title: NKT cell stimulation with glycolipid antigen in vivo: costimulation-dependent expansion, Bim-dependent contraction, and hyporesponsiveness to further antigenic challenge.
abstract: Activation of NKT cells using the glycolipid alpha-galactosylceramide (alpha-GalCer) has availed many investigations into their immunoregulatory and therapeutic potential. However, it remains unclear how they respond to stimulation in vivo, which costimulatory pathways are important, and what factors (e.g., Ag availability and activation-induced cell death) limit their response. We have explored these questions in the context of an in vivo model of NKT cell dynamics spanning activation, population expansion, and subsequent contraction. Neither the B7/CD28 nor the CD40/CD40L costimulatory pathway was necessary for cytokine production by activated NKT cells, either early (2 h) or late (3 days) after initial stimulation, but both pathways were necessary for normal proliferative expansion of NKT cells in vivo. The proapoptotic Bcl-2 family member Bim was necessary for normal contraction of the NKT cell population between days 3-9 after stimulation, suggesting that the pool size is regulated by apoptotic death, similar to that of conventional T cells. Ag availability was not the limiting factor for NKT cell expansion in vivo, and a second alpha-GalCer injection induced a very blunted response, whereby cytokine production was reduced and further expansion did not occur. This appeared to be a form of anergy that was intrinsic to NKT cells and was not associated with inhibitory NK receptor signaling. Furthermore, NKT cells from mice pre-challenged with alpha-GalCer in vivo showed little cytokine production and reduced proliferation in vitro. In summary, this study significantly enhances our understanding of how NKT cells respond to primary and secondary antigenic challenge in vivo.
authors.affiliation: Department Microbiology and Immunology, University of Melbourne, Parkville, Victoria, 3010, Australia.
authors.forename: Adam P
authors.initials: AP
authors.lastname: Uldrich
authors.affiliation: Department Microbiology and Immunology, University of Melbourne, Parkville, Victoria, 3010, Australia.
authors.forename: Nadine Y
authors.initials: NY
authors.lastname: Crowe
authors.affiliation: Department Microbiology and Immunology, University of Melbourne, Parkville, Victoria, 3010, Australia.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Kyparissoudis
authors.affiliation: Department Microbiology and Immunology, University of Melbourne, Parkville, Victoria, 3010, Australia.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Pellicci
authors.affiliation: Walter and Eliza Hall Institute, Melbourne, Victoria 3050 Australia.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Zhan
authors.affiliation: Walter and Eliza Hall Institute, Melbourne, Victoria 3050 Australia.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Lew
authors.affiliation: Walter and Eliza Hall Institute, Melbourne, Victoria 3050 Australia.
authors.forename: Philippe
authors.initials: P
authors.lastname: Bouillet
authors.affiliation: Walter and Eliza Hall Institute, Melbourne, Victoria 3050 Australia.
authors.forename: Andreas
authors.initials: A
authors.lastname: Strasser
authors.affiliation: Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, Victoria, 3002, Australia.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Smyth
authors.affiliation: Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, Victoria, 3002, Australia.
authors.forename: Dale I
authors.initials: DI
authors.lastname: Godfrey
mesh_terms: D000818:Animals; D051017:Apoptosis Regulatory Proteins; D000072224:Bcl-2-Like Protein 11; D018106:CD28 Antigens / Q000502:physiology; D019013:CD40 Antigens / Q000502:physiology; D002352:Carrier Proteins / Q000502:physiology*; D016207:Cytokines / Q000096:biosynthesis; D005699:Galactosylceramides / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology / Q000502:physiology; D008213:Lymphocyte Activation; D008565:Membrane Proteins / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D011518:Proto-Oncogene Proteins / Q000502:physiology*; D015398:Signal Transduction
chemical_list: D051017:Apoptosis Regulatory Proteins; D000072224:Bcl-2-Like Protein 11; C000606776:Bcl2l11 protein, mouse; D018106:CD28 Antigens; D019013:CD40 Antigens; D002352:Carrier Proteins; D016207:Cytokines; D005699:Galactosylceramides; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; C493154:alpha-galactosylceramide