Production of IL-3 by non-transformed primary neonatal murine keratinocytes: evidence for constitutive IL-3 gene expression in neonatal epidermis.
Interleukin 3 (IL-3) is a cytokine produced by activated T lymphocytes that is best understood as a hematopoietic growth and differentiation factor. Production of IL-3 by other cell types is controversial; while certain transformed non-lymphocyte cell lines can produce IL-3, it is generally assumed that their non-transformed counterparts do not. It has been previously reported that Pam 212, a transformed murine keratinocyte cell line, produces IL-3. In this study we report that IL-3 can also be secreted by normal murine keratinocytes. Using a cell line (FL5.12) which is responsive to IL-3 and not to other keratinocyte derived cytokines, (e.g. GM-CSF, IL-1 and IL-6), we tested conditioned media from cultures of normal neonatal keratinocytes for biologically active IL-3. These media stimulated the proliferation of FL5.12, and the effect could be neutralized by specific antibodies to IL-3. The presence of IL-3 mRNA was demonstrated by polymerase chain reaction (PCR) amplification of reverse transcribed IL-3 mRNA from cultured normal neonatal keratinocytes and confirmed by Southern blot analysis. By similar techniques, IL-3 mRNA could be identified in freshly isolated neonatal epidermis but not dermis. These data indicated that IL-3 is produced by keratinocytes in the skin of normal neonatal mice, raising the likelihood that the neonatal epidermal microenvironment may have hematopoietic or lymphopoietic properties.
Peterseim
U M
UM
Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.
Sarkar
S N
SN
Kupper
T S
TS
D000818:Animals; D000831:Animals, Newborn; D002460:Cell Line; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D046508:Culture Techniques / Q000379:methods; D016207:Cytokines / Q000494:pharmacology*; D018076:DNA, Complementary / Q000302:isolation & purification; D004587:Electrophoresis, Agar Gel; D004817:Epidermis / Q000378:metabolism*; D015870:Gene Expression; D007376:Interleukin-2 / Q000032:analysis; D007377:Interleukin-3 / Q000032:analysis / Q000096:biosynthesis* / Q000494:pharmacology; D015847:Interleukin-4 / Q000032:analysis; D015603:Keratinocytes / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D017077:Culture Media, Conditioned; D016207:Cytokines; D018076:DNA, Complementary; D007376:Interleukin-2; D007377:Interleukin-3; D012333:RNA, Messenger; D011994:Recombinant Proteins; D015847:Interleukin-4