HIV Flashcards
specialized medical care for people living with a serious illness, making life easier even without proper cure.
Palliative Care
Prevention of HIV
- Modification of sexual behavior
- Measures to protect infection of blood and blood products
- Search on effective vaccine is still on
How does antiretroviral drug work?
Through the involvement of gp120 and gp41 inhibitors, thus increase survivability period.
(The ARD does not kill the virus but block different stages of its life cycle, thus the virus will be unable to replicate.
If the treatment will continue, the viral population will drop)
Drug classes called “Combined ARD”:
- Attachment inhibitors
- Nucleoside Reverse Transcriptase Inhibitor (NRTI)
- Non-nucleoside Reverse Transcriptase Inhibitor
(NNRTI) - Protein Inhibitors
- Integrase Inhibitors
- Boosters/ Pharmacokinetic enhancer
prevents the virus from attaching and entering the cells
Gp120
blocks the ability of the virus to fuse with immune cells
Gp41
Last stage of HIV
AIDS
Cells that HIV attacks
CD4 cells
Can prevent HIV from spreading and advancing it to AIDS
Antiretroviral Treatment (ART)
HIV comes from what family?
Retroviridae
Causes AIDS
HIV
limited; primarily found to West Africa
HIV-2
predominant strain; found worldwide
HIV-1
Subtypes of HIV-1 and identify the major subtype
Subtypes:
M - major
N
O - outlier
TRUE or FALSE: Both serogroups are transmitted the same manner but
HIV-2 is more pathogenic but has lower rate of transmission.
FALSE. Both serogroups are transmitted the same manner but
HIV-2 is LESS pathogenic and has lower rate of transmission.
TRUE or FALSE: As HIV infection advances to AIDS, the amount of HIV in the body increases and the number of CD4 cells decreases.
TRUE: The more HIV in the body, the more CD4 cells will be attacked and killed, which caused its depletion and result to lower immunity.
HIV treatment that increases survival time and decreases mortality
Retrovir (Zidovudine)
Additional effects of HIV
a. Decreased natural killer cell activity
b. Defective chemotaxis in monocytes and macrophages
c. Enhanced release of interleukin-1 and cachectin by monocytes.
WHY IS IT DIFFICULT TO HAVE A CURE AGAINST HIV?
Because it hijacks body’s immune response, they turn T cells into breeding grounds of the virus itself.
SEQUENCING: Label the order of the replication process of HIV in numbers (1-5)
______ The replication process kills the infected cell and leads to a diminishing number of T helper cells.
______ The RNA is transcribed to the DNA by the activity of the viral enzyme reverse transcriptase. Viral DNA is then inserted into the host cell’s DNA by viral integrase.
______ HIV penetrates the plasma membrane of the cell, and the viral RNA is released.
______ HIV bind to the CD4 molecule on T helper cells, monocytes, macrophages, and other cells. Secondary receptors (co-receptors) are also important in viral binding. T helper cells are the primary target.
______ The viral DNA is transcribed into mRNA, which is then translated into viral proteins. Mature viruses leave the host cell by budding.
5, 3, 2, 1, 4
involved in MHC 2
- Induces other immune cells to trigger
immune response by secreting cytokines
upon recognizing certain antigen.
CD4
involved in MHC 1
- Induce cell death of the virus infected cells by cell lysis or apoptosis.
CD8
Normal ratio of CD4 to CD8
2:1
The stage where HIV binds or attaches itself to receptors on the surface of a CD4 cell
Binding/attachment (Stage 1)
These receptors are important in viral binding
Secondary receptors or co-receptors
In the stage of Reverse Transcription, HIV releases this HIV enzyme to convert its genetic material - HIV RNA - into HIV DNA.
Reverse transcriptase
In this stage, HIV begins to use the machinery of CD4 cells to make long chains of HIV proteins (building blocks) after HIV RNA is integrated into the CD4 cell DNA
Replication (Stage 5)
What will happen in the stage of Fusion?
The HIV envelope and the CD4 cell membrane fuse or join together, which allows the virus to enter the CD4 cell.
Newly formed immature HIV pushes itself out of the host CD4 cell
Budding
New HIV proteins and HIV RNA move to the surface of the cell and assemble into immature/noninfectious HIV
Assembly
This enzyme breaks up the long chains of protein in the immature virus which creates mature virus.
Proteases
Viral DNA is then inserted into the host cell’s DNA by ______________.
Viral integrase
The stage that involves rapid replication of the virus in the lymphoid tissue
Clinical latency
Stage where the patient develop a number of infections caused by opportunistic pathogens
ARC (AIDS-related complex)
Stage that involve depletion of T cells resulting in severe opportunistic infections
Final stage or Full Blown Stage
Promotes cell survival proliferation, differentiation and death.
Cachectin (TNF)
Identify its functions:
IL - 1
IL - 2
IL - 3
IL - 4
IL - 5
IL - 6
Responsible for fever (IL 1)
Stimulates T-cells (IL 2)
Stimulates Bone marrow (IL 3)
Stimulates IgE production (IL 4)
Stimulates IgA production (IL 5)
Stimulates acute-phase protein production (IL 6)
Antibodies to HIV generally appear about ______________ after infection.
These are the first antibodies detected by __________________________.
12 weeks ; ELISA and Western Blot assays
How does HIV escape the immune response?
By undergoing antigenic variation
Why is there no vaccine for HIV?
HIV mutates rapidly, it’s extremely challenging to develop a single
vaccine to target all the strains and mutations. HIV is also unique in how it hides from the immune system, so even if you eradicate the circulating virus, the hidden HIV can spread the infection.
Virus infects the very cells of the immune system that any vaccine is supposed to induce.
Test to detect antibodies to HIV and HIV antigen.
ELISA
Can detect replicating viruses
Genetic probes
Confirmatory serological test for HIV
Western Blot Assay
Polymerase chain reaction assay detect nucleic acid gene sequences in HIV-1 and HIV-2.
Reverse Transcriptase
Used to detect HIV antigen in infected cells and can be used as a confirmatory test
Indirect Immunofluorescence assay
2 important blood test to detect HIV (indicate their principles)
- HIV viral load test – monitor the amount of HIV in blood
- CD4 lymphocyte cell count – measures how HIV affected the immune system; low count CD4 means very immunosuppressed immune system.
Summary of “Life Cycle” of HIV (process of its infection)
- Binding
- Fusion
- Reverse transcription
- Integration
- Replication
- Assembly
- Budding
Stages of Inflammation
- Activation of inflammatory chemicals
- Margination
- Diapedesis
- Chemotaxis
- Phagocytosis
TRUE or FALSE
HIV-1 is transmitted by unprotected sex, contaminated blood or blood products, contaminated needles, or perinatally.
TRUE
Laboratory Tests for HIV
ELISA
WESTERN BLOT ASSAY
REVERSE TRANSCRIPTASE
INDIRECT IMMUNOFLUORESCENCE ASSAY