title: Immunolocalization of clavanins in Styela clava hemocytes.
abstract: Antimicrobial peptides play an important role in innate host defenses against infection. Clavanins are histidine-rich, amidated, 23-residue alpha-helical antimicrobial peptides that were isolated from a mixed population of Styela clava hemocytes. To learn which types of hemocytes contained clavanins, we raised a polyclonal antibody that recognized five different clavanins, and used it to localize these peptides by light and electron microscopy. Clavanins were present in the cytoplasmic granules and/or cytoplasm of five different types of granulocytes and they also occurred throughout the cytoplasm of macrophages. The orange G component of Mallory's trichrome stain had a high affinity for clavanins, and for the cytoplasmic granules of S. clava's hemocytes. Semiquantitative analysis of acid urea-PAGE gels suggested that clavanins and styelins comprised between 10 and 20% of the total cellular protein of eosinophilic granulocytes. Orange G and the century-old trichrome stain may provide simple screening tools for identifying cells that contain large amounts of antimicrobial peptides in mixed hemocyte populations.
authors.affiliation: Department of Medicine, UCLA School of Medicine, CHS 37-062, 10833 LeConte Avenue, Los Angeles, CA 90095-1690,USA.
authors.forename: Lorenzo P
authors.initials: LP
authors.lastname: Menzel
authors.forename: In Hee
authors.initials: IH
authors.lastname: Lee
authors.forename: Birgitta
authors.initials: B
authors.lastname: Sjostrand
authors.forename: Robert I
authors.initials: RI
authors.lastname: Lehrer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001391:Azo Compounds / Q000737:chemistry; D001798:Blood Proteins / Q000276:immunology* / Q000378:metabolism; D015153:Blotting, Western; D004396:Coloring Agents / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004801:Eosine Yellowish-(YS) / Q000737:chemistry; D006434:Hemocytes / Q000276:immunology* / Q000378:metabolism / Q000648:ultrastructure; D007150:Immunohistochemistry; D008739:Methyl Green / Q000737:chemistry; D008854:Microscopy, Electron; D008858:Microscopy, Phase-Contrast; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D014561:Urochordata / Q000166:cytology / Q000276:immunology* / Q000378:metabolism
chemical_list: D001391:Azo Compounds; D001798:Blood Proteins; D004396:Coloring Agents; C106713:clavanin A; C017768:trichrome stain; D008739:Methyl Green; D004801:Eosine Yellowish-(YS)