Targeting natural killer T cells might help prevent bone destruction in rheumatoid arthritis, the results of a preclinical study suggest.

Natural killer T (NKT) cells stimulated by the glycolipid alpha-galactosylceramide (alphaGalCer) were found to have a regulatory effect on the development of osteoclasts, a type of bone cell that resorbs bone and is integral to bone repair and maintenance. These cells could have a protective effect on inflammatory bone destruction, the research team suggested after also finding that the cells’ effects were diminished in patients with RA versus healthy controls.

Hye-Mi Jin of the department of rheumatology at Chonnam National University Medical School and Hospital in Gwangju, South Korea, and associates isolated and cultured NKT cells from 25 subjects with and 15 without RA and performed in vitro experiments to investigate the role played by NKT cells in osteoclastogenesis. They also looked at the in vivo effects of the alphaGalCer-stimulated cells in a mouse model of collagen-induced arthritis (Arthritis Rheumatol. 2015 June 19 [doi:10.1002/art.39244]).

The in vitro studies showed that alphaGalCer significantly inhibited osteoclastogenesis in healthy individuals but not in patients with RA and that the effect was mediated by NKT cells. Mice treated with the glycolipid showed less severe arthritis and reduced bone destruction.

“Further studies are needed to investigate ways of repairing NKT cell dysfunction in RA,” the investigators proposed.