A “promising cure” for HIV and Aids has recently been discovered, according to the scientists who led a study which managed to almost entirely eradicate the destructive immune disease from infected mice.
The researchers asserted that they had displayed the “feasibility and efficiency” of removing the HIV-1 provirus through the use of a gene-editing technique called Crispr.
The scientists conceded that there were still some practical issues that must be overcome, but they maintained that their work was a “significant step” in the direction of carrying out clinical trials of the technique on humans.
Writing in the journal Molecular Therapy, the scientists detailed how some of the mice had been “humanized” after being given some human immune cells in preparation for the study.
In these animals, “successful proviral excision was detected … in the spleen, lungs, heart, colon, and brain after a single intravenous injection” of the gene-editing protein involved.
Alleged innovations in animal models typically come across problems later in the process of developing a treatment that can be used for humans.
Regardless of such a pattern, the researchers, which are from Temple University and Pittsburgh University, confidently stated in their study in the journal that this type of genome editing “provides a promising cure for HIV-1/Aids.”
“Here, we demonstrate the feasibility and efficiency of excising the HIV-1 provirus in three different animal models,” the researchers declared.
“Excision of HIV-1 proviral DNA by [this method in a living animal] in solid tissues/organs can be achieved … [which is] a significant step toward human clinical trials.
“To our knowledge, this study is the first to demonstrate the effective excision of HIV-1 proviral DNA from the host genome in pre-clinical animal models [using this method],” they concluded.
However, they added that “gene delivery efficiency … remains an obstacle to overcome” in a living animal.
The researchers informed the Daily Mail that the subsequent step would be to replicate the study using primates, who are designated as a “more suitable animal model where HIV infection induces disease” prior to the “eventual goal” of human clinical trials.
Dr. Wenhui Hu, a researcher from Temple University, revealed to the Mail that the recent study built upon earlier research but was simply “more comprehensive.”
“We confirmed the data from our previous work and have improved the efficiency of our gene-editing strategy,” Dr. Hu said. “We also show that the strategy is effective in two additional mouse models, one representing acute infection in mouse cells and the other representing chronic, or latent, infection in human cells.”
Professor Jonathan Ball, who is an expert in molecular virology at Nottingham University, explained to The Independent that gene editing was viewed as a possible method to successfully cure people of the disease.
As of now, the medical field has drugs that can impede HIV from replicating inside the body and producing Aids, but a dormant reservoir of the virus stays within the patient’s body.
This indicates that if the patient ceases to take the drugs for whatever reason, it is highly probable that they will then get the full-blown disease.
Professor Ball argued that the new study indicated which technique “can effectively deliver the Crispr/Cas gene-editing machinery in order to target/excise HIV sequences.”
“They claim that by combining a number of the tools necessary for gene editing in a single delivery vector they have increased the efficiency of gene targeting,” he added.
“This undoubtedly shows promise but some big questions remain – how much of the latent reservoir do you need to target and will it work in humans?”
It is plausible that decreasing the dormant HIV to a low enough level would potentially be considered an effective cure as some HIV would remain, but that remainder would not enough to cause Aids.
However, according to Professor Ball, it could additionally be that HIV would need to be wholly eradicated from the body to prevent it from “bouncing back” following the end of the treatment.
“I’m pretty sure that these targeting approaches will be able to deplete at least some of the HIV reservoir, but at the moment I think most researchers in the field worry that it might not be enough to bring about cure,” he continued.
Dr. Nicola Patron, synthetic biology group leader at the Earlham Institute, stated that: “Retroviruses like HIV integrate a proviral DNA into the genome of the host cells during infection to enable replication.
“Although drugs currently used to treat HIV can suppress replication, they cannot remove the proviral DNA from the infected cell’s genome.
“This work uses CRISPR/Cas9 genome editing technology to excise proviral DNA from infected human cells embedded in the tissues of experimental animals.
“If similar techniques can be made to work in primates and humans, it could potentially lead to a permanent cure.”
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