title: Plasmid-encoded NP73-102 modulates atrial natriuretic peptide receptor signaling and plays a critical role in inducing tolerogenic dendritic cells.
abstract: BACKGROUND
  Atrial natriuretic peptide (ANP) is an important endogenous hormone that controls inflammation and immunity by acting on dendritic cells (DCs); however, the mechanism remains unclear.
  
  
  OBJECTIVE
  We analyzed the downstream signaling events resulting from the binding of ANP to its receptor, NPRA, and sought to determine what aspects of this signaling modulate DC function.
  
  
  METHODS
  We utilized the inhibitory peptide, NP73-102, to block NPRA signaling in human monocyte-derived DCs (hmDCs) and examined the effect on DC maturation and induced immune responses. The potential downstream molecules and interactions among these molecules involved in NPRA signaling were identified by immunoprecipitation and immunoblotting. Changes in T cell phenotype and function were determined by flow cytometry and BrdU proliferation ELISA. To determine if adoptively transferred DCs could alter the in vivo immune response, bone marrow-derived DCs from wild-type C57BL/6 mice were incubated with ovalbumin (OVA) and injected i.v. into C57BL/6 NPRA-/- knockout mice sensitized and challenged with OVA. Lung sections were stained and examined for inflammation and cytokines were measured in bronchoalveolar lavage fluid collected from parallel groups of mice.
  
  
  RESULTS
  Inhibition of NPRA signaling in DCs primes them to induce regulatory T cells. Adoptive transfer of wild type DCs into NPRA-/- mice reverses the attenuation of lung inflammation seen in the NPRA-knockout model. NPRA is associated with TLR-2, SOCS3 and STAT3, and inhibiting NPRA alters expression of IL-6, IL-10 and TGF-β, but not IL-12.
  
  
  CONCLUSIONS
  Modulation of NPRA signaling in DCs leads to immune tolerance and TLR2 and SOCS3 are involved in this induction.
authors.affiliation: Department of Internal Medicine, Division of Allergy and Immunology, University of South Florida College of Medicine, Tampa, FL 33612, USA.
authors.forename: Weidong
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FL 33612, USA.
authors.forename: Xueqin
authors.initials: X
authors.lastname: Cao
authors.affiliation: Department of Internal Medicine, Division of Allergy and Immunology, University of South Florida College of Medicine, Tampa, FL 33612, USA.
authors.forename: Dongqing
authors.initials: D
authors.lastname: Chen
authors.affiliation: James A. Haley Veterans Hospital Medical Center, Tampa, FL 33612, USA.
authors.forename: Jia-Wang
authors.initials: JW
authors.lastname: Wang
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, University of South Florida College of Medicine, Tampa, FL 33612, USA.
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
authors.affiliation: Donald A. Adam Comprehensive Melanoma Research Center, Moffitt Cancer Center, 12902 Magnolia Drive, SRB-24324, Tampa, FL 33612, USA.
authors.forename: Wenshi
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FL 33612, USA.|Department of Internal Medicine, Division of Translational Medicine, University of South Florida College of Medicine, Tampa, FL 33612, USA.
authors.forename: Subhra
authors.initials: S
authors.lastname: Mohapatra
authors.affiliation: Department of Internal Medicine, Division of Allergy and Immunology, University of South Florida College of Medicine, Tampa, FL 33612, USA.
authors.forename: Gary
authors.initials: G
authors.lastname: Hellermann
authors.affiliation: Department of Internal Medicine, Division of Allergy and Immunology, University of South Florida College of Medicine, Tampa, FL 33612, USA.
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Kong
authors.affiliation: Department of Internal Medicine, Division of Allergy and Immunology, University of South Florida College of Medicine, Tampa, FL 33612, USA.|James A. Haley Veterans Hospital Medical Center, Tampa, FL 33612, USA.
authors.forename: Richard F
authors.initials: RF
authors.lastname: Lockey
authors.affiliation: Department of Internal Medicine, Division of Allergy and Immunology, University of South Florida College of Medicine, Tampa, FL 33612, USA.|James A. Haley Veterans Hospital Medical Center, Tampa, FL 33612, USA.|Department of Internal Medicine, Division of Translational Medicine, University of South Florida College of Medicine, Tampa, FL 33612, USA.
authors.forename: Shyam S
authors.initials: SS
authors.lastname: Mohapatra