Week 7 Flashcards
(11 cards)
What is the unique feature of retrovirus replication?
use reverse transcriptase to convert RNA into DNA, which is then integrated into the host cell’s genome.
What is the function of Gp120 and Gp41 in HIV infection?
Gp120: Binds to the CD4 receptor on T-helper cells and chemokine receptors (CCR5 or CXCR4).
Gp41: Facilitates membrane fusion to allow viral entry into the host cell.
What are the two types of human retroviruses?
Oncogenic retroviruses: E.g., HTLV-1
Immunosuppressive retroviruses: E.g., HIV
How does HIV affect the immune system?
HIV targets CD4+ T-helper cells, leading to their depletion, which impairs immune function and makes the body more susceptible to opportunistic infections.
What are the stages of HIV infection?
Primary infection: Initial viral replication and immune response.
Latent period: Gradual loss of CD4+ T cells.
AIDS: Severe immune suppression, with CD4+ counts falling below 200 cells/µL.
What are antiretroviral drugs (ARVs)?
target specific stages of the HIV life cycle
What are the three main classes of antiretroviral drugs?
NRTIs (Nucleoside Reverse Transcriptase Inhibitors)
NNRTIs (Non-Nucleoside Reverse Transcriptase Inhibitors)
PIs (Protease Inhibitors)
How does antigenic drift occur in the influenza virus?
Involves minor mutations in the Hemagglutinin (HA) and Neuraminidase (NA) proteins, resulting in the production of new influenza strains that evade the immune system.
Why are H5N1 and H7N9 influenza viruses concerning?
avian influenza strains with the potential to cause severe respiratory illness
How does Influenza virus cause cell damage?
infects and destroys epithelial cells in the upper and lower respiratory tract, leading to cell death, inflammation, and increased susceptibility to secondary infections.
What is the role of Neuraminidase in influenza infection?
helps the virus release new virions from the host cell by cleaving sialic acid on the host cell membrane, facilitating viral spread.
