London: A new vaginal microbicide gel could be highly effective in blocking infection by the AIDS virus, a new study has claimed.
Researchers led by Dereuddre-Bosquet from the European Combined Highly Active Anti-Retroviral Microbicides (CHAARM) Consortium describe the gel's key ingredient, which are small peptides engineered to present a decoy to bind up the virus and prevent it from entering and infecting the body cells.
Because this is a gel it can be topically applied and could represent a powerful preventative agent against sexual transmission of HIV.
The scientific community, worldwide, is working on the development of a vaccine against HIV. To date, few treatments that block virus entry have shown promising protection.
Research is also focused on the reduction of the spread of the virus by the application of a microbicide gel to protect users during intercourse which is a time of first exposure to virus.
Bosquet and colleagues engineered peptides named "miniCD4s" because they mimic the CD4 receptor used by HIV to gain entry into immune cells of the body.
The study shows that the miniCD4s blocks HIV entry into isolated cells in a dish and tissue models that mimic mucous membranes which are points of virus entry.
The authors then formulated miniCD4s at 0.3 per cent in a microbicide gel that was vaginally applied to six female cynomolgus macaques monkeys for one hour before the animals were given a high dose of the virus also in the vagina.
This dose would ordinarily make the animals prone to infection but instead, five of the six were completely protected from HIV infection. No trace of virus was found in any body tissue.
They were also unable to detect any antibodies to the virus in the plasma of the animals, indicating that the virus was completely repelled and there was full protection.
This study provides a proof of principle that for a promising strategy for the prevention and protection against HIV transmission during sexual intercourse.
Importantly, the protection was demonstrated in a non human primate model which represents an essential step prior needed to progress to a prospective clinical trial.
The study was published in the journal PLOS Pathogens.