Stimulation of mucosal mast cell growth in normal and nude rat bone marrow cultures.

Abstract

Mast cells with the morphological and biochemical properties of mucosal mast cells (MMC) appear and proliferate to form the predominant cell type in rat bone marrow cultures stimulated with factors from antigen-or mitogen-activated lymphocytes. Conditioned media causing a selective proliferation of MMC were derived from mesenteric lymph node cells of Nippostrongylus brasiliensis-infected rats restimulated in vitro with specific antigen or from normal or infected rat mesenteric lymph node cells stimulated with concanavalin A. MMC growth factor is not produced by T-cell-depleted mesenteric lymph node cells or by the mesenteric lymph node cells of athymic rats. By contrast, MMC precursors are present in the bone marrow of athymic rats and are normally receptive to the growth factor produced by the lymphocytes of thymus-intact rats. The thymus dependence of MMC hyperplasia is thus based on the requirement of a thymusindependent precursor for a T-cell-derived growth promoter.We recently reported that lymphocytes of helminth-infected rats, on in vitro restimulation with specific antigen, release factors that cause the emergence and selective proliferation of mast cells in normal rat bone marrow cultures (1). We identified these cells as mucosal mast cells (MMC) because, although exhibiting the characteristic morphology and IgE-binding property common to all mast cells, they contained fewer and more variable sized granules than peritoneal mast cells and, unlike the latter, were astra blue-positive at pH 0.3 after Carnoy fixation. These features have been shown to distinguish MMC from the classical mature connective tissue type of mast cells of which the peritoneal cell is a representative (2). Additionally, we found that the cultured mast cells synthesized large amounts of a chymotrypsin-like serine protease, designated rat mast cell protease II (RMCP II) (3), which is distinct from the protease of connective tissue mast cells and has been specifically localized to mast cells of the mucous membranes (4).The experiments described here were performed to determine if MMC growth factor would be produced by mitogenas well as antigen-activated lymphocytes and to explore the basis of the thymus dependency of MMC proliferation. 1-,um latex spheres (Polyscience, Northampton, United Kingdom). Immunoglobulin-bearing (Ig+) cells were depleted by immunoadsorption to sheep F(ab')2 anti-rat Ig coupled to CNBractivated Sepharose 6MB (Pharmacia). Sheep anti-rat Ig antibodies were purified by affinity chromatography to rat gamma globulin-Sepharose 4B. The antibodies were pepsin-digested and F(ab')2 fragments were isolated by gel filtration by using standard techniques. A sample of 108 cells in 1 ml of Hanks' balanced salt solution/0. 1% sodium azide/0.3% bovine serum albumin was run into the column, which was incubated at room Abbreviations: CM, conditioned medium; MLN, mesenteric lymph node cell; MMC, mucosal mast cell; RMCP, rat mast cell protease; Con A, concanavalin A. 4499The publication costs of this article were defrayed...

Stem cell factor enhances immunoglobulin E‐dependent mediator release from cultured rat bone marrow‐derived mast cells: activation of previously unresponsive cells demonstrated by a novel ELISPOT assay

“…In some experiments, cells were challenged directly with goat anti-rat IgE (provided by Dr E. Hall, Glasgow Veterinary School, UK), because cultured rat BMMC maintained in LNCM are ordinarily exposed to 1-2 m g rat IgE per ml, 25 and binding of this endogenous IgE to BMMC was detected throughout culture by flow cytometry (not shown). In other experiments (see legends), IgE binding was increased (shown by flow cytometry) by passively sensitizing the BMMC with monoclonal mouse IgE anti-dinitrophenyl (DNP) (SPE-7, Sigma).…”

Thymus Dependence of Compound 48/80-Induced Mucosal Mast Cell Proliferation

“…The growth of these cells is critically dependent on a T cell-derived factor, inter leukin 3 [Ihle et al, 1983]. Similarly, T cell-dependent MMC-like mast cells have been cultured from rat bone marrow [Haig et al, 1982[Haig et al, , 1983. However, the differentiation and maintenance of tissue mast cells in the unstimulated animal may not require an intact thymus.…”

Homology of the rat basophilic leukemia cell and the rat mucosal mast cell.

“…Disodium cromoglycate and theophylline inhibit the activation of the connective tissue mast cell but not of the mucosal mast cell (12). Homogeneous populations of mast cells resembling the mucosal mast cell subclass have been obtained in vitro from rat bone marrow cultured in the presence of conditioned medium from antigen-activated immune mesenteric lymph nodes (13,14). These mast cells stain with alcian blue but not safranin, have low amounts of histamine, contain RMCP-II, and appear to have a non-heparin proteoglycan (15).…”