Fig. 1.

Fragments of genomic dsDNA induce tumour necrosis factor (TNF)‐α production in keratinocytes. Normal human epidermal keratinocytes maintained in KB2 basal medium were transfected with fragments of human genomic dsDNA or ssDNA for the indicated time‐periods. (a) Relative TNFA mRNA levels were evaluated by real‐time polymerase chain reaction (PCR). (b) TNF‐α protein levels in the culture medium were measured by enzyme‐linked immunosorbent assay (ELISA). Data are presented as means ± standard deviation (s.d.) relative to the non‐transfected controls. **P < 0·001, compared with the unstimulated control group.