Hosts: Vincent Racaniello, Alan Dove, and Kathy Spindler
Vincent, Alan, and Kathy discuss finding viruses in outer space, varying results obtained from personal genetic testing, and depletion of CD4 cells during HIV infection by pyroptosis.
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Download TWiV 266 (70 MB .mp3, 97 min)
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Links for this episode
- We should hunt for viruses in space (New Scientist)
- I had my DNA picture taken (NY Times)
- CD4 cell death by pyroptosis (Nature)
- Abortive HIV infection in lymphoid tissue (Cell)
- IFI16 sensor required for HIV mediated cell death (Science)
- PubMed Commons
- Preferential CTL targeting of Gag (Cell Rep)
- Exonic transcription protein binding (Science)
- Letters read on TWiV 266
- Video of this episode – view above or at YouTube
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Send your virology questions and comments (email or mp3 file) to twiv@microbe.tv
Guys don’t you think that it is little bit weird that a guy who lives 30 years with HIV and is still alive, and he is the example how HIV kills CD4 in vivo?
Most of the data in the paper were done with normal lymphoid tissue explants. The experiments with the elite controller were confirmatory but did not establish the concept. I don’t think it’s weird at all – most people with AIDS would be treated and hence not suitable for this study.
Why would you use an example that contradicts your data.The elite controllers are small percentage among people who have HIV .
They present this process of cell death as fast end efficient and then they show a guy who presumably dealt with that for 30 years? For me it means that you can have low number of CD4 and live normally without taking any drugs.
I do understand your concern. I’m going to bring this up on TWiV this Friday and see what the others think. It is strange to demonstrate pyroptosis in an individual who is free from disease!
He is not free from disease! He has very low CD4 T-cell count (156 cells / ul) and high viral load (85,756 copies/ml at the time of lymph node resection. He decided not to take ART since he was diagnosed.
Interesting. Many elite controllers have normal CD4 T cell counts. The viral load would make him *not* an elite controller.
One cannot hunt for viruses anywhere if we haven’t yet found a host for the viruses to infect in the first place.
If one found a virus somewhere it would be an evidence that more complex form of life must exist there.(or possibly it could be a contaminant from Earth)
Also, it would have to be a complete virus, otherwise just because you found a protein or other biomolecule it may not be possible to assign it to a virus or bacteria. Also, in the case that we did find something that resembles something here on earth we could not be sure of it’s function because it is under different conditions. For example if we found there something that looks like a capsid here on earth, on other planet it may be used as a receptor, since that planet’s conditions may allow it to behave that way.
Our view is restricted (no doubts), but we can presume that some principles of life on Earth can be similar to those on the planets with similar permissible conditions, so finding a partial viral genome sequence may give us possibility to say that life exists there and resembles life on earth. Of course, we should search only on the certain planets. I think it is quite hard or impossible to predict principles of life, others than on Earth, to seek for on the other planets, therefore hunting for viruses in space is much easier.