Nav: Home

Proteins linked to HIV transmission could actually be beneficial for reproduction

June 27, 2017

SAN FRANCISCO, CA--June 27, 2017--Protein fragments found in semen, and previously only known for their ability to enhance HIV infection, also appear to play an important role in reproductive biology. A team of researchers from the Gladstone Institutes, the University of California, San Francisco (UCSF), and Ulm University in Germany discovered that these fragments could help dispose of damaged or unneeded sperm.

In recent years, scientists made the surprising discovery that seminal fluid harbors fragments of proteins that clump together, forming structures called amyloid fibrils.

"Amyloid fibrils are normally only found in diseases caused by protein misfolding, such as Alzheimer's or Parkinson's disease, so the natural presence of multiple amyloids in the semen of healthy men was completely unexpected," said Warner C. Greene, MD, PhD, senior investigator and director of the Gladstone Institute of Virology and Immunology. "While these semen amyloids can promote infection by HIV and other sexually transmitted viruses, we speculated they must have a different natural function."

Greene, together with Gladstone Visiting Investigator Nadia R. Roan, PhD, and their colleagues set out to identify the natural function of these semen amyloids by focusing on whether they participate in reproduction. Specifically, they looked at their potential effect on sperm activity.

"We found that semen amyloids entrap excess, damaged, and defective sperm, which facilitates their disposal by immune cells that migrate into the female reproductive tract," explained Roan, lead author of the study.

Their findings, published in the scientific journal eLife, suggest that semen amyloids may be responsible for rapidly removing leftover sperm and sperm fragments, which could elicit an unfavorable immune response against foreign male proteins.

"In addition, this process could form a quality-control mechanism to ensure that only the fittest sperm reach the site of fertilization, thus favorably contributing to reproduction," added Roan, who is also an assistant professor in the Department of Urology at UCSF. "Our results support the increasingly accepted notion that amyloids may not always be harmful and markers of disease, but, instead, may carry out important functions in the human body."

"We need to consider these findings and their impact on other fields including HIV virology," stated Greene. "For instance, efforts to block the infection-enhancing activity of these semen amyloids for STD prevention must now consider the potential effects of such interventions on sperm quality and immune recognition of male antigens."

Now that researchers know semen amyloids physiologically help dispose of unwanted or damaged sperm, future studies at Gladstone will examine the processes that regulate semen amyloid production, and whether disruptions in these processes ever give rise to male infertility.
-end-
About the research project

The paper's main authors include Gladstone's Nadia R. Roan (co-first author) and Warner C. Greene (co-last author), Nargis Kohgadai (co-first author) from UCSF, and Jan Münch (co-last author) and Nathallie Sandi-Monroy (co-first author) from Ulm University.

Other researchers who took part in the study include Jason Neidleman, Mauricio Montano, and Marielle Cavrois from Gladstone; Jan Münch, Ludger Ständker, Annika Röcker, Friedrich Gagsteiger, Olena Sakk, and Frank Kirchhoff from Ulm University; Kara Marson, James F. Smith, and Christopher D. Pilcher from UCSF; Shariq M. Usmani from Harvard Medical School; Katherine G. Hamil and Michael O'Rand from EPPIN Pharma; and Jared Rosen and Polina V. Lishko from UC Berkeley.

This work was supported by the National Institutes of Health (grants K99AI104262, R00AI104262, R21AI116252, R01AI127219, R01HD074511, P30 AI027763, P01 AI083050), and the German Research Foundation (DFG).

About the Gladstone Institutes

To ensure our work does the greatest good, the Gladstone Institutes focuses on conditions with profound medical, economic, and social impact--unsolved diseases. Gladstone is an independent, nonprofit life science research organization that uses visionary science and technology to overcome disease. It has an academic affiliation with the University of California, San Francisco.

Gladstone Institutes

Related Hiv Articles:

BEAT-HIV Delaney collaboratory issues recommendations measuring persistent HIV reservoirs
Spearheaded by Wistar scientists, top worldwide HIV researchers from the BEAT-HIV Martin Delaney Collaboratory to Cure HIV-1 Infection by Combination Immunotherapy (BEAT-HIV Collaboratory) compiled the first comprehensive set of recommendations on how to best measure the size of persistent HIV reservoirs during cure-directed clinical studies.
The Lancet HIV: Study suggests a second patient has been cured of HIV
A study of the second HIV patient to undergo successful stem cell transplantation from donors with a HIV-resistant gene, finds that there was no active viral infection in the patient's blood 30 months after they stopped anti-retroviral therapy, according to a case report published in The Lancet HIV journal and presented at CROI (Conference on Retroviruses and Opportunistic Infections).
Children with HIV score below HIV-negative peers in cognitive, motor function tests
Children who acquired HIV in utero or during birth or breastfeeding did not perform as well as their peers who do not have HIV on tests measuring cognitive ability, motor function and attention, according to a report published online today in Clinical Infectious Diseases.
Efforts to end the HIV epidemic must not ignore people already living with HIV
Efforts to prevent new HIV transmissions in the US must be accompanied by addressing HIV-associated comorbidities to improve the health of people already living with HIV, NIH experts assert in the third of a series of JAMA commentaries.
The Lancet HIV: Severe anti-LGBT legislations associated with lower testing and awareness of HIV in African countries
This first systematic review to investigate HIV testing, treatment and viral suppression in men who have sex with men in Africa finds that among the most recent studies (conducted after 2011) only half of men have been tested for HIV in the past 12 months.
The Lancet HIV: Tenfold increase in number of adolescents on HIV treatment in South Africa since 2010, but many still untreated
A new study of more than 700,000 one to 19-year olds being treated for HIV infection suggests a ten-fold increase in the number of adolescents aged 15 to 19 receiving HIV treatment in South Africa, according to results published in The Lancet HIV journal.
Starting HIV treatment in ERs may be key to ending HIV spread worldwide
In a follow-up study conducted in South Africa, Johns Hopkins Medicine researchers say they have evidence that hospital emergency departments (EDs) worldwide may be key strategic settings for curbing the spread of HIV infections in hard-to-reach populations if the EDs jump-start treatment and case management as well as diagnosis of the disease.
NIH HIV experts prioritize research to achieve sustained ART-free HIV remission
Achieving sustained remission of HIV without life-long antiretroviral therapy (ART) is a top HIV research priority, according to a new commentary in JAMA by experts at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.
The Lancet HIV: PrEP implementation is associated with a rapid decline in new HIV infections
Study from Australia is the first to evaluate a population-level roll-out of pre-exposure prophylaxis (PrEP) in men who have sex with men.
Researchers date 'hibernating' HIV strains, advancing BC's leadership in HIV cure research
Researchers have developed a novel way for dating 'hibernating' HIV strains, in an advancement for HIV cure research.
More HIV News and HIV Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Warped Reality
False information on the internet makes it harder and harder to know what's true, and the consequences have been devastating. This hour, TED speakers explore ideas around technology and deception. Guests include law professor Danielle Citron, journalist Andrew Marantz, and computer scientist Joy Buolamwini.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.