Ovarian cavity fluid of the viviparous surfperch Neoditrema ransonnetii suppresses the spontaneous cytotoxic activity of head-kidney leucocytes against xenogeneic targets

Abstract

In this study, the effect of ovarian cavity fluid (OCF) from a surfperch Neoditrema ransonnetii on the cytotoxic activity of leucocytes was investigated. In an assay targeting RTG-2, a cell line derived from rainbow trout Oncorhynchus mykiss gonads, leucocytes from both the spleen and head kidney showed spontaneous killing activity. Pre-incubation with OCF significantly suppressed the cytotoxic activity of head-kidney leucocytes towards RTG-2. This suppressive activity was due to the presence of low molecular-mass materials. These results suggest that OCF plays significant roles in pregnancy by its ability to modulate cytotoxicity with maternal leucocytes.