AIDS virus shown different in semen versus blood

August 19, 2010

The virus that causes AIDS may undergo changes in the genital tract rendering HIV-1 in semen different than HIV-1 in the blood, according to researchers from the University of North Carolina at Chapel Hill, the Edward Jenner Institute for Vaccine Research (United Kingdom), and the Baylor Pediatric Center of Excellence (Malawi). The research, published August 19 in the open-access journal PLoS Pathogens, advances our understanding of HIV-1 replication in the male genital tract.

Worldwide, much of the transmission of HIV-1 is through sexual contact, men being the transmitting partner in a majority of cases. The nature of the virus in the male genital tract is of central importance to understanding the transmission process and the selective pressures that may impact the transmitted virus. Ultimately, a vaccine or microbicide must block the transmitted virus.

The researchers examined the gene encoding the major surface protein of HIV-1 (the Env protein) in the viral populations in paired blood plasma and semen samples to determine any differences in the virus at the site of transmission, i.e., semen.

"In some men, the virus population in semen was similar to that in the blood, suggesting that virus was being imported from the blood into the genital tract and not being generated locally in the genital tract," said author Ronald Swanstrom, PhD. "However, we found two mechanisms that significantly altered the virus population in the semen, showing that virus can grow in the seminal tract in two different ways."

In one way, one or more viruses grow rapidly in the seminal tract over a short period such that the viral population in semen is relatively homogeneous (compared to the complex population in the blood). In the other way, the virus replicates in T cells in the seminal tract over a long period, creating a separate population of virus in semen that is both complex and distinct from the virus in the blood.

"While it remains unknown how these differences change the biology of the virus or if these changes are important for the transmission process, it is clear that the virus in the blood does not always represent the virus at the site of transmission," said author Dr. Jeffrey Anderson.

"Making molecular clones of these compartmentalized viral env genes is an important next step that will allow us to study these differences," said author Dr. Li-Hua Ping.
-end-
Volunteers participating in this study were attending the Kamuzu Central Hospital and the UNC Project in Lilongwe, Malawi.

FINANCIAL DISCLOSURE: This work was supported by the Center for HIV/AIDS Vaccine Immunology (NIH award U01 AI067854) and by an NIH award to MSC (R37 DK049381). We also acknowledge the efforts of the UNC CFAR Virology Core (NIH award P30 AI50410). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

COMPETING INTERESTS: The authors have declared that no competing interests exist.

PLEASE ADD THIS LINK TO THE PUBLISHED ARTICLE IN ONLINE VERSIONS OF YOUR REPORT: http://dx.plos.org/10.1371/journal.ppat.1001053 (link will go live upon embargo lift)

CITATION: Anderson JA, Ping L-H, Dibben O, Jabara CB, Arney L, et al. (2010) HIV-1 Populations in Semen Arise through Multiple Mechanisms. PLoS Pathog 6(8): e1001053. doi:10.1371/journal.ppat.1001053

PRESS-ONLY PDF: http://www.plos.org/press/plpa-06-08-19-swanstrom.pdf

CONTACT:

Dr. Ronald Swanstrom
University of North Carolina at Chapel Hill
risunc@med.unc.edu

PLOS

Related Aids Articles from Brightsurf:

Developing a new vaccination strategy against AIDS
Infection researchers from the German Primate Center (DPZ) -- Leibniz Institute for Primate Research have in cooperation with international colleagues tested a new vaccination strategy against the HIV-related simian immunodeficiency virus (SIV) in rhesus monkeys.

HIV-AIDS: Following your gut
Researchers find a way to reduce replication of the AIDS virus in the gastrointestinal tract.

A path toward ending AIDS in the US by 2025
Using prevention surveillance data to model rates of HIV incidence, prevalence and mortality, investigators at Brigham and Women's Hospital and Johns Hopkins Bloomberg School of Public Health set targets, specifically a decrease in new infections to 21,000 by 2020 and to 12,000 by 2025, that would mark a transition toward ending the HIV/AIDS epidemic.

What does it take for an AIDS virus to infect a person?
Researchers examined the characteristics of HIV-1 strains that were successful in traversing the genital mucosa that forms a boundary to entry by viruses and bacteria.

How AIDS conquered North America
A new technique that allowed researchers to analyze genetic material from serum samples of HIV patients taken before AIDS was known provides a glimpse of unprecedented detail into the beginnings of the AIDS epidemic in North America.

New research could help build better hearing aids
Scientists at Binghamton University, State University of New York want to improve sensor technology critical to billions of devices made every year.

NY State Department of Health AIDS Institute funds HIV/AIDS prevention in high-risk youth
NewYork-Presbyterian's Comprehensive Health Program and Project STAY, an initiative of the Harlem Heath Promotion Center (HHPC) at Columbia University's Mailman School of Public Health has received two grants totaling more than $3.75 million from the New York State Department of Health AIDS Institute for their continued efforts to prevent HIV/AIDS in at-risk youth.

A new way to nip AIDS in the bud
When new HIV particles bud from an infected cell, the enzyme protease activates to help the viruses infect more cells.

AIDS research prize for Warwick academic
A researcher at the University of Warwick has received international recognition for his contribution to AIDS research.

Insects inspire next generation of hearing aids
An insect-inspired microphone that can tackle the problem of locating sounds and eliminate background noise is set to revolutionize modern-day hearing aid systems.

Read More: Aids News and Aids Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.