Murine hematopoietic progenitor cells produce IL-6 in response to IgE.
Similarly to interleukin-3 (IL-3), IgE is capable of inducing IL-6 production by murine bone marrow cells (BMC). IgE responder cells do not belong to the mature bone marrow compartment but coenrich with hematopoietic progenitors in the low-density fraction of a discontinuous Ficoll gradient. A significant enhancement of IL-6 production is observed after a 4-hour stimulation, reaching a maximum between 24 and 48 hours and is preceded by increased mRNA expression. The effect of IgE on IL-6 production is not mediated by IL-3 since it is not modified by anti-IL-3 antibodies. Upon a 4-hour exposure to IgE or IL-3, a similar percentage of progenitor-enriched BMC expresses IL-6 mRNA (3.9 and 5.4%, respectively, as determined by in situ hybridization), which is not further increased by a combination of both stimuli. IgE and IL-3 responder cells also cannot be distinguished on the basis of size, internal structure, and rhodamine (Rh) retention. The BMC sorted in the most fluorescent Rhbright subset (approximately 0.2% of total BMC) produce 30- to 40-fold more IL-6 than unfractionated cells and are similarly enriched for CFU-cells (CFU-C). The most primitive cells concentrated in the Rhdull fraction do not express this biological activity. The sorted Rhbright population does not contain mature mast cells/basophils or monocytes, and IL-6 is not produced in response to Fc epsilon RI cross-linkage after presensitization with IgE.
Schneider
E
E
CNRS URA 1461, Hôpital Necker, Paris, France.
Salachas
F
F
Lemoine
F M
FM
Arnould
A
A
Machavoine
F
F
Ploemacher
R E
RE
Dy
M
M
D000818:Animals; D001853:Bone Marrow / Q000378:metabolism; D001854:Bone Marrow Cells; D002469:Cell Separation; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects; D006410:Hematopoiesis / Q000187:drug effects; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D007073:Immunoglobulin E / Q000494:pharmacology*; D007074:Immunoglobulin G / Q000378:metabolism; D017403:In Situ Hybridization; D007377:Interleukin-3 / Q000494:pharmacology; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000235:genetics; D011961:Receptors, Fc / Q000378:metabolism; D011994:Recombinant Proteins
D007074:Immunoglobulin G; D007377:Interleukin-3; D015850:Interleukin-6; D012333:RNA, Messenger; D011961:Receptors, Fc; D011994:Recombinant Proteins; D007073:Immunoglobulin E