Co-culture of human keratinocytes on post-mitotic human dermal fibroblast feeder cells: production of large amounts of interleukin 6.
A large synthesis of human IL-6 was demonstrated in co-cultures of human keratinocytes on post-mitotic human dermal fibroblast (HDF) feeder layers. Immunoreactive IL-1 beta could be detected in the co-cultures and the addition of rabbit anti-IL-1 beta antibodies to the co-cultures considerably reduced the IL-6 synthesis, suggesting that it was induced by endogenous IL-1 beta. Addition of saturating concentrations of IL-1 beta to HDF feeder layers as well as to subcultures of keratinocytes induced in both similar but moderate IL-6 production. Conditioned medium from keratinocyte cultures induced IL-6 secretion in HDF feeder cells, whereas the conditioned medium from HDF feeder layers led to only minimal increase of keratinocyte IL-6 production. The co-cultures of keratinocytes on HDF feeder layers produced much larger amounts of IL-6 than the sum of the IL-6 produced by the feeder cell and keratinocyte cultures after the addition of IL-1 beta. The co-cultures of keratinocytes with HDF feeder layers separated by a permeable membrane in a two-chamber system produced significantly lower amounts of IL-6 than the unseparated co-cultures. These findings indicate that a direct cell contact between keratinocytes and feeder cells is involved in the overproportioned increase of IL-6 production and secretion into the medium.
Waelti
E R
ER
Department of Pathology, University of Berne, Switzerland.
Inaebnit
S P
SP
Rast
H P
HP
Hunziker
T
T
Limat
A
A
Braathen
L R
LR
Wiesmann
U
U
D002450:Cell Communication; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D015850:Interleukin-6 / Q000096:biosynthesis; D015603:Keratinocytes / Q000166:cytology*; D008938:Mitosis; D012867:Skin / Q000166:cytology
D007375:Interleukin-1; D015850:Interleukin-6