Posts

Novel immune-suppressant vaccine

A novel and relatively simple vaccine that can be administered orally has managed to completely block rectal infection with SIV, the monkey equivalent of HIV, in rhesus macaques and produced rapid re-suppression of viral load in monkeys who were previously infected with SIV.

The vaccine, whose success at blocking infection was described by its own designers as ‘surprising’ and ‘unexpected’, appears to work by stimulating the production of a previously unknown group of CD8 T-cells that stopped the monkeys’ CD4 cells from recognising SIV as a foreign invader, thereby preventing an immune response to SIV. This suppressant effect – which works in the opposite way to a traditional vaccine – means that the SIV is deprived of the SIV-specific immune-activated CD4 cells it needs in order to proliferate and establish an infection in the body.

The vaccine consisted of inactivated SIV administered alongside doses of familiar bacteria – in the first case the TB-suppressant bacterium BCG, and subsequently with gut bacteria of the Lactobacillus genus, including one type commonly used in probiotic supplements. This suggests that if human studies replicate the success seen in monkeys (by no means assured in vaccine studies) the vaccine could be administered in a drink.

Two initial safety trials are now planned in humans. In one, HIV-negative volunteers at low risk of HIV will be given the vaccine to see if it stimulates the same immune- and virus-suppressant responses. In the other, HIV-positive volunteers on fully-suppressive antiviral therapy will be given the vaccine and then taken off ART six months later if test tube results suggest the vaccine has produced such responses.

First published – Aug 26 2014 – AIDS Map

Breaking : HIV Kick Out From Infected Cells

The technique addresses the problem of hidden reservoirs of HIV in the body, and could herald a new way of battling the viral infection

Once HIV invades the body, it doesn’t want to leave. Every strategy that scientists have developed or are developing so far to fight the virus – from powerful anti-HIV drugs to promising vaccines that target it – suffers from the same weakness. None can ferret out every last virus in the body, and HIV has a tendency to hide out, remaining inert for years, until it flares up again to cause disease.

None, that is, until now. Kamel Khalili, director of the Comprehensive NeuroAIDS Center at Temple University School of Medicine, and his colleagues took advantage of a new gene editing technique to splice the virus out of the cells they infected – essentially returning them to their pre-infection state. The strategy relies on detecting and binding HIV-related genetic material, and therefore represents the first anti-HIV platform that could find even the dormant virus sequestered in immune cells.

Read on…


 

First Published on Time.com – July 21 2014

Portfolio Items