http://www.sciencecodex.com/drugs_fail_to_reawaken_dormant_hiv_infection-130239

Drugs fail to reawaken dormant HIV infection
March 23, 2014 - 6:30pm

Scientists at Johns Hopkins report that compounds they hoped would "wake up" dormant reservoirs of HIV inside immune system T cells — a strategy designed to reverse latency and make the cells vulnerable to destruction — have failed to do so in laboratory tests of such white blood cells taken directly from patients infected with HIV. "Despite our high hopes, none of the compounds we tested in HIV-infected cells taken directly from patients activated the latent virus," says Robert F. Siliciano, M.D., Ph.D., a professor of medicine at the Johns Hopkins University School of Medicine and a Howard Hughes Medical Institute investigator. Siliciano is senior author of a report on the disappointing results published online March 23 in Nature Medicine. The failure challenges the idea that a single so-called latency-reversing agent can uncover the HIV hiding out in the cells of patients whose viral load is essentially undetectable with blood tests. [...]

VIH : En France, une découverte sur 4 reste tardive

"Chaque année en France, plus de 6.000 personnes découvrent leur séroposivité. Ce bilan, proposé par l’Institut de veille sanitaire dans son bulletin hebdomadaire (BEH) révèle, qu’en 2012, 27% des découvertes restent tardives, c’est-à-dire avec une charge virale très élevée, chez des patients déjà à stade avancé dans la maladie et très en deçà de la de la barre des 500 CD4/mm3. Un résultat préoccupant qui contribue à expliquer que le nombre de cas de sida chez des personnes ignorant leur séropositivité avant le sida ne diminue plus depuis de nombreuses années."

http://www.santelog.com/news/VIH-sida-VHC/vih...relasuite.htm#lirelasuite

Rilpivirine combination product in pretreated HIV-1 patients: Added benefit not proven

"A Rilpivirine combination product in HIV-1 patients with previous antiretroviral treatment was not shown to demonstrate any added benefit in a recent study. The only study cited in the dossier was too short for the assessment of an added benefit, and the appropriate comparator therapy was not implemented."

http://www.sciencedaily.com/releases/2014/04/...ily%3A+Top+Health+News%29

Double whammy of multiple sex partners, drinking in HIV/STI prevention

"The more you drink and sleep around, the less likely you are to participate in HIV intervention counseling, research shows. Understanding why someone does -- or does not -- enroll in a prevention program is a significant piece of information for public health departments. Yet relatively little is known about what motivates individuals to participate in HIV-prevention programs or whether some audiences are more or less willing to take advantage of the HIV-prevention counseling programs commonly provided at health clinics."

http://www.sciencedaily.com/releases/2014/04/...ily%3A+Top+Health+News%29

http://www.sciencedaily.com/releases/2014/04/140424124702.htm

A team led by scientists at The Scripps Research Institute (TSRI) working with the International AIDS Vaccine Initiative (IAVI) has discovered a new vulnerable site on the HIV virus. The newly identified site can be attacked by human antibodies in a way that neutralizes the infectivity of a wide variety of HIV strains. [...] HIV generally conceals these vulnerable conserved sites under a dense layer of difficult-to-grasp sugars and fast-mutating parts of the virus surface. Much of the antibody response to infection is directed against the fast-mutating parts and thus is only transiently effective. Prior to the new findings, scientists had been able to identify only a few different sets of "broadly neutralizing" antibodies, capable of reaching four conserved vulnerable sites on the virus. All these sites are on HIV's only exposed surface antigen, the flower-like envelope (Env) protein (gp140) that sprouts from the viral membrane and is designed to grab and penetrate host cells. [...] The scientists determined that the two broadest neutralizers among these antibodies, PGT151 and PGT152, could block the infectivity of about two-thirds of a large panel of HIV strains found in patients worldwide.

Curiously, despite their broad neutralizing ability, these antibodies did not bind to any previously described vulnerable sites, or epitopes, on Env -- and indeed failed to bind tightly anywhere on purified copies of gp120 or gp41, the two protein subunits of Env. Most previously described broadly neutralizing HIV antibodies bind to one or the other Env subunit. The researchers eventually determined, however, that PGT151 and PGT152 attach not just to gp120 or gp41 but to bits of both. In fact, gp120 and gp41 assemble into an Env structure not as one gp120-gp41 combination but as three intertwined ones -- a trimer, in biologists' parlance. PGT151 and 152 (which are nearly identical) turned out to have a binding site that occurs only on this mature and properly assembled Env trimer structure. "These are the first HIV neutralizing antibodies we've found that unequivocally distinguish mature Env trimer from all other forms of Env," said Falkowska. "That's important because this is the form of Env that the virus uses to infect cells." [...] Although the PGT151 site is valuable in itself as an attack point for an HIV vaccine, its discovery also hints at the existence of other similar complex and vulnerable epitopes on HIV.