This Week in HIV Research: Viral Suppression Without Treatment in Monkeys
This week, a study review finds that early interventions in monkeys, such as administering broadly neutralizing antibodies, can help lead to viral suppression without treatment. Meanwhile, Swaziland reports major progress in reaching 90-90-90 goals after reducing new infections by half and doubling the rate of viral suppression. And digoxin, a heart medication, may impede the expression of certain HIV genes, providing more clues and insight into how HIV attacks the immune system. To beat HIV, you have to follow the science!
In Monkeys, Early Interventions Lead to HIV Suppression Without Treatment
Studies in non-human primates (NHP) have shown that HIV-specific CD8 immune responses can be triggered to control the simian version of HIV with little or no antiretroviral therapy, a review published in AIDS said.
One study that was reviewed administered broadly neutralizing antibodies (bNAbs) during very early HIV infection. The control group was treated with early antiretrovirals. While the virus rebounded in both study arms, CD4 counts remained high in the bNAb group and those animals were able to re-suppress HIV without further treatment.
In another animal study that was reviewed, a therapeutic vaccine was administered after antiretroviral therapy had suppressed viral loads. A third of the NHPs continued to control HIV without further treatment.
"Whether the same effects can be achieved in humans remain[s] to been seen but these exciting findings raise the possibility that early immunological interventions aimed at boosting and/or maintaining the initial HIV-1-specific immunity with or without latency reversal could lead to durable control of the infection," the authors concluded.
Swaziland Making Great Strides Against HIV
In Swaziland, cases of new transmissions dropped by almost half since 2011, Velephi Okello, M.B.B.S., M.P.H. , reported at the 2017 IAS Conference on HIV Science. The number of people whose viral load was undetectable doubled during the same period in Swaziland, a small country that borders Mozambique and South Africa.
The data come from a population-based HIV impact assessment conducted for the second time in Swaziland and were published in a related press release. The first such survey was held in 2011.
In 2016, more than a quarter of the population (27%) lived with HIV, and almost a third (32.5%) of women had seroconverted. More women were virally suppressed (76%) than men (67.6%). The country is getting close to the UNAIDS "90-90-90" targets, which specify that 90% of people living with HIV are aware of their status, 90% of those who know that they live with HIV are on antiretroviral treatment, and 90% of those on treatment have undetectable viral loads.
In Swaziland, the corresponding figures are 84-87-91, leaving room for more progress. "We understand that the battle is not over, and therefore we must maintain the momentum," concluded Senator Sibongile Ndlela-Simelane, the country's minister of health, according to the press release.
Heart Drug Digoxin Inhibits T-Cell Activation in Vitro
Digoxin, a drug used to treat some heart conditions, impedes the expression of certain HIV genes and the activation and metabolism of CD4 cells, a study published in PLOS Pathogens showed.
This insight helps to explain why HIV preferentially targets human genes that have already gone through the initial stage of gene expression, a related press release noted.
Researchers compared the behavior of a "wild type" of HIV to a mutant strain when both were exposed to various chemicals. Wild type HIV is more likely to insert its DNA near genes that affect CD4 T-cell activation than is mutant virus. Digoxin attacks precisely these genes.
As a result, wild type HIV can be stopped by the drug more easily than can mutant virus. The functional connection between the integration of HIV into a cell and activation of T cells that was discovered may be important for understanding how the latent HIV reservoir is formed and how the virus is reactivated from there, study authors concluded.