Retroviruses Flashcards
Main population at risk of Human T-cell Lymphotropic Virus (HTLV-1) infection.
IV drug users
Pathogenesis of HTLV-1
- Infects CD4 T cells
- causes hyperproliferation of T cells thru secretion of IL-2
- This leads to a high percentage population of T cells that only recognize 1 MHCII on an antigen presenting cell leading to an immunocompromised condition
Characteristic of lymphocytes on blood smear in a patient infected with HTLV-1.
Cloverleaf Nuclei
Another name for Reverse Transcriptase
RNA dependent DNA polymerase
Major cell type infected with HIV.
CD4 Tcells
lesser extent: monocytes, dendritic cells
Name the most important HIV accessory gene and its function.
nef gene: the infection influences the Cytokine production of CD4 cells altering activation of CD8 and NK cells, allowing progression to AIDS
Name the two co-receptors in addition to CD4 that HIV needs to infect a host cell.
- CXCR4 (T tropic): on T cells
- CCR5 (M tropic): on macrophages and T cells
(only needs one of the two along with CD4)
Function of the gp120 viral protein.
Binds CD4 and CCR5 (or CXCR4) to bring the virus closer to the host cell membrane
Function of the gp41 viral protein.
Fuses to the cell membrane to allow endocytosis of the virus into the cytoplasm.
Name the steps in an HIV infection of a host cell.
- Virus binds CD4
- Fusion and entry into the host cytoplasm
- Uncoating and RT creates a viral DNA copy
- Integrase integrates viral DNA into host genome
- Transcription creates viral mRNA
- some Viral mRNA is cleaved by viral protease to create viral proteins and some is left alone to be a template for new viruses
- Viral proteins and RNA are packaged into new viruses and exocytosed out of the cell
How is HIV infection diagnosed?
Run 2 serological tests, if they are both (+) then run a Western Blot
