Natures wonders: social amoeba's immunity (Introduction)

by David Turell , Wednesday, March 02, 2016, 16:31 (3186 days ago) @ David Turell

Some amoebas bunch together much like a multicellular organism and have differing functions, but some maintain their trapping mechanisms like engulfing to offer immune protection from predators:-http://www.the-scientist.com/?articles.view/articleNo/45484/title/Amoebae-Have-Human-Like-Immunity/&utm_campaign=NEWSLETTER_TS_The-Scientist-Daily_2016&utm_source=hs_email&utm_medium=email&utm_content=26843367&_hsenc=p2ANqtz-97JpYJwq3uKmjIw7c48gRy-FCa0zn608CedhXZK9QEu1sDbvZGtaq2U0nBluPdOZ0Fz35ZGZIdlRDHDos8m0aaUrpGrA&_hsmi=26843367/-"When resources get low, the social amoeba Dictyostelium discoideum come together by the thousands to form a stalk topped by a mass of spores, which can blow off in the wind to more-plentiful environments. About 80 percent of the amoeba that contribute to this cooperative structure become spores; approximately 20 percent form the stalk, sacrificing their own survival and reproduction for the success of the group. But there is also a third set of cells—about 1 percent of the population—that maintain the amoeba's typical phagocytic functions, according to a study published yesterday.-"This last percentage is made up of cells called sentinel cells,” study coauthor Thierry Soldati of the University of Geneva in Switzerland said in a press release. “They make up the primitive innate immune system of the slug and play the same role as immune cells in animals. Indeed, they also use phagocytosis and DNA nets to exterminate bacteria that would jeopardize the survival of the slug.” -***- "Amoeba can similarly engulf bacteria in their environment; Soldati and his colleagues in Geneva and at the Baylor College of Medicine in Houston, Texas, found that amoeba sentinel cells also produce DNA-based extracellular traps (ETs) when threatened with bacteria or lipopolysaccharides. Moreover, interfering with this process decreased the colony's ability to clear infection.-“'We have thus discovered that what we believed to be an invention of higher animals is actually a strategy that was already active in unicellular organisms one billion years ago,'”-Comment: In an animal world where everyone is lunch protections are necessary. it started with the earliest organisms.