In preclinical models of B-cell malignancies, -galactosylceramide is an adjuvant to tumor vaccination, enhancing tumor-specific T-cell responses and prolonging survival. chronic lymphocytic leukemia and age-matched settings. Cytokine profile and proliferative capacity were determined. Patient- and control-derived invariant natural killer T-cell lines were generated and characterized, and allogeneic and autologous reactions to -galactosylce-ramide-treated leukemia cells were assessed. Absolute figures and phenotype of invariant natural killer T cells were normal in individuals with untreated chronic lymphocytic leukemia, and cytokine profile and proliferative capacity were intact. Chemotherapy-treated individuals had reduced numbers of invariant natural killer T cells and myeloid dendritic cells, but -galactosylceramide-induced proliferation was maintained. Invariant natural killer T-cell lines from individuals lysed CD1d-expressing focuses on. Irradiated -galactosylceramide-treated leukemic cells elicited allogeneic and autologous invariant natural killer T-cell proliferation, and -galactosylceramide treatment led to improved proliferation of standard T cells in response to tumor. In conclusion, the invariant natural killer T-cell and CD1d axis is definitely fundamentally intact in individuals with early-stage chronic lymphocytic leukemia and, despite reduced circulating figures, function is retained in fludarabine-treated individuals. Immunotherapies exploiting the adjuvant effect of -galactosylceramide may be feasible. Introduction Invariant natural killer T (iNKT) cells are innate-like T cells expressing a semi-invariant T-cell receptor that recognizes glycolipid antigens offered from the evolutionarily-conserved CD1d molecule. iNKT cell Calcipotriol monohydrate agonists can be used as adjuvants to tumor vaccination for the cellular immunotherapy of malignancy.1 In preclinical models, co-administration of the prototypical iNKT agonist -galactosylceramide (-GalCer)2 with tumor-associated antigens prospects to enhanced proliferation of peptide-specific CD4+ and CD8+ T cells,3 and protective immunity against subsequent tumor challenge.4C7 The mechanism of this adjuvant activity involves presentation of -GalCer to iNKT cells by resident dendritic cells (DC),8 DC maturation,4 and enhanced DC production of interleukin-12.9 Chronic lymphocytic leukemia (CLL) signifies an attractive target for cellular immunotherapy: a graft-and anti-iNKT cell antibody (clone 6B11), which we while others have shown is comparable to the -GalCer-loaded CD1d tetramer Myeloid DC were identified as Lin1-, HLA-DRhigh, CD11chigh – in validation experiments, a median of 98.5% of cells gated with this strategy expressed the specific myeloid DC Calcipotriol monohydrate marker, CD1c. ZAP-70 status of CLL cells was identified as previously explained. 26 Further details of surface and intracellular staining and circulation cytometry are given in the ideals of < 0. 05 were regarded as statistically significant. Results Characteristics of the donors Thirty untreated individuals, ten chemotherapy-treated individuals, and 30 healthy, age-matched settings participated in the study. Patient and control organizations were Calcipotriol monohydrate closely age-matched (proliferation of iNKT cells from healthy settings (n=20) and individuals (n=20) (***proliferation (assessment of iNKT cell cytotoxic function was not feasible due to the low rate of recurrence of circulating iNKT cells, we generated polyclonal iNKT cell lines from four individuals and four settings. All iNKT cell lines generated were >98% CD4+ (iNKT Calcipotriol monohydrate cell proliferation is definitely reduced in untreated chronic myeloid leukemia.23 In the present study, cytokine production by, and proliferation of, iNKT cells, was intact in CLL compared to age-matched settings. Although we did not Rabbit Polyclonal to CARD11 find major variations in iNKT cell number and function in the clinically advanced and chemotherapy-treated instances tested, most individuals we studied experienced indolent CLL. We cannot exclude the possibility that numerical or practical iNKT cell problems would have emerged had a larger cohort of individuals with advanced CLL been analyzed. Because of the limited prognostic info available and the size of this cohort of individuals, we cannot determine whether CLL cell cytogenetic changes Calcipotriol monohydrate or immunoglobulin weighty chain variable gene (status,26 experienced no obvious impact on iNKT cell rate of recurrence. Healthy donor-derived iNKT cell lines have been reported to lyse -GalCer-pulsed CLL cells tradition of iNKT cells we used yielded a CD4+ iNKT cell human population producing high levels of Th2-type cytokines, a feature.