral integrases
What does env code?
Env codes the proteins that are responsible for the attachment of the virus and entry into the cell
What are the other 6 genes responsible for in the HIV virus?
The translation of regulatory proteins required for infection
Name the 3 structural genes of an HIV virus.
“PEG”
1) P - pol
2) E - env
3) G - gag
How many genes is HIV composed of?
NINE GENES
Name the structural gene that encodes major structural proteins of the HIV virus.
gag
Name the structural gene that encodes the reverse transcriptase, the proteases, and the viral integrase.
pol
Name the structural gene that codes the proteins that are responsible for the attachment of the HIV virus and entry into the cell.
env
T/F: The HIV virus replicates in human cells.
TRUE
What is the term for small viruses formed resulting from replication?
VIRONS
How do new viral particles escape from the cell in HIV?
New viral particles escape from the cell by BUDDING from the plasma membrane
How does the HIV virus enter cells (CD4+)?
-By gp120 and gp41
HIV enters cells by means of a complex of two non-covalently associated viral glycoproteins, ___ and ___, in the viral envelope.
HIV enters cells by means of a complex of two non-covalently associated glycoproteins, gp120 and gp41, in the viral envelope.
Which portion of the glycoprotein binds with high affinity to CD4 on the cell surface?
gp120 portion
What draws the HIV virus to CD4 T cells and to macrophages, which also express some CD4 receptors?
gp120
What component of the glycoprotein mediates fusion of the viral envelope with the plasma membrane of the cell?
gp41
What allows the viral genome and associated viral proteins to enter the cytoplasm?
gp41 mediating fusion of the viral envelope with the plasma membrane of the cell
Which glycoprotein is responsible for binding to target host cell?
gp120
Which glycoprotein is involved in fusing 2 cells and allowing HIV to enter?
gp41
T/F: HIV does not kill macrophages.
TRUE
In HIV, the interactions involve the trimeric envelope complex, (____), CD4, and a _____ receptor.
In HIV, the interactions involve the trimeric envelope complex, (gp160), CD4 and a CHEMOKINE receptor.
What are the names of the chemokine receptors that interact?
CCR5 or CXCR4
What 3 things are required for HIV to enter CD4+ cells?
1) gp160 (which is gp140 and gp41 together)
2) CD4 receptor
3) Chemokine receptor
T/F: Virus cannot replicate unless the host cell, the lymphocyte is replicating.
TRUE
T/F: Replication of lymphocytes is necessary for the replication of the HIV virus.
TRUE
___ ___ T cells are susceptible to infection.
MEMORY CD4+ T cells are susceptible to infection.
What happens after activation of infected memory cells in the lymph nodes?
It results in viral replication and the destruction of infected cells
Does HIV kill macrophages?
NO
HIV causes abnormal patterns of ___ secretion from macrophages that could account for wasting that commonly occurs in AIDS pts.
HIV causes abnormal patterns of CYTOKINE secretion from macrophages that could account for wasting that commonly occurs in AIDS pts.
What type of cell is an important reservoir of infection, and also a means of spreading the virus to other tissues such as the brain?
MACROPHAGES
Name 4 criteria for AIDS diagnosis.
1) Certain opportunistic infections
2) Certain cancers - Kaposi Sarcoma, B cell lymphoma
3) HIV-related encephalopathy
4) HIV-induced wasting syndrome
Name the two common forms of cancer.
1) Kaposi Sarcoma
2) B cell lymphoma
In the lifecycle of HIV in CD4 T cells, how does the virus bind to CD4?
gp120
In the lifecycle of HIV in CD4 T cells, what mediates fusion with the target cell?
gp41
In the lifecycle of HIV in CD4 T cells, once in the cytoplasm, the RNA genome is ____ ____ into double-stranded ____.
In the lifecycle of HIV in CD4 T cells, once in the cytoplasm, the RNA genome is REVERSE TRANSCRIBED into double-stranded cDNA.
What happens with cDNA in the lifecycle of HIV in CD4 T cells?
It migrates to the nucleus, is integrated into the host cell genome and is called a provirus
List the four “steps” in HIV lifecycle.
1) Virus particle binds to CD4 on T cell
2) Viral envelope fuses with cell membrane allowing viral genome to enter the cell
3) Reverse transcriptase copies viral RNA genome into double-stranded cDNA
4) Viral cDNA enters nucleus and is integrated into host DNA; it remains quiescent until T cell is activated
Name the two regulatory genes in the lifecycle of HIV.
1) Tat
2) Rev
What do Tat and Rev develop into?
Regulatory proteins
Name the term that describes a large family of small chemotactic cytokines released by many cell types.
CHEMOKINES
T/F: Chemokine receptors are a family of G protein-coupled receptors.
TRUE
Name two G protein-coupled receptors involved in the binding of gp120, resulting in penetration of gp41 into cell membrane.
1) CCR5
2) CXCR4
What are the two G protein-coupled receptors that are involved in binding of gp120, which results in penetration of gp41 into the cell membrane?
1) CCR5
2) CXCR4
What is the generic name for Maraviroc?
Selzentry
What is the brand name for Selzentry?
Maraviroc
_____ is an antagonist of a chemokine receptor, CCR5.
MARAVIROC is an antagonist of a chemokine receptor, CCR5.
What is Maraviroc indicated for?
Pts infected with only CCR5-tropic HIV-1, in combination with other antiretroviral agents
What drug is indicated for CCR5-tropic HIV-1?
Maraviroc (Selzentry)
Name the drug that is a an antagonist of a chemokine receptor, CCR5.
MARAVIROC
T/F: Maraviroc is a first-line drug treatment.
FALSE
-Not a beginning drug; used when pts have developed resistance to other anti-retroviral agents
Maraviroc inhibits entry of ____ into ___ ___.
Maraviroc inhibits entry of HIV into CD4+ cells.
What two things are important for administration of Maraviroc (Selzentry)?
1) Tropism testing
2) Treatment hx
T/F: Maraviroc is not recommended in pts with CXCR4-tropic HIV-1.
TRUE
What are the SE of Maraviroc (Selzentry)?
- Hepatotoxcity
- Cardiovascular events
- Increased risk of infection
- GI disorders
What are people called when they are living with HIV without developing AIDS?
Long term Non-progressors
Long term Non-progressors are _______ carriers for ____ ___ mutation in ____.
Long term Non-progressors are HOMOZYGOUS carriers for DELTA 32 mutation in CCR5.
What do long term non-progressors have high levels of?
Alpha-defensin
What do high levels of alpha-defensin do?
Slow down replication of virus
-high in saliva, thus not transmitted in saliva
What results because of a delta 32 mutation in CCR5?
HIV is not able to enter CD4+ cells, but is still surviving in the blood
What is the name of the mutation in CCR5 that allows people to live with HIV and it not progress to AIDS?
Delta 32
Name 5 types/approaches to Immunorestorative therapy.
1) IL-2
2) CSF
3) Isoprinosine
4) Bone marrow transplantation from homonzygous Delta 32 mutation carriers
6) IV immunoglobulins
T/F: There are many vaccines for AIDs.
FALSE
-There are none available, but many in developmental stages
What are some problems associated with the development of AIDS vaccines?
