title: Selective gene expression and activation-dependent regulation of vasoactive intestinal peptide receptor type 1 and type 2 in human T cells.
abstract: Vasoactive intestinal peptide (VIP) has potent antiproliferative and anti-inflammatory functions in the immune system. Two structurally distinct G-protein-associated receptors, VIP receptor type 1 (VPAC1) and VIP receptor type 2 (VPAC2), mediate the biological effects of VIP. The regulation of VIP receptor gene expression and the distribution of these receptors in different compartments of the human immune systems are unknown. This study reports, for the first time, a quantitative analysis of VPAC1 and VPAC2 mRNA expression in resting and activated T cells as well as in resting monocytes. Purified human peripheral blood CD4(+) T cells and CD8(+) T cells were stimulated via the TCR/CD3 receptor complex. Using the novel fluorometric-based kinetic (real-time) RT-PCR, we determined that VPAC1 is constitutively expressed in resting T cells and monocytes; the levels of expression were significantly higher in monocytes and CD4(+) T cells than in CD8(+) T cells. VPAC1 mRNA expression is significantly higher relative to VPAC2 in resting CD4(+) T cells and CD8(+) T cells. VPAC2 is expressed at very low levels in resting T cells but is not detectable in resting monocytes. In vitro stimulation of Th cells with soluble anti-CD3 plus PMA induced a T cell activation-dependent down-regulation of VPAC1. VPAC1 is down-regulated under conditions of optimal T cell stimulation. Our results suggest that selective VIP effects on T cell function may be mediated via selective expression of VPAC1 and VPAC2 on T cells and monocytes. Furthermore, down-regulation of VPAC1 in CD4(+) T cell subpopulations is highly correlated with T cell activation.
authors.affiliation: Children's Research Institute, Departments of Pediatrics, Molecular Immunology, Virology, and Human Genetics, and Internal Medicine, Comprehensive Cancer Center, Ohio State University, Columbus, OH 43205, USA.
authors.forename: M
authors.initials: M
authors.lastname: Lara-Marquez
authors.forename: M
authors.initials: M
authors.lastname: O'Dorisio
authors.forename: T
authors.initials: T
authors.lastname: O'Dorisio
authors.forename: M
authors.initials: M
authors.lastname: Shah
authors.forename: B
authors.initials: B
authors.lastname: Karacay
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D017252:CD3 Complex / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D015536:Down-Regulation / Q000276:immunology; D005260:Female; D005786:Gene Expression Regulation / Q000276:immunology*; D019073:HT29 Cells; D006801:Humans; D007399:Interphase / Q000235:genetics / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism; D018005:Receptors, Vasoactive Intestinal Peptide / Q000096:biosynthesis* / Q000235:genetics*; D051239:Receptors, Vasoactive Intestinal Peptide, Type II; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I; D012995:Solubility; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D017252:CD3 Complex; D011948:Receptors, Antigen, T-Cell; D018005:Receptors, Vasoactive Intestinal Peptide; D051239:Receptors, Vasoactive Intestinal Peptide, Type II; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I; C495509:VIPR2 protein, human; D013755:Tetradecanoylphorbol Acetate