Podcast Summary: The Great Detectives Present Dragnet (Old Time Radio)

Episode Title: You Might Also Like: Incubation
Host: Adam Graham
Release Date: December 7, 2024

Introduction to Viral Dark Matter

In this episode of "The Great Detectives Present Dragnet," host Adam Graham delves into the enigmatic world of viruses that remain largely unidentified, often referred to as "viral dark matter." The discussion begins with an exploration of the ubiquity of viruses in our environment and bodies, highlighting the vast number of undiscovered viral species.

Jacob Goldstein [00:04]: "Viruses are in the air we breathe, in the water we drink. They're in the ground we walk on... we're surrounded and permeated by viral dark matter, by viruses that we don't even know exist."

Interview with Ken Stedman: Exploring Viral Dark Matter

Ken Stedman, a professor of biology at Portland State University, shares his pioneering research into viral dark matter. His work involves collecting samples from extreme environments, such as volcanic hot springs, to discover novel viruses.

• Discovery Methods: Stedman explains the methodology of collecting samples from harsh environments like Boiling Springs Lake in Lassen Volcanic National Park, where temperatures reach 130-140°F and the pH is around 2, making it highly acidic.

  Ken Stedman [03:19]: "We just took about 200 liters worth of water from the lake and then purified all of the virus-sized particles in it, then determined what their genetic sequences were."

• Unprecedented Findings: Upon analyzing the genetic sequences, Stedman's team found that over 90% of the sequences did not match any known viruses, confirming the vast extent of viral dark matter.

  Jacob Goldstein [06:04]: "Does that mean that we don't know about 90% of the viruses that are out in the world?"
  Ken Stedman [06:12]: "That is exactly what it implies."

• Cruciviruses: A breakthrough discovery by Stedman and his team revealed a new class of viruses called "cruciviruses," which appear to be a hybrid between DNA and RNA viruses. This challenges the long-held belief that DNA and RNA viruses are evolutionarily distinct with minimal interaction.

  Ken Stedman [09:05]: "But we'd sequence DNA. And when I say we mostly... we have what we're now calling crucie viruses that appear to have evolved by DNA viruses and RNA viruses coming together."

• Global Presence: Cruciviruses have been identified in diverse locations, including Antarctic lakes, deep-sea sediments, and even within microbial ecosystems in various environments, indicating their widespread presence.

  Ken Stedman [11:30]: "Basically anywhere that we have looked, we found these cruciviruses, very low amounts of them, but seem to be very ubiquitous."

Transition to Shiraz Ali Shah: The Human Virome and Asthma

The episode transitions to an interview with Shiraz Ali Shah, a senior researcher at Copenhagen University Hospital Gentofte, who focuses on the human virome—the collection of viruses residing in the human gut.

• Copenhagen Prospective Studies for Asthma in Childhood (COPSAC): Shah discusses the long-term study tracking 700 children from birth to analyze various factors contributing to the development of asthma and other chronic diseases.

  Shiraz Ali Shah [17:16]: "So there's more and more evidence showing that if you are not exposed to a diverse array of good bacteria in the body... you're way more prone to chronic inflammatory or immune diseases in the future."

• Virome Analysis: Shah explains the complexities of identifying viruses in gut samples, noting that traditional methods often miss the majority of viral diversity. His team manually curated viral families from vast genetic data, uncovering approximately 250 viral families, most of which were previously unknown.

  Shiraz Ali Shah [23:29]: "What we first do is we assemble all the sequences like a piece of a puzzle... and manually look through 10,000 clusters of sequences, and out of those 10,000, around 300 of them were the ones that I could confidently say were viruses."

• Link to Asthma: A significant finding from Shah's research indicates that certain temperate bacteriophages (viruses that infect bacteria) present in the gut at one year of age are predictive of asthma development by age five. Specifically, lower levels of 19 distinct temperate phage families correlate with a higher risk of developing asthma.

  Shiraz Ali Shah [27:15]: "So Christina... found that it was the temperate bacteriophages that were predictive of later asthma... the children that end up developing Asthma by age 5, they had way more temperate phages in their gut at age 1."

Implications and Future Directions

Both Stedman and Shah emphasize the potential significance of their discoveries in understanding human health and disease. While Stedman's exploration of viral dark matter opens new avenues in virology and evolution, Shah's findings suggest that the virome plays a crucial role in immune system development and the prevention of chronic diseases like asthma.

• Potential for Disease Prevention: Shah expresses hope that future research will enable the manipulation of the virome and microbiome to prevent chronic diseases.

  Shiraz Ali Shah [31:07]: "I'm hoping in the future that we have a much better overview... so that we can prevent maybe 10, 20, 30 years from now, we can prevent a lot of chronic diseases..."

• Environmental Factors: The studies indicate that environmental factors such as living in rural areas and consuming whole foods may promote a more diverse and beneficial virome and microbiome, potentially reducing the risk of developing asthma and other diseases.

  Shiraz Ali Shah [30:08]: "The ones that really live in a rural environment have a much more diverse ecosystem in the gut."

Conclusion

Adam Graham wraps up the episode by highlighting the groundbreaking work of both Ken Stedman and Shiraz Ali Shah. Their research not only expands our understanding of the vast and largely unknown viral world but also opens up possibilities for novel approaches to disease prevention and health optimization.

Notable Quotes with Timestamps:

• Jacob Goldstein [00:04]: "Viruses are in the air we breathe... we're surrounded and permeated by viral dark matter."
• Ken Stedman [03:19]: "We just took about 200 liters worth of water from the lake... determined what their genetic sequences were."
• Shiraz Ali Shah [27:15]: "They had way more temperate phages in their gut at age 1."
• Shiraz Ali Shah [31:07]: "We can prevent a lot of chronic diseases by giving babies viruses or bacteria..."

This episode of "The Great Detectives Present Dragnet" offers a fascinating glimpse into the hidden world of viruses that inhabit our environment and bodies, shedding light on their potentially profound impact on health and disease.