Scripps Researchers announce immune system breakthrough

SAN DIEGO - Scientists at the Scripps Research Institute Sunday announced a breakthrough discovery about a molecule in connection with the human body's immune system.

B lymphocyte is an immune system cell that is created in the human bone marrow.

A regulatory molecule called CD22 works to keep the B lymphocyte from running rampant on healthy cells.

When it is time to fight viral and bacterial infection however, the CD22 — a glycoprotein — has a way of shutting itself down in order to allow B lymphocyte activation, Scripps spokesperson Jason Bardi said.

In order to shut itself down, the CD22 has to bind to a sugar known as sialic acid, which decorates glycoproteins, Bardi said.

Scientists worked to identify the sialic acid-decorated glycoprotein to which CD22 binds.

Today those scientists announced that they have determined the other glycoprotein to be CD22 itself.

B cells have a single gene that makes the sialic-producing enzyme sequence that is recognized by CD22, thus making the molecule a likely candidate for auto-immune response research.

This makes CD22 a "good potential target for developing inhibitors that might help to modulate the immune response," Bardi said.

"This work is also significant … because the team's method provides a general approach useful for probing what proteins of interest are interacting on the surfaces of living cells and controlling cell signaling," Bardi said.


