Immune roles of a rhamnose-binding lectin in the colonial ascidian Botryllus schlosseri.
The present paper describes the immune role played by a recently identified (Gasparini et al. 2008) member of the rhamnose-binding lectin (RBL) family from the colonial ascidian Botryllus schlosseri. B. schlosseri RBL (BsRBL) can activate phagocytes through: (i) induction of their directional movement towards the source of the molecule; (ii) modification of cytoskeleton, required for shape changes; (iii) stimulation of the respiratory burst, and consequent production of reactive oxygen species (ROS) with microbicidal activity, including superoxide anions and peroxides; and (iv) increase in the ability to phagocytose foreign particles. RBL also induces the synthesis and release, by cytotoxic morula cells (MCs), of cytokines recognised by anti-IL1α and anti-TNFα antibodies. At high concentrations, BsRBL induces degranulation of MCs and the consequent release of the cytotoxic enzyme phenoloxidase into the medium. Results are consistent with the existence of cross-talk between B. schlosseri immunocytes (phagocytes and MCs). In addition, a three-dimensional model for BsRBL is presented.
Department of Biology, University of Padova, Via U. Bassi 58/B, 35131 Padova, Italy.
Nicola
N
Franchi
Filippo
F
Schiavon
Matteo
M
Carletto
Fabio
F
Gasparini
Giulio
G
Bertoloni
Silvio C E
SC
Tosatto
Loriano
L
Ballarin
D000371:Agglutination / Q000187:drug effects / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000187:drug effects / Q000276:immunology; D015550:Cell Degranulation / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D004912:Erythrocytes / Q000187:drug effects / Q000276:immunology; D053582:Interleukin-1alpha / Q000276:immunology; D037102:Lectins / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism* / Q000494:pharmacology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010586:Phagocytes / Q000187:drug effects / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D011487:Protein Conformation; D011817:Rabbits; D012210:Rhamnose / Q000276:immunology* / Q000378:metabolism*; D016415:Sequence Alignment; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology; D014561:Urochordata / Q000276:immunology* / Q000378:metabolism*; D015003:Yeasts / Q000187:drug effects / Q000276:immunology
D053582:Interleukin-1alpha; D037102:Lectins; D014409:Tumor Necrosis Factor-alpha; D012210:Rhamnose