Discovery: How Sunlight Triggers Lupus

LRI Researcher in Boston Starts to Unravel the Mystery

While scientists have long known that sunlight’s ultraviolet rays can trigger cutaneous (skin) as well as systemic lupus in some people, it’s been unclear exactly how this happens.

Now LRI investigator Vicki Rubin Kelley, PhD, unravels some of the mystery, reporting in November 2008’s Journal of Immunology that the damaging sequence is triggered when sunlight stimulates the skin to produce something called Colony Stimulating Factor 1 (CSF-1).

Vicki Rubin Kelley, PhD

Vicki Kelley, PhD

The Discovery

Dr. Kelley and colleagues show that once CSF-1 is produced, it then recruits and modifies white blood cells, which in turn stimulates the most common form of skin lupus in genetically susceptible individuals: the red, scaly and inflamed lesions of discoid lupus that can permanently damage and scar the skin.

Exciting future studies are being planned, she said, to explore whether blocking CSF-1 with a topical (skin) lotion or other agent might provide greater therapeutic benefit than commercially available sunscreens that people with lupus currently use to protect themselves from sun exposure.

Dr. Kelley, who works at the Brigham and Women’s Hospital in Boston, is reporting her findings just one year after being awarded funding from the Lupus Research Institute (in 2007). She is one of 85 researchers who to have won a 3-year, $300,000 Novel Research grants from the Lupus Research Institute (LRI) since it was founded in 2000.

Next Steps

Dr. Kelley and colleagues are currently validating their findings in people with cutaneous lupus-the research was originally done in mice-and are also examining what role UVB-induced CSF-1 plays in triggering multi-organ “systemic” lupus (particularly lupus-related kidney disease).

She also is working to identify the genes a person inherits from their parents to make them susceptible to skin lupus in the first place-the “tinder”-as described in the journal article, which is then triggered by “the match” of CSF-1.

“In a very brief period of time,” said LRI President Margaret Dowd, “Dr. Kelley took an LRI Novel Research Grant and was able to make a critical new insight that could soon lead to better tools for protecting against this often disfiguring lupus complication that sometimes leads to the even more serious multi-organ ‘systemic’ lupus.”

“It’s just the kind of pioneering and innovative research,” Dowd said, “that is moving very rapidly to making a significant difference in the lives of people with lupus.”

The Journal’s cover featured an image from Dr. Kelley’s research—a highpower photo of cutaneous lupus (discoid lupus) in the mouse.