Scientists investigate genetics of HIV-1 resistance

October 26, 2012
Scientists investigate genetics of HIV-1 resistance
Credit: Shutterstock

Investigating the genetic footprint that drug resistance causes in HIV, researchers in Europe have discovered that compensatory polymorphisms enable resistant viruses to survive. Presented in the journal Retrovirology, the study was supported in part by three EU-funded projects: VIROLAB, EURESIST and CHAIN.

Both the VIROLAB ('A for decision support in treatment') and EURESIST ('Integration of viral genomics with clinical data to predict response to anti-') projects were funded under the 'Information society technologies' (IST) Thematic area of the EU's Sixth Framework Programme (FP6) to the tune of EUR 3.3 million and EUR 2.1 million, respectively. CHAIN ('Collaborative HIV and anti- network') has received almost EUR 10 million under the Health Theme of the EU's Seventh Framework Programme (FP7).

Preventing viral replication is the current mode of HIV-1 infection treatment. Researchers measure the number of viral particles in the blood and analyse the cluster of differentiation 4 (CD4) count to repair the immune system. Since the early 1990s, the research world has seen a marked improvement in the treatment and life expectancy of HIV patients. But drug resistance has forced researchers and physicians to come up with an array of drugs to obtain complete .

According to the researchers, virus drug resistance comes at a cost. The virus carrying is less 'fit' than the wild-type virus when the drug is not present. Because of this, replication should be no simple task. During interruptions to treatment, wild-type viruses quickly predominate. But newly infected people can be drug resistant even before treatment begins for them.

The SPREAD project researchers monitored HIV infections across Europe, assessing 1 600 individuals who were newly infected with HIV-1 subtype B. They found that HIV-1 harboured transmitted (TDR) in 10 % of the subjects. The team measured virus production and CD4 count, observing there was no indication that these strains of HIV-1 were weaker.

Recent studies have put the spotlight on polymorphisms, naturally occurring differences in the genes that lead to differences between animals of the same species, including blood groups. They may also increase propensity for certain diseases like cancer and type 2 diabetes. However, viruses also harbour polymorphisms.

In this study, the team discovered that polymorphisms in these strains of HIV-1, specific polymorphisms in the gene coding for protease, which is needed for viral replication, and known to act as compensatory mechanisms, make resistant strains 'fitter', even in the absence of the drug. 'Our worry is that over time we will be seeing more people presenting with TDR HIV-1,' said lead author Kristof Theys of the University of Leuven in Belgium.

Senior author Professor Anne-Mieke Vandamme, also from the University of Leuven, said: 'Contrary to what was expected, transmission of TDR virus may also contribute to a "fitter" and more virulent HIV, which has important clinical implications in how we best treat these people.'

Explore further: Drug designer: New tool reveals mutations that cause HIV-drug resistance

Related Stories

The genetics of HIV-1 resistance

October 2, 2012

Drug resistance is a major problem when treating infections. This problem is multiplied when the infection, like HIV-1, is chronic. New research published in BioMed Central's open access journal Retrovirology has examined ...

Recommended for you

Targeting HIV in semen to shut down AIDS

August 18, 2015

There may be two new ways to fight AIDS—using a heat shock protein or a small molecule - to attack fibrils in semen associated with the human immunodeficiency virus (HIV) during the initial phases of infection, according ...

Vitamin D status related to immune response to HIV-1

June 15, 2015

Vitamin D plays an important part in the human immune response and deficiency can leave individuals less able to fight infections like HIV-1. Now an international team of researchers has found that high-dose vitamin D supplementation ...

HVTN 505 vaccine induced antibodies nonspecific for HIV

July 30, 2015

A study by researchers at the National Institute of Allergy and Infectious Diseases and Duke University helps explain why the candidate vaccine used in the HVTN 505 clinical trial was not protective against HIV infection ...

Why HIV's cloak has a long tail

June 2, 2015

Virologists at Emory University School of Medicine, Yerkes National Primate Research Center, and Children's Healthcare of Atlanta have uncovered a critical detail explaining how HIV assembles its infectious yet stealthy clothing.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.