Read on Twitter
Glycans / Sugars / Spike Protein /The Secret action of C19 
1/19 This is mainly because HIV co-opts its host's cellular mechanism to cover itself with human glycans. The surface protein of the virus that allows it to bind and enter human cells is completely covered with these sugars: at least half the mass of the working protein is
This is mainly because HIV co-opts its host's cellular mechanism to cover itself with human glycans. The surface protein of the virus that allows it to bind and enter human cells is completely covered with these sugars: at least half the mass of the working protein is
2/10 made up of carbohydrates. This so-called glycan shield camouflages the virus itself to hide it from the immune system. "It's like a wolf in sheep's clothing," said Philip Gordts, a glycobiologist at the University of California, San Diego. How glycans
3/10 protect viral proteins. Lucy Reading-Ikkanda / Quanta Magazine In fact, researchers have begun to realize that HIV is covered by so many glycans that it "almost exceeds protection," Crispin said. There is such a high density of sugars that not all of them
4/10 are as accessible to be chemically modified as human glycans normally would be. As a result, some glycan stains on the virus remain in a less mature and more primitive chemical form. Those primitive glycan patches are both crucial to HIV success and a key weakness.
5/10 By presenting the patches to circulating immune cells, the virus is carried to the lymph nodes where it can infect the T cells which are its main target. But after a few years, in about one third of chronically infected patients, the immune system begins to recognize
6/10 those glycans as foreign and generate antibodies to fight the pathogen. In fact, when the first of these antibodies was discovered, the researchers were shocked to see that it recognized a particular group of glycans on HIV. The antibodies usually seen targeting
proteins, not sugars - and these sugars seemed particularly unlikely targets because they had been produced for the virus by human cells; chasing them could lead to an autoimmune response. "That was the ingrained dogma," Crispin said, "that you don't get antibodies to those
8/10 sugars." 
(The researchers were so sure of this that they dubbed the sugar-coated surface of HIV the "silent face".) https://www.quantamagazine.org/sugars-on-coronavirus-spike-protein-offer-vaccine-clues-20200505/
(The researchers were so sure of this that they dubbed the sugar-coated surface of HIV the "silent face".) https://www.quantamagazine.org/sugars-on-coronavirus-spike-protein-offer-vaccine-clues-20200505/
