scientific questions, from a prospective microbiologist
Mar 20, 2007
Hey Dr. BOB, I have 2 questions, that have been bugging me. 1.Since we know that the black plague offered a resistence to HIV due to a genetic mutation. Are scientists out there using this information on genetic mutation of cells to develope a Therapeutic vacine to prevent more t cell loss, and a preventative vaccine to prevent HIV infection totally? 2. Would this type vaccine work if a cellular genetic mutation could be provoked by this possible vaccine?
Thanks Dr. BOB, all my best wishes. Tim
Response from Dr. Frascino
Hi Future Microbiologist,
Vaccines don't induce genetic mutations. They elicit immune responses.
To answer your question about genetic factors involved in host immune defenses to HIV, yes, studies are indeed underway.
One such study is the "Elite Controller Study," which is a collaborative effort to understand the factors associated with HIV-positive long-term non-progressors. "Elite Controllers" are defined as HIV-positive individuals who are able to maintain plasma HIV RNA levels below 50 copies/mL (undetectable). The researchers are assessing multiple viral and host characteristics, including genetic variations, such as the CCR5 delta 32 mutation. (See below for additional information about this mutation and its relationship to the black plague and smallpox.) The study is being conducted by immunologist Bruce Walker, M.D. in Boston and includes participating sites in Chicago, Durham, Los Angeles, Nashville, New York, San Diego, San Francisco, Seattle and several cities in Canada, Europe and Australia.
delta 32 Mar 17, 2007
Dr. Bob ...
I think I may have heard everything now! So, I'm on Craigslist just 'poking' around and I see this guy who wants to have sex - but, he only does it bb. Now, here is where it gets wacky! He's HIV Negative and says, "I just got tested in January, but, I just do that so guys will know the right answer. I don't worry about HIV ... I'm delta 32."
What does that mean? I went to a link, that he provided, and it talked about smallpox, and the plague.
What gives? Is this guy a bit crazy or is he really "safe?"
Can you shed some light, my friend?? :)
Thanks!! Oh and P.S., I thought I found Prince Charming ... But, it wasn't him! I'm still looking! You have any cute friends in Orange County?
Response from Dr. Frascino
So you were poking around Craigslist looking for some poking?
Delta 32 is a bit complex to explain, but I'll give it a shot. First, some background. HIV can only infect certain cells that have specific "receptors" on their surface that allow HIV to enter. HIV attaches to CD4 receptors. However, CD4 alone isn't enough for viral entry. Another protein called CCR5 is also needed. CCR5 is called a co-receptor. Some folks have a mutation in the CCR5 gene called CCR5-delta 32 mutation. This mutation changes the configuration of the CCR5 protein such that HIV cannot bind to it. Genes, of course, are inherited. If you inherit a CCR5-delta 32 gene mutation from both parents, your chances of becoming HIV infected are dramatically reduced. This occurs in about 1-3% of Caucasians. If you inherit one CCR5-delta 32 mutation (from just one parent), it will confer some protection against acquiring HIV and may make HIV disease less severe if you do become infected. Current estimates are that 10-25% of Caucasians may have a single CCR5-delta 32 mutation.
So should Craigslist Delta-32 Boy "not worry" about HIV? Absofrickinlutely NOT! It is downright dangerous to assume you are safe if you have the CCR5-delta 32 mutation. It is not a guarantee of HIV immunity. HIV is much too smart for that. Some strains of HIV use proteins other than CCR5 as co-receptors to enter CD4 cells.
As for the bubonic plague (Black Death) and smallpox link, it appears that the CCR5-delta 32 mutation may have arisen to protect folks in Europe from these illnesses. The mutation affords protection from these ailments and could have arisen via an evolutionary process. (Yes, right-wing religious wing-nuts, evolution does indeed exist!)
So if you happen to hook up with Delta-32 Boy, you might want to give him a science lesson along with his poke.
Finally, hotties in Orange County? Sure, I know some Prince Charmings in that zip code, but unfortunately none are currently single. So I guess you'll just have to continue kissing those toads until your prince arrives.
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