News Release

STDs disrupt genetic bottleneck that usually constrains HIV infection

Peer-Reviewed Publication

PLOS

Scientists have shown that HIV faces a genetic "bottleneck" when the virus is transmitted heterosexually from one person to another, by way of the genital mucosa. The results, published January 23 in the open-access journal PLoS Pathogens, explain why prior infection by other sexually-transmitted diseases (STDs) makes individuals more susceptible to HIV infection.

The team of researchers, lead by Eric Hunter of Emory University, identified 20 heterosexual couples soon after infection occurred and obtained viral genetic sequences from both partners. They examined the most variable region of the virus' env gene, which encodes a protein forming the outer coat of the virus. Approximately 90% of the couple recipients were found to be infected by a single viral variant of HIV-1. However, that variant was not the same in each case.

For comparison, the researchers also analyzed a group of newly infected individuals who were infected by someone other than their spouse. This group showed more variety in viral sequences, with 3 out of 7 individuals infected by multiple variants. Overall, out of 42 newly infected people studied to date, all five infected by multiple viral variants had evidence of genital inflammation or ulceration.

In these cases, it appears that the bottleneck was enlarged due to the disruption of normally protective mucosal barriers by STDs. These findings suggest that the genital mucosa provides a natural barrier to infection by multiple genetic variants of HIV-1 that can be lowered by inflammatory genital infections.

To identify newly infected individuals, the team collaborated with public health programs directed by Susan Allen of Emory's Rollins School of Public Health that enroll thousands of heterosexual couples with one HIV-positive partner in Rwanda and Zambia.

###

The research was funded by grants from the National Institutes of Health, the Bill & Melinda Gates Foundation Grand Challenges Program and the International AIDS Vaccine Initiative.

PLEASE ADD THIS LINK TO THE PUBLISHED ARTICLE IN ONLINE VERSIONS OF YOUR REPORT: http://dx.plos.org/10.1371/journal.ppat.1000274 (link will go live on Friday, January 23)

CITATION: Haaland RE, Hawkins PA, Salazar-Gonzalez J, Johnson A, Tichacek A, et al. (2009) Inflammatory Genital Infections Mitigate a Severe Genetic Bottleneck in Heterosexual Transmission of Subtype A and C HIV-1. PLoS Pathog 5(1): e1000274. doi:10.1371/journal.ppat.1000274

CONTACT:

Holly Korschun
hkorsch@emory.edu
(404) 727-3990


Disclaimer

This press release refers to an upcoming article in PLoS Pathogens. The release is provided by the article authors and their institutions. Any opinions expressed in these releases or articles are the personal views of the journal staff and/or article contributors, and do not necessarily represent the views or policies of PLoS. PLoS expressly disclaims any and all warranties and liability in connection with the information found in the releases and articles and your use of such information.

About PLoS Pathogens

PLoS Pathogens (www.plospathogens.org) publishes outstanding original articles that significantly advance the understanding of pathogens and how they interact with their host organisms. All works published in PLoS Pathogens are open access. Everything is immediately available subject only to the condition that the original authorship and source are properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.

About the Public Library of Science

The Public Library of Science (PLoS) is a non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource. For more information, visit http://www.plos.org


Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.