Separated hemocyte populations from the ascidian Ciona intestinalis contain and release in vitro opsonizing Ca2+-independent and β-galactoside specific lectins

Abstract

Cytosolic lectins, Ca2+-independent and β-galactoside-specific, were determined to be containedin hemocyte and pharynx lysate supernatants of Ciona intestinalis, as revealed by hemagglutinationassay with trypsinized rabbit erythrocytes. Ca2+-independence and decreasing β-galactosidesinhibitory capacity (TDG > LacNAc ≥ Lactose > Galactose) have been considered properties typical ofgalectins. These lectins can be promptly released by hemocytes maintained in vitro suggesting theirinvolvement in defense responses including inflammatory reactions. Both cell lysate supernatants andhemocyte culture medium presented β-galactoside-inhibitable opsonizing activity versus yeast.Although a Percoll density gradient separation method showed that several hemocyte types containand release β-galactoside-specific molecules, results suggest that hyaline and granular amoebocytesare the primary source of these molecules.

Keywords

• hemocyte lectins
• hemagglutinins: β-galactosides
• phagocytosis
• opsonization
• hemocytes
• tunicates
• ciona intestinalis