Effect of human leucocyte interferon on DNA synthesis in human psoriatic skin cultured in diffusion chambers.

Pieces of human psoriatic skin were cultured for five days in diffusion chambers implanted intraperitoneally in mice. Partially purified human leucocyte interferon was injected into the experimental animals daily during the culture period. Phosphate buffered saline and, in one experiment, also mock interferon were used as control materials. On the fifth day, incorporation of 3H-thymidine into the epidermal cells was studied autoradiographically. The results showed that human leucocyte interferon does not depress DNA synthesis in human psoriatic epidermal cells cultured by this method. In fact, DNA synthesis seemed to be stimulated in two of the three experiments but the effect was not statistically significant.