Viral Pathogens :Classification,Biology and Disease 2 Flashcards
What is the typical course of HIV-1 infection?
It mainly infects T cells as they contain the CD4 molecule which is required for entry.
It recognised CD4 t cells and this leads to the killing of T cells.
In a typical patients, billions of virions are made and are destroyed.The depletion of CD4 T cells leads to AIDS +opportunistic infections .
What is the viral load set point ?
This is the minimum number of HIV particles you can have without immune system detecting it but the virus is still detecting
-Clinical latency -no obvious symptoms
Why is the state of immunodeficiency advantageous to viruses?
Viruses must evade immune response.
Some immune responses are mediated by specific cells of the immune system
These cells will recognise and kills infected cells.
To avoid this , some viruses will replicate within immune cells
This allows viruses to ‘hide; and inhibits immune cell function
Therefore this allows other pathogen to replicate in virus infected hosts and disease will occur .
What are the ways in which HIV can kill T cells?
Directly or Indirectly
Directly is through the infection of T -cells-but there are only 5% of permissive T cells.
Non-permissive cells allow the virus to enter however there is activation of innate antiviral inflammatory response.
Outline T cell killing
SLIDE
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
Major cause of fatal disease is viral
What are the possible methods of infection in HIV patients ?
Primary infection
Reactivation from latency
Primary infection can be resolved and infection moves to sites in the host in which immune system cannot access- Latency
Reactivation from latency = immunodeficiency
What is the typical life cycle of a herpes cell?
SLIDE
What are some of the viruses which can lead to cancer ?
SLIDE
