Immunological effects of Chondrus armatus carrageenans and their low molecular weight degradation products.

Ability of high molecular weight (HMW) κ- and λ-carrageenans of the red marine algae Chondrus armatus and their low molecular weight degradation products (LMWDPs) (0.7-20 and 10-170 kDa respectively) to influence functional properties (motility and phagocytosis) of murine peritoneal macrophages was assessed in this study as an in vitro and a weeklong feeding experiment. We demonstrated that, with an exception of one, all carrageenan samples at 100 µg/ml increased cellular motility and dose-dependently decreased phagocytic activity; LMWDPs of λ-carrageenan suppressed motility and had no effect on phagocytosis. Oral administration of all the carrageenan samples at 100 µg/kg/day for 7 days to mice had no effect on their clinical appearance, body weight, weight of their liver, spleen or thymus or development of noticeable changes to their inner organs. All samples induced a shift of the cell composition of the peritoneal cavity towards macrophages. Consumption of LMWDPs of κ-carrageenan resulted in development of leukopenia, however, no changes to relative WBC count were introduced by either of the samples. All samples decreased murine peritoneal macrophages phagocytic activity, with λ-samples possessing higher efficacy than their κ-counterparts; all LMWDPs stimulated peritoneal macrophages motility, with κ-samples possessing higher efficacy than their λ-counterparts In conclusion, we have shown that κ- and λ-carrageenans of the C. armatus and their LMWDPs suppress phagocytotic activity of peritoneal macrophages under both in vitro and in vivo conditions. This allows them to be viewed as pharmacologically active substances andpropagates the need for their further investigation as such.

Reactivation of rolB transgene expression in Vitis amurensis Rupr. cells upon retransformation with 2b gene from Cucumovirus isolate NK.

OBJECTIVE: Studies concerning 2b protein from Cucumovirus showed 2b to effectively repress functioning of the plant silencing complex, current study aimed whether retransformation with 2b gene able to restore silenced transgene expression in plant cells. RESULTS: A rolB-transgenic cell culture of Vitis amurensis Rupr. that was continuously subcultured during more than 10 years and exhibited decreased transcription of the rolB transgene was retransformed with the 2b gene of Cucumovirus-NK. Three cell lines retransformed with 2b showed a significant up-regulation of rolB expression accompanied with enhancements in their stilbenes content level in more than 2,7-fold compared to parental rolB-transgenic cell line. The mentioned increase in the level of stilbenes content was due to activation of certain stilbene synthase genes expression responsible for stilbenes biosynthesis in V. amurensis cells. Restoration of rolB expression upon 2b-retransformation led to increase in the expression levels of VaSTS2-VaSTS5 and VaSTS7 isoforms. CONCLUSIONS: 2b from CMV-NK can reactivate a silenced transgene expression, even after 10 years of subcultivation, nevertheless, optimization of the methods concerning 2b introduction in plant genomes is necessary to avoid undesirable silencing effects.