title: IL-12 stimulates the osteoclast inhibitory peptide-1 (OIP-1/hSca) gene expression in CD4+ T cells.
abstract: Immune cell products such as interferon (IFN)-gamma and interleukin (IL)-12 are potent inhibitors of osteoclast formation. We previously characterized the human osteoclast inhibitory peptide-1 (OIP-1/hSca), a Ly-6 gene family member and showed IFN-gamma modulation of OIP-1 expression in bone marrow cells. Whether, IL-12 regulates OIP-1 expression in the bone microenvironment is unclear. Real-time PCR analysis revealed that IL-12 treatment significantly enhanced OIP-1 mRNA expression in human bone marrow mononuclear cells. Because IL-12 induces IFN-gamma production by T cells, we tested whether IFN-gamma participates in IL-12 stimulation of OIP-1 gene expression in these cells. IL-12 treatment in the presence of IFN-gamma neutralizing antibody significantly increased OIP-1 mRNA expression, suggesting that IL-12 directly regulates OIP-1 gene expression. Interestingly, real-time PCR analysis demonstrated that IL-12 induces OIP-1 expression (3.2-fold) in CD4+ T cells; however, there was no significant change in CD8+ T cells. Also, IL-12 (10 ng/ml) treatment of Jurkat cells transfected with OIP-1 gene (-1 to -1,988 bp) promoter-luciferase reporter plasmid demonstrated a 5-fold and 2.7-fold increase in OIP-1 gene promoter activity in the presence and absence of antibody against IFN-gamma, respectively. We showed that STAT-1,3 inhibitors treatment significantly decreased IL-12 stimulated OIP-1 promoter activity. Chromatin immunoprecipitation (ChIP) assay confirmed STAT-3, but not STAT-1 binding to the OIP-1 gene promoter in response to IL-12 stimulation. These results suggest that IL-12 stimulates the OIP-1 gene expression through STAT-3 activation in CD4+ T cells.
authors.affiliation: Charles P Darby Children's Research Institute, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Shanmugarajan
authors.forename: Noriaki
authors.initials: N
authors.lastname: Kawanabe
authors.forename: Masanori
authors.initials: M
authors.lastname: Koide
authors.forename: Eichi
authors.initials: E
authors.lastname: Tsuruga
authors.forename: Jazmine E
authors.initials: JE
authors.lastname: Arroyo
authors.forename: Lyndon L
authors.initials: LL
authors.lastname: Key
authors.forename: Sakamuri V
authors.initials: SV
authors.lastname: Reddy
mesh_terms: D000074183:ATPases Associated with Diverse Cellular Activities; D048868:Adaptor Proteins, Signal Transducing / Q000096:biosynthesis* / Q000235:genetics; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D015870:Gene Expression; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism*; D019169:Jurkat Cells; D060588:LIM Domain Proteins; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D046988:Proteasome Endopeptidase Complex; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050796:STAT3 Transcription Factor / Q000378:metabolism; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D060588:LIM Domain Proteins; C092282:PSMC5 protein, human; D012333:RNA, Messenger; D050796:STAT3 Transcription Factor; D014157:Transcription Factors; D018664:Interleukin-12; D007371:Interferon-gamma; D046988:Proteasome Endopeptidase Complex; D000074183:ATPases Associated with Diverse Cellular Activities