Designer Cells Treat Psoriasis

Psoriasis is a chronic skin condition that causes itchy, scaly lesions over parts of the body. Engineered “designer cells,” placed in microcapsules and implanted in mice, now offer hope for a psoriasis treatment that goes beyond daily pills and injections.

“The cell recognizes the disease metabolite and coordinates a specific response,” said study coauthor Martin Fussenegger, a bioengineer at ETH Zürich. “That leads to the production, secretion, and delivery of a therapeutic protein which goes back to the bloodstream.” The designer cells successfully prevented and treated the skin lesions in a mouse model of psoriasis.

Psoriasis lesions result from an increase in small cell-signaling proteins called cytokines that cause inflammation, particularly tumor necrosis factor (TNF) and interleukin 22 (IL22). Current treatments for the condition rely on either daily injections or oral therapies of antibodies and other compounds that systemically flood a patient’s entire body to target the cytokines. But psoriasis flare-ups are unpredictable, and so these treatment options are reactive.

“If you realize that you a have a psoriatic flare, it’s too late—it’s already started,” said Fussenegger. “The designer cells, which constantly measure the proinflammatory cytokines, can immediately counteract and stop the onset of this inflammation,” he added.

Fussenegger and his colleagues first engineered human embryonic kidney cells to detect TNF. If the cytokine was present and bound to a TNF receptor on the cell, it induced a signaling cascade that ultimately produced an IL22 receptor to detect this second cytokine. If both inflammatory compounds are present, the designer cells are programmed to kick into gear to release the anti-inflammatory cytokines IL4 and IL10. These anti-inflammatory proteins combat the psoriatic flare-up.