title: Glucocorticosteroid-induced immunoglobulin production requires intimate contact between B cells and monocytes.
abstract: Glucocorticosteroid (GCS)-induced immunoglobulin (Ig) production in vitro is dependent on the functions of T cells and monocytes. T cells produce a replacing factor (TRF-S) which, with monocytes and a broad spectrum of concentrations (both above and below the physiologic range) of GCS, stimulates B cells to synthesize Ig. TRF-S is produced by T cells in cultures of mononuclear cells in the absence of stimulation over the initial 72 hr in culture. T cells, however, require the presence of monocytes or small quantities of interleukin 1 in order for the synthesis of TRF-S to occur. In addition to their role in stimulating TRF-S production, monocytes are also required in cultures of B cells responding to GCS and the cytokine. These experiments demonstrate that this monocyte function cannot be replaced by IL-1 or crude supernatants of monocyte cultures. Furthermore, exposure of TRF-S containing supernatants to oxidizing conditions does not alter the dependence of the cytokine on monocytes or GCS. Coculture of B cells and monocytes separated by a permeable membrane demonstrated that the influence of monocytes on GCS-induced Ig production is unlikely to be mediated by stable soluble factors. Thus, GCS-induced Ig production requires intimate contact between monocytes and B cells in the form of surface contact or unstable soluble mediators.
authors.affiliation: Department of Internal Medicine, Baylor College of Medicine, Houston, Texas.
authors.forename: F M
authors.initials: FM
authors.lastname: Orson
authors.forename: C A
authors.initials: CA
authors.lastname: Auzenne
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D002450:Cell Communication / Q000187:drug effects; D003907:Dexamethasone / Q000494:pharmacology*; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology*; D007136:Immunoglobulins / Q000096:biosynthesis*; D015848:Interleukin-5; D007378:Interleukins / Q000378:metabolism; D009000:Monocytes / Q000276:immunology / Q000502:physiology*
chemical_list: D007136:Immunoglobulins; D015848:Interleukin-5; D007378:Interleukins; D003907:Dexamethasone; D006854:Hydrocortisone