Journal article
Preprosomatostatin messenger RNA is expressed by inflammatory cells and induced by inflammatory mediators and cytokines
The Journal of immunology (1950), Vol.160(8), pp.3997-4003
04/15/1998
DOI: 10.4049/jimmunol.160.8.3997
PMID: 9558108
Abstract
Somatostatin (SOM) is a 14-amino acid cyclic peptide that regulates granulomatous inflammation. SOM inhibits the release of IFN-gamma from murine granuloma T cells that express SOM receptors. SOM is synthesized as preprosomatostatin (ppSOM), a precursor peptide that is cleaved to release active SOM. In this paper, we demonstrate that granuloma cells express mRNA for this important immunoregulator, and that inflammatory mediators rapidly induce ppSOM mRNA in the splenocytes of uninfected, normal (NL) mice. We developed a sensitive, quantitative PCR assay that measures ppSOM mRNA down to 100 transcripts per microg of total RNA. Dispersed granuloma cells expressed authentic ppSOM mRNA as determined by RT-PCR and cDNA sequencing. The PCR assay readily detected ppSOM mRNA in splenocytes isolated from schistosome-infected mice, but not in splenocytes from NL mice. Splenic ppSOM mRNA expression correlated with the onset of parasite egg deposition and granuloma formation. A 4-h in vitro stimulation with LPS, rIL-10, rIFN-gamma, rTNF-alpha, prostaglandin E2, or dibutyryl cAMP induced ppSOM mRNA in NL splenocytes that otherwise lacked this transcript. Splenocytes from severe combined immunodeficient or recombination activating gene 1-deficient mice expressed ppSOM after exposure to rIL-10, suggesting that neither T nor B cells are necessary for ppSOM mRNA induction. A survey of cell lines demonstrated expression of ppSOM mRNA by P388D1 and J774A.1 macrophage-like cells. These data suggest that SOM, which is probably derived from macrophages, is an inducible component of the innate immune system that regulates T cell IFN-gamma production.
Details
- Title: Subtitle
- Preprosomatostatin messenger RNA is expressed by inflammatory cells and induced by inflammatory mediators and cytokines
- Creators
- David E Elliott - Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242, USAArthur M BlumJie LiAhmed MetwaliJoel V Weinstock
- Resource Type
- Journal article
- Publication Details
- The Journal of immunology (1950), Vol.160(8), pp.3997-4003
- DOI
- 10.4049/jimmunol.160.8.3997
- PMID
- 9558108
- ISSN
- 0022-1767
- eISSN
- 1550-6606
- Grant note
- AM38327 / NIADDK NIH HHS T2DK07663 / NIDDK NIH HHS DK02428 / NIDDK NIH HHS
- Language
- English
- Date published
- 04/15/1998
- Academic Unit
- Gastroenterology and Hepatology; Internal Medicine
- Record Identifier
- 9984094580202771
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