IntroductionHuman V␣24 ϩ V␤11 ϩ natural killer T (NKT) cells are a distinct CD1d-restricted lymphoid subset specifically activated and induced to proliferate by ␣-galactosylceramide (␣-GalCer) (KRN7000) presented by CD1d on antigen-presenting cells (APCs), including dendritic cells (DCs) and monocyte-derived DCs (MoDCs). [1][2][3][4][5] Preclinical murine in vivo and human in vitro data suggest NKT cell activation may be therapeutic for human malignancy. 6,7 NKT cells have direct antitumor cytotoxicity, dependent on and independent of target CD1d expression, 8 and antiproliferative actions 9 that may contribute to clinical antitumor activity.Potentially critical for successful human tumor eradication are secondary immune effects, including cytokine release 9,10 and activation of conventional T cells 11 and NK cells [12][13][14][15][16][17] resulting from the hypothesized pivotal role of NKT cells in bridging, coordinating, and activating innate and acquired immunity. 11 A human clinical study showed that direct intravenous administration of ␣-GalCer results in disappearance of peripheral blood (PB) NKT cells within 24 hours, and with multiple administrations at weekly intervals, NKT cell numbers remain below pretreatment levels. 18 Furthermore, it has been demonstrated in murine models that administration of ␣-GalCer-pulsed DCs has more potent antitumour activities than direct administration of ␣-GalCer alone. 19 In addition to their essential role in NKT cell activation, DCs may have a crucial intermediary role in secondary immune effects of activated NKT cells as the latter alter DC functions, including cytokine production. 20,21 In view of these earlier murine and clinical studies and to confirm the proposed key immune-activating activities of NKT cells, we have undertaken a clinical phase 1 study to determine the effects of ␣-GalCer-pulsed DCs in human subjects. We evaluated clinical and immunologic effects of ␣-GalCer-pulsed MoDCs administered at 2-week intervals to 12 human subjects with metastatic malignancy. Materials and methods Overview of study designThe study was a phase 1, open-labeled clinical study involving 12 patients with metastatic malignancy (Table 1). Subjects received a median of 5 ϫ 10 6 CD1d-expressing immature MoDCs generated from plastic adherent monocytes cultured with interleukin 4 (IL-4) and granulocytemacrophage colony-stimulating factor (GM-CSF). Subjects involved in another of our studies with metastatic malignancy (n ϭ 3) receiving therapy with MoDCs prepared with the use of identical protocols, but with addition of tumor lysate or tumor-specific peptides rather than ␣-GalCer, were used as controls but had less extensive immunologic evaluations than for the study described here. One subject (KS103) received 2 series of treatments with KRN7000-pulsed MoDCs, several months apart, and subsequently (6 months later) a series of treatments with tumor lysate-pulsed MoDCs. Protocols were based on those previously described 22 with our minor modifications, 23 except that 100 ng/mL ␣-GalCe...

Background:Adoptive transfer of ex vivo expanded autologous Vγ9Vδ2 T cells may be of therapeutic benefit for cancer because of their potent direct cytotoxicity towards tumour cells, synergistic cytotoxicity when combined with aminobisphosphonates and enhancement of antibody-dependent cell-mediated cytotoxicity.Methods:To determine the feasibility and clinical safety of therapy with ex vivo expanded, activated Vγ9Vδ2 T cells in combination with zoledronate, we enrolled 18 subjects with advanced solid tumours into a phase I clinical study. Administered indium111-oxine-labelled Vγ9Vδ2 T cells were tracked in a cohort of patients.Results:Administered Vγ9Vδ2 T cells had an activated effector memory phenotype, expressed chemokine receptors predictive of homing to peripheral tissues and were cytotoxic in vitro against tumour targets. Adoptively transferred Vγ9Vδ2 T cells trafficked predominantly to the lungs, liver and spleen and, in some patients, to metastatic tumour sites outside these organs. No dose-limiting toxicity was observed, but most patients progressed on study therapy. However, three patients administered Vγ9Vδ2 T cells while continuing previously ineffective therapy had disease responses, suggesting an additive effect.Conclusion:Therapy with aminobisphosphonate-activated Vγ9Vδ2 T cells is feasible and well tolerated, but therapeutic benefits appear only likely when used in combination with other therapies.

IntroductionHuman V␣24NKT cells are a subpopulation of T cells, highly conserved between mice (V␣14NKT cells) and humans (V␣24NKT cells), which can be stimulated by ␣-galactocylceramide (␣-GalCer, KRN7000) in a CD1d-dependent and a T-cell receptor (TCR)-mediated manner. [1][2][3] Most human peripheral blood V␣24NKT cells have a double-negative (DN; CD4 Ϫ CD8 Ϫ ) or CD4 ϩ phenotype and coexpress CD161. Other surface markers of natural killer (NK) cells (CD16, CD56, and CD57) and immunoglobulin (Ig)-type NK receptors such as p58.1, p58.2, and p70 are not expressed. Expression of CD94, a lectin-type NK receptor, varies probably depending on V␣24NKT cell subpopulations. [2][3][4] There is evidence for a role of these cells in preventing or controlling malignancy. Mice injected with ␣-GalCer were protected from experimentally induced tumors, and it is clear that V␣14NKT cells were responsible for these antitumor effects. [5][6][7] Similar antitumor effects were seen when murine V␣14NKT cells or human V␣24NKT cells were adoptively transferred into tumorbearing mice. 8 We have recently shown in vitro susceptibility of human malignant cell lines to cytotoxic activity of V␣24NKT cells. U937 (a cell line with monocytic characteristics), THP-1 (monocytic leukemia cell line), and Molt-4 (T-cell lymphoma) were sensitive to the cytotoxic activity of DNV␣24NKT cells, but neither K562 (chronic myelogeneous leukemia cell line) nor Daudi (Burkitt lymphoma cell line) were sensitive. 9 Among tumor cell lines we have tested, U937 was the most susceptible to the cytotoxic activity of both DN and CD4 ϩ V␣24NKT cells.These previous in vitro studies showing cytotoxic activity against human hematologic malignancies suggested that V␣24NKT cells, activated by ␣-GalCer, warranted further investigation for a possible immune therapeutic role in the treatment of acute myeloid leukemia (AML), particularly those of monocytic origin. AML encompasses a group of disorders characterized by clonal accumulation of immature and abnormal myeloid cells in the blood and marrow. Most adult patients with AML cannot be cured with current treatments involving maximum tolerated doses of chemotherapy; novel therapeutic strategies such as immune-based therapies are needed to sustain remission and increase the cure rate.Although antitumor activity of V␣24NKT has been clearly demonstrated in vitro, the mechanisms for selective killing of malignant cells have not been defined to date. Activation of V␣24NKT cells is dependent on the presentation of ␣-GalCer by CD1d, but neither is essential for their cytotoxic activity against some malignant cells. It is still unknown how V␣24NKT cells kill malignant targets. Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a recently identified type II integral membrane protein belonging to the TNF family that selectively induces apoptosis of various tumor cell lines. [10][11][12][13][14] Lymphoid cells such as T cells and NK cells express TRAIL, and these TRAIL-expressing cells induce apoptotic cell death i...