Malgorzata Czystowska - Academia.edu (original) (raw)

Papers by Malgorzata Czystowska

PDF file - 57 KB, Results of the experimental verification of the two predictive models

PDF file - 1978 KB, Decreased percentages of circulating apoptosis-resistant CD8+CCR7+ T cells in... more PDF file - 1978 KB, Decreased percentages of circulating apoptosis-resistant CD8+CCR7+ T cells in HNSCC patients and NC

Purpose: Patients with cancer have an increased frequency of circulating apoptosis-sensitive CD8+... more Purpose: Patients with cancer have an increased frequency of circulating apoptosis-sensitive CD8+CCR7neg T cells and few CD8+CCR7+ T cells versus normal controls. The functional and clinical significance of this imbalance was investigated using peripheral blood of patients with squamous cell carcinoma of the head and neck (HNSCC).Experimental Design: The frequency of circulating CD8+ T cells co-expressing CCR7, CD45RO, CD28, and Annexin V (ANXV) was evaluated in 67 patients and 57 normal controls by flow cytometry. Spearman rank correlations among immunophenotypic profiles were analyzed. Recursive partitioning classified subjects as patients or normal controls based on CD8+CCR7+ T-cell percentages. Kaplan–Meier plots estimated disease-free survival (DFS).Results: The CD8+CCR7+ T-cell frequency was low, whereas that of total CD8+CCR7neg and ANXV-binding CD8+CCR7neg T cells was higher in patients with HNSCC than in normal controls (P < 0.001–0.0001). ANXV binding correlated with th...

PDF file - 61 KB, Percentages of ANX-binding cells within the peripheral memory (TPM) and termina... more PDF file - 61 KB, Percentages of ANX-binding cells within the peripheral memory (TPM) and terminally differentiating (TTD)subsets in the circulation of HNSCC patients and normal controls

PDF file - 3533 KB, The presence of CD8+CCR7+ T cells in HNSCC in situ

Supplementary Figure 2 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck S... more Supplementary Figure 2 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck Squamous Cell Carcinoma Promotes Tumor Development and Protects the Tumor from Immune Attack

Supplementary Figure 1 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck S... more Supplementary Figure 1 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck Squamous Cell Carcinoma Promotes Tumor Development and Protects the Tumor from Immune Attack

Supplementary Figure Legends 1-3 from Triggering of Toll-like Receptor 4 Expressed on Human Head ... more Supplementary Figure Legends 1-3 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck Squamous Cell Carcinoma Promotes Tumor Development and Protects the Tumor from Immune Attack

Toll-like receptors (TLR) expressed on inflammatory cells play a key role in host defense against... more Toll-like receptors (TLR) expressed on inflammatory cells play a key role in host defense against pathogens, benefiting the host. TLR are also expressed on tumor cells. To evaluate the role of TLR in tumor cells, we investigated TLR4 signaling effects on human head and neck squamous cell carcinoma (HNSCC). Tumor tissues were obtained from 27 patients with laryngeal and 12 with oral cavity cancers. Normal mucosa was obtained from 10 patients with nonneoplastic disorders. Smears for bacteria were taken from all patients during surgery. TLR4 expression in tumors and HNSCC cell lines (PCI-1, PCI-13, and PCI-30) was detected by reverse transcription-PCR and immunohistochemistry. Cell growth, apoptosis, nuclear factor-κB (NF-κB) translocation, and MyD88 and IRAK-4 expression, as well as Akt phosphorylation were measured following tumor cell exposure to the TLR4 ligand lipopolysaccharide (LPS). Tumor cell sensitivity to NK-92–mediated lysis was evaluated in 4-hour 51Cr-release assays. Cyto...

Supplementary Figure 3 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck S... more Supplementary Figure 3 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck Squamous Cell Carcinoma Promotes Tumor Development and Protects the Tumor from Immune Attack

ABSTRACT Toll-like receptors (TLRs) expressed on immune cells trigger inflammatory responses. TLR... more ABSTRACT Toll-like receptors (TLRs) expressed on immune cells trigger inflammatory responses. TLRs are also expressed on ovarian cancer (OvCa) cells, but the consequences of signaling by the TLR4/MyD88 pathway in these cells are unclear. Here, TLR4 and MyD88 expression in OvCa tissues (n=20) and cell lines (OVCAR3, SKOV3, AD10, A2780 and CP70) was evaluated by reverse transcriptase-PCR, western blots and immunohistochemistry. Cell growth, apoptosis, nuclear factor-kappaB (NF-kappaB) translocation, IRAK4 and TRIF expression and cJun phosphorylation were measured following tumor cell exposure to the TLR4 ligands, lipopolysaccharide (LPS) or paclitaxel (PTX). Culture supernatants were tested for cytokine levels. TLR4 was expressed in all tumors, tumor cell lines and normal epithelium. MyD88 was detectable in tumor tissues and in 3/5 OvCa lines but not in normal cells. In MyD88(+) SCOV3 cells, LPS or PTX binding to TLR4 induced IRAK4 activation and cJun phosphorylation, activated the NF-kappaB pathway and promoted interleukin (IL)-8, IL-6, vascular endothelial growth factor and monocyte chemotactic protein-1 production and resistance to drug-induced apoptosis. Silencing of TLR4 in SCOV3 cells with small interference RNA resulted in phosphorylated-cJun (p-cJun) downregulation and a loss of PTX resistance. In PTX-sensitive, MyD88(neg) A2780 cells, TLR4 stimulation upregulated TRIF, and TLR4 silencing eliminated this effect. Thus, TLR4/MyD88 signaling supports OvCa progression and chemoresistance, promoting immune escape.

Cancer Research, 2008

1035 Introduction: Toll-like receptor 4 (TLR4), a main receptor for bacterial lipopolysaccharide ... more 1035 Introduction: Toll-like receptor 4 (TLR4), a main receptor for bacterial lipopolysaccharide (LPS) is highly expressed on antigen presenting cells and play important role in innate immunity. Recently, TLR4 has been found to be expressed by various types of human tumor cells. However, the role and biological significance of TLR4 expressed by tumor cells are unknown. The goal of this study was to analyze TLR4 expression on ovarian cancer cells and the effects of LPS and Paclitaxel on tumor cell proliferation and sensitivity to apoptosis. Materials and methods: TLR4 and adaptor protein MyD88 expression in human OVCAR-3 and SKOV-3 cell lines was determined using reverse transcription RT-PCR analysis and immunohistochemistry assays. Activation of the NF-κB translocation was measured by confocal microscopy. Culture supernatants were tested for levels of cytokines/chemokines in a Luminex-based assay. Proliferation of cancer cells was measured in CFSE assays. Annexin V (Anx) binding to ...

Autophagy in Immune Response: Impact on Cancer Immunotherapy, 2020

Abstract The eukaryotic endomembrane system plays a key role in responses of cells to stress and ... more Abstract The eukaryotic endomembrane system plays a key role in responses of cells to stress and maintains cell homeostasis in health and disease. Its two components, exosome biogenesis and autophagy are linked through the shared molecular machinery in the endolysosomal pathway. The distinction between exosomes derived from the endosome and extracellular vesicles (EVs) produced by secretory autophagy is difficult, because of molecular crosstalk existing between the exosome and autophagy pathways. Dichotomous effects these EVs mediate in health and disease suggest they comprise vesicles derived from both pathways. The crosstalk between these pathways provides the host immune cells with context-dependent signals that might differentially drive innate and adaptive immune responses. The messages carried by autophagy-derived EVs may be distinct from messages exosomes deliver to immune cells and might induce immune responses that are qualitatively and quantitatively different. The presence of exosome biogenesis and autophagy might allow for the calibration of immune responses under various environmental stress conditions. This hypothesis is an attempt to explain why autophagy and exosome biogenesis exist as distinct albeit interactive and partially overlapping cellular pathways. By simultaneously engaging the host immune system, exosomes and autophagy maintain the balance required for cellular homeostasis under physiological and pathological conditions.

Journal of Clinical Oncology, 2009

e16508 Background: TLR4, expressed by the cells of the immune system play a role in the protectio... more e16508 Background: TLR4, expressed by the cells of the immune system play a role in the protection of the host against pathogens. TLRs are also expressed on human cancer cells, but their role in tumor growth is unknown. The aim of this study was to correlate the presence of TLR4 and MyD88 expression with clinicopathologic outcome in patients with ovarian cancer and to analyze the consequences of signaling via the TLR4/MyD88 pathway in ovarian cancer cell lines. Methods: Tumor specimens from 41 patients with ovarian carcinoma were evaluated for TLR4 and MyD88 by immunohistochemistry and correlated with clinical and pathologic disease features. TLR4/MyD88 expression in OVCAR3, SKOV3, and A2780 was determined using RT-PCR, WB, and immunohistochemistry. NF-kB translocation to nucleus was measured by confocal microscopy. Culture supernatants were tested for levels of cytokines in Luminex-based assays. Proliferation of cancer cells was measured in the CFSE assays. Their sensitivity to pac...

Blood, 2008

An elevated frequency of CD4+CD25high regulatory T cells (Treg) has been reported in the peripher... more An elevated frequency of CD4+CD25high regulatory T cells (Treg) has been reported in the peripheral blood in patients with various solid tumors and hematologic malignancies. Although the increase in Treg seems to be a characteristic feature of most tumors, the functional role of Treg and the mechanisms of suppression, especially in patients with hematologic malignancies, have been less well defined. We investigated Treg-mediated suppression and the responsible mechanisms in thirty newly diagnosed acute myeloid leukemia (AML) patients prior to any treatment and twenty five healthy donors (NC). The percentage of circulating CD4+ CD25high Treg was higher (p <0.0001) in the AML patients (4.5 ±0.2%, range 1.7–8.2%) compared to NC (1.5 ± 0.08%, range 0.9–3.1 %). To evaluate the suppressive function, CD4+CD25high T cells (S) were co-cultured with sorted, CFSE-labeled autologous CD4+CD25high T cells (R) at different S/R ratios. Suppression mediated by Treg co-incubated with proliferating...

Blood, 2008

Interleukin-15 (IL-15) has been demonstrated to play a critical role in the regulation of natural... more Interleukin-15 (IL-15) has been demonstrated to play a critical role in the regulation of natural killer (NK) cells. IL-15 induces the differentiation of NK cells from hematopoietic progenitors, stimulates the expansion of peripheral NK cells, and supports their survival. We investigated the role of IL-15 as a homeostatic regulator of NK cells in 29 patients diagnosed with acute myeloid leukemia (AML) and the potential role of IL-15 in enhancing the anti-tumor activity of NK cells in AML patients. The percentage of circulating NK cells was lower (p<0.0001) in the AML patients (6%± 0.7, range 1–17%) compared to the NK cells of healthy donors (12%± 1, range 9–17 %). At diagnosis the mean level of IL-15 in patient plasma was 1.9 pg/ml (range 0.03–8.9) and increased (p <0.02) to 5.2 pg/ml (range 0.06–13.4) after the completion of induction chemotherapy, when the NK levels had been reduced to zero cells/microliter. The mean level of IL-15 subsequently decreased to pre-treatment lev...

Blood, 2007

Natural killer (NK) cells lyse malignant cells without prior antigen-specific priming and play a ... more Natural killer (NK) cells lyse malignant cells without prior antigen-specific priming and play a critical role in the innate immune response. A balance of signals from activating and inhibiting receptors expressed on each NK cell controls its activity. The growth, differentiation and survival of NK cells have been found to be dependent on interleukin-15 (IL-15). Using multicolor flow cytometry we investigated the receptor repertoire and also measured the NK cell activity in twenty three patients with newly diagnosed acute myeloid leukemia (AML) prior to any treatment. Further, we investigated the ex-vivo effect of IL-15 on the NK cell repertoire and NK cell cytotoxicity. The percentage of circulating NK cells was lower (p<0.0001) in the AML patients (6%± 0.7, range 1–17%) compared to the NK cells of healthy donors (12%± 1, range 9–17%). The expression of the activating natural cytotoxicity (NCR) receptors NKp30 and NKp46 and the C-type lectin receptors NKG2D and NKG2C was signifi...

Journal of Clinical Oncology, 2007

7054 Background: Regulatory CD4+CD25+ T cells (T reg) are critical regulators of immune tolerance... more 7054 Background: Regulatory CD4+CD25+ T cells (T reg) are critical regulators of immune tolerance. However, the functional role of T reg in human tumor immunity has been less well studied. The frequency of circulating Treg is increased in patients with solid malignancies. We evaluated the frequency, phenotype and suppressive function of T reg in patients with acute myeloid leukemia (AML). Methods: The frequency and phenotype of CD4+ CD25high T cells were investigated in the peripheral blood of fifteen newly diagnosed AML patients prior to any treatment and fifteen healthy donors by multiparameter flow cytometry. The suppressive function of Treg was evaluated using CFSE-labeled fresh autologous CD4+CD25- T cells activated with an anti-CD3 antibody. Results: The percentage of circulating CD4+ CD25high Treg was higher (p <0.001) in the AML patients (5.2 ± 1.3%, range 0.4 −7%) compared to healthy donors (1.1 ± 0.2%, range 0.8–1.5%). T reg expressing Foxp3, CTLA-4, CD45 RO, CCR4 and F...

Journal of Clinical Oncology, 2007

3011 Background: 50% of ovarian cancers carry a p53 mutation, most of which can lead to overexpre... more 3011 Background: 50% of ovarian cancers carry a p53 mutation, most of which can lead to overexpression of the protein, providing a unique target for vaccine therapy. Preclinical data shows cytotoxic T-lymphocytes can be generated against wild-type peptide and can lyse tumor cells overexpressing p53. There are many methods of antigen delivery for cancer vaccines and very few comparative studies have been conducted to determine the best of these. Here we report findings for this completed study comparing two methods of vaccination. Methods: Eligible patients had Stage III, IV, or recurrent ovarian cancer and were clinically NED at study entry. Elevated CA-125 was allowed. HLA-A2.1 and overexpression of p53 were required. A wild-type epitope (264–272) with high HLA-A2.1 affinity was utilized for vaccination. Two techniques were randomly compared: subcutaneous (SQ) peptide admixed with ISA-51 and GM-CSF adjuvants or peptide-pulsed dendritic cells given intravenously (IV). Both arms rece...

PDF file - 57 KB, Results of the experimental verification of the two predictive models

PDF file - 1978 KB, Decreased percentages of circulating apoptosis-resistant CD8+CCR7+ T cells in... more PDF file - 1978 KB, Decreased percentages of circulating apoptosis-resistant CD8+CCR7+ T cells in HNSCC patients and NC

Purpose: Patients with cancer have an increased frequency of circulating apoptosis-sensitive CD8+... more Purpose: Patients with cancer have an increased frequency of circulating apoptosis-sensitive CD8+CCR7neg T cells and few CD8+CCR7+ T cells versus normal controls. The functional and clinical significance of this imbalance was investigated using peripheral blood of patients with squamous cell carcinoma of the head and neck (HNSCC).Experimental Design: The frequency of circulating CD8+ T cells co-expressing CCR7, CD45RO, CD28, and Annexin V (ANXV) was evaluated in 67 patients and 57 normal controls by flow cytometry. Spearman rank correlations among immunophenotypic profiles were analyzed. Recursive partitioning classified subjects as patients or normal controls based on CD8+CCR7+ T-cell percentages. Kaplan–Meier plots estimated disease-free survival (DFS).Results: The CD8+CCR7+ T-cell frequency was low, whereas that of total CD8+CCR7neg and ANXV-binding CD8+CCR7neg T cells was higher in patients with HNSCC than in normal controls (P < 0.001–0.0001). ANXV binding correlated with th...

PDF file - 61 KB, Percentages of ANX-binding cells within the peripheral memory (TPM) and termina... more PDF file - 61 KB, Percentages of ANX-binding cells within the peripheral memory (TPM) and terminally differentiating (TTD)subsets in the circulation of HNSCC patients and normal controls

PDF file - 3533 KB, The presence of CD8+CCR7+ T cells in HNSCC in situ

Supplementary Figure 2 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck S... more Supplementary Figure 2 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck Squamous Cell Carcinoma Promotes Tumor Development and Protects the Tumor from Immune Attack

Supplementary Figure 1 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck S... more Supplementary Figure 1 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck Squamous Cell Carcinoma Promotes Tumor Development and Protects the Tumor from Immune Attack

Supplementary Figure Legends 1-3 from Triggering of Toll-like Receptor 4 Expressed on Human Head ... more Supplementary Figure Legends 1-3 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck Squamous Cell Carcinoma Promotes Tumor Development and Protects the Tumor from Immune Attack

Toll-like receptors (TLR) expressed on inflammatory cells play a key role in host defense against... more Toll-like receptors (TLR) expressed on inflammatory cells play a key role in host defense against pathogens, benefiting the host. TLR are also expressed on tumor cells. To evaluate the role of TLR in tumor cells, we investigated TLR4 signaling effects on human head and neck squamous cell carcinoma (HNSCC). Tumor tissues were obtained from 27 patients with laryngeal and 12 with oral cavity cancers. Normal mucosa was obtained from 10 patients with nonneoplastic disorders. Smears for bacteria were taken from all patients during surgery. TLR4 expression in tumors and HNSCC cell lines (PCI-1, PCI-13, and PCI-30) was detected by reverse transcription-PCR and immunohistochemistry. Cell growth, apoptosis, nuclear factor-κB (NF-κB) translocation, and MyD88 and IRAK-4 expression, as well as Akt phosphorylation were measured following tumor cell exposure to the TLR4 ligand lipopolysaccharide (LPS). Tumor cell sensitivity to NK-92–mediated lysis was evaluated in 4-hour 51Cr-release assays. Cyto...

Supplementary Figure 3 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck S... more Supplementary Figure 3 from Triggering of Toll-like Receptor 4 Expressed on Human Head and Neck Squamous Cell Carcinoma Promotes Tumor Development and Protects the Tumor from Immune Attack

ABSTRACT Toll-like receptors (TLRs) expressed on immune cells trigger inflammatory responses. TLR... more ABSTRACT Toll-like receptors (TLRs) expressed on immune cells trigger inflammatory responses. TLRs are also expressed on ovarian cancer (OvCa) cells, but the consequences of signaling by the TLR4/MyD88 pathway in these cells are unclear. Here, TLR4 and MyD88 expression in OvCa tissues (n=20) and cell lines (OVCAR3, SKOV3, AD10, A2780 and CP70) was evaluated by reverse transcriptase-PCR, western blots and immunohistochemistry. Cell growth, apoptosis, nuclear factor-kappaB (NF-kappaB) translocation, IRAK4 and TRIF expression and cJun phosphorylation were measured following tumor cell exposure to the TLR4 ligands, lipopolysaccharide (LPS) or paclitaxel (PTX). Culture supernatants were tested for cytokine levels. TLR4 was expressed in all tumors, tumor cell lines and normal epithelium. MyD88 was detectable in tumor tissues and in 3/5 OvCa lines but not in normal cells. In MyD88(+) SCOV3 cells, LPS or PTX binding to TLR4 induced IRAK4 activation and cJun phosphorylation, activated the NF-kappaB pathway and promoted interleukin (IL)-8, IL-6, vascular endothelial growth factor and monocyte chemotactic protein-1 production and resistance to drug-induced apoptosis. Silencing of TLR4 in SCOV3 cells with small interference RNA resulted in phosphorylated-cJun (p-cJun) downregulation and a loss of PTX resistance. In PTX-sensitive, MyD88(neg) A2780 cells, TLR4 stimulation upregulated TRIF, and TLR4 silencing eliminated this effect. Thus, TLR4/MyD88 signaling supports OvCa progression and chemoresistance, promoting immune escape.

Cancer Research, 2008

1035 Introduction: Toll-like receptor 4 (TLR4), a main receptor for bacterial lipopolysaccharide ... more 1035 Introduction: Toll-like receptor 4 (TLR4), a main receptor for bacterial lipopolysaccharide (LPS) is highly expressed on antigen presenting cells and play important role in innate immunity. Recently, TLR4 has been found to be expressed by various types of human tumor cells. However, the role and biological significance of TLR4 expressed by tumor cells are unknown. The goal of this study was to analyze TLR4 expression on ovarian cancer cells and the effects of LPS and Paclitaxel on tumor cell proliferation and sensitivity to apoptosis. Materials and methods: TLR4 and adaptor protein MyD88 expression in human OVCAR-3 and SKOV-3 cell lines was determined using reverse transcription RT-PCR analysis and immunohistochemistry assays. Activation of the NF-κB translocation was measured by confocal microscopy. Culture supernatants were tested for levels of cytokines/chemokines in a Luminex-based assay. Proliferation of cancer cells was measured in CFSE assays. Annexin V (Anx) binding to ...

Autophagy in Immune Response: Impact on Cancer Immunotherapy, 2020

Abstract The eukaryotic endomembrane system plays a key role in responses of cells to stress and ... more Abstract The eukaryotic endomembrane system plays a key role in responses of cells to stress and maintains cell homeostasis in health and disease. Its two components, exosome biogenesis and autophagy are linked through the shared molecular machinery in the endolysosomal pathway. The distinction between exosomes derived from the endosome and extracellular vesicles (EVs) produced by secretory autophagy is difficult, because of molecular crosstalk existing between the exosome and autophagy pathways. Dichotomous effects these EVs mediate in health and disease suggest they comprise vesicles derived from both pathways. The crosstalk between these pathways provides the host immune cells with context-dependent signals that might differentially drive innate and adaptive immune responses. The messages carried by autophagy-derived EVs may be distinct from messages exosomes deliver to immune cells and might induce immune responses that are qualitatively and quantitatively different. The presence of exosome biogenesis and autophagy might allow for the calibration of immune responses under various environmental stress conditions. This hypothesis is an attempt to explain why autophagy and exosome biogenesis exist as distinct albeit interactive and partially overlapping cellular pathways. By simultaneously engaging the host immune system, exosomes and autophagy maintain the balance required for cellular homeostasis under physiological and pathological conditions.

Journal of Clinical Oncology, 2009

e16508 Background: TLR4, expressed by the cells of the immune system play a role in the protectio... more e16508 Background: TLR4, expressed by the cells of the immune system play a role in the protection of the host against pathogens. TLRs are also expressed on human cancer cells, but their role in tumor growth is unknown. The aim of this study was to correlate the presence of TLR4 and MyD88 expression with clinicopathologic outcome in patients with ovarian cancer and to analyze the consequences of signaling via the TLR4/MyD88 pathway in ovarian cancer cell lines. Methods: Tumor specimens from 41 patients with ovarian carcinoma were evaluated for TLR4 and MyD88 by immunohistochemistry and correlated with clinical and pathologic disease features. TLR4/MyD88 expression in OVCAR3, SKOV3, and A2780 was determined using RT-PCR, WB, and immunohistochemistry. NF-kB translocation to nucleus was measured by confocal microscopy. Culture supernatants were tested for levels of cytokines in Luminex-based assays. Proliferation of cancer cells was measured in the CFSE assays. Their sensitivity to pac...

Blood, 2008

An elevated frequency of CD4+CD25high regulatory T cells (Treg) has been reported in the peripher... more An elevated frequency of CD4+CD25high regulatory T cells (Treg) has been reported in the peripheral blood in patients with various solid tumors and hematologic malignancies. Although the increase in Treg seems to be a characteristic feature of most tumors, the functional role of Treg and the mechanisms of suppression, especially in patients with hematologic malignancies, have been less well defined. We investigated Treg-mediated suppression and the responsible mechanisms in thirty newly diagnosed acute myeloid leukemia (AML) patients prior to any treatment and twenty five healthy donors (NC). The percentage of circulating CD4+ CD25high Treg was higher (p <0.0001) in the AML patients (4.5 ±0.2%, range 1.7–8.2%) compared to NC (1.5 ± 0.08%, range 0.9–3.1 %). To evaluate the suppressive function, CD4+CD25high T cells (S) were co-cultured with sorted, CFSE-labeled autologous CD4+CD25high T cells (R) at different S/R ratios. Suppression mediated by Treg co-incubated with proliferating...

Blood, 2008

Interleukin-15 (IL-15) has been demonstrated to play a critical role in the regulation of natural... more Interleukin-15 (IL-15) has been demonstrated to play a critical role in the regulation of natural killer (NK) cells. IL-15 induces the differentiation of NK cells from hematopoietic progenitors, stimulates the expansion of peripheral NK cells, and supports their survival. We investigated the role of IL-15 as a homeostatic regulator of NK cells in 29 patients diagnosed with acute myeloid leukemia (AML) and the potential role of IL-15 in enhancing the anti-tumor activity of NK cells in AML patients. The percentage of circulating NK cells was lower (p<0.0001) in the AML patients (6%± 0.7, range 1–17%) compared to the NK cells of healthy donors (12%± 1, range 9–17 %). At diagnosis the mean level of IL-15 in patient plasma was 1.9 pg/ml (range 0.03–8.9) and increased (p <0.02) to 5.2 pg/ml (range 0.06–13.4) after the completion of induction chemotherapy, when the NK levels had been reduced to zero cells/microliter. The mean level of IL-15 subsequently decreased to pre-treatment lev...

Blood, 2007

Natural killer (NK) cells lyse malignant cells without prior antigen-specific priming and play a ... more Natural killer (NK) cells lyse malignant cells without prior antigen-specific priming and play a critical role in the innate immune response. A balance of signals from activating and inhibiting receptors expressed on each NK cell controls its activity. The growth, differentiation and survival of NK cells have been found to be dependent on interleukin-15 (IL-15). Using multicolor flow cytometry we investigated the receptor repertoire and also measured the NK cell activity in twenty three patients with newly diagnosed acute myeloid leukemia (AML) prior to any treatment. Further, we investigated the ex-vivo effect of IL-15 on the NK cell repertoire and NK cell cytotoxicity. The percentage of circulating NK cells was lower (p<0.0001) in the AML patients (6%± 0.7, range 1–17%) compared to the NK cells of healthy donors (12%± 1, range 9–17%). The expression of the activating natural cytotoxicity (NCR) receptors NKp30 and NKp46 and the C-type lectin receptors NKG2D and NKG2C was signifi...

Journal of Clinical Oncology, 2007

7054 Background: Regulatory CD4+CD25+ T cells (T reg) are critical regulators of immune tolerance... more 7054 Background: Regulatory CD4+CD25+ T cells (T reg) are critical regulators of immune tolerance. However, the functional role of T reg in human tumor immunity has been less well studied. The frequency of circulating Treg is increased in patients with solid malignancies. We evaluated the frequency, phenotype and suppressive function of T reg in patients with acute myeloid leukemia (AML). Methods: The frequency and phenotype of CD4+ CD25high T cells were investigated in the peripheral blood of fifteen newly diagnosed AML patients prior to any treatment and fifteen healthy donors by multiparameter flow cytometry. The suppressive function of Treg was evaluated using CFSE-labeled fresh autologous CD4+CD25- T cells activated with an anti-CD3 antibody. Results: The percentage of circulating CD4+ CD25high Treg was higher (p <0.001) in the AML patients (5.2 ± 1.3%, range 0.4 −7%) compared to healthy donors (1.1 ± 0.2%, range 0.8–1.5%). T reg expressing Foxp3, CTLA-4, CD45 RO, CCR4 and F...

Journal of Clinical Oncology, 2007

3011 Background: 50% of ovarian cancers carry a p53 mutation, most of which can lead to overexpre... more 3011 Background: 50% of ovarian cancers carry a p53 mutation, most of which can lead to overexpression of the protein, providing a unique target for vaccine therapy. Preclinical data shows cytotoxic T-lymphocytes can be generated against wild-type peptide and can lyse tumor cells overexpressing p53. There are many methods of antigen delivery for cancer vaccines and very few comparative studies have been conducted to determine the best of these. Here we report findings for this completed study comparing two methods of vaccination. Methods: Eligible patients had Stage III, IV, or recurrent ovarian cancer and were clinically NED at study entry. Elevated CA-125 was allowed. HLA-A2.1 and overexpression of p53 were required. A wild-type epitope (264–272) with high HLA-A2.1 affinity was utilized for vaccination. Two techniques were randomly compared: subcutaneous (SQ) peptide admixed with ISA-51 and GM-CSF adjuvants or peptide-pulsed dendritic cells given intravenously (IV). Both arms rece...