Complement-like activity in the sea star, Asterias forbesi

L. A. Leonard, J. D. Strandberg, J. A. Winkelstein

Research output: Contribution to journalArticlepeer-review


The coelomic fluid (CF) of Asterias forbesi was examined for the presence of complement-like activity. Cell-free CF contains hemolytic activity for unsensitized rabbit erythrocytes (E) but not unsensitized or antibody-coated sheep E. Target E sensitivity is not dependent upon phylogenetic proximity of erythrocyte species to Asterias. The activity is optimally assayed at 25°C, has a sigmoidal dose-response curve, and is heat-sensitive (56°C). The activity is divalent cation dependent, although Ca++ and Mg++ are not required. Nonlytic CF does not contain an inhibitor; rather, combining nonlytic and lytic CFs results in an increase in hemolysis. Activity can be consumed by treatment with zymosan, pronase, trypsin, and PMSF. Enzymatic desialidation converts sheep E into activators of the hemolytic pathway. No phospholipase activity is present in CF. Biological function is demonstrated by bactericidal activity against Vibrio tubiashii by lytic CF. These results suggest that a primitive complement system is operating in Asterias.

Original languageEnglish (US)
Pages (from-to)19-30
Number of pages12
JournalDevelopmental and Comparative Immunology
Issue number1
StatePublished - 1990


  • Alternative pathway
  • Asterias forbesi
  • Bactericidal
  • Biochemical characterization
  • Complement
  • Echinodermata
  • Hemolytic
  • Sea star

ASJC Scopus subject areas

  • Immunology
  • Developmental Biology


Dive into the research topics of 'Complement-like activity in the sea star, Asterias forbesi'. Together they form a unique fingerprint.

Cite this