Scavenger receptor A (SR-A) plays a crucial role in affecting the dendritic cell-mediated presentation of cancer testis antigens to T cells against human cancer cells Here we use a dendritic cell-mediated model to verify that a sulphated polysaccharide, fucoidin, can regulate the adverse regulatory function of SR-A, and lead to the up-regulation of the anti-tumor immunological response SR-A is a receptor of calreticulin (CRT) existing on the surface of dendritic cells (DCs) CRT is a specific receptor for a NY-ESO-1 cancer testis antigen, and CRT itself is responsible for the cross-presentation of NY-ESO-1 to CD8+ cells and the induction of antitumor immunity Flow cytometrical analysis (FACS) showed that fucoidin was able to significantly enhance the binding ratio of NY-ESO-1 to human DCs in a concentration dependent manner, and that the addition of fucoidin promoted the DC maturation upon stimulation of NY-ESO-1 Results from a cytotoxicity assay indicated that fucoidin-treated DCs Stimulated the CD8+ T cells more effectively than non-treated DCs via a cross-presentation pathway Furthermore, It Was found that after stimulated by fucoidin-treated DCs, the CD8+ T cells can release more IFN-gamma than non-fucoidin-treated cells as detected by intracellular IFN-gamma staining We conclude that fucoidin enhances the cross-presentation NY-ESO-1 to T cells leading to an increase of T-cell cytotoxicity against NY-ESO-1 expressing human cancer cells (C) 2010 Elsevier Inc All rights reserved.