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ABSTRACT: 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.
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 indium(111)-oxine-labelled Vγ9Vδ2 T cells were tracked in a cohort of patients.
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.
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.
British Journal of Cancer 08/2011; 105(6):778-86. · 5.04 Impact Factor
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K. Tokunaga,
E. W. Sideltseva,
H. Tanaka,
C. Uchikawa, M. Nieda,
V. V. Sideltsev,
E. Zhuravleva,
T. Imanishi,
K. Itoh,
T. Akaza,
K. Takahashi,
V. Khalturin,
L. P. Alexeev,
T. Juji
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ABSTRACT: Polymorphisms of HLA-A, B, C, DR, and DQ antigens were investigated in a Mongoloid population named Buryat living in Siberia. HLA gene and haplotype frequencies were calculated from the population data obtained from 141 unrelated healthy Buryat adults. Gene frequencies of class I antigens A2, A24, A1, B61, Cw10, and Cw6 were estimated to be more than 10%. For class II, DR4, DR7, DR13, DQ7, and DQ1 antigens were predominant. A phylogenetic tree was constructed based on HLA gene frequencies, and the Buryat population was clustered with the Mongoloid groups in Northeast Asia. In the analysis of HLA-A, C, B, DR, and DQ five-locus haplotype frequencies, seven kinds of haplotypes were calculated to occur at frequencies of more than 2%. Five of the seven common haplotypes have also been described in the other human populations thus far. Some of the haplotypes have been described in European populations, while the others were shared with Northeast Asian Mongoloids as well as Amerindians. Similar situation was also found in the analysis of class I (HLA-A, C, B) three locus haplotypes. These observations suggest the unique genetic background of this Buryat population.
Tissue Antigens 12/2008; 45(2):98 - 102. · 2.59 Impact Factor
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ABSTRACT: The cytotoxic effects of anticancer immune cells are mediated by perforin/granzyme-B, Fas ligand and tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), and therefore depend on intact apoptotic responses in target tumour cells. As killing by all three of these mechanisms is blocked by the frequently overexpressed antiapoptotic oncoprotein Bcl-2, we hypothesised that coexposure to a Bcl-2 inhibitor might enhance anticancer immune responses. We evaluated this in U937 lymphoma cells, and A02 melanoma cells, which both show strong Bcl-2 expression. Valpha24(+) Vbeta11(+) natural killer T (NKT) cells expanded from peripheral blood of normal donors (n=3) were coincubated with PKH26-labelled U937 cells, and cytotoxicity was determined by flow cytometry after annexin-V-FITC and 7-AAD staining. In all cases, addition of the HA14-1 small-molecule Bcl-2 inhibitor to the cocultures significantly increased apoptosis in the target U937 cells. Using a similar assay, killing of A02 cells by the cytotoxic T-lymphocyte clone 1H3 was shown to be amplified by coexposure to the potent small-molecule Bcl-2 inhibitor ABT-737. Experiments with immune effectors preincubated with concanamycin-A suggested that sensitisation to perforin/granzyme-B may underlie enhanced target-cell killing observed in the presence of Bcl-2 inhibitors. We conclude that immune destruction of malignant cells can be amplified by molecular interventions that overcome Bcl-2-mediated resistance to apoptosis.
British Journal of Cancer 03/2007; 96(4):600-8. · 5.04 Impact Factor
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ABSTRACT: Immunotherapy strategies aimed at increasing human Valpha24(+)Vbeta11(+) natural killer T (NKT) cell numbers are currently a major focus. To provide further information towards the goal of NKT cell-based immunotherapy, we assessed the effects of age, cancer status and prior anticancer treatment on NKT cell numbers and their expansion capacity following alpha-galactosylceramide (alpha-GalCer) stimulation. The percentage and absolute number of peripheral blood NKT cells was assessed in 40 healthy donors and 109 solid cancer patients (colorectal (n=33), breast (n=10), melanoma (n=17), lung (n=8), renal cell carcinoma (n=10), other cancers (n=31)). Responsiveness to alpha-GalCer stimulation was also assessed in 28 of the cancer patients and 37 of the healthy donors. Natural killer T cell numbers were significantly reduced in melanoma and breast cancer patients. While NKT numbers decreased with age in healthy donors, NKT cells were decreased in these cancer subgroups despite age and sex adjustments. Prior radiation treatment was shown to contribute to the observed reduction in melanoma patients. Although cancer patient NKT cells were significantly less responsive to alpha-GalCer stimulation, they remained capable of substantial expansion. Natural killer T cells are therefore modulated by age, malignancy and prior anticancer treatment; however, cancer patient NKT cells remain capable of responding to alpha-GalCer-based immenotherapies.
British Journal of Cancer 12/2004; 91(11):1880-6. · 5.04 Impact Factor
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ABSTRACT: Many clinical trials of DC-based immunotherapy involve administration of monocyte-derived DCs (Mo-DC) on multiple occasion. We aimed to determine tbe optimal cell processing procedures and timing (leukapheresis, RBC depletion and cryopreservation) for generation of Mo-DC for clinical purposes.
Leukapheresis was undertaken using a COBE Spectra. Two instrument settings were compared - the standard semi-automated software (Version 4.7) (n = 10) and the fully automated software (Version 6.0) (N = 40). Density gradient centrifugation using Ficoll, Percoll, a combination of these methods or neither for RBC depletion were compared. Outcomes (including cell yield and purity) were compared for cryopreserved unmanipulated monocytes and cryopreserved Mo-DC.
Software Version 6.0 provided significantly better enrichment for monocytes (P < 0.05) but 25% fewer total monocytes. Final Mo-DC purity was not influenced by leukapheresis or RBC depletion method, but was critically dependent on monocyte adherence. Version 6.0 produced significantly lower RBC and platelet contamination (P < 0.0005) but in vitro RBC depletion could not routinely be omitted. Only 5-6% of monocytes harvested resulted in Mo-DC (95% lost in cell processing or failing to differentiate).
Cell losses remained significant despite attempts to minimise processing steps during Mo-DC generation. Reduction in RBC and platelets achieved with software version 6.0 was insufficient to offset the disadvantage of the lower monocyte yield. Substantial savings in materials and other costs can be achieved if Mo-DC for multiple treatments are generated from cryopreserved monocytes rather than from fresh monocytes.
Cytotherapy 01/2003; 5(1):31-9. · 3.63 Impact Factor
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M. Okai, M. Nieda,
A. Tazbirkova,
D. Horley,
A. Kikuchi,
S. Durrant,
T. Takahashi,
A. Boyd,
R. Abraham,
H. Yagita,
T. Juji,
A. Nicol
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ABSTRACT: Background and Objectives We have undertaken the first clinical trial involving the administration of α-GalactosylCeramine (α-GalCer)-pulsed dendritic cells (DCs) to human subjects, to determine safety, optimal dose, optimal administration route and immunological effects.Materials and Methods Subjects (n = 4) with metastatic malignancy received two infusions of α-GalCer-pulsed DCs intravenously, and two infusions intradermally. The percentages of Vα24 Vβ11 NKT cells in peripheral blood (PB) were determined by three-colour flow cytometry and the PB NKT cell numbers were calculated using the total number of PB lymphocytes/ml determined by automated full-blood counts.Results No serious treatment related adverse events were observed during the study period. Administration of α-GalCer-pulsed DCs in vivo can significantly (P < 0·03) increase PB Vα24+ Vβ11+ NKT cell numbers above pretreatment baseline levels after the transient fall in the NKT numbers within 48 h.Conclusions Administration of α-GalCer-pulsed DCs is well tolerated, modulates PB Vα24+ Vβ11+ NKT cells and may have a role in the therapy of malignancies sensitive to activities of Vα24+ Vβ11+ NKT cells, or for autoimmune diseases.
Vox Sanguinis 10/2002; 83(3):250 - 253. · 2.86 Impact Factor
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M Okai, M Nieda,
A Tazbirkova,
D Horley,
A Kikuchi,
S Durrant,
T Takahashi,
A Boyd,
R Abraham,
H Yagita,
T Juji,
A Nicol
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ABSTRACT: We have undertaken the first clinical trial involving the administration of alpha-GalactosylCeramine (alpha-GalCer)-pulsed dendritic cells (DCs) to human subjects, to determine safety, optimal dose, optimal administration route and immunological effects.
Subjects (n = 4) with metastatic malignancy received two infusions of alpha-GalCer-pulsed DCs intravenously, and two infusions intradermally. The percentages of Valpha24 Vbeta11 NKT cells in peripheral blood (PB) were determined by three-colour flow cytometry and the PB NKT cell numbers were calculated using the total number of PB lymphocytes/ml determined by automated full-blood counts.
No serious treatment related adverse events were observed during the study period. Administration of alpha-GalCer-pulsed DCs in vivo can significantly (P < 0.03) increase PB Valpha24+ Vbeta11+ NKT cell numbers above pretreatment baseline levels after the transient fall in the NKT numbers within 48 h.
Administration of alpha-GalCer-pulsed DCs is well tolerated, modulates PB Valpha24+ Vbeta11+ NKT cells and may have a role in the therapy of malignancies sensitive to activities of Valpha24+ Vbeta11+ NKT cells, or for autoimmune diseases.
Vox Sanguinis 10/2002; 83(3):250-3. · 2.86 Impact Factor
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ABSTRACT: In vitro proliferation and functional activation of V alpha 24NKT cells following stimulation with alpha-galactosylceramide (alpha-GalCer)-pulsed dendritic cells (DCs) have been observed. Because little is known about the molecular events on DCs following interaction with alpha-GalCer, we performed gene expression profiling of 2400 genes in monocytes and monocyte-derived immature DCs pulsed with alpha-GalCer (alpha-GalCer-imDCs). Overall, the expression levels of 48 genes were up-regulated and 28 were down-regulated in alpha-GalCer-imDCs. Semiquantitative RT-PCR analysis on monocytes, imDCs, alpha-GalCer-imDCs, and mature DCs confirmed the up- and down-regulation of the mRNA expression levels of 28 selected genes. Notably, we identified the specific up-regulation of mRNA expression levels of ribonuclease A and collapsin response mediator protein upon the stimulation of imDC with alpha-GalCer, suggesting a novel immunomodulating effect of alpha-GalCer on imDCs. In this study, we used imDCs prepared by culturing of monocytes with GM-CSF and IL-4 for 5 days and mDCs prepared by further culturing of imDCs with TNF alpha for two extra days.
Biochemical and Biophysical Research Communications 12/2001; 289(2):531-8. · 2.48 Impact Factor
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A Kikuchi, M Nieda,
C Schmidt,
Y Koezuka,
S Ishihara,
Y Ishikawa,
K Tadokoro,
S Durrant,
A Boyd,
T Juji,
A Nicol
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ABSTRACT: alpha-galactosylceramide (KRN 7000, alpha-GalCer) has shown potent in vivo anti-tumour activity in mice, including against melanoma and the highly specific effect of inducing proliferation and activation of human Valpha24+NKT-cells. We hypothesized that human Valpha24+NKT-cells activated by alpha-GalCer might exhibit anti-tumour activity against human melanoma. To investigate this, Valpha24+NKT-cells were generated from the peripheral blood of patients with melanoma after stimulation with alpha-GalCer pulsed monocyte-derived dendritic cells (Mo-DCs). Valpha24+NKT-cells did not exhibit cytolytic activity against the primary autologous or allogeneic melanoma cell lines tested. However, proliferation of the melanoma cell lines was markedly suppressed by co-culture with activated Valpha24+NKT-cells (mean +/- SD inhibition of proliferation 63.9 +/- 1.3%). Culture supernatants of activated Valpha24+NKT-cell cultures stimulated with alpha-GalCer pulsed Mo-DCs exhibited similar antiproliferative activities against melanoma cells, indicating that the majority of the inhibitory effects were due to soluble mediators rather than direct cell-to-cell interactions. This effect was predominantly due to release of IFN-gamma, and to a lesser extent IL-12. Other cytokines, including IL-4 and IL-10, were released but these cytokines had less antiproliferative effects. These in vitro results show that Valpha24+NKT-cells stimulated by alpha-GalCer-pulsed Mo-DCs have anti-tumour activities against human melanoma through antiproliferative effects exerted by soluble mediators rather than cytolytic effects as observed against some other tumours. Induction of local cytokine release by activated Valpha24+NKT-cells may contribute to clinical anti-tumour effects of alpha-GalCer.
British Journal of Cancer 10/2001; 85(5):741-6. · 5.04 Impact Factor
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ABSTRACT: Using a human cDNA expression array, we obtained expression profiles of 588 genes in CD14+ monocytes and monocyte-derived dendritic cells (DCs). Overall, 22 genes were upregulated, and nine genes were downregulated in DCs of both samples from two different individuals. Many of the genes that were upregulated in DCs encode proteins that are related to differentiation, cell structure, migration, termination of cell cycle as well as proliferation, e.g. tumour necrosis factor-alpha (TNF-alpha), tumour necrosis factor receptor II (TNFRII), thymosin beta-10, epithelial discoidin domain receptor 1, replication factor C, putative transcription factor DB1, alpha catenin, transforming growth factor-beta 1, prohibitin, p53-regulating protein and neu differentiation factor. Among the downregulated genes in DCs were genes that encode proteins of cell cycle regulation: mitotic growth and transcription activator, platelet-derived growth factor receptor-beta subunit, interleukin 2 receptor (IL-2R)-gamma subunit, IL-7R-alpha subunit, leucocyte interferon-gamma (IFN-gamma) and granulocyte-macrophage colony-stimulating factor receptor (GM-CSFR). Semi-quantitative reverse transcription-polymerase chain reaction method confirmed the upregulated expression levels in DCs for TNFRII, TNF-alpha, alpha catenin and downregulation of IFN-gamma, GM-CSFR on four different donor samples of DCs and monocytes. Moreover, our data show the presence of a 'switch-on' step for the TNF-alpha and TNFRII gene expression in immature DCs for further differentiation into mature DCs.
British Journal of Haematology 08/2001; 114(1):191-7. · 4.94 Impact Factor
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ABSTRACT: Using a cDNA glass microarray, the expression of 1081 genes in immature and mature dendritic cells (DCs) of two different individuals has been studied. The upregulation of mRNA transcripts of genes encoding the transcription factor ZFM1, Mos proto-oncogene serine/threonine-protein kinase, B-cell-specific transcription factor, preB-cell growth stimulating factor, ets translocation variant 6, and epidermal growth-factor-like CRIPTO was for the first time detected in DCs. Using semiquantitative RT-PCR analysis the upregulation of the transforming growth factor-alpha, integrin alpha 6 and ZFM 1 transcription factor in mature DCs was confirmed in samples from four different individuals. On the other hand, the downregulation of renin-binding protein transcript was detected in mature DCs using a cDNA microarray. For the first time, the expression of renin-angiotensin system genes was evaluated during maturation of DCs in samples from four donors by semiquantitative RT-PCR. A possible role of the renin-angiotensin system in DCs is discussed.
Biochemical and Biophysical Research Communications 08/2001; 285(4):1059-65. · 2.48 Impact Factor
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M Nieda,
A Nicol,
Y Koezuka,
A Kikuchi,
N Lapteva,
Y Tanaka,
K Tokunaga,
K Suzuki,
N Kayagaki,
H Yagita,
H Hirai,
T Juji
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ABSTRACT: Human Valpha24NKT cells are activated by alpha-galactosylceramide (alpha-GalCer)-pulsed dendritic cells in a CD1d-dependent and a T-cell receptor-mediated manner. Here, we demonstrate that CD4(+)V alpha 24NKT cells derived from a patient with acute myeloid leukemia (AML) M4 are phenotypically similar to those of healthy donors and, in common with those derived from healthy donors, express tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) when the cells are activated by alpha-GalCer-pulsed dendritic cells but not prior to activation. We also show that myeloid leukemia cells from patients with AML M4, but not from patients with AML M0 or M1, undergo apoptosis following culture with TRAIL-expressing autologous or allogeneic healthy donor V alpha 24NKT cells. Apoptosis of AML M4 leukemia cells from patient peripheral blood was almost completely blocked by a neutralizing monoclonal antibody against TRAIL, indicating that TRAIL on V alpha 24NKT cells is essential for the induction of apoptosis in AML M4 leukemia cells. A nonobese diabetic-severe combined immunodeficient human leukemia (AML M4) model showed that human activated CD4(+)V alpha 24NKT cells induced apoptosis of human leukemia cells in vivo. This is the first evidence that activated V alpha 24NKT cells express TRAIL and that TRAIL causes apoptosis of monocytic leukemia cells from patients with AML M4 in vitro and in vivo. Adoptive immune therapy with activated V alpha 24NKT cells, or other strategies to increase activated V alpha 24NKT cells in vivo, may be of benefit to patients with AML M4. (Blood. 2001;97:2067-2074)
Blood 05/2001; 97(7):2067-74. · 9.90 Impact Factor
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M Nieda,
A Kikuchi,
A nicol,
Y Koezuka,
Y Ando,
S Ishihara,
N Lapteva,
T Yabe,
K Tokunaga,
K Tadokoro,
T Juji
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ABSTRACT: Human Valpha24 natural killer T (Valpha24NKT) cells are activated by alpha-glycosylceramide-pulsed dendritic cells (DCs) in a CD1d-dependent and T-cell receptor-mediated manner. There are two major subpopulations of Valpha24NKT cells, CD4- CD8- Valpha24NKT and CD4+ Valpha24NKT cells. We have recently shown that activated CD4- CD8- Valpha24NKT cells have cytotoxic activity against DCs, but knowledge of the molecules responsible for cytotoxicity of Valpha24NKT cells is currently limited. We aimed to investigate whether CD4+ Valpha24NKT cells also have cytotoxic activity against DCs and to determine the mechanisms underlying any observed cytotoxic activity. We demonstrated that activated CD4+ Valpha24NKT cells [CD40 ligand (CD40L) -positive] have cytotoxic activity against DCs (strongly CD40-positive), but not against monocytes (weakly CD40-positive) or phytohaemagglutinin blast T cells (CD40-negative), and that apoptosis of DCs significantly contributes to the observed cytotoxicity. The apoptosis of DCs following culture with activated CD4+ Valpha24NKT cells, but not with resting CD4+ Valpha24NKT cells (CD40L-negative), was partially inhibited by anti-CD40L mAb. Direct ligation of CD40 on the DCs by the anti-CD40 antibody also induced apoptosis of DCs. Our results suggest that CD40-CD40L interaction plays an important role in the induction of apoptosis of DCs following culture with activated CD4+ Valpha24NKT cells. The apoptosis of DCs from normal donors, triggered by the CD40-CD40L interaction, may contribute to the homeostatic regulation of the normal human immune system, preventing the interminable activation of activated CD4+ Valpha24NKT cells by virtue of apoptosis of DCs.
Immunology 03/2001; 102(2):137-45. · 3.32 Impact Factor
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S Ishihara, M Nieda,
J Kitayama,
T Osada,
T Yabe,
A Kikuchi,
Y Koezuka,
S A Porcelli,
K Tadokoro,
H Nagawa,
T Juji
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ABSTRACT: Alpha-glycosylceramides, such as alpha-galactosylceramide and alpha-glucosylceramide, induce antitumor immunity in various murine cancer models. In the murine hepatic metastasis model, V alpha 14 TCR+NK1.1+ T cells, which accumulate preferentially in the liver, are considered to play a key role in the induction of antitumor immunity by alpha-glycosylceramides. We recently reported that V alpha 24 TCR+ NKT cells, the human homologues of murine V alpha 14 TCR+NK1.1+ cells, are rarely seen among freshly isolated human hepatic lymphocytes. Therefore, it is important to examine whether alpha-glycosylceramides also enhance the antitumor cytotoxicity of human hepatic lymphocytes, as they have been shown to do in murine systems, to determine the usefulness of alpha-glycosylceramides in cancer immunotherapy in humans. Here, we show that alpha-glycosylceramides greatly enhance the cytotoxicity of human hepatic lymphocytes obtained from cancer patients against the tumor cell lines, K562 and Colo201, in vitro. The direct effector cells of the elicited cytotoxicity were CD3-CD56+ NK cells. Even though V alpha 24 TCR+NKT cells proliferated remarkably in response to alpha-glycosylceramides, they did not contribute directly to the cytotoxicity. Our observations strongly suggest the potential usefulness of alpha-glycosylceramides for immunotherapy of liver cancer in humans based on their ability to activate CD3-CD56+ NK cells in the liver.
The Journal of Immunology 09/2000; 165(3):1659-64. · 5.79 Impact Factor
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ABSTRACT: Human V alpha 24+ NKT cells with an invariant TCR (V alpha 24-J alpha Q) have been shown to be specifically activated by synthetic glycolipids such as alpha-galactosylceramide and alpha-glucosylceramide in a CD1d-restricted and V alpha 24 TCR-mediated manner. We recently characterized V alpha 24+ CD4- CD8- double negative (DN) NKT cells using alpha-galactosylceramide-pulsed monocyte-derived dendritic cells. Here, we compare V alpha 24+ CD4+ NKT cells with human V alpha 24+ DN NKT cells from the same donor using alpha-galactosylceramide-pulsed monocyte-derived dendritic cells. Human V alpha 24+ CD4+ NKT cells were phenotypically and functionally similar to the human V alpha 24+ DN NKT cells characterized previously. Both of them use V alpha 24-J alpha Q-V beta 11 TCR and express CD161 (NKR-P1A), but not the other NK receptors tested so far. They also produce cytokines such as IL-4 and IFN-gamma, and, in regard to IL-4 production, V alpha 24+ CD4+ NKT cells produce more IL-4 than V alpha 24+ DN NKT cells. The cells exhibit marked cytotoxic activity against the U937 tumor cell line, but not against the NK target cell line, K562. Although at least some of the factors responsible for the stimulation of V alpha 24+ NKT cells have been clarified, little is known regarding the killing phase of these cells. Here we show that the cytotoxic activity of V alpha 24+ NKT cells against U937 cells is mediated mainly through the perforin pathway and that ICAM-1/LFA-1 as well as CD44/hyaluronic acid interactions are important for the effector phase of V alpha 24+ NKT cell-mediated cytotoxicity against U937 cells.
The Journal of Immunology 06/2000; 164(9):4458-64. · 5.79 Impact Factor
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ABSTRACT: A small population of cells in acute lymphoblastic leukaemia is characterized by a specific translocation of the c-abl oncogene on chromosome 9 to the break point cluster lesion (bcr) on chromosome 22, t(9; 22)(q34; q11) (e1a2). Theoretically, the junction-spanning sequences of oncogene fusion proteins might be ideal targets for immunotherapy because these are not present in normal cells. In this study, we show for the first time that in vitro immunization with a 17-mer e1a2 peptide representing the p190 minor bcr-abl fusion protein resulted in HLA-DRB1*1501-restricted peptide-specific proliferative CD4+ T lymphocytes, using peptide-pulsed monocyte-derived dendritic cells as the antigen-presenting cells.
British Journal of Haematology 06/2000; 109(2):435-7. · 4.94 Impact Factor
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ABSTRACT: Human invariant Valpha24+ natural killer T (NKT) cells, a subpopulation of NK cell-receptor (NKR-P1A)-expressing T cells with an invariant Valpha24JalphaQ T-cell receptor (TCR), are stimulated by the glycolipid a-galactosylceramide (KRN7000), in a CD1d-dependent, TCR-mediated fashion. Little is known about invariant Valpha24+ NKT cell function or mechanisms of effector activity. Evidence suggests this cell population protects against autoimmunity and has antitumor effects against leukemia and solid tumors.
We compared the phenotype and function of invariant Valpha24+ NKT cells, from patients with chronic myeloid leukemia (CML) and normal donors, generated by stimulation of peripheral blood mononuclear cells with alpha-galactosylceramide pulsed monocyte-derived dendritic cells. The CD4(-)CD8(-) (double negative) population was studied further.
Activated human invariant Valpha24+ NKT cells were cytotoxic against autologous and allogeneic peripheral blood dendritic cells and monocyte-derived dendritic cells but not against autologous or allogeneic T-cell PHA blasts, B-cell lymphoblastoid cell lines, monocytes, or leukemic cells from patients with CML. The findings are consistent with previous observations showing the importance of CD1d in target cell recognition. None of the Valpha24+ NKT cell lines expressed the NK markers CD16, CD56, CD94, or killer inhibitory receptors, but all expressed NKR-P1A. There was no difference in phenotype, function, or ease of generation of invariant Valpha24+ NKT cells between normal donors and patients with CML.
Based on our results and the previous evidence linking reduced Valpha24+ NKT cells to autoimmunity, we propose that double-negative Valpha24+ NKT cells have important immune regulatory functions, including contribution to the prevention of excessive antigen stimulation by virtue of cytotoxic activity against antigen presenting cells, particularly in dendritic cells.
Experimental Hematology 04/2000; 28(3):276-82. · 2.90 Impact Factor
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ABSTRACT: Human Valpha24 + NKT cells, a subpopulation of natural killer cell receptor (NKR-P1A) expressing T cells with an invariant T-cell receptor (TCR; Valpha24JalphaQ) are stimulated by the glycolipid, alpha-galactosylceramide (KRN7000), in a CD1d-dependent, TCR-mediated fashion. Little is known about Valpha24 + NKT-cell function. The murine counterpart, Valpha14 + NKT cells, appear to have an important role in controlling malignancy. There are no human data examining the role of Valpha24 + NKT cells in controlling human malignancy. We report that Valpha24 + NKT cells have perforin-mediated cytotoxicity against haemopoietic malignancies. Valpha24 TCR, CD1d and alpha-galactosylceramide may all play a role in cytotoxicity but are not absolute requirements. The greatest cytotoxicity was observed against the U937 tumour cell line (95 +/- 5% lysis). THP-1, Molt4, C1R cells and allogeneic mismatched dendritic cells were also sensitive to Valpha24 + NKT cytotoxicity but neither the NK target, K562, nor lymphokine-activated killer-sensitive Daudi cells, were sensitive. These results indicate a killing pattern distinct from conventional major histocompatibility complex-restricted T cells, NK cells and other cytotoxic lymphoid cells previously described. We conclude that human Valpha24 + NKT cells have cytotoxic anti-tumour activity against haemopoietic malignancies through effector mechanisms distinct from conventional T cells and NK cells and that their specific stimulator KRN7000 may have therapeutic potential.
Immunology 03/2000; 99(2):229-34. · 3.32 Impact Factor
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ABSTRACT: Human Vα24 + NKT cells, a subpopulation of natural killer cell receptor (NKR-P1A) expressing T cells with an invariant T-cell receptor (TCR; Vα24JαQ) are stimulated by the glycolipid, α-galactosylceramide (KRN7000), in a CD1d-dependent, TCR-mediated fashion. Little is known about Vα24 + NKT-cell function. The murine counterpart, Vα14 + NKT cells, appear to have an important role in controlling malignancy. There are no human data examining the role of Vα24 + NKT cells in controlling human malignancy. We report that Vα24 + NKT cells have perforin-mediated cytotoxicity against haemopoietic malignancies. Vα24 TCR, CD1d and α-galactosylceramide may all play a role in cytotoxicity but are not absolute requirements. The greatest cytotoxicity was observed against the U937 tumour cell line (95 ± 5% lysis). THP-1, Molt4, C1R cells and allogeneic mismatched dendritic cells were also sensitive to Vα24 + NKT cytotoxicity but neither the NK target, K562, nor lymphokine-activated killer-sensitive Daudi cells, were sensitive. These results indicate a killing pattern distinct from conventional major histocompatibility complex-restricted T cells, NK cells and other cytotoxic lymphoid cells previously described. We conclude that human Vα24 + NKT cells have cytotoxic anti-tumour activity against haemopoietic malignancies through effector mechanisms distinct from conventional T cells and NK cells and that their specific stimulator KRN7000 may have therapeutic potential.
Immunology 01/2000; 99(2):229 - 234. · 3.32 Impact Factor
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ABSTRACT: A unique subset of T cells that co-express NKR-P1, which is a lectin type of NK receptor and is thought to have a major role in triggering NK activity, has been identified. In mice, NK1.1 (mouse NKR-P1C)(+) T cells, called NKT cells, preferentially accumulate in the liver and bone marrow. They predominantly use invariant Valpha14 chain TCR and phenotypically are CD4(+)CD8(-) or CD4(-)CD8(-) T cells. In this study, we analyzed, phenotypically and functionally, the NKR-P1A (analogue of murine NKR-P1C)(+) T cells resident in the human liver. Here, we show that in complete contrast to the NKT cells in the mouse liver, the majority of NKR-P1A(+) T cells in the human liver are CD8(+) and their TCR repertoire is not skewed to Valpha24 TCR, the homologue of murine Valpha14 TCR. Almost all of the NKR-P1A(+) T cells in the human liver expressed CD69, suggesting that they were activated. Furthermore, the NKR-P1A(+) T cells in the human liver exhibited strong cytotoxicity against a variety of tumor cell lines including K562, Molt4 and some colonic adenocarcinoma cell lines.
European Journal of Immunology 09/1999; 29(8):2406-13. · 5.10 Impact Factor
