Extreme extremophiles: from the very deep sea (Introduction)

by David Turell , Tuesday, March 16, 2021, 20:10 (1135 days ago) @ David Turell

New, never seen before bacteria our immune system does not recognize:

https://medicalxpress.com/news/2021-03-deep-sea-microbes-invisible-human.html

"To deep-sea bacteria, humans are Martians, and vice versa. The novel bacteria from the deep sea that we collected and tested would never have had the natural opportunity to interact with humans—since they live thousands of meters below the surface. So, we asked the questions, what would happen when organisms from these distinct ecosystems interact? Fast-forward five years, thousands of plates poured, and an immeasurable number of conversations, we have evidence that the immune system of mammals has the ability to detect microbial bacteria from our home habitat, not habitats that are foreign like the deep ocean. The inability of immune receptors to detect most bacteria from a different ecosystem suggests that pattern recognition strategies may be defined locally, not globally.

"All bacteria cells have an outer coating. Lipopolysaccharide, or LPS, is the outermost layer of the bacterial membrane. This outermost layer is what allows other organisms to recognize it. LPS receptors of human cells, mice and horseshoe crab were unable to detect 80% of deep-sea bacteria examined. Now that we know this, there is a pressing need to learn more about host-microbe interactions in every ecosystem, as new discoveries may be made in each habitat.

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"The bacteria are collected from the deep sea, using a tethered SUV-sized robot called the SuBastian controlled from the surface. The robot collected corals, slurped sediment, and sucked up water that was then analyzed at our labs back in Massachusetts. We were out [at sea] culturing the bacteria, but no one was expecting immunosilence."

Comment: Our innate immune system we are born with carries an inheritance from the bugs our ancestors met over the hundreds of thousands of years. Only now do we have technology to reach these new deep sea regions. The results are not surprising. It also explains a point made before. Many different preceding hominins helped produced the effective immune system we now have against the bugs we can meet in everyday living.