Biologic properties of homogeneous interleukin 3. I. Demonstration of WEHI-3 growth factor activity, mast cell growth factor activity, p cell-stimulating factor activity, colony-stimulating factor activity, and histamine-producing cell-stimulating factor activity.
Interleukin 3 (IL 3) was initially defined as a factor in conditioned media from concanavalin A-stimulated lymphocytes (Con A CM) that induces the enzyme 20-alpha-hydroxysteroid dehydrogenase (20 alpha SDH) in cultures of nu/nu splenic lymphocytes. To determine the spectrum of additional "biologic" activities, IL 3 was purified to homogeneity and its properties were assessed. The protein preparation was judged to be homogeneous IL 3 by the following criteria: 1) elution of a peak of IL 3 with a constant specific activity in the last step of purification, 2) presence of a single protein by SDS-PAGE analysis, 3) receptor-binding activity against IL 3-dependent cell lines, 4) a specific activity of congruent to 0.2 ng/ml required for 50% of maximal biologic activity, and 5) the presence of a single amino terminal sequence. With the use of this preparation of IL 3, the dose-response curves for 20 alpha SDH induction were identical or similar to the dose-response curves for the activities of 1) WEHI-3 growth factor, 2) mast cell growth factor, 3) P cell-stimulating factor, and 4) histamine-producing cell-stimulating factor. In addition, homogeneous IL 3 had colony-stimulating factor activity, although only approximately 2% of the total CSF activity found in Con A CM was associated with IL 3. The major peak of CSF activity could be resolved from IL 3 by DEAE column chromatography and lacked many of the biologic activities associated with IL 3.
D000818:Animals; D001665:Binding Sites; D001854:Bone Marrow Cells; D002460:Cell Line; D003115:Colony-Stimulating Factors / Q000502:physiology*; D003470:Culture Media; D006133:Growth Substances / Q000502:physiology*; D006636:Histamine Release; D007377:Interleukin-3; D008222:Lymphokines / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D008407:Mast Cells / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude
D003115:Colony-Stimulating Factors; D003470:Culture Media; D006133:Growth Substances; D007377:Interleukin-3; D008222:Lymphokines