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Evolutionary virologist Daniel Blanco-Melo seeks out ancient pathogens

BY Ketab360

“He rebuilt two viruses that arrived in the Americas when Europeans came there a long time ago.“

Long ago, people from Europe brought illnesses like smallpox, measles, and mumps to the Americas. These diseases made many Native Americans very sick, and lots of them died. We still don’t know exactly which germs caused these illnesses.

Daniel Blanco-Melo is trying to figure out that puzzle from history. He studies really old viruses using very advanced tools at the Fred Hutchinson Cancer Center in Seattle. His goal is to understand how these viruses have influenced human evolution and history. In his latest research, Blanco-Melo and his team put together information about two viruses that were spreading in Mexico when Europeans came there a long time ago.

Our investigation into old viruses is fascinating because it lets us learn about the past,” says Blanco-Melo. This research is not just interesting for him, but it’s also special because he grew up in Mexico. By using genetic detective work, he can explore something that means a lot to him. He says, “I get to truly understand those events from history using molecular biology, and it’s something that’s close to my heart.

Viruses shape human evolution.

Blanco-Melo’s fascination with viruses started when he was in high school. It all began when he came across a book called Genome by Matt Ridley. Originally, he bought the book as a gift for his dad on Father’s Day, but he ended up reading it himself. His biology teacher encouraged him, and he decided to study genomics at the National Autonomous University of Mexico, or UNAM, in Cuernavaca.

As a student doing his Ph.D. at the Rockefeller University in New York City, Blanco-Melo first met really old viruses. His studies were all about special viruses known as endogenous retroviruses. These are bits left behind from viruses that made people sick a long time ago, but now they’re like parts of a puzzle in the instructions that make us who we are.

Blanco-Melo started by making a list of the leftover genes from an old virus called HERV-T. This virus was around a very, very long time ago, when our ancestors were more like monkeys. After looking at the genes more closely, he found a special gene that helps the virus get inside a cell and make it sick. Surprisingly, this gene has been with monkeys and even us, humans, for a very, very long time, although it doesn’t work anymore.

This shows how, as time went on and animals changed, a virus’s own genetic material could be turned against it. Blanco-Melo says, “This project not only answered my questions, but we turned it into a complete story about how a virus changed and appeared, and then disappeared.” Maybe scientists today can use what they learned to fight against current viruses, especially a big one called HIV, Blanco-Melo suggests.

Delineating historical events.

Recently, Blanco-Melo joined forces with María Ávila-Arcos, a scientist who studies how living things change over time at UNAM, and also a friend of his from a long time ago. Together, they are looking into times when a lot of Native American people got very sick and many of them passed away because of viral infections.

Blanco-Melo, Ávila-Arcos, and a group of scientists took out and separated the DNA of viruses from old bones. These bones were from a really long time ago, around when people wore fancy clothes like in fairy tales. The bones were found in big graves at a hospital and a church in what is now Mexico City. The records from the olden days say that the bones belonged to Native American people and some Africans who were not free. They got very sick and passed away during big sicknesses in the 1500s and 1600s.

Because of what they discovered, the team put together the special instructions of two viruses that people didn’t know were around back then. These viruses are called human parvovirus B19 and a human hepatitis B virus.

The research, which came out in a book called eLife in 2021, might be the first one to find really old viral codes from the Americas. Jesse Bloom, a person who studies viruses but didn’t help with this project, mentioned this.

Learning about viruses that made people sick a long, long time ago is really important for scientists and people who like to know about history. Jesse Bloom says it’s especially interesting in the Americas, which is a big part of the world. The team discovered that the old viruses were a lot like the ones in Africa today. Blanco-Melo says these viruses came to Mexico not long after the Europeans came, but they didn’t come from Europe. They came from Africa, and how they got here is connected to something called the transatlantic slave trade.

Blanco-Melo is working together with others, making sure they don’t do what’s called ‘helicopter research.’ That’s when people from somewhere else come, collect information, and then act like it was all their idea. He thinks the things they find in Mexico should be looked at by Mexican researchers, people who live there. And all the things they discover will be shared with the communities there. That’s what they want to do.

Why is this special gene from the virus still here after so long? Blanco-Melo wondered. He asked himself, ‘What good thing did it do for animals over a really, really long time?’ After looking at cells in a lab, he thinks that a very long time ago, animals like monkeys must have borrowed this gene from the virus. They used the protein from the gene to stop the virus from getting inside their cells, like a clever way to keep themselves safe and healthy.

Even though the two viruses they found may not have caused really big sicknesses, they could have made other diseases worse. More projects with the same samples from Mexico are trying to find different viruses and even tiny parts called peptides to understand more about the viruses from that time. They want to figure out which ones caused the big problems. Blanco-Melo says, ‘There’s a lot more research to do to find those other things that made people sick.

About Daniel Blanco-Melo, PhD

Assistant Professor at Fred Hutch in the Vaccine and Infectious Disease Division, and also a Joint Assistant Professor in the Herbold Computational Biology Program within the Public Health Sciences Division at Fred Hutch. He is also a member of the Translational Data Science Integrated Research Center (TDS IRC) at Fred Hutch.

Dr. Daniel Blanco-Melo is a scientist who looks at how animals have developed ways to fight off viruses over a really, really long time. He wants to understand how our methods to stop viruses have changed because of the ongoing fight with old and new viruses. In his lab, they focus on the complicated processes that happen inside cells when they get infected. They study important viruses that affect humans, like the flu and the virus that causes COVID-19. They also look at really old viruses and how they influenced the way animals protect themselves from getting sick.

Dr. Blanco-Melo and his team use different tools like molecular biology, genetics, and super smart computer techniques to learn more about how our bodies fight off viruses. Their goal is to find new ways to make medicines that can help us stay healthy and fight against viruses that exist now and ones that might come in the future.