Featured Research

from universities, journals, and other organizations

Linking microbial, immune environment in semen to HIV viral load, transmission

Date:
July 24, 2014
Source:
PLOS
Summary:
HIV infection re-shapes the relationship between semen bacteria and immune factors which in turn affects viral load, suggesting that the semen microbiome plays a role in sexual transmission of HIV, researchers report. While HIV is found in many body fluids, sexual transmission through semen is the most common route of infection.

While HIV is found in many body fluids, sexual transmission through semen is the most common route of infection. Consequently, the amount of virus in semen (the semen viral load) affects the likelihood of HIV transmission. Besides sperm, semen also contains immune factors and communities of bacteria, an environment that could influence the viral load. Research published on July 24th in PLOS Pathogens reports that HIV infection re-shapes the relationship between semen bacteria and immune factors which in turn affects viral load, suggesting that the semen microbiome plays a role in sexual transmission of HIV.

Related Articles


Researchers led by Lance Price, from the Translational Genomics Research Institute, USA, and Rupert Kaul, from the University of Toronto, Canada, studied the relationship of semen bacteria with HIV infection by analyzing semen samples from 49 men who have sex with men (MSM). They focused on MSM because of the high risk of sexual HIV transmission in this population. 27 of the men were HIV infected, and provided samples both before they started anti-retroviral therapy (ART) and one and six months after. Samples from 22 MSM not infected with HIV served as controls.

In HIV-infected men not on ART, overall numbers of bacteria in the samples -- the semen bacterial load -- was correlated with HIV viral load. Analyzing the bacterial DNA in the samples, the researchers detected a total of 248 unique types of bacteria in semen from the controls, on average 71 different ones per sample. In samples from HIV-infected untreated men, semen microbiome diversity was markedly reduced, and the relative abundance of the more common bacterial groups differed. ART for six months reduced semen viral load to undetectable levels, and restored bacterial diversity and composition to a situation similar to the controls.

There was no correlation in uninfected controls between levels of immune factors and semen bacterial load. In contrast, in HIV-infected men, several factors, and most strongly one called interleukin-1beta (IL-1b), a mediator of inflammation, showed a correlation with both semen bacterial load and semen viral load.

"While delineating the directionality and causality of the complex relationships they observed will require further studies," the researchers say, their data "suggest an interaction between semen microbiome, local immunology, and semen viral load. Higher bacterial load in semen could lead to higher IL-1b levels, which in turn could induce viral shedding, thereby increasing viral load." They conclude that the results "support the hypothesis that semen bacteria play a role in local inflammation and HIV shedding, and that they are a possible target for reducing HIV transmission."


Story Source:

The above story is based on materials provided by PLOS. Note: Materials may be edited for content and length.


Journal Reference:

  1. Liu CM, Osborne BJW, Hungate BA, Shahabi K, Huibner S, et al. The Semen Microbiome and Its Relationship with Local Immunology and Viral Load in HIV Infection. PLoS Pathog, July 2014 DOI: 10.1371/journal.ppat.1004262

Cite This Page:

PLOS. "Linking microbial, immune environment in semen to HIV viral load, transmission." ScienceDaily. ScienceDaily, 24 July 2014. <www.sciencedaily.com/releases/2014/07/140724144247.htm>.
PLOS. (2014, July 24). Linking microbial, immune environment in semen to HIV viral load, transmission. ScienceDaily. Retrieved February 27, 2015 from www.sciencedaily.com/releases/2014/07/140724144247.htm
PLOS. "Linking microbial, immune environment in semen to HIV viral load, transmission." ScienceDaily. www.sciencedaily.com/releases/2014/07/140724144247.htm (accessed February 27, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, February 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Sleeping Too Much Or Too Little Might Increase Stroke Risk

Sleeping Too Much Or Too Little Might Increase Stroke Risk

Newsy (Feb. 26, 2015) People who sleep more than eight hours per night are 45 percent more likely to have a stroke, according to a University of Cambridge study. Video provided by Newsy
Powered by NewsLook.com
London Show Dissects History of Forensic Science

London Show Dissects History of Forensic Science

AFP (Feb. 25, 2015) Forensic science, which has fascinated generations with its unravelling of gruesome crime mysteries, is being put under the microscope in an exhibition of real criminal investigations in London. Duration: 00:53 Video provided by AFP
Powered by NewsLook.com
Michigan Couple Celebrates Identical Triplets

Michigan Couple Celebrates Identical Triplets

AP (Feb. 25, 2015) A suburban Detroit couple who have two older children are adjusting to life after becoming parents to identical triplets _ a multiple birth a doctor calls rare. (Feb. 25) Video provided by AP
Powered by NewsLook.com
Mayor Says District of Columbia to Go Ahead With Pot Legalization

Mayor Says District of Columbia to Go Ahead With Pot Legalization

Reuters - News Video Online (Feb. 25, 2015) Washington&apos;s mayor says the District of Columbia will move forward with marijuana legalization, despite pushback from Congress. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins