title: Antigen processing and presentation of a naturally glycosylated protein elicits major histocompatibility complex class II-restricted, carbohydrate-specific T cells.
abstract: It is well known that T cells recognize antigen as processed peptides bound to major histocompatibility complex molecules on the surface of antigen-presenting cells. Recently, it has been shown that T cells can specifically recognize synthetic glycopeptides. However, whether glycopeptides are selected for presentation during antigen processing of glycoproteins and eventually elicit carbohydrate-specific T cells is still an open question. In this study, we utilized synthetic glycopeptides to analyze T cell recognition of the naturally glycosylated immunodominant peptide representing type II collagen (CII) residues 256-270. In this peptide, lysines at positions 264 and 270 may be post-translationally modified by hydroxylation and subsequent O-linked glycosylation with beta-galactosyl or alpha-glucosyl-(1-->2)-beta-galactosyl residues. T cell hybridomas established from type II collagen-immunized mice specifically recognized CII 256-270 with either galactose or glucosyl-galactose at position 264. The T cell hybridoma recognizing glucosyl-galactose displayed no cross-reactivity either to galactose or to the structurally different alpha-galactosyl-(1-->4)-beta-galactose. Furthermore, the T cell hybridoma recognizing galactose did not cross-react to glucosyl-galactose or galactosyl-galactose, indicating that the antigen-presenting cells (bulk spleen cells, lipopolysaccharide-stimulated spleen cells, anti-CD40-stimulated spleen cells, peritoneal exudate cells or CFA-primed lymph node cells) inefficiently processed carbohydrates when the antigen was given as a glycopeptide.
authors.affiliation: Department of Cell and Molecular Biology, Lund University, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Michaëlsson
authors.forename: J
authors.initials: J
authors.lastname: Broddefalk
authors.forename: A
authors.initials: A
authors.lastname: Engström
authors.forename: J
authors.initials: J
authors.lastname: Kihlberg
authors.forename: R
authors.initials: R
authors.lastname: Holmdahl
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D050260:Carbohydrate Metabolism; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000737:chemistry / Q000276:immunology*; D003094:Collagen / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D000939:Epitopes / Q000276:immunology*; D006031:Glycosylation; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008969:Molecular Sequence Data; D051381:Rats; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
chemical_list: D002241:Carbohydrates; D000939:Epitopes; D000949:Histocompatibility Antigens Class II; D003094:Collagen