21. Hayakawa Y, Takeda K, Yagita H, Van Kaer L, Saiki I, Okumura K. Differential regulation of Th1 and Th2 functions of NKT cells by CD28 and CD40 costi- mulatory pathways. J Immunol 2001; 166:6012-8; PMID:11342617 22. Ikarashi Y, Mikami R, Bendelac A, Terme M, Chaput N, Terada M, et al. Dendritic cell maturation overrules H-2D-mediated natural killer T (NKT) cell inhibition: critical role for B7 in CD1d-dependent NKT cell inter- feron gamma production. J Exp Med 2001; 194:1179- 86; PMID:11602646; http://dx.doi.org/10.1084/jem. 194.8.1179 23. Kaneda H, Takeda K, Ota T, Kaduka Y, Akiba H, Ikarashi Y, et al. ICOS costimulates invariant NKT cell activation. Biochem Biophys Res Commun 2005; 327: 201-7; PMID:15629449; http://dx.doi.org/10.1016/j. bbrc.2004.12.004 24. Cross AH, Lyons JA, San M, Keeling RM, Ku G, Racke MK. T cells are the main cell type expressing B7-1 and B7-2 in the central nervous system during acute, relapsing and chronic experimental autoimmune encephalomyelitis. Eur J Immunol 1999; 29:3140-7; PMID:10540325; http://dx.doi.org/10.1002/(SICI) 1521-4141(199910)29:10,3140::AID-IMMU3140. 3.0.CO;2-W 26. Nurieva R, Thomas S, Nguyen T, Martin-Orozco N, Wang Y, Kaja MK, et al. T-cell tolerance or function is determined by combinatorial costimulatory signals. EMBO J 2006; 25:2623-33; PMID:16724117; http:// dx.doi.org/10.1038/sj.emboj.7601146 27. Martin-Orozco N, Wang YH, Yagita H, Dong C. Cutting Edge: Programmed death (PD) ligand-1/PD-1 interaction is required for CD8+ T cell tolerance to tissue antigens. J Immunol 2006; 177:8291-5; PMID: 17142723 28. Exley M, Garcia J, Wilson SB, Spada F, Gerdes D, Tahir SM, et al. CD1d structure and regulation on human thymocytes, peripheral blood T cells, B cells and monocytes. Immunology 2000; 100:37-47; PMID:10809957; http://dx.doi.org/10.1046/j.1365- 2567.2000.00001.x 29. Nebozhyn M, Loboda A, Kari L, Rook AH, Vonderheid EC, Lessin S, et al. Quantitative PCR on 5 genes reliably identifies CTCL patients with 5% to 99% circulating tumor cells with 90% accuracy. Blood 2006; 107:3189-96; PMID:16403914; http://dx.doi. org/10.1182/blood-2005-07-2813 30. Nurieva RI, Mai XM, Forbush K, Bevan MJ, Dong C. B7h is required for T cell activation, differentiation, and effector function. Proc Natl Acad Sci USA 2003; 100: 14163-8; PMID:14615582; http://dx.doi.org/10. 1073/pnas.2335041100 31. Nurieva R, Yang XO, Martinez G, Zhang Y, Panopoulos AD, Ma L, et al. Essential autocrine regulation by IL-21 in the generation of inflammatory T cells. Nature 2007; 448:480-3; PMID:17581589; http://dx.doi.org/10.1038/nature05969 32. He L, Hakimi J, Salha D, Miron I, Dunn P, Radvanyi L. A sensitive flow cytometry-based cytotoxic T-lymphocyte assay through detection of cleaved caspase 3 in target cells. J Immunol Methods 2005; 304:43-59; PMID:16076473; http://dx.doi.org/10. 1016/j.jim.2005.06.005 33. Coles RM, Mueller SN, Heath WR, Carbone FR, Brooks AG. Progression of armed CTL from draining lymph node to spleen shortly after localized infection with herpes simplex virus 1. J Immunol 2002; 168: 834-8; PMID:11777979 25. Taylor PA, Lees CJ, Fournier S, Allison JP, Sharpe AH, Blazar BR. B7 expression on T cells down-regulates ©PMID:124688306012 Landes Bioscience. immune responses through CTLA-4 ligation via T-T interactions. [corrections]. J Immunol 2004; 172:34-9; Do not distribute. www.landesbioscience.com OncoImmunology 151