title: Assessment of roles for calreticulin in the cross-presentation of soluble and bead-associated antigens.
abstract: Antigen cross-presentation involves the uptake and processing of exogenously derived antigens and their assembly with major histocompatibility complex (MHC) class I molecules. Antigen presenting cells (APC) load peptides derived from the exogenous antigens onto MHC class I molecules for presentation to CD8 T cells. Calreticulin has been suggested to mediate and enhance antigen cross-presentation of soluble and cell-derived antigens. In this study, we examined roles for calreticulin in cross-presentation of ovalbumin using a number of models. Our findings indicate that calreticulin does not enhance in vitro cross-presentation of an ovalbumin-derived peptide, or of fused or bead-associated ovalbumin. Additionally, in vivo, calreticulin fusion or co-conjugation does not enhance the efficiency of CD8 T cell activation by soluble or bead-associated ovalbumin either in wild type mice or in mice lacking Toll-like receptor 4 (TLR4). Furthermore, we detect no significant differences in cross-presentation efficiencies of glycosylated vs. non-glycosylated forms of ovalbumin. Together, these results point to the redundancies in pathways for uptake of soluble and bead-associated antigens.
authors: Graduate Program in Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America.
authors: Natasha
authors: N
authors: Del Cid
authors: Lianjun
authors: L
authors: Shen
authors: Janice
authors: J
authors: Belleisle
authors: Malini
authors: M
authors: Raghavan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D037282:Calreticulin / Q000378:metabolism*; D002460:Cell Line; D045142:Cross-Priming; D006031:Glycosylation; D051379:Mice; D008863:Microspheres; D010047:Ovalbumin / Q000737:chemistry* / Q000276:immunology*; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology; D012995:Solubility
chemical_list: D037282:Calreticulin; D010446:Peptide Fragments; D010047:Ovalbumin