title: Expression of CD1c enhances human invariant NKT cell activation by α-GalCer.
abstract: Invariant natural killer T (iNKT) cells are innate T lymphocytes that specifically recognize α-linked glycosphingolipids (α-GSLs) as antigens presented by CD1d molecules. Activating iNKT cells by administering α-GSLs improves disease outcomes in murine cancer models and, thus, there is great interest in the clinical potential of these lipids for treating human cancers. However, humans possess several other CD1 isoforms that are not present in mice and it is not clear whether these CD1 molecules, which also bind lipids, affect human iNKT cell responses. We demonstrate here that CD1c, which is co-expressed with CD1d on blood dendritic cells and on a fraction of B cells, is able to present α-galactosylceramide (α-GalCer) as a weak agonist to human iNKT cells, and that the presence of CD1c synergistically enhances α-GalCerdependent activation of iNKT cells by CD1d. Primary human B cells expressing CD1c induced stronger iNKT cell responses to α-GalCer than the CD1c- subset, and an antibody against CD1c inhibited iNKT cell cytokine secretion. These results suggest that therapeutic activation of human iNKT cells by α-GSLs will be driven preferentially by CD1c+ cell types. Thus, B cell neoplasias that co-express CD1c and CD1d may be particularly susceptible to α-GSL therapy, and cancer vaccines using α-GSLs as adjuvants may be most effective when presented by CD1c+ antigen-presenting cells.
authors.affiliation: Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Fox
authors.forename: Jennifer
authors.initials: J
authors.lastname: Miksanek
authors.forename: Nathan A
authors.initials: NA
authors.lastname: May
authors.forename: Louise
authors.initials: L
authors.lastname: Scharf
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Lockridge
authors.forename: Natacha
authors.initials: N
authors.lastname: Veerapen
authors.forename: Gurdyal S
authors.initials: GS
authors.lastname: Besra
authors.forename: Erin J
authors.initials: EJ
authors.lastname: Adams
authors.forename: Amy W
authors.initials: AW
authors.lastname: Hudson
authors.forename: Jenny E
authors.initials: JE
authors.lastname: Gumperz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018949:Antigens, CD1 / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D005699:Galactosylceramides / Q000276:immunology*; D006023:Glycoproteins / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D055611:Natural Killer T-Cells / Q000276:immunology*; D011485:Protein Binding
chemical_list: D018949:Antigens, CD1; C437944:CD1C protein, human; D005699:Galactosylceramides; D006023:Glycoproteins; C493154:alpha-galactosylceramide
keywords: CD1 molecules; human; iNKT cells; α-GalCer