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Fig. 2. Dose-response effect of TGF-ß1 on the proliferation and expansion of
keratinocytes. (A) Long-term cultures were initiated with keratinocytes of the
Adh+++ or Adh-/+ populations, and maintained with or
without addition of exogenous TGF-ß1 at a concentration of 10, 30, 100 or
300 pg/ml throughout the culture period, as specified. Results are expressed
as a cumulated cell output. (B) Long-term cultures were initiated with sorted
keratinocytes of the Adh+++EGF-R-/+ subpopulation, and
maintained in the presence or absence of exogenous TGF-ß1 at a
concentration of 10 or 100 pg/ml throughout the culture period. Results are
expressed as a cumulated cell output. Data represent means±s.d. of four
replicate cultures from one typical experiment. (C) Long-term cultures were
initiated with sorted keratinocytes of the
Adh+++EGF-R-/+ subpopulation and maintained in the
presence or absence of TGF-ß1 at the concentration that promotes
self-renewal of immature keratinocytes (10 pg/ml). Typical morphology of the
cells obtained in these two conditions after 85 and 95 days of culture is
illustrated in Fig. 2C.