It could function as a vaccine but also as a treatment; powerful at all phases of the disease, and even possibly, a remedy for it. The promise is that of an HIV meta-drug.
By ‘hacking’ the incredibly powerful and well-attuned immune responses offered by bacteria against a viral infection, it may be possible to wield something similar to ‘cellular scissors’ against HIV. This is what researchers at the Salk Institute are currently chasing. After three decades in the HIV/AIDS research trenches, it sounds like a cruel tease.
The approach depends on a bacterial defense mechanism. The Salk group, led by biochemist Hsinkai (Ken) Liao, describes their most recent efforts:
‘Clustered Regularly Interspaced Short Palindromic Repeats’ (or CRISPR) does its work by functioning as a sort of genetic editor–or a pair of ‘mobile scissors’–with the ability of snipping the viral genome in just the proper places to allow it to become benign.
Here, the reverse-transcribed products of viral RNA are targeted and disrupted directly, and throughout their life cycle, within host cells. The group has, to date, screened several possible target sites for their effectiveness in offering long-term and lasting protection against the disease. Using gene-editing is an option that is being actively explored and looking promising, with several recent studies finding some success.
Once integrated, the virus blends in and becomes part of a ‘latent infection,’ foiling any additional possible immune response just by being extremely great at hiding out and by being patient. The effect is ‘editing out’ HIV from the human genome; the particular kind of virus being targeted here, the ‘lentivirus,’ is among the most challenging that individuals face.
We can beat down the active virus well enough via highly-active anti-retroviral therapy; an ability in existence since the mid-90’s that’s effectively turned HIV from an immanently deadly disease into a chronic, manageable disease, but we can’t get rid of it. If the virus is latent, it’s invisible to the immune system and, likewise, to treatments. This latency, where the virus simply hangs out in an immune cell disguise, is part of the entire issue of curing and treating HIV.
“Patients usually want drugs every day or every week for their whole lives, because of the HIV that might be latent,” Liao noted, in a Salk Institute statement. This really is why HIV treatment requires daily care that is demanding; left to its own devices, the virus will eventually start replicating, assaulting and beating down the immune system until the HIV disease becomes AIDS, which is where lives begin to get lost. Thus, managing the illness means constantly and actively forcing it into latency, if not into submission. This of course takes time, a lot of effort and costs money.
A lentivirus, fairly unexpectedly is just an ordinary, exposed virus. Liao and his team had the ability to hack this portion of the CRISPR system, redirecting those cuts to be most effective against HIV, thereby deactivating the virus as it lies in wait. This is done using what is called ‘guide RNAs,’ which are merely instructions for where those reductions should go to be the most effective. With CRISPR, bacteria have the ability to order the required molecular slices and wounds to neutralize lentiviruses at their ‘base-level’ state, that is dormant. In the efforts of ‘editing out’ HIV from the human genome, bacteria appears to be the way forward, nevertheless.
“We reduce the odds the virus can develop resistance if we target multiple areas at the exact same time. The HIV virus can mutate very rapidly,” says Liao. This allows the virus to evade ‘shields,’ outrunning them, in a sense. Its own adaptability also characterizes HIV. None of this is that simple, needless to say, and this aspect remains an open question.
SOURCE:
“Bacteria Are Already Making the Best HIV Treatment in Nature.” Motherboard. N.p., n.d. Web. 13 Mar. 2015. http://motherboard.vice.com/read/bacteria-are-already-making-the-best-hiv-treatment-in-nature
