HIV Flashcards
HIV damages the immune system by killing?
CD4+ cells
last stage of HIV infection
AIDS
as the HIV infection advances to AIDS, the amount of HIV in the body ____; number of CD4 ___
amount of hIV increases
number of CD4 decreases
HIV is member of the family __
Retroviridae
human immunodeficiency virus causes?
acquired immunodeficiency syndrome
classify the two serogroups of HIV
HIV-1 = predominant strain worldwide
HIV-2 = limited primarily to West Africa
3 subtypes of HIV-1
M, N, O
O and M = major
HIV binds to the CD4 molecule, on what cells?
- T helper cells
- monocytes
- macrophages
- and other cells
important for viral binding of HIV
secondary receptors
primary target of viral binding
T helper cells
RNA is transcribed to DNA by the activity of the viral enzyme ___. Viral DNA is then inserted into the host cell’s DNA by ___
activity = reverse transcriptase
host cell’s dna = viral integrase
mature viruses leave the the host cell by?
budding
HIV replication
- HIV binds CD4
- HIV penetrates plasma membrane, viral RNA release
- RNA transcribed to DNA
- viral DNA transcribed into mRNA
- mRNA to viral proteins
Antibodies to HIV generally appear about ___ after infection
12 weeks
first antibodies to appear are detected by?
ELISA and western blot assays
these antibodies able to interfere with infection of host cells appear about ___ after infection
neutralizing antibodies
appear about 1 year after infection
HIV is able to escape the immune response by under undergoing?
antigenic variation
HIV-2 is limited primarily to?
West Africa
HIV-2 is less pathogenic and has a lower rate of transmission
what cells will deplete as the disease progresses?
CD4+ T helper cells
normal ratio of CD4 to CD8 cells
2:1
additional effects of HIV
- Decreases natural killer cell activity
- Defective chemotaxis in monocytes and macrophages
- Enhanced release of interleukin-1 and cachectin by monocytes
HIV is transmitted via:
- unprotected sex (vaginal and anal intercourse)
- parenteral (contact with contaminated blood or blood products, needles)
- perinetally (during pregnancy)
acute phase, infected persons will experience ___
asymptomatic or can have minor symptoms resembling infectious mononucleosis
virus continues to replicate rapidly in the lymphoid tissue, this stage is referred to as __
clinical latency
in this stage of AIDS-related complex (ARC), the patient will develop ___
T cells begins to decrease and the patient develops a number of infections caused by opportunistic pathogens
opportunistic pathogens: Candida, herpes simplex virus, cytomegalovirus
what happen when the patient reached the final stage (full-blown AIDS)?
- T cell depletion
- severe opportunistic infections and cancers such as esophageal candidiasis, cryptococcosis, systemic cytomegalovirus and herpes simplex virus infections, pneumocystis jiroveci pneumonia, and Kaposi’s sarcoma
used to stage the severity of disease
CD4+ T cell counts
used to detect antibodies to HIV and HIV antigen
ELISA test
confirmatory tests for repeatedly positive samples (ELISA test)
- Western blot assay
- immunofluorescent test
Western blot is the confirmatory serological test for HIV in which —- must appear.
two of the three bands
p24, gp41, or gp20/160
this test can detect replicating viruses
genetic probes
detect nucleic acid gene sequences in HIV-1 and HIV-2
Reverse Transciptase - PCR
used to detect HIV antigen in infected cells and this can also be used as a confirmatory test
indirect immunofluorescence assay
what is the treatment?
Retrovir
(Zidovudine)
increases survival time and decreases mortality
enumerate the prevention
- modification of sexual behavior
- self-referral among high risk groups
- screening of blood and organ donors
- HIV screening during pregnancy (frm stevens)
- heating blood plasma @ 68C for 24 hrs
HIV is the etiologic agent of?
Acquired Immunodeficiency Syndrome (AIDS)
enumeration
isolates of HIV-1
- group M (majority of HIV-1 infections worldwide)
- group O (outlier group)
- group N and P (newer group)
group N, O, P are largely confined to West Africa
why HIV is classified as a retrovirus?
bcos it contains RNA as its nuclecid acid and a reverse transcriptase
enumeration
major structural genes
gag, env, and pol
enumeration
protein product/s of gag gene
- p6
- p9
- p17
- p24
enumeration
protein product/s of env gene
- gp120
- gp41
protein product/s of pol gene
- p66
- p51
- p31
- p10
identify
infectivity factor
vif gene p23
identify
enhances HIV replication
nef gene p27
individuals who have a genetic mutation in the CXCR4 gene have been found to be resistant to HIV infection
true or false
false, it is the CCR5
INTERPRET
Bands present: p24 and gp120
POSITIVE
For the test to be valid, the ____ should be ___
the negative control should produce no bands and the positive control should be reactive with p17, p24, p31, gp41, p51, p55, p66, and gp120/160.
INTERPRET
Bands present: p24 and p55
INDETERMINATE
This proteins appear relatively early after exposure.
p24 and p55
how does the treatment works?
through GP-120 and GP-41 inhibitor
prevents the virus from attaching and entering the cells
GP-120 inhibitor
blocks the virus ability to fused with human immune cells
GP-41
true or false
antiretroviral drugs directly kills the virus.
false
does not kill but it will block diff. stages of the virus
enumeration
6 classes of antiretroviral therapy
- Attachment inhibitors
- nucleoside reverse transcriptase inhibitor (NRTI)
- Non-nucleoside reverse transcriptase inhibitor (NNRTI)
- Protease inhibitors
- Integrase inhibitors
- Pharmacokinetic enhancers (boosters)
