HIV Flashcards
what type of virus is HIV
retrovirus
what glycoproteins are on the surface of HIV cells
gp120
gp41
what kinds of cells does HIV target
cells that have CD4 receptors or a cytokine receptor
types of cells that have CD4 receptors
CD4+Helper T cells mononuclear phagocytes B lymphocytes neural cells of monocyte origin dendritic cells (dementia) bone marrow stromal cells intestinal epithelial cells
process of HIV spread
- Binding
- Viral RNA enters cell
- Uncoating
- Reverse Transcriptionase
- Viral DNA enters cell nucleus
- Viral DNA inserted into DNA of host cell
- viral mRNA manufactured
- Viral mRNA provides manufacture of HIV structural proteins
- new HIV released from cell
what happens during binding phase
HIV binds to CD4 receptor or cytokine receptor and attaches utilizing gp120 and gp41
how does viral RNA enter host cell
it is enveloped in nucleocapsid
what happens during uncoating
viral RNA leaves the nucleocapsid
what happens during reverse transcriptionase
double stranded DNA manufactured from viral RNA template
what enzyme inserts viral DNA into DNA of host cell
integrase
Viral DNA can remain dormant for a long period of time. What happens when it is activated?
initiate translation of viral mRNA
begin production of HIV protein
This leads to formation of new virons, lysis, and death of host cell
primary immunologic effect of HIV
decline in number of helper T cells in body
how does HIV destroy helper T cells
- new viron production causes cell lysis
- HIV infected cells express new surface antigens and are attacked by other T cells
- shedding of the gp120 envelope protein can interact with other healthy T-cells, causing them to fuse and be destroyed
activated T cells are (more/less) susceptible to HIV attachment, invasion, and replication
more
what happens to T-cells when viral antigen present
they activate
