Effects of various pollutant mixtures on immune responses of the blue mussel (Mytilus edulis) collected at a salinity gradient in Danish coastal waters

Abstract

a b s t r a c tThe Baltic Sea is a semi-enclosed sea with a steady salinity gradient (3&e30&). Organisms have adapted to such low salinities, but are suspected to be more susceptible to stress. Within the frame of the integrated environmental monitoring BONUS þ project "BEAST" the applicability of immune responses of the blue mussel was investigated in Danish coastal waters. The sampling sites were characterised by a salinity range (11e19&) and different mixtures of contaminants (metals, PAHs and POPs), according to chemical analysis of mussel tissues. Variation partitioning (redundancy analysis) was applied to decompose salinity and contamination effects. The results indicated that cellular immune responses (total and differential haemocyte count, phagocytic activity and apoptosis) were mainly influenced by contaminants, whereas humoral factors (haemolytic activity) were mainly impacted by salinity. Hence, cellular immune functions may be suitable as biomarkers in monitoring programmes for the Baltic Sea and other geographic regions with salinity variances of the studied range.Crown

Cell tracking and velocimetric parameters analysis as an approach to assess activity of mussel (Mytilus edulis) hemocytes in vitro

“…unit/hemolymph lL with r 2 = 0.9925 responses in fresh hemolymph samples. This result can be accounted for by interindividual diffrences in total hemocyte count or in distribution between circulating and infiltrated cells, as already suggested (Cajaraville and Pal 1995;Hoher et al 2012;Hughes et al 1991;Li et al 2008), but also by a poor reproducibility in hemolymph sampling. However, in our experients, MTT OD varied linearly as a function of plated hemolymph volumes.…”

“…Given that (1) fluorescent nuclei were randomly selected for cell tracking and (2) hemocytes were capable of fast shape changes, we consider that these differences cannot be definitely attributed to the occurrence of previously characterized less-motile small round basophils and spread eosinophilic granulocytes (Le Foll et al 2010). Again, fast shape changes associated to hemocyte motion and cell to cell interactions should trigger caution when interpreting morphological variations as makers of effects (Magazine et al 1996;Hoher et al 2012). In addition, attention should be drawn to variability of MTT Fig.…”

The cell cultures and the use of haemocytes from marine molluscs for ecotoxicology assessment

“…Cells preparation for in vitro exposure For many applications, e.g., morphological or functional testing, several authors showed that stimulation of fresh (Gagnaire et al 2004(Gagnaire et al , 2006Höher et al 2012) or primary cultured haemocytes in an artificial medium for a short time is sufficient (Mottin et al 2010;Ladhar-Chaabouni et al 2014;Astuya et al 2015;Katsumiti et al 2015). However, to determine the effect of low-level environmental toxicants on haemocyte viability or function, establishment of longer-term cultures would be required.…”

“…The phagocytosis activity was significantly reduced in presence of fluorene, pyrene and heavy fuel oil (HFO). Such reduction was determined by Höher et al (2012) who showed that the lowered phagocytic activity (uptake of NR stained zymosan particles) of M. edulis haemocytes was determined in mussels with the highest PCB body burden. Similarly, Gagnaire et al (2006) showed that a mixture of eight pesticides during 24 h decreased phagocytotic activity of C. gigas haemocytes using flow cytometry.…”

Effects of pyrene exposure on immune response and oxidative stress in the pearl oyster, Pinctada martensii

“…Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants in the marine environment, which possess immunotoxic characteristics, carcinogenic and mutagenic [7,56], such as which can disrupt the immune defenses of Crassostrea gigas [5], Pecten maximus [32], Haliotis diversicolor [27], Mytilus edulis [33] and Venerupis philippinarum [48]. PAHs occur in crude petroleum oil or as a result of incomplete combustion and have been considered priority pollutants by the U.S. Environmental Protection Agency [38].…”