Ka. Garreis et al., THE EFFECTS OF PERKINSUS-MARINUS EXTRACELLULAR PRODUCTS AND PURIFIED PROTEASES ON OYSTER DEFENSE PARAMETERS IN-VITRO, Fish & shellfish immunology, 6(8), 1996, pp. 581-597
The effects of extracellular products (ECP) and purified proteases fro
m the protozoan parasite Perkinsus marinus on three host defence param
eters (haemocyte motility, lysozyme and haemagglutinin) of the eastern
oyster, Crassostrea virginica, were investigated. ECP with high prote
olytic activities, as well as purified proteases, significantly decrea
sed the random migration of haemocytes through micro-porous filters in
Boyden chambers. Stimulation of haemocyte migration by P. marinus cel
ls or P. marinus cell lysate was also dramatically reduced by ECP and
purified proteases. Incubation of oyster plasma with ECP and purified
proteases caused a significant decrease in lysozyme activity and also
appeared to reduce haemagglutinin titres. These data suggest that P. m
arinus ECP, as well as the proteolytic fraction of the ECP, can modula
te some defence parameters of oysters in vitro. (C) 1996 Academic Pres
s Limited