Research Interests:
Many helminth parasites have evolved strategies to evade the immune response of their hosts, which includes immunomodulation. Prostaglandin E2 (PGE2) is one of the best-described immunomodulators in mammalian helminth parasite infections.... more
Many helminth parasites have evolved strategies to evade the immune response of their hosts, which
includes immunomodulation. Prostaglandin E2 (PGE2) is one of the best-described immunomodulators in
mammalian helminth parasite infections. We hypothesized that also in teleost fish anti-helminthic
immune responses are regulated via PGE2. We used a model system consisting of the tapeworm Schistocephalus
solidus and its host, the three-spined stickleback (Gasterosteus aculeatus), to investigate in vitro
effects of PGE2 on head kidney leucocytes (HKL) derived from sticklebacks that were experimentally
infected with S. solidus. PGE2 was tested alone or in combination with either S. solidus antigens or
bacterial lipopolysaccharides (LPS). After in vitro culture, cell viability and changes in leucocyte subpopulations
(granulocytes to lymphocytes ratios) were monitored by flow cytometry and HKL were
tested for their capacity to produce reactive oxygen species (ROS) with a chemiluminescence assay. In
short term (2 h) HKL cultures PGE2 did not change the total numbers of live HKL, but the production of
ROS decreased significantly with high (0.1 mmol L1) PGE2 concentrations. In long-term (96 h) cultures
high PGE2 concentrations induced a sharp decrease of leucocytes viability, while low (0.1 pmol L1) and
intermediate (0.1 nmol L1) concentrations of PGE2 caused elevated leucocyte viability compared to
controls. This coincided with reduced ROS production in cultures with high PGE2 and elevated ROS
production in cultures with low PGE2. Granulocyte to lymphocyte ratios increased with high PGE2
concentrations alone and in combination with S. solidus antigens and LPS, most prominently with HKL
from S. solidus infected sticklebacks. The present study supports the hypothesis that PGE2 might be an
immunomodulator in tapewormefish parasiteehost interactions.
includes immunomodulation. Prostaglandin E2 (PGE2) is one of the best-described immunomodulators in
mammalian helminth parasite infections. We hypothesized that also in teleost fish anti-helminthic
immune responses are regulated via PGE2. We used a model system consisting of the tapeworm Schistocephalus
solidus and its host, the three-spined stickleback (Gasterosteus aculeatus), to investigate in vitro
effects of PGE2 on head kidney leucocytes (HKL) derived from sticklebacks that were experimentally
infected with S. solidus. PGE2 was tested alone or in combination with either S. solidus antigens or
bacterial lipopolysaccharides (LPS). After in vitro culture, cell viability and changes in leucocyte subpopulations
(granulocytes to lymphocytes ratios) were monitored by flow cytometry and HKL were
tested for their capacity to produce reactive oxygen species (ROS) with a chemiluminescence assay. In
short term (2 h) HKL cultures PGE2 did not change the total numbers of live HKL, but the production of
ROS decreased significantly with high (0.1 mmol L1) PGE2 concentrations. In long-term (96 h) cultures
high PGE2 concentrations induced a sharp decrease of leucocytes viability, while low (0.1 pmol L1) and
intermediate (0.1 nmol L1) concentrations of PGE2 caused elevated leucocyte viability compared to
controls. This coincided with reduced ROS production in cultures with high PGE2 and elevated ROS
production in cultures with low PGE2. Granulocyte to lymphocyte ratios increased with high PGE2
concentrations alone and in combination with S. solidus antigens and LPS, most prominently with HKL
from S. solidus infected sticklebacks. The present study supports the hypothesis that PGE2 might be an
immunomodulator in tapewormefish parasiteehost interactions.