Snapshots of Life: Finding Where HIV Hides


Credit: Nadia Roan, University of California, San Francisco

Researchers have learned a tremendous amount about how the human immunodeficiency virus (HIV),  which causes AIDS, infects immune cells. Much of that information comes from studying immune cells in the bloodstream of HIV-positive people. Less detailed is the picture of how HIV interacts with immune cells inside the lymph nodes, where the virus can hide.

In this image of lymph tissue taken from the neck of a person with uncontrolled HIV infection, you can see areas where HIV is replicating (red) amid a sea of immune cells (blue dots). Areas of greatest HIV replication are associated with a high density of a subtype of human CD4 T-cells (yellow circles) that have been found to be especially susceptible to HIV infection.

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Ebola Virus: Lessons from a Unique Survivor

Ebola virus

Caption: Ebola virus (green) is shown on cell surface.
Credit: National Institutes of Allergy and Infectious Diseases, NIH

There are new reports of an outbreak of Ebola virus disease in the Democratic Republic of Congo. This news comes just two years after international control efforts eventually contained an Ebola outbreak in West Africa, though before control was achieved, more than 11,000 people died—the largest known Ebola outbreak in human history [1]. While considerable progress continues to be made in understanding the infection and preparing for new outbreaks, many questions remain about why some people die from Ebola and others survive.

Now, some answers are beginning to emerge thanks to a new detailed analysis of the immune responses of a unique Ebola survivor, a 34-year-old American health-care worker who was critically ill and cared for at the NIH Special Clinical Studies Unit in 2015 [2]. The NIH-led team used the patient’s blood samples, which were drawn every day, to measure the number of viral particles and monitor how his immune system reacted over the course of his Ebola infection, from early symptoms through multiple organ failures and, ultimately, his recovery.

The researchers identified unexpectedly large shifts in immune responses that preceded observable improvements in the patient’s symptoms. The researchers say that, through further study and close monitoring of such shifts, health care workers may be able to develop more effective ways to care for Ebola patients.

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Creative Minds: Preparing for Future Pandemics

Jonathan Abraham

Jonathan Abraham / Credit: ChieYu Lin

Growing up in Queens, NY, Jonathan Abraham developed a love for books and an interest in infectious diseases. One day Abraham got his hands on a copy of Laurie Garrett’s The Coming Plague, a 1990s bestseller warning of future global pandemics, and he sensed his life’s calling. He would help people around the world survive deadly viral outbreaks, particularly from Ebola, Marburg, and other really bad bugs that cause deadly hemorrhagic fevers.

Abraham, now a physician-scientist at Brigham and Women’s Hospital, Boston, continues to chase that dream. With support from an NIH Director’s 2016 Early Independence Award, Abraham has set out to help design the next generation of treatments to enable more people to survive future outbreaks of viral hemorrhagic fever. His research strategy: find antibodies in the blood of known survivors that helped them overcome their infections. With further study, he hopes to develop purified forms of the antibodies as potentially life-saving treatments for people whose own immune systems may not make them in time. This therapeutic strategy is called passive immunity.

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Snapshots of Life: Virus Hunting with Carbon Nanotubes

H5N2 trapped in carbon nanotubes

Credit: Penn State University

The purple pods that you see in this scanning electron micrograph are the H5N2 avian flu virus, a costly threat to the poultry and egg industry and, in very rare instances, a health risk for humans. However, these particular pods are unlikely to infect anything because they are trapped in a gray mesh of carbon nanotubes. Made by linking carbon atoms into a cylindrical pattern, such nanotubes are about 10,000 times smaller than width of a human hair.

The nanotubes above have been carefully aligned on a special type of silicon chip called a carbon-nanotube size-tunable-enrichment-microdevice (CNT-STEM). As described recently in Science Advances, this ultrasensitive device is designed to capture viruses rapidly based on their size, not their molecular characteristics [1]. This unique feature enables researchers to detect completely unknown viruses, even when they are present in extremely low numbers. In proof-of-principle studies, CNT-STEM made it possible to collect and detect viruses in a sample at concentrations 100 times lower than with other methods, suggesting the device and its new approach will be helpful in the ongoing hunt for new and emerging viruses, including those that infect people.

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Could Zika Virus Have Lasting Impact on Male Fertility?


Caption: Immunofluorescence staining showing that the testes of Zika-free mice (left) are full of developing sperm (pink), while the testes of Zika-infected mice (right) contain very few sperm.
Credit: Prabagaran Esakky, Washington University School of Medicine, St. Louis

Recent research has shown that the mosquito-borne Zika virus has the potential to cause serious health problems, including severe birth defects in humans. But the damaging effects of Zika might not end there: results of a new mouse study show that the virus may also have an unexpected negative—and possibly long-lasting—impact on male fertility.

In work published in the journal Nature, an NIH-funded research team found that Zika infections can persist for many weeks in the reproductive systems of male mice [1]. As a result of this infection, levels of testosterone and other sex hormones drop, sperm counts fall, and, in some animals, the testicles shrink to 1/10th of their normal size, possibly irreversibly. All of this adds up to Zika-infected male mice that are significantly less fertile than their healthy counterparts—producing about a quarter as many viable offspring as normal when mated with female mice. While mice are certainly not humans, the results underscore the urgent need for additional research to examine the full spectrum of Zika’s health effects in men, women, and children of both sexes.

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