(PM3A) HIV & Anti-Retroviral Therapy Flashcards
How many people have died from HIV?
33 million
How many people in the world are living with HIV?
38 million
Where is HIV most prevalent?
Africa - 2/3 of total HIV cases
How many people die from HIV every year?
700,000
How many new HIV infections are there every year?
1.7 million
How many people have access to anti-retroviral therapy?
25.4 million
How many people in the UK are living with HIV?
105,000
What age range is affected most by HIV infection?
35-49
What is UNAIDS 90-90-90?
A global target set for countries to have:
(1) ≥90% HIV+ to be diagnosed
(2) ≥90% HIV+ to be on ART
(3) ≥90% HIV+ to have viral load depressed
What is ART
Anti-retroviral therapy
What does HIV stand for?
Human Immuno-deficiency Virus
What is the cause of HIV?
Lentivirus - a type of retrovirus
What type of virus is lentivirus?
- Group IV
- ssRNA
- Positive sense
- Enveloped
How does lentivirus cause HIV?
Infects immune cells
What are the immune cells infected by lentivirus to cause HIV?
(1) CD4+ T helper cells
(2) Macrophages
(3) Dendritic cells
What is a CD4+ T cell also known as?
Helper T cell
What is a helper T cell also known as?
CD4+ T Cell
(1) What is most commonly caused by lentivirus?
(2) What is also caused by lentivirus?
(1) HIV-1
(2) HIV-2 - less virulent and less infective
How does the infection of immune cells by lentivirus lead to low levels of helper T cells?
(1) Direct viral killing of infected cells
(2) Increased apoptosis of infected cells
(3) Killing of infected CD4+ T cells by CD8 cytotoxic lymphocytes
What does a CD8 cytotoxic lymphocyte do?
Kills infected CD4+ (Helper) T cells
What white blood cell kills CD4+ (Helper) T cells?
CD8 cytotoxic lymphocytes
What effect does increased death of CD4+ (Helper) T cells have?
(1) Increased susceptibility to opportunistic infections
(2) Susceptibility increases as CD4+ (Helper) T cell count falls below critical level
What is the 1st stage of the HIV life cycle?
Lentivirus binds to CD4 receptor to fuse with host cell membrane
What is the 2nd stage of the HIV life cycle?
Virus uncoats and viral RNA + proteins enter host cell
What is the 3rd stage of the HIV life cycle?
Viral DNA is transcribed via reverse transcriptase
What is the 4th stage of the HIV life cycle?
Viral DNA enters nucleus
Integrates into host genome using viral integrase
What is the 5th stage of the HIV life cycle?
New viral DNA is used as genomic RNA
This is used to make new viral proteins
What is the 6th stage of the HIV life cycle?
Viral RNA and viral proteins gather at the cell membrane
What is the 7th stage of the HIV life cycle?
Budding leads to a mature viral particle being released from the cell