title: In vivo administration of the frog skin peptide frenatin 2.1S induces immunostimulatory phenotypes of mouse mononuclear cells.
abstract: Host-defense peptides secreted by epithelial cells exhibit cytotoxic and immunoregulatory effects in order to protect the organism against invading microorganisms. Antimicrobial peptides derived from frog skin display both immunostimulatory and immunosuppressive actions as demonstrated by in vitro cytokine production by macrophages. Frenatin 2.1S, first isolated from skin secretions of the frog, Sphaenorhynchus lacteus (Hylidae), enhances the in vitro production of pro-inflammatory IL-1β, TNF-α and IL-23 by mouse peritoneal cells. In order to test whether the immunostimulatory action of frenatin 2.1S may be reproduced in vivo, effects of intraperitoneal injections of this peptide on mononuclear cells in the peritoneum and spleen were determined 24h after administration. The data indicate that frenatin 2.1S enhances the activation state and homing capacity of Th1 type lymphocytes and NKT cells in the mouse peritoneal cavity, as evaluated by increased expression of early activation marker CD69 among T and NKT cells and chemokine receptor CXCR3 among T cells. Frenatin 2.1S significantly increases the percentage of (F4/80(+)CD11c(+)CD206(+)) pro-inflammatory M1 macrophages and enhances the expression of MHC class II molecules on F4/80(+)CD11c(+) macrophages in the mouse peritoneal cavity. Additionally, injection of frenatin 2.1S, in the presence or absence of lipopolysaccharide, increases the percentage of peritoneal B cells of the (CD19(+)CD11b(+)CD5(+)) B1a phenotype thus contributing to an inflammatory milieu. We suggest that the immunostimulatory effect of frenatin 2.1S may have therapeutic relevance in disease states, such as certain types of cancer, in which an enhanced inflammatory response may be beneficial.
authors: Center for Molecular Medicine and Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia.
authors: Jelena M
authors: JM
authors: Pantic
authors: Center for Molecular Medicine and Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia.
authors: Gordana D
authors: GD
authors: Radosavljevic
authors: Center for Molecular Medicine and Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia.
authors: Ivan P
authors: IP
authors: Jovanovic
authors: Center for Molecular Medicine and Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia.
authors: Nebojsa N
authors: NN
authors: Arsenijevic
authors: SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, UK. Electronic address: m.conlon@ulster.ac.uk.
authors: J Michael
authors: JM
authors: Conlon
authors: Center for Molecular Medicine and Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia.
authors: Miodrag L
authors: ML
authors: Lukic
mesh_terms: D000276:Adjuvants, Immunologic / Q000737:chemistry / Q000494:pharmacology*; D029845:Amphibian Proteins / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D001001:Anura; D005786:Gene Expression Regulation / Q000187:drug effects / Q000276:immunology; D017737:Macrophages, Peritoneal / Q000276:immunology*; D051379:Mice; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D054367:Receptors, CXCR3 / Q000276:immunology; D012867:Skin / Q000737:chemistry*
chemical_list: D000276:Adjuvants, Immunologic; D029845:Amphibian Proteins; D015703:Antigens, CD; C515188:Cxcr3 protein, mouse; D010455:Peptides; D054367:Receptors, CXCR3
keywords: B1 lymphocyte; Frenatin 2.1S; Peritoneal macrophage; Pro-inflammatory cytokine; Th1 lymphocyte