AIDS Virus Risk In Women May Be Enhanced

May 14, 1997

Women may be more vulnerable than previously assumed to contracting the AIDS virus from their male sexual partners, according to findings by Dartmouth Medical School and VA Medical Center researchers.

Their studies, the first to demonstrate that the AIDS virus infects normal tissues throughout the female reproductive tract, could help unlock new approaches for AIDS treatment and prevention.

The implications are far-ranging. Vaccine development and disease prevention should aim to confer protection throughout the female reproductive tract and the right protocols could exclude the AIDS virus from the body by containing and destroying it within the tract.

The researchers have discovered that HIV, the AIDS-causing virus, can invade cells within any female reproductive tract organ--vagina, cervix, uterus, fallopian tubes--meaning that the entire tract is at risk. Until now, infection was presumed to occur when cells infected with HIV or HIV itself entered the body through the vagina or cervix.

A team headed by immunologist Alexandra Howell, a medical school research associate professor at the White River Junction VA, reported their results in the May issue of the Journal of Virology. Colleagues include Charles Wira, Michael Fanger, Grant Yeaman, Robert Edkins, Sherry Rier and Judy Stern.

"Our findings suggest that efforts to control heterosexual transmission of HIV-1 should include protection at all sites, not just the lower reproductive tract," Howell said.

Howell and her colleagues are part of a broad Dartmouth Medical School collaboration that is exploring immunity in the female reproductive tract to learn how hormones regulate protection.

The program, headed by co-author Wira, focuses on the lining of the female reproductive tract organs. This mucosa constitute a remarkably diverse protective system that fluctuates with the reproductive cycle and functions differently in each organ, offering some intriguing clues to disease susceptibility and protection.

As Wira explained, "Until this time, we thought that HIV infection was through a tear in the vaginal mucosa that allows virus to contact the blood, or after cells in the vagina pick up virus and transfer it to the body. These studies indicate that not only do cervical and vaginal cells have the potential to become infected, but so do uterine and fallopian tube cells." Virus may travel up the reproductive tract either free or in association with sperm and non-motile cells that are known to reach the fallopian tube, the site of fertilization.

The Dartmouth team obtained reproductive tract tissues from normal women undergoing hysterectomy for medical reasons. In the laboratory, they infected tissue sections as well as single cells from each organ with several strains of the human immunodeficiency virus-type 1 (HIV-1). They found that HIV-l infected cells at all sites, including the upper tract (fallopian tube) and that it infected other types of cells besides T cells and macrophages.

The researchers are currently examining whether female sex hormones, whose levels fluctuate during the normal menstrual cycle, alter susceptibility to HIV-1. The investigation builds on related Dartmouth findings that immune protection in the uterus is turned off during the latter part of the menstrual cycle, when implantation occurs. "This may mean that women are more susceptible to HIV infection during certain stages of the menstrual cycle," Howell said.

Linking results of several projects, Wira sets a possible scenario. "Hormonal changes during the menstrual cycle may create a window of opportunity for HIV infection via the uterus. Studies by (microbiologist) Hillary White, a program member, suggest that immune cells that would normally kill virally infected cells are shut down during the second half of the menstrual cycle when implantation is most likely to occur. HIV, which may be in the ejaculate, can enter into the uterus. Uterine surface cells not only become infected, but transmit virus systemically."

-DMS-
-end-


The Geisel School of Medicine at Dartmouth

Related HIV Articles from Brightsurf:

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.

Read More: HIV News and HIV 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.