Immunity system complexity: spe cial lung cells (Introduction)

by David Turell , Wednesday, June 15, 2022, 17:07 (1024 days ago) @ David Turell

Two different types found in lung blood vessels:

https://www.sciencedaily.com/releases/2022/06/220614153727.htm

"Scientists at the University of Illinois Chicago have analyzed gene expression data from more than 35,000 blood vessel cells from the lungs of mice and identified two subtypes.

"One subtype, which they call immune endothelial cells, or immuneECs, preferentially expressed more genes involved in inflammation and the regulation of the immune response. The devEC subtype, for developmental endothelial cells, expressed more genes involved in cell development, like cell regeneration and proliferation.

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"They found multiple groups of endothelial cells, with two dominant cell types -- immuneECs and devECs -- which changed over time during inflammation.

"'Across our experiments, consistently we observed that the blood vessel cells of the lung seem to have these different functions and groupings, and the two predominant groups become even more distinct when responding to infection or stress," said Rehman, UIC professor in the department of pharmacology and regenerative medicine and the department of medicine at the College of Medicine.

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"As illness or injury progressed, immuneECs expressed more immune response genes, like major histocompatibility complex genes that act as a beacon for infection-fighting T-cells. As the lungs improved, devECs expressed more repair genes, like the vascular development gene Sox17, which promotes blood vessel growth and regeneration. Upon analyzing the RNA profiles of lung endothelial cells obtained from nonhuman primates with a SARS-CoV-2 infection, the researchers also found distinct groups of lung endothelial cells.

"'Part of the blood vessel endothelial cells become highly inflammatory, and part of them retain that ability to regenerate," Rehman said. "Our data also suggested that after some time, the developmental subtype, which is essentially primed to regenerate, gives rise to cells that start proliferating and regenerating the blood vessels that were damaged during the infection."

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"Rehman said the findings are a good reminder, too, that our lungs are always in contact with the outside world, and this may be why lung blood vessels need such a fine-tuned balance between endothelial cell subtypes, which can activate or amplify the immune response, whereas other endothelial cells can help repair the blood vessels after the infection starts subsiding.

"'We're always breathing in pathogens, unlike other organs such as the heart or the brain which are much more shielded from the pathogens of the outside world. That's why that balance, this intricate system having both an inflammatory and a regenerative response, is so important in the lungs," Rehman said.

Comment: these different cells are very necessary as Rehman notes. In design theory it is reasonably proposed lungs were first designed with these cells in place, or lunged species would not h ave survived.