Scientists investigate genetics of HIV-1 resistance

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.'

Related Stories

The genetics of HIV-1 resistance

date Oct 02, 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 the ge ...

Herpes drug inhibits HIV replication, but with a price

date Nov 06, 2008

The anti-herpes drug acyclovir can also directly slow down HIV infection by targeting the reverse transcriptase (RT) enzyme, researchers report in this week's JBC. This beneficial effect does pose a risk though, as HIV-in ...

Mutation breaks HIV's resistance to drugs

date Sep 13, 2012

The human immunodeficiency virus (HIV) can contain dozens of different mutations, called polymorphisms. In a recent study an international team of researchers, including MU scientists, found that one of those mutations, called ...

Recommended for you

Indiana HIV outbreak, hepatitis C epidemic sparks US alert

date 20 hours ago

Federal health officials helping to contain an HIV outbreak in Indiana state issued an alert to health departments across the U.S. on Friday, urging them to take steps to identify and track HIV and hepatitis C cases in an ...

Why are HIV survival rates lower in the Deep South than the rest of the US?

date Apr 22, 2015

The Deep South region has become the epicenter of the US HIV epidemic. Despite having only 28% of the total US population, nine states in the Deep South account for nearly 40% of national HIV diagnoses. This region has the highest HIV diagnosis rates and the highest number of people living with HIV of any ...

A bad buzz: Men with HIV need fewer drinks to feel effects

date Apr 20, 2015

Researchers at Yale and the VA Pittsburgh Healthcare System compared the number of drinks that men with HIV infection, versus those without it, needed to get a buzz. They found that HIV-infected men were more sensitive to ...

Research informs HIV treatment policy for inmates

date Apr 16, 2015

A national, five-year study of care for inmates with HIV brought strangers together, produced policy change in the Delaware Department of Corrections and documented the importance of good communication and ...

User 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.