CBD Flashcards
Describe the typical course of HIV-1 infection
→number of CD4+ Tcells decrease
→viral load increase
How is viral genome detected in HIV-1?
→RT-PCR
How do virus avoid being recognised by immune cells?
→viruses replicate in the immune cells
Why do viruses inhibit immune cells?
→allows other pathogens to replicate in virus infected hosts
What are the two ways HIV infect cells?
→directly
→indirectly- recruitment of T cells to site of inflammation
What are the two types of direct T-Cells?
→non-permissive CD4 T-cell
→permissive CD4 T-cell
Why are there non permissive CD4 cells?
→do not have CD4 receptors
→viruses cannot replicate once in cells
What does infection of permissive CD4 T-Cells result in?
→apoptosis
How is cell death induced in non-permissive CD cells?
→pyroptosis
What is pyroptosis?
→ inflammatory form of lytic programmed cell death
How does pyroptosis increase T cell infection of HIV?
→cause inflammation so recruitment of more T-cells to site of infection
→positive feedback
What is opportunistic infections?
→Inhibition of immune cell function allows other pathogens to replicate in virus infected hosts
What are some HIV associated pathogens?
→virus- Herpes simplex virus (HSV)
Kaposi’s sarcoma herpesvirus (KSHV)
→bacteria- Mycobacterium tuberculosis Salmonella
→fungus- Candida
Cryptococcus neoformans
→parasite- Cryptosporidium Toxoplasma gondii
Which of the HIV associated pathogens most likely cause death?
→viruses
What are two possible routes of infection in HIV opportunistic infections?
→primary infection
→reactivation from latency
When does reactivation from latency occur?
→immunodeficiency
Describe the mechanism of neuron viruses
→Sits on the dendrites without replication
→immune system doesn’t see virus in dendrites due to BBB.
→When stimulated to reactivate, the virus moves down back to epithelial
What is immune privilege?
→ sites in the body able to tolerate the introduction of antigens without eliciting an inflammatory
What can reactivation of sarcoma lead to?
→oncogenesis
What are some examples of cancer causing viruses?
→Human papilloma viruses (HPVs) – Papilloma virus, circular dsDNA genome, skin cancer
Epstein-Barr virus (EBV) – Herpes virus, linear dsDNA genome, lymphoma
Hepatitis B virus (HBV) – Hepadnavirus, circular dsDNA genome, carcinoma
Hepatitis C virus (HCV) – Flavivirus, ssRNA genome, carcinoma
Human herpes virus 8 (HHV-8) - Herpes virus, linear dsDNA genome, lymphoma
Human T-lymphotrophic virus-1 (HTLV-1) – Retrovirus, RNA-DNA genome, leukemia/ lymphoma
Merkel cell polyomavirus (MCV) – Polyomavirus, dsDNA genome, carcinoma
