by Julie Halpert
David Sherman, Ph.D., does much of his field work underwater, diving as deep as 130 feet to collect microbial samples that can become the basis for new drugs to treat infectious diseases and cancers.
Sherman, a faculty member at the University of Michigan Life Sciences Institute, has been on roughly 50 diving expeditions, the most recent to the Red Sea. But for his latest journey, he sought higher ground — at 18,000 feet in Nepal. And he had an unusual research partner: his 22-year-old daughter, Hannah, who graduated this past spring from U-M with a degree in Earth and Environmental Science.
Not only was Sherman collecting new samples to analyze in his lab at the LSI, but he was also assisting with an effort she was involved in to study water quality in the area — which took on increased importance in the wake of a devastating earthquake that hit the region last year.
To satisfy a graduation requirement for a field course, Hannah had received approval to head to Nepal with professor Kirsten Nicholson of Ball State University, who has long been studying water quality around Mount Everest. Her team's intent was to better understand the causes of contaminated water, which has spread illness among the native population.
“The goal of our research is to analyze the water and figure out where the main sources of the pollution are,” says Nicholson. “This information will help us to identify the causes of the pollution and also the sources of the cleanest water.”
When Sherman heard about the expedition, he was eager to go along, seeing a rare opportunity to lend a hand while also collecting new samples from a high-altitude region.
No one has studied the organisms from these areas, he explains. “We didn't know what was there, but we assumed, based on other examples, that there was likely to be a whole lot of interesting material,” notes Sherman, who is also the Hans W. Vahlteich Professor of Medicinal Chemistry in the U-M College of Pharmacy; professor of chemistry in the College of Literature, Science, and the Arts; and professor of microbiology and immunology in the Medical School.
Many of our anti-cancer drugs and antibiotics come from microorganisms originally found in the soil. Scientists have been exploring these sources for new drugs for decades. And in 2015, the Nobel Prize in Physiology of Medicine was awarded to three scientists for their development of anti-parasitic and anti-malarial drugs that came from natural sources.
Sherman has spent the past 25 years identifying new microorganisms and molecules, characterizing their genetic information that encode the enzymes that make molecules. Once their biological activity is understood, medicinal chemists and pharmacologists can determine if the molecule can be turned into a clinical agent. Among Sherman's many discoveries are new antibiotics that work against E. coli and molecules that show promise against HIV.
A Journey Postponed
The three-week trip to Mount Everest was initially scheduled for 2015, but tragedy struck in the form of a magnitude 7.8 earthquake, which killed more than 8,000 people and injured 21,000. So, the expedition was postponed until this April.
The Shermans flew into the base of the Himalayas, hiking six to eight hours a day and stopping at rustic tea houses along the way. The journey was challenging. “You're taking on a high level of risk when you go up,” says Hannah. Sherman adds that altitude sickness and unpaved steep, rocky paths make for a difficult trek: "I fell twice and it was pretty scary."
Fortunately, the weather was perfect. "We saw Everest clearly at every point possible and it was phenomenal," Hannah says.
Delaying the trip for a year also meant that Hannah missed her commencement ceremony. She instead spent it at Everest Base Camp, at an altitude of 17,598 feet perched in the middle of the mountains, wearing a University of Michigan cap underneath a party hat.
Sherman was busy collecting soil and sediment samples along the path, as well as lichens found on rocks in the area. “No one has studied them and they're a great source of the kind of molecules that I like to find for drug discovery purposes,” he says.
In all, Sherman was able to collect 600 samples — but they almost didn't make it back after they were held up by U.S. Customs officials at Abu Dhabi International Airport, who insisted they be shipped by a courier. So, in the middle of the night, he managed to track down a courier who could mail them, and they arrived three days later.
It will be months before the organisms can be analyzed. The soil and sediment samples are now in Sherman’s laboratory, where the high-altitude bacteria are being grown on petri dishes and in flasks. Extracts from those bacteria will then be screened for medicinal properties — potentially leading to the discovery of new antibiotics, anti-cancer agents or compounds that can combat other targets.
“We'll have the largest collection of high altitude microorganisms for drug discovery right here at Michigan," says Sherman. He’s looking forward to seeing how the high-altitude organisms in the new collection will differ from those found in marine sediments. “It's an amazing opportunity to start a project that addresses those questions,” he adds.
Meanwhile, data from the water quality project are still being analyzed, Nicholson notes. The researchers hope to publish their findings soon, and then use them to improve water quality for the native population, which has suffered from a lack of modern sanitation as well as problems caused by the impacts of tourism on the area.
Like Father Like Daughter
A certified scuba diver, Sherman doesn't take for granted the ability to conduct his research in spectacular environments. “There's a synergy to my love of the natural world and my ability to actually collect samples that directly come from nature and discover new science,” he says.
Growing up hearing stories of his adventures, Hannah had longed to join her father on his expeditions since she was 10. “I wanted to go before I understood what he was doing,” she says. A certified scuba diver herself, she finally got a chance to head with him to Costa Rica at age 16.
Tropical storms made for conditions so fierce she was hurled into a rock wall where her regulator dislodged and they promptly returned to the surface. Still, Hannah looks back with fondness on the journey: “We had a lot of fun. It's not something a lot of other people my age have had the ability to do.”
Sherman adds, “It's fantastic to bring your own child on this kind of experience, to be able to show them what it's really like to work in a country and have a focused purpose.”
Experiencing Nepal on the heels of her college graduation was particularly significant for Hannah.
“Having the ability to be in nature and reflect on the past four years and what I wanted coming next, it was a really good ending,” she says. “And then having my dad there with me to reflect on what I was going through and celebrate finishing a big occasion in my life was really special.”
Sherman is already planning his next expedition, eyeing Tibet, on the other side of the Himalayas. And Hannah is starting a full-time job in corporate sustainability in Washington, D.C., focusing on global water programs. But she said she would willingly use all her vacation days for a chance to go with him again.
“It's not something I intend to give up,” she says.