Mouse bone marrow-derived mast cells (mBMMC) obtained in vitro from mice that are mast cell-deficient in vivo express the same panel of granule proteases as mBMMC and serosal mast cells from their normal littermates.

Abstract

SummaryThe ear, skin, and purified serosal mast calls of WBB6F1/J-+/+ (WB-+/+) and WCB6Ft/J-+/+ (WC-+/+) mice contain high steady-state levels of the transcripts that encode mouse mast cell protease (mMCP) 2, mMCP-4, mMCP-5, mMCP-6, and mouse mast cell carboxypeptidase A (mMC-CPA). In contrast, no mast cell protease transcripts are present in abundance in the ear and skin of and WCB6F1/J-SI/S1 d (SI/SI a) mice which are mast cell-deficient in vivo due to defects in their c-kit and c-kit ligand genes, respectively. We now report that the immature bone marrow-derived mast cells (mBMMC) obtained in vitro with recombinant interleukin 3 (rIL-3) or WEHI-3 cell conditioned medium from WB-+/+, WC-+/+, W/W ~, and SI/SI d mice all contain high steady-state levels of the mMCP-2, mMCP-4, mMCP-5, mMCP-6, and mMC-CPA transcripts. As assessed immunohistochemically, mMCP-2 protein and mMCP-5 protein are also present in the granules of mBMMC from WB-+/+, WC-+/+, and W/W ~ mice. That SI/SI d and W/W ~ mBMMC contain high steady-state levels of five granule protease transcripts expressed by the mature serosal, ear, and skin mast cells of their normal +/+ littermates suggests that c-kit-mediated signal transduction is not essential for inducing transcription of these protease genes. Because rlL-4 inhibits the rlL-10-induced expression of mMCP-1 and mMCP-2 in BALB/cJ mBMMC, the ability of rlL-4 to influence protease mRNA levels in WC-+/+ mBMMC and W/W ~ mBMMC was investigated. Although rlL-10 induced expression of the mMCP-1 transcript in WC-+/+ and W/W ~ mBMMC, rIL-4 was not able to suppress the steady-state levels of the mMCP-1 transcript or any other protease transcript in these cuhured mast cells. Thus, not only do BALB/cJ mBMMC express fewer granule proteases than mBMMC from mast cell-deficient strains and their normal littermates but the subsequent induction of late-expressed proteases in BALB/cJ mBMMC is more tightly regulated by IL-3 and IL-4.

Independent Influence of Strain Difference and mi Transcription Factor on the Expression of Mouse Mast Cell Chymases

“…This is consistent with the results of Eklund et al 27 The poor expression of mMCP-7 gene in the B6 mice is because of the presence of a stop codon. The resulting truncated transcript degraded quickly in CMCs.…”

“…On the other hand, the expression of mMCP-2 and -4 genes was much higher in CMCs derived from WB-ϩ/ϩ mice than in CMCs of B6-ϩ/ϩ mice. 16,27 The effect of MITF on the expression of mMCP-2 and -4 genes remained to be examined in the WB strain. In the present study, we crossed WB-ϩ/ϩ mice to B6-mi/ϩ mice to obtain the mice that possessed the WB strain-derived mMCP-2 genes and the double gene dose of mutant mi allele.…”

An intrinsic adrenergic system in mammalian heart.

“…Antibodies (IgG) against neuron-specific enolase (NSE) and protein gene product 9.5 were also used at 1:5,000 dilution. Isolated intrinsic cardiac adrenergic (ICA) cells (see below) from adult rat hearts were stained using an alkaline phosphatase immunohistochemical method (9). Antibodies against TH and NSE were used at 1:50 and 1:100 dilution, respectively.…”

Loss of Histochemical Identity in Mast Cells Lacking Carboxypeptidase A

“…Mc-cpa, a mast cellspecific gene (32), is expressed in the earliest known mast cell-committed progenitors identified in fetal blood as cells expressing high levels of c-Kit and low levels of Thy-1 and lacking FcεRI expression (34). Mc-cpa is also, albeit weakly, expressed in immature bone marrow (BM)-derived mast cell cultures (BMMC) (5,14,36). In mature mast cells, Mc-cpa is abundantly expressed in CTMC but only weakly in MMC (14,36).…”