OMRF researchers discover two new categories of cells

OKLAHOMA CITY, June 14, 2005 — Scientists at the Oklahoma Medical Research Foundation have identified two new categories of cells in the immune system. OMRF researchers Paul Kincade, Ph.D., and Rosana Pelayo, Ph.D., have chronicled this discovery in the June 1 issue of the journal Blood.

The previously unknown types of cells, which Kincade and Pelayo have named Plasmacytoid dendritic cells 1 and 2 (or pDC1 and pDC2), are part of the so-called innate immune system, a first line defense against disease-causing organisms. The OMRF researchers have determined that these cells play an important function in keeping the body healthy.

"These cells are like soldiers in the body's immune system," said Kincade, who heads OMRF's Immunobiology and Cancer Research Program and hold the William H. and Rita Bell Chair in Biomedical Research. "They sense viruses, then respond by producing interferon, a protein that inhibits the spread of virus and alerts other components of the immune system to the infection."

The cells were discovered in mice, whose immune systems are very similar to those of humans. "The next step will be to determine whether the human body also produces pDC1 and pDC2," said Pelayo, an associate research scientist at OMRF.

Scientists suspect that pDC1 and pDC2 may also play distinctive roles in the development of autoimmune diseases. In these conditions, which include lupus, multiple sclerosis and rheumatoid arthritis, the body mistakenly turns the weapons of the immune system against itself. The national Institutes of Health estimate that autoimmune diseases affect as many as 23.5 million Americans.

"Efforts are underway in our lab to learn if pDC1 and pDC2 are abnormally made or activated in autoimmune diseases," said Pelayo. "These experiments could prove very important in understanding and treating these conditions."

For Kincade, who has been studying immunology for almost four decades, the discovery is a reminder of how much remains unknown about the human body. "It's exciting to think that after all this time, we can still discover new cell types that have special jobs to do," he said. "The more we're able to learn, the better we'll be able to combat human disease."

About OMRF:
Chartered in 1946, OMRF (www.omrf.org) is a nonprofit biomedical research institute dedicated to understanding and curing human disease. Its scientists focus on such critical research areas as Alzheimer’s disease, cancer, lupus and cardiovascular disease. OMRF is home to Oklahoma's only member of the National Academy of Sciences.

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