A Novel Tumor-Associated Pancreatic Glycoprotein Is Internalized by Human Dendritic Cells and Induces Their Maturation

Abstract

Aberrant glycosylation or overexpression of cell-surface glycosylated tumor-associated Ags (TAA) distinguish neoplastic from normal cells. Interactions of TAA MUC1 and HER2/neu with dendritic cells (DC) preclude efficient processing, which impairs immune responses. It is thus important to define the mechanisms of interactions between DC and glycosylated TAA and their trafficking and processing for further T cell activation. In this work, we study interactions between DC and the oncofetal fucose-rich glycovariants of bile salt-dependent lipase (BSDL), expressed in pancreatic cancer tissues and referred to as pathological BSDL carrying the fucosylated J28 glycotope (pBSDL-J28) because it is characterized by the mAb J28. The expression of pBSDL-J28 was assessed by immunohistochemistry and quantified by confocal microscopy. Nontumoral pancreatic tissues and cells do not express pBSDL-J28. Using multidisciplinary approaches and functional studies, we provide the first evidence, to our knowledge, that this tumoral glycoprotein is rapidly internalized by human DC through macropinocytosis and endocytosis via mannose receptors and then transported to late endosomes for processing. Interestingly, pBSDL-J28 per se induced DC maturation with increased expression of costimulatory and CD83 molecules associated with cytokine secretion (IL-8 and IL-6). Surprisingly, DC retained their full ability to internalize Ags, making this maturation atypical. Finally, the allogeneic pBSDL-J28–treated DC stimulated lymphocyte proliferation. Besides, pulsing DC with pBSDL-J28 C-terminal glycopolypeptide and maturation with CD40L triggered CD4+ and CD8+ T cell proliferation. Therefore, interactions of pBSDL-J28, expressed on tumoral pancreatic tissue, with DC may lead to adequate Ag trafficking and processing and result in T cell activation.

A pancreatic tumor-specific biomarker characterized in humans and mice as an immunogenic onco-glycoprotein is efficient in dendritic cell vaccination

“…Cells were labeled as described in [ 12 ] using 2 or 4% paraformaldehyde fixation. For intracellular staining, cells were incubated for 4 hours at 37°C with monensin (GolgiStop, BD Pharmingen, San Diego, CA).…”

“…We studied fucose-rich glycovariants of bile salt-dependent lipase (BSDL), which appear during fetal development and pancreatic oncogenesis processes [ 9 , 10 ] and are characterized by monoclonal antibody J28 (mAbJ28) immunoreactivity (BSDL-J28 + ) [ 10 , 11 ]. BSDL-J28 + is expressed in human pancreatic tumors [ 12 ] and cell lines [ 13 ] and so designated pathological (p)BSDL-J28 + ; non-tumor pancreatic tissue or cells do not express pBSDL-J28 + [ 9 , 12 ]. The mAbJ28 recognizes carbohydrate-dependent antigenic structures, termed J28 glycotopes, located within the O-glycosylated mucin-like C-terminal moiety (C-ter-J28 + ) of pBSDL-J28 + [ 14 ].…”

“…The nature of the tumor glycans may influence the uptake of the tumor-associated-carbohydrate antigens (TAAs) by immature DC, and thus affect the presentation to naive T cells of glycopeptides loaded onto MHC molecules, as well as DC maturation and function [ 16 ]. We showed that, unlike the TAAs MUC1 and HER2/Neu [ 17 ], which present structures that are differently glycosylated, pBSDL-J28 + can be delivered into the HLA class II pathway [ 12 ]. Thus, the expression of pBSDL-J28 + restricted to pancreatic tumor cells and tissues as well as their immunogenic potential led us testing the potential use of glycotope-J28 + -loaded DC in DC-immunotherapy against PDAC.…”

Investigation of a new tumor-associated glycosylated antigen as target for dendritic cell vaccination in pancreatic cancer

“…pBSDL-J28 is expressed on human tumoral pancreas 12 and on human pancreatic tumor cell lines 13 14 .…”

“…pBSDL-J28 binds to MR (CD206) expressed on iMoDC surface 12 . Thus, oligosaccharides recognized by C-type lectin-like carbohydrate recognition domains of MR terminating in mannose, N-acetylglucosamine, and/or fucose residues, the latter being crucial elements of the J28 glycotope structure for mAbJ28 recognition, can be involved in DC’s binding (for a review see ref.…”