Study Shows Molecule Can Infiltrate Immune Cells to Treat Rheumatoid Arthritis
Jan. 28, 2010 – A ghostly “suicide” drug wafts into immune cells in joints, making the cells self-destruct and reducing rheumatoid arthritis in mice.
The drug, technically a BH3 mimetic dubbed TAT-BH3, is a man-made molecule. One part of the molecule lets it drift through cell walls. The other part mimics a chemical signal missing in the macrophage immune cells that build up inside joints afflicted by rheumatoid arthritis (RA).
Because they are missing this signal, macrophages in RA joints don’t die off as they are supposed to do. They live on, destroying bone and inflaming the joint, says Harris Perlman, PhD, associate professor of medicine at Chicago’s Northwestern University Feinberg School of Medicine.
“In RA, there is this persistent inflammation that never shuts down. Part of the reason is these macrophages are missing a protein they need to die off,” Perlman tells WebMD. “So this drug says OK, let’s replace this protein. Let’s bring back the death pathway.”
Perhaps because normal cells aren’t clinging to life like the zombie macrophages involved in RA, the drug doesn’t kill normal macrophages. The drug was not toxic to mice.