Immunomodulating polysaccharides from North Atlantic Sea cucumber (Cucumaria frondosa)

Chondroitin sulfate (CS) is a glycosaminoglycan composed of a chain of alternating sugars (N- acetyl galactosamine and glucuronic acid) and present in cartilage tissue of most animals. CS is mostly sulfated at C-6 and/or C-4 position of N- acetyl galactosamine. The type and amount of sulfo groups on CS varies with source organism, tissue, location with in the tissue and age. Novel type of fucose branched CS has been isolated from sea cucumbers. The aim of the study was to investigate whether chondroitin sulfate isolated from the cartilage of the North Atlantic sea cucumber (Cucumaria frondosa) affected maturation of human dendritic cells and their ability to activate allogeneic CD4⁺ T cells in vitro. The CS polysaccharides were separated into three different fractions on an anion-exchange column and named CS-1A, CS-1B and CS-1C. The fraction CS-1B suppressed the secretion of IL-10 and IL-12p40 from human monocyte-derived dendritic cells and allogeneic CD4⁺ T cells co-cultured with dendritic cells that had been matured in the presence of CS-1B secreted reduced levels of IFN-γ and increased levels of IL-17 than allogeneic CD4⁺ T cells co-cultured with dendritic cells that had been matured without any CS. These data suggest that saccharide composition of CS-1B can affect the maturation of dendritic cells and their ability to activate T cells. The effects on T cells are suggestive of increased Th17 and reduced Th1 activity.