ABSTRACT
The in vitro and in vivo immunoregulatory activity of a water-soluble sulfated fucan AL1-1 from the sea cucumber A. leucoprocta was elucidated. In vitro experiments showed that AL1-1 up-regulated immunostimulatory activities in RAW264.7 cells and that it could successfully promote ROS production and phagocytic activity, increase secretion levels of iNOS, and induce the production of considerable amounts of cytokines (TNF-α, IL-6, IL-1ß and IL-12). We found that toll-like receptor 4 (TLR4) was mainly involved in AL1-1 mediated macrophage activation. AL1-1's in vivo immunomodulatory activity on cyclophosphamide (CY)-treated mice was investigated and it was shown that it could strongly enhance Sig A levels, promote the total antioxidant capacity (T-AOC), and reduce malondialdehyde (MDA) level in the intestine. It could also increase activities of superoxidase dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX). These results demonstrate that AL1-1 has a significant effect on enhancing in vivo and in vitro immune response.
Subject(s)
Immunity, Mucosal/drug effects , Immunomodulating Agents/pharmacology , Intestinal Mucosa/drug effects , Macrophage Activation/drug effects , Macrophages/drug effects , Polysaccharides/pharmacology , Sea Cucumbers , Animals , Antioxidants/metabolism , Cytokines/metabolism , Female , Free Radical Scavengers/isolation & purification , Free Radical Scavengers/pharmacology , Immunoglobulin A, Secretory/metabolism , Immunomodulating Agents/isolation & purification , Intestinal Mucosa/immunology , Intestinal Mucosa/metabolism , Macrophages/immunology , Macrophages/metabolism , Mice , Mice, Inbred ICR , Nitric Oxide Synthase Type II/metabolism , Phagocytosis/drug effects , Polysaccharides/isolation & purification , RAW 264.7 Cells , Reactive Oxygen Species/metabolism , Sea Cucumbers/chemistry , Toll-Like Receptor 4/metabolismABSTRACT
Noroviruses (NoVs) are one of the most important foodborne viral pathogens worldwide. Shellfish are the most common carriers of NoVs as they can concentrate and accumulate large amounts of the virus through filter feeding from seawater. Shellfish may selectively accumulate NoVs with different genotypes, and this bioaccumulation may depend on the season and location. Our previous studies found various histo-blood group antigens (HBGAs) in shellfish tissues. While HBGAs might be the main reason that NoVs are accumulated in shellfish, the detailed mechanism behind NoV concentration and bioaccumulation in shellfish is not clear. Here we review current research into NoV bioaccumulation, tissue distribution, seasonal variation, and binding mechanism in shellfish. This paper may provide insight into controlling NoV transmission and decreasing the risks associated with shellfish consumption.
