A. Van Den Eertwegh - Academia.edu (original) (raw)

Papers by A. Van Den Eertwegh

Research paper thumbnail of In Vivo Localisation Patterns and Cell-Cell Interactions of Cytokine Producing T-Cells and Specific Antibody Forming B-Cells

Advances in Experimental Medicine and Biology, 1994

Because of its central position in the bloodstream and the large amount of migrating lymphocytes,... more Because of its central position in the bloodstream and the large amount of migrating lymphocytes, the spleen plays a central role in the primary defense against bloodstream infections. Two critical functions of the spleen can be recognized: it serves as a large phagocytic filter and it is a major antibody producing organ1. Although the spleen participates significantly in host defense mechanisms, it is not essential for life. Nevertheless, its removal increases the risk on overwhelming infections by bacteria with polysaccharide capsules, e.g. Streptococcus pneumonia, Neisseria meningitidis orHaemo-philus influenza 2. After primary i.v. immunization, the spleen is the major site of antibody production3. Since eight times more lymphocytes recirculate via the spleen than via all lymph nodes together4, it is most likely that the entire antigen-specific B- T-cell repertoire is available in the spleen. The complex anatomical organization of the spleen with distinct compartments containing specialized cell types provides a unique micro-environment allowing cell-cell interactions which are essential for the initiation and continuation of various immune responses5 (fig. 1). To fully understand the role of the spleen in the immune response it is obviously necessary to look at this organ in a functional in vivo way. This means that one should switch from conventional phenotyping of immunocompetent cells to a more functional characterisation (e.g. resting vs activated). In looking at B-cells one should for example clearly separate membrane-Ig positive, memory and plasma cells. The latter group can be further subdivided by looking at the antigen specificity of the produced antibodies. For this purpose we developed new methodology for the detection of antigen specific antibody forming B-cells (AFCs) in tissue sections. By double staining we could also simultaneously determine the isotype of these AFCs (reviewed in: 6).

Research paper thumbnail of Use of New Therapies and Hospital Admission Near the End of Life in Castration Resistant Prostate Cancer (CRPC) in the Castration Resistant Prostate Cancer Registry (CAPRI) in the Netherlands

Value in Health, Oct 1, 2017

by grades were abstracted (or calculated) to assess variability. Results: 119 distinct AEs were r... more by grades were abstracted (or calculated) to assess variability. Results: 119 distinct AEs were reported across 10 products. Events occurring in > 30% of patients included: anemia, diarrhea, fatigue, leukopenia lymphopenia, neutropenia, pneumonia and thrombocytopenia. 41 events were found occurring in > 5% of the population. Nearly 50% (19/41) events had rates reported differently between the trial and PI with 12/19 differences in pomalidomide materials. For example, grade 3/4 pneumonia was reported in 19.6% and 28.6% of patients, respectively in the trial publication versus PI. A small but potentially clinically meaningful difference in the rate of cardiac failure was noted for cafilizomib (6.4% trial publication v 6.0% PI). Other differences, such as 17.0% v 9.3% were noted in the pomalidomide trial publication v PI for asthenia and fatigue. ConClusions: There is heterogeneity in both the criteria used and the rates reported for common and serious AEs related to MM treatment across and within published materials. Meta-analysis, budget impact models, and value calculators utilize these data, often with vague references to sources. Source material used should be clarified and investigation of these findings should be confirmed in other tumor types.

Research paper thumbnail of Pre-operative intradermal administration of CpG-B ± GM-CSF in stage I-III melanoma patients arms the sentinel lymph node: evidence for reduced tumor spread

Journal for ImmunoTherapy of Cancer, 2013

Research paper thumbnail of Arming the Melanoma SLN through local administration of CpG-B and GM-CSF: recruitment and activation of BDCA3/CD141+ DC and enhanced cross-presentation

Cancer immunology research, Jan 29, 2015

Melanoma-induced suppression of Dendritic Cells (DC) in the Sentinel Lymph Node (SLN) interferes ... more Melanoma-induced suppression of Dendritic Cells (DC) in the Sentinel Lymph Node (SLN) interferes with the generation of protective anti-tumor immunity. In an effort to strengthen immune defenses against metastatic spread, 28 Stage I-III melanoma patients were randomized in a 3-arm Phase-II study to receive i.d. injections around the primary tumor excision site of saline or low-dose CpG-B, alone or combined with GM-CSF, prior to excision of the SLN. Combined CpG/GM-CSF administration resulted in enhanced maturation of all identifiable conventional (cDC) and plasmacytoid (pDC) DC subsets and selectively induced increased frequencies of SLN-resident BDCA3/CD141+ cDC subsets that also expressed the C-type Lectin Receptor CLEC9A. Correlative in vivo analyses and in vitro studies provided evidence that these subsets were derived from BDCA3+ cDC precursors in the blood that were recruited to the SLN in a type-1 interferon-dependent manner and subsequently matured under the combined influen...

Research paper thumbnail of In vitro Evaluation of Buffy-Coat-Derived Platelet Concentrates Stored in a Synthetic Medium

Vox Sanguinis, 1991

Human blood platelets, prepared by the buffy-coat method, were prepared and stored in different s... more Human blood platelets, prepared by the buffy-coat method, were prepared and stored in different synthetic media. In a synthetic medium based on gluconate, acetate and citrate (GAC), the pH was 6.8 on day 6. This medium was chosen for further evaluation. The total platelet count and the leukocyte contamination were significantly lower in the platelet concentrates (PCs) prepared in GAC compared to PCs prepared in plasma. Platelets stored in plasma or in GAC were equally functional when tested for aggregation and adenosine triphosphate (ATP) secretion. Only stimuli that act through the arachidonic-acid pathway induced a lower platelet response in GAC. Platelet morphology was quantified by measuring the difference in light transmission during stirring at different rates in an aggregometer; no significant differences for platelets stored in GAC as compared to plasma were observed. Activation of platelets was measured by binding of monoclonal antibodies (McAb) against the Gp IIbAIIa complex and against activation-dependent antigens (GMP 140 from the a-granules and a 53-kD glycoprotein from the lysosomal granules). There was no difference in binding of these McAb between platelets prepared and stored in plasma or GAC. We conclude that platelets prepared by the buffy-coat method and stored in GAC have the same in vitro qualitities as platelets stored in plasma, except for the lower aggregation response by the archidonic-acid pathway, This is probably due to an acetate-induced decrease in intracellular pH.

Research paper thumbnail of Improved Survival with Ipilimumab in Patients with Metastatic Melanoma

New England Journal of Medicine, 2010

Ipilimumab, with or without a gp100 peptide vaccine, as compared with gp100 alone, improved overa... more Ipilimumab, with or without a gp100 peptide vaccine, as compared with gp100 alone, improved overall survival in patients with previously treated metastatic melanoma. Adverse events can be severe, long-lasting, or both, but most are reversible with appropriate treatment. (Funded by Medarex and Bristol-Myers Squibb; ClinicalTrials.gov number, NCT00094653.

Research paper thumbnail of The effects of pre-operative administration of CpG 7909 on dendritic and T cell subsets in the sentinel lymph node of stage I/II melanoma patients

Research paper thumbnail of Selective Decrease in Circulating Vα24+Vβ11+NKT Cells During HIV Type 1 Infection

The Journal of Immunology, 2002

CD1d-restricted NKT cells express an invariant TCR and have been demonstrated to play an importan... more CD1d-restricted NKT cells express an invariant TCR and have been demonstrated to play an important regulatory role in a variety of immune responses. Invariant NKT cells down-regulate autoimmune responses by production of type 2 cytokines and can initiate antitumor and antimicrobial immune responses by production of type 1 cytokines. Although defects in the (invariant) V␣24 ؉ V␤11 ؉ NKT cell population have been observed in patients with cancer and autoimmune diseases, little is known regarding the protective role of V␣24 ؉ V␤11 ؉ NKT cells in human infectious disease. In a cross-sectional study in HIV-1-infected individuals, we found circulating numbers of V␣24 ؉ V␤11 ؉ NKT cells to be reduced, independent of CD4 ؉ T cell counts, CD4:CD8 ratios, and viral load. Because a small minority of V␣24 ؉ V␤11 ؉ NKT cells of healthy donors expressed HIV-1 (co)receptors and the vast majority of V␣24 ؉ V␤11 ؉ NKT cells in HIV-1-infected individuals expressed the Fas receptor, the depletion was more likely due to Fas-mediated apoptosis than to preferential infection of V␣24 ؉ V␤11 ؉ NKT cells by HIV-1. A longitudinal cohort study, in which patients were analyzed before seroconversion and 1 and 5 years after seroconversion, demonstrated that a large proportion of the depletion occurred within the first year postseroconversion. In this longitudinal study no evidence was found to support an important role of V␣24 ؉ V␤11 ؉ NKT cells in determining the rate of progression during HIV-1 infection.

Research paper thumbnail of Identification and Characterization of ErbB-3-Binding Protein-1 as a Target for Immunotherapy

The Journal of Immunology, 2007

Based on immune reactivity in response to a whole-cell colon tumor vaccine and using serological ... more Based on immune reactivity in response to a whole-cell colon tumor vaccine and using serological identification of Ags by recombinant cDNA expression cloning, we here describe the molecular and functional identification of a novel human tumor Ag. By screening a cDNA expression library derived from the coloncarcinoma cell line HT-29 with pooled colorectal cancer patients' sera, 26 clones reactive with IgG Abs could be identified. Characterization of these cDNA clones by sequence analysis and alignment, and detailed serological analysis revealed cancer-related immunoreactivity for the ErbB-3-binding protein-1 (Ebp1). Immunohistochemical staining of colorectal tumors and neighboring normal colon tissue indicated the observed cancer-related immunogenicity of Ebp1 to be related to overexpression. Via reverse immunology, five potential HLA-A2-restricted T cell epitopes were identified, of which two (Ebp1 45-54 and Ebp1 59-67) bound HLA-A2 with intermediate and high affinity, respectively. Analysis of their immunogenicity in vitro indicated that only the high-affinity Ebp1 59 epitope gave rise to CD8 ؉ T cells capable of recognizing both exogenously loaded Ebp1 peptide and endogenously expressed Ebp1 on target cells. In addition, in vivo CD8 ؉ T cell responsiveness against the Ebp1 59 epitope could be detected in two of nine and three of six cancer patients PBMC and tumor draining lymph nodes, respectively, but not in nine of nine healthy donors tested. These data confirm that Ebp1 is an immunogenic protein, capable of eliciting CD8-mediated responses in vivo and in vitro, providing a rationale for further exploration of Ebp1 as a possible target for anticancer immunotherapy.

Research paper thumbnail of Tumour necrosis factor-  production during cytomegalovirus infection in immunosuppressed rats

Journal of General Virology, 1994

Research paper thumbnail of Circulating Invariant Natural Killer T-Cell Numbers Predict Outcome in Head and Neck Squamous Cell Carcinoma: Updated Analysis With 10-Year Follow-Up

Journal of Clinical Oncology, 2012

NOTE: Patients were stratified in three groups before to the start of radiotherapy as follows: pa... more NOTE: Patients were stratified in three groups before to the start of radiotherapy as follows: patients with iNKT/10 6 T cells below the 25th percentile (Ͻ 48), within the 25th and 75th percentiles (48-242) and above the 75th percentile (Ͼ 242). The stepwise forward Cox proportional hazard model was used to investigate the predictive value of the iNKT level and age with regard to OS, DSS, LRC, and DM. Abbreviations: DM, development of distant metastases; DSS, disease-specific survival; iNKT, invariant natural killer T; LRC, locoregional control; NA, not applicable. ‫ء‬ P values refer to the overall significance of the regression model (omnibus test). †Grades 1-2 denote a well-differentiated to moderately differentiated tumor, and grades 3-4 denote a poorly differentiated to undifferentiated tumor. ‡Parameter was not significantly associated with relative risk for the event (P Ͼ .05). §T1-T4 denote the extent of the primary tumor according to the TNM classification (International Union Against Cancer criteria of tumor response 1997).

Research paper thumbnail of Effects of α-galactosylceramide (KRN7000), interleukin-12 and interleukin-7 on phenotype and cytokine profile of human Vα24+  Vβ11+ T cells

Immunology, 1999

The a-galactosylceramide KRN7000 was reported to be presented by CD1d to natural killer (NK) T ce... more The a-galactosylceramide KRN7000 was reported to be presented by CD1d to natural killer (NK) T cells, cells that are thought to play an important role in the rejection of malignant tumours and in the regulation of several autoimmune diseases. Here we analysed human peripheral blood (PB) NK T cells (Va24 + Vb11 + T cells) before and after a short-term culture in the presence of KRN7000. KRN7000 strongly activated PB Va24 + Vb11 + T cells and, when stimulated, the vast majority of these cells expressed interferon-c (IFN-c). Exposure of these KRN7000-cultured Va24 + Vb11 + T cells to interleukin-12 (IL-12), but not to IL-7, resulted in a relative increase in IFN-c-expressing Va24 + Vb11 + T cells, compared with IL-4-expressing Va24 + Vb11 + T cells, indicating a shift towards a T-helper type 1 (Th1) phenotype. KRN7000 strongly up-regulated the expression of the cytotoxic molecule granzyme B (GrB) in Va24 + Vb11 + T cells. Although IL-7 resulted in a decrease in GrB levels in KRN7000-cultured Va24 + Vb11 + T cells, IL-12 increased GrB levels in both Va24 + Vb11 + T cells and in Va24 + Vb11 + T-cell clones and increased cytotoxicity against hCD1dtransfected HeLa cells. Our data provide further insight into the characteristics of human Va24 + Vb11 + T cells and indicate that KRN7000 is a potent activator of Va24 + Vb11 + T cells. Combined with the established anti-tumour effects of KRN7000 in mouse models, these results may support the use of KRN7000 as an anti-tumour agent in man.

Research paper thumbnail of Immunomodulation of the melanoma sentinel lymph node: A novel adjuvant therapeutic option

Immunobiology, 2006

Cutaneous melanoma is the most aggressive type of skin cancer. Paradoxically, melanoma is also th... more Cutaneous melanoma is the most aggressive type of skin cancer. Paradoxically, melanoma is also the most immunogenic tumour identified to date: tumour-reactive T cells are detectable both in the blood and in tumour-draining lymph nodes (TDLN) of melanoma patients and their frequency can be increased by specific vaccination. However, early melanoma development is accompanied by impaired immune effector functions in the initial TDLN, the sentinel lymph node (SLN). Most notably, a reduced frequency and activation state of dendritic cells (DC) interferes with the uptake and presentation of tumour-associated antigens (TAA) to specific anti-tumour cytotoxic T-lymphocytes (CTL) and T helper cells (Th). These impaired immune effector functions may contribute to the early metastatic events that are associated with this tumour type. Since complete surgical excision at an early stage remains the only curative treatment option (adjuvant therapy options are limited and show no survival benefits), immunopotentiation of the SLN to jump-start or boost tumour specific immunity in early stage melanoma may be a valuable adjuvant treatment option that can be generally applied with minimal discomfort to the patient. Early clinical studies indicate that local Granulocyte/Macrophage-Colony Stimulating Factor (GM-CSF) or Cytosine-phosphate-Guanine (CpG) administration leads to activation of different DC subsets and conditions the SLN microenvironment to be more conducive to the generation of T-cell-mediated anti-tumour immunity.

Research paper thumbnail of 4-1BB-mediated expansion affords superior detection of in vivo primed effector memory CD8+ T cells from melanoma sentinel lymph nodes

Clinical Immunology, 2010

We have been studying the re-activation of tumor-associated antigen (TAA)-specific CD8 + T cells ... more We have been studying the re-activation of tumor-associated antigen (TAA)-specific CD8 + T cells in sentinel lymph nodes (SLN) of melanoma patients upon intradermal administration of the CpG-B oligodeoxynucleotide PF-3512676. To facilitate functional testing of T cells from small SLN samples, high-efficiency polyclonal T cell expansion is required. In this study, SLN cells were expanded via classic methodologies with plate-or bead-bound anti-CD3/CD28 antibodies and with the K562/CD32/4-1BBL artificial APC system (K32/4-1BBL aAPC) and analyzed for responsiveness to common recall or TAA-derived peptides. K32/4-1BBL-expanded T cell populations contained significantly more effector/memory CD8 + T cells. Moreover, recall and melanoma antigen-specific CD8 + T cells were more frequently detected in K32/4-1BBL-expanded samples as compared with anti-CD3/CD28-expanded samples. We conclude that K32/4-1BBL aAPC are superior to anti-CD3/CD28 antibodies for the expansion of in vivo-primed specific CD8 + T cells and that their use facilitates the sensitive monitoring of functional anti-tumor T cell immunity in SLN.

Research paper thumbnail of Circulating Vα24+ Vβ11+ NKT Cell Numbers Are Decreased in a Wide Variety of Diseases That Are Characterized by Autoreactive Tissue Damage

Clinical Immunology, 2001

Natural killer T (NKT) cells have been implicated as playing an important role in regulating immu... more Natural killer T (NKT) cells have been implicated as playing an important role in regulating immune responses. Defects in the NKT cell population were reported in animal autoimmune disease models and in distinct human autoimmune diseases. Here, we report that circulating V(alpha24+) Vbeta11+ NKT cell numbers are decreased in a broad variety of disorders with (auto)immune-mediated pathology, affecting the skin, bowel, central nervous system, and joints, regardless of disease duration or activity. Remarkably, normal circulating V(alpha24+) Vbeta11+ NKT cell numbers were found in Graves disease and coeliac disease. Since earlier studies noted a rise in NKT cells in myasthenia gravis, the picture emerges in which a defective NKT cell population is associated with autoreactive tissue damage rather than with the propensity to develop autoimmune disease. The present data support the idea that therapies aiming at the in vivo expansion of regulatory NKT cells might help to control immune-mediated damage in autoimmune disease.

Research paper thumbnail of Local Administration of PF-3512676 CpG-B Instigates Tumor-Specific CD8+ T-Cell Reactivity in Melanoma Patients

Clinical Cancer Research, 2008

Purpose: Impaired immune effector functions in the melanoma sentinel lymph node (SLN) may allow f... more Purpose: Impaired immune effector functions in the melanoma sentinel lymph node (SLN) may allow for early metastatic events. Local administration of PF-3512676 (formerly known as CpG 7909) has shown immunostimulatory effects of both dendritic cell and T-cell subsets in the melanoma SLN. Here, we set out to ascertain whether these PF-3512676-induced immunostimulatory effects translate into higher frequencies of melanoma-specific CD8+ T cells. Experimental Design: Twenty-four stage I to III melanoma patients were randomized to preoperative local administration of either PF-3512676 or saline. CD8+ T cells from SLN and peripheral blood were tested for reactivity by IFN-γ ELISPOT assay against several HLA-A1/A2/A3-restricted epitopes derived from various melanoma-associated antigens (MAA) in 21 of 24 enrolled patients. Frequencies of natural killer (NK) cells and frequencies and maturation state of dendritic cell subsets in the SLN were determined by flow cytometry. Results: Melanoma-spe...

Research paper thumbnail of Intradermal CpG-B Activates Both Plasmacytoid and Myeloid Dendritic Cells in the Sentinel Lymph Node of Melanoma Patients

Clinical Cancer Research, 2007

Purpose: A decrease in the frequency and activation state of dendritic cells in the sentinel lymp... more Purpose: A decrease in the frequency and activation state of dendritic cells in the sentinel lymph node (SLN) has been observed in early stages of melanoma development. This may hinder the generation of effective antitumor T-cell responses and increase the likelihood of metastatic spread. Immunopotentiation of the melanoma SLN may therefore be a valuable adjuvant treatment option. One way to achieve this is through the use of bacterially derived unmethylated cytosine-phosphate-guanine (CpG) DNA sequences that bind Toll-like receptor 9 and activate plasmacytoid dendritic cells (PDC). CpG-activated PDC, in turn, release IFNα and may thus boost T-cell and natural killer cell responses as well as activate conventional myeloid dendritic cells (MDC). Experimental Design: We studied the effects of preoperative local administration of the CpG B-type oligodeoxynucleotide (ODN) PF-3512676 (formerly known as CPG 7909) on dendritic cell and T-cell subsets in the SLN of 23 stage I to III melanom...

Research paper thumbnail of Sunitinib-Induced Myeloid Lineage Redistribution in Renal Cell Cancer Patients: CD1c+ Dendritic Cell Frequency Predicts Progression-Free Survival

Clinical Cancer Research, 2008

Purpose: A disturbed myeloid lineage development with abnormally abundant neutrophils and impaire... more Purpose: A disturbed myeloid lineage development with abnormally abundant neutrophils and impaired dendritic cell (DC) differentiation may contribute to tumor immune escape. We investigated the effect of sunitinib, a tyrosine kinase inhibitor of fms-like tyrosine kinase-3, KIT, and vascular endothelial growth factor receptors, on myeloid differentiation in renal cell cancer (RCC) patients. Experimental Design: Twenty-six advanced RCC patients were treated with sunitinib in a 4-week on/2-week off schedule. Enumeration and extensive phenotyping of myeloid subsets in the blood was done at baseline and at weeks 4 and 6 of the first treatment cycle. Baseline patient data were compared with sex- and age-matched healthy donor data. Results: Baseline frequencies of DC subsets were lower in RCC patients than in healthy donors. After 4 weeks of sunitinib treatment, a generalized decrease in myeloid frequencies was observed. Whereas neutrophils and monocytes, which were both abnormally high at...

Research paper thumbnail of Defective Differentiation of Myeloid and Plasmacytoid Dendritic Cells in Advanced Cancer Patients is not Normalized by Tyrosine Kinase Inhibition of the Vascular Endothelial Growth Factor Receptor

Clinical and Developmental Immunology, 2007

Tumor-derived vascular endothelial growth factor (VEGF) has previously been identified as a causa... more Tumor-derived vascular endothelial growth factor (VEGF) has previously been identified as a causative factor in the disturbed differentiation of myeloid dendritic cells (DC) in advanced cancer patients. Here, we investigated the potential of vascular endothelial growth factor receptor (VEGFR) tyrosine kinase (TK) inhibition to overcome this defective DC differentiation. To this end, peripheral blood DC (PBDC) precursor and subset frequencies were measured in 13 patients with advanced cancer before and after treatment with AZD2171, a TK inhibitor (TKI) of VEGFR, coadministered with gefitinib, and an epidermal growth factor receptor (EGFR) TKI. Of note, not only myeloid DC but also plasmacytoid DC frequencies were significantly reduced in the blood of the cancer patients prior to treatment, as compared to healthy controls. Moreover, besides an accumulated population of immature myeloid cells (ImC), a population of myeloid suppressor cells (MSC) was significantly increased. Upon system...

Research paper thumbnail of Potent Antitumor Immunity Generated by a CD40-Targeted Adenoviral Vaccine

Cancer Research, 2011

In situ delivery of tumor-associated antigen (TAA) genes into dendritic cells (DC) has great pote... more In situ delivery of tumor-associated antigen (TAA) genes into dendritic cells (DC) has great potential as a generally applicable tumor vaccination approach. Although adenoviruses (Ad) are an attractive vaccine vehicle in this regard, Ad-mediated transduction of DCs is hampered by the lack of expression of the Ad receptor CAR on the DC surface. DC activation also requires interaction of CD40 with its ligand CD40L to generate protective T-cell–mediated tumor immunity. Therefore, to create a strategy to target Ads to DCs in vivo, we constructed a bispecific adaptor molecule with the CAR ectodomain linked to the CD40L extracellular domain via a trimerization motif (CFm40L). By targeting Ad to CD40 with the use of CFm40L, we enhanced both transduction and maturation of cultured bone marrow–derived DCs. Moreover, we improved transduction efficiency of DCs in lymph node and splenic cell suspensions in vitro and in skin and vaccination site–draining lymph nodes in vivo. Furthermore, CD40 ta...

Research paper thumbnail of In Vivo Localisation Patterns and Cell-Cell Interactions of Cytokine Producing T-Cells and Specific Antibody Forming B-Cells

Advances in Experimental Medicine and Biology, 1994

Because of its central position in the bloodstream and the large amount of migrating lymphocytes,... more Because of its central position in the bloodstream and the large amount of migrating lymphocytes, the spleen plays a central role in the primary defense against bloodstream infections. Two critical functions of the spleen can be recognized: it serves as a large phagocytic filter and it is a major antibody producing organ1. Although the spleen participates significantly in host defense mechanisms, it is not essential for life. Nevertheless, its removal increases the risk on overwhelming infections by bacteria with polysaccharide capsules, e.g. Streptococcus pneumonia, Neisseria meningitidis orHaemo-philus influenza 2. After primary i.v. immunization, the spleen is the major site of antibody production3. Since eight times more lymphocytes recirculate via the spleen than via all lymph nodes together4, it is most likely that the entire antigen-specific B- T-cell repertoire is available in the spleen. The complex anatomical organization of the spleen with distinct compartments containing specialized cell types provides a unique micro-environment allowing cell-cell interactions which are essential for the initiation and continuation of various immune responses5 (fig. 1). To fully understand the role of the spleen in the immune response it is obviously necessary to look at this organ in a functional in vivo way. This means that one should switch from conventional phenotyping of immunocompetent cells to a more functional characterisation (e.g. resting vs activated). In looking at B-cells one should for example clearly separate membrane-Ig positive, memory and plasma cells. The latter group can be further subdivided by looking at the antigen specificity of the produced antibodies. For this purpose we developed new methodology for the detection of antigen specific antibody forming B-cells (AFCs) in tissue sections. By double staining we could also simultaneously determine the isotype of these AFCs (reviewed in: 6).

Research paper thumbnail of Use of New Therapies and Hospital Admission Near the End of Life in Castration Resistant Prostate Cancer (CRPC) in the Castration Resistant Prostate Cancer Registry (CAPRI) in the Netherlands

Value in Health, Oct 1, 2017

by grades were abstracted (or calculated) to assess variability. Results: 119 distinct AEs were r... more by grades were abstracted (or calculated) to assess variability. Results: 119 distinct AEs were reported across 10 products. Events occurring in > 30% of patients included: anemia, diarrhea, fatigue, leukopenia lymphopenia, neutropenia, pneumonia and thrombocytopenia. 41 events were found occurring in > 5% of the population. Nearly 50% (19/41) events had rates reported differently between the trial and PI with 12/19 differences in pomalidomide materials. For example, grade 3/4 pneumonia was reported in 19.6% and 28.6% of patients, respectively in the trial publication versus PI. A small but potentially clinically meaningful difference in the rate of cardiac failure was noted for cafilizomib (6.4% trial publication v 6.0% PI). Other differences, such as 17.0% v 9.3% were noted in the pomalidomide trial publication v PI for asthenia and fatigue. ConClusions: There is heterogeneity in both the criteria used and the rates reported for common and serious AEs related to MM treatment across and within published materials. Meta-analysis, budget impact models, and value calculators utilize these data, often with vague references to sources. Source material used should be clarified and investigation of these findings should be confirmed in other tumor types.

Research paper thumbnail of Pre-operative intradermal administration of CpG-B ± GM-CSF in stage I-III melanoma patients arms the sentinel lymph node: evidence for reduced tumor spread

Journal for ImmunoTherapy of Cancer, 2013

Research paper thumbnail of Arming the Melanoma SLN through local administration of CpG-B and GM-CSF: recruitment and activation of BDCA3/CD141+ DC and enhanced cross-presentation

Cancer immunology research, Jan 29, 2015

Melanoma-induced suppression of Dendritic Cells (DC) in the Sentinel Lymph Node (SLN) interferes ... more Melanoma-induced suppression of Dendritic Cells (DC) in the Sentinel Lymph Node (SLN) interferes with the generation of protective anti-tumor immunity. In an effort to strengthen immune defenses against metastatic spread, 28 Stage I-III melanoma patients were randomized in a 3-arm Phase-II study to receive i.d. injections around the primary tumor excision site of saline or low-dose CpG-B, alone or combined with GM-CSF, prior to excision of the SLN. Combined CpG/GM-CSF administration resulted in enhanced maturation of all identifiable conventional (cDC) and plasmacytoid (pDC) DC subsets and selectively induced increased frequencies of SLN-resident BDCA3/CD141+ cDC subsets that also expressed the C-type Lectin Receptor CLEC9A. Correlative in vivo analyses and in vitro studies provided evidence that these subsets were derived from BDCA3+ cDC precursors in the blood that were recruited to the SLN in a type-1 interferon-dependent manner and subsequently matured under the combined influen...

Research paper thumbnail of In vitro Evaluation of Buffy-Coat-Derived Platelet Concentrates Stored in a Synthetic Medium

Vox Sanguinis, 1991

Human blood platelets, prepared by the buffy-coat method, were prepared and stored in different s... more Human blood platelets, prepared by the buffy-coat method, were prepared and stored in different synthetic media. In a synthetic medium based on gluconate, acetate and citrate (GAC), the pH was 6.8 on day 6. This medium was chosen for further evaluation. The total platelet count and the leukocyte contamination were significantly lower in the platelet concentrates (PCs) prepared in GAC compared to PCs prepared in plasma. Platelets stored in plasma or in GAC were equally functional when tested for aggregation and adenosine triphosphate (ATP) secretion. Only stimuli that act through the arachidonic-acid pathway induced a lower platelet response in GAC. Platelet morphology was quantified by measuring the difference in light transmission during stirring at different rates in an aggregometer; no significant differences for platelets stored in GAC as compared to plasma were observed. Activation of platelets was measured by binding of monoclonal antibodies (McAb) against the Gp IIbAIIa complex and against activation-dependent antigens (GMP 140 from the a-granules and a 53-kD glycoprotein from the lysosomal granules). There was no difference in binding of these McAb between platelets prepared and stored in plasma or GAC. We conclude that platelets prepared by the buffy-coat method and stored in GAC have the same in vitro qualitities as platelets stored in plasma, except for the lower aggregation response by the archidonic-acid pathway, This is probably due to an acetate-induced decrease in intracellular pH.

Research paper thumbnail of Improved Survival with Ipilimumab in Patients with Metastatic Melanoma

New England Journal of Medicine, 2010

Ipilimumab, with or without a gp100 peptide vaccine, as compared with gp100 alone, improved overa... more Ipilimumab, with or without a gp100 peptide vaccine, as compared with gp100 alone, improved overall survival in patients with previously treated metastatic melanoma. Adverse events can be severe, long-lasting, or both, but most are reversible with appropriate treatment. (Funded by Medarex and Bristol-Myers Squibb; ClinicalTrials.gov number, NCT00094653.

Research paper thumbnail of The effects of pre-operative administration of CpG 7909 on dendritic and T cell subsets in the sentinel lymph node of stage I/II melanoma patients

Research paper thumbnail of Selective Decrease in Circulating Vα24+Vβ11+NKT Cells During HIV Type 1 Infection

The Journal of Immunology, 2002

CD1d-restricted NKT cells express an invariant TCR and have been demonstrated to play an importan... more CD1d-restricted NKT cells express an invariant TCR and have been demonstrated to play an important regulatory role in a variety of immune responses. Invariant NKT cells down-regulate autoimmune responses by production of type 2 cytokines and can initiate antitumor and antimicrobial immune responses by production of type 1 cytokines. Although defects in the (invariant) V␣24 ؉ V␤11 ؉ NKT cell population have been observed in patients with cancer and autoimmune diseases, little is known regarding the protective role of V␣24 ؉ V␤11 ؉ NKT cells in human infectious disease. In a cross-sectional study in HIV-1-infected individuals, we found circulating numbers of V␣24 ؉ V␤11 ؉ NKT cells to be reduced, independent of CD4 ؉ T cell counts, CD4:CD8 ratios, and viral load. Because a small minority of V␣24 ؉ V␤11 ؉ NKT cells of healthy donors expressed HIV-1 (co)receptors and the vast majority of V␣24 ؉ V␤11 ؉ NKT cells in HIV-1-infected individuals expressed the Fas receptor, the depletion was more likely due to Fas-mediated apoptosis than to preferential infection of V␣24 ؉ V␤11 ؉ NKT cells by HIV-1. A longitudinal cohort study, in which patients were analyzed before seroconversion and 1 and 5 years after seroconversion, demonstrated that a large proportion of the depletion occurred within the first year postseroconversion. In this longitudinal study no evidence was found to support an important role of V␣24 ؉ V␤11 ؉ NKT cells in determining the rate of progression during HIV-1 infection.

Research paper thumbnail of Identification and Characterization of ErbB-3-Binding Protein-1 as a Target for Immunotherapy

The Journal of Immunology, 2007

Based on immune reactivity in response to a whole-cell colon tumor vaccine and using serological ... more Based on immune reactivity in response to a whole-cell colon tumor vaccine and using serological identification of Ags by recombinant cDNA expression cloning, we here describe the molecular and functional identification of a novel human tumor Ag. By screening a cDNA expression library derived from the coloncarcinoma cell line HT-29 with pooled colorectal cancer patients' sera, 26 clones reactive with IgG Abs could be identified. Characterization of these cDNA clones by sequence analysis and alignment, and detailed serological analysis revealed cancer-related immunoreactivity for the ErbB-3-binding protein-1 (Ebp1). Immunohistochemical staining of colorectal tumors and neighboring normal colon tissue indicated the observed cancer-related immunogenicity of Ebp1 to be related to overexpression. Via reverse immunology, five potential HLA-A2-restricted T cell epitopes were identified, of which two (Ebp1 45-54 and Ebp1 59-67) bound HLA-A2 with intermediate and high affinity, respectively. Analysis of their immunogenicity in vitro indicated that only the high-affinity Ebp1 59 epitope gave rise to CD8 ؉ T cells capable of recognizing both exogenously loaded Ebp1 peptide and endogenously expressed Ebp1 on target cells. In addition, in vivo CD8 ؉ T cell responsiveness against the Ebp1 59 epitope could be detected in two of nine and three of six cancer patients PBMC and tumor draining lymph nodes, respectively, but not in nine of nine healthy donors tested. These data confirm that Ebp1 is an immunogenic protein, capable of eliciting CD8-mediated responses in vivo and in vitro, providing a rationale for further exploration of Ebp1 as a possible target for anticancer immunotherapy.

Research paper thumbnail of Tumour necrosis factor-  production during cytomegalovirus infection in immunosuppressed rats

Journal of General Virology, 1994

Research paper thumbnail of Circulating Invariant Natural Killer T-Cell Numbers Predict Outcome in Head and Neck Squamous Cell Carcinoma: Updated Analysis With 10-Year Follow-Up

Journal of Clinical Oncology, 2012

NOTE: Patients were stratified in three groups before to the start of radiotherapy as follows: pa... more NOTE: Patients were stratified in three groups before to the start of radiotherapy as follows: patients with iNKT/10 6 T cells below the 25th percentile (Ͻ 48), within the 25th and 75th percentiles (48-242) and above the 75th percentile (Ͼ 242). The stepwise forward Cox proportional hazard model was used to investigate the predictive value of the iNKT level and age with regard to OS, DSS, LRC, and DM. Abbreviations: DM, development of distant metastases; DSS, disease-specific survival; iNKT, invariant natural killer T; LRC, locoregional control; NA, not applicable. ‫ء‬ P values refer to the overall significance of the regression model (omnibus test). †Grades 1-2 denote a well-differentiated to moderately differentiated tumor, and grades 3-4 denote a poorly differentiated to undifferentiated tumor. ‡Parameter was not significantly associated with relative risk for the event (P Ͼ .05). §T1-T4 denote the extent of the primary tumor according to the TNM classification (International Union Against Cancer criteria of tumor response 1997).

Research paper thumbnail of Effects of α-galactosylceramide (KRN7000), interleukin-12 and interleukin-7 on phenotype and cytokine profile of human Vα24+  Vβ11+ T cells

Immunology, 1999

The a-galactosylceramide KRN7000 was reported to be presented by CD1d to natural killer (NK) T ce... more The a-galactosylceramide KRN7000 was reported to be presented by CD1d to natural killer (NK) T cells, cells that are thought to play an important role in the rejection of malignant tumours and in the regulation of several autoimmune diseases. Here we analysed human peripheral blood (PB) NK T cells (Va24 + Vb11 + T cells) before and after a short-term culture in the presence of KRN7000. KRN7000 strongly activated PB Va24 + Vb11 + T cells and, when stimulated, the vast majority of these cells expressed interferon-c (IFN-c). Exposure of these KRN7000-cultured Va24 + Vb11 + T cells to interleukin-12 (IL-12), but not to IL-7, resulted in a relative increase in IFN-c-expressing Va24 + Vb11 + T cells, compared with IL-4-expressing Va24 + Vb11 + T cells, indicating a shift towards a T-helper type 1 (Th1) phenotype. KRN7000 strongly up-regulated the expression of the cytotoxic molecule granzyme B (GrB) in Va24 + Vb11 + T cells. Although IL-7 resulted in a decrease in GrB levels in KRN7000-cultured Va24 + Vb11 + T cells, IL-12 increased GrB levels in both Va24 + Vb11 + T cells and in Va24 + Vb11 + T-cell clones and increased cytotoxicity against hCD1dtransfected HeLa cells. Our data provide further insight into the characteristics of human Va24 + Vb11 + T cells and indicate that KRN7000 is a potent activator of Va24 + Vb11 + T cells. Combined with the established anti-tumour effects of KRN7000 in mouse models, these results may support the use of KRN7000 as an anti-tumour agent in man.

Research paper thumbnail of Immunomodulation of the melanoma sentinel lymph node: A novel adjuvant therapeutic option

Immunobiology, 2006

Cutaneous melanoma is the most aggressive type of skin cancer. Paradoxically, melanoma is also th... more Cutaneous melanoma is the most aggressive type of skin cancer. Paradoxically, melanoma is also the most immunogenic tumour identified to date: tumour-reactive T cells are detectable both in the blood and in tumour-draining lymph nodes (TDLN) of melanoma patients and their frequency can be increased by specific vaccination. However, early melanoma development is accompanied by impaired immune effector functions in the initial TDLN, the sentinel lymph node (SLN). Most notably, a reduced frequency and activation state of dendritic cells (DC) interferes with the uptake and presentation of tumour-associated antigens (TAA) to specific anti-tumour cytotoxic T-lymphocytes (CTL) and T helper cells (Th). These impaired immune effector functions may contribute to the early metastatic events that are associated with this tumour type. Since complete surgical excision at an early stage remains the only curative treatment option (adjuvant therapy options are limited and show no survival benefits), immunopotentiation of the SLN to jump-start or boost tumour specific immunity in early stage melanoma may be a valuable adjuvant treatment option that can be generally applied with minimal discomfort to the patient. Early clinical studies indicate that local Granulocyte/Macrophage-Colony Stimulating Factor (GM-CSF) or Cytosine-phosphate-Guanine (CpG) administration leads to activation of different DC subsets and conditions the SLN microenvironment to be more conducive to the generation of T-cell-mediated anti-tumour immunity.

Research paper thumbnail of 4-1BB-mediated expansion affords superior detection of in vivo primed effector memory CD8+ T cells from melanoma sentinel lymph nodes

Clinical Immunology, 2010

We have been studying the re-activation of tumor-associated antigen (TAA)-specific CD8 + T cells ... more We have been studying the re-activation of tumor-associated antigen (TAA)-specific CD8 + T cells in sentinel lymph nodes (SLN) of melanoma patients upon intradermal administration of the CpG-B oligodeoxynucleotide PF-3512676. To facilitate functional testing of T cells from small SLN samples, high-efficiency polyclonal T cell expansion is required. In this study, SLN cells were expanded via classic methodologies with plate-or bead-bound anti-CD3/CD28 antibodies and with the K562/CD32/4-1BBL artificial APC system (K32/4-1BBL aAPC) and analyzed for responsiveness to common recall or TAA-derived peptides. K32/4-1BBL-expanded T cell populations contained significantly more effector/memory CD8 + T cells. Moreover, recall and melanoma antigen-specific CD8 + T cells were more frequently detected in K32/4-1BBL-expanded samples as compared with anti-CD3/CD28-expanded samples. We conclude that K32/4-1BBL aAPC are superior to anti-CD3/CD28 antibodies for the expansion of in vivo-primed specific CD8 + T cells and that their use facilitates the sensitive monitoring of functional anti-tumor T cell immunity in SLN.

Research paper thumbnail of Circulating Vα24+ Vβ11+ NKT Cell Numbers Are Decreased in a Wide Variety of Diseases That Are Characterized by Autoreactive Tissue Damage

Clinical Immunology, 2001

Natural killer T (NKT) cells have been implicated as playing an important role in regulating immu... more Natural killer T (NKT) cells have been implicated as playing an important role in regulating immune responses. Defects in the NKT cell population were reported in animal autoimmune disease models and in distinct human autoimmune diseases. Here, we report that circulating V(alpha24+) Vbeta11+ NKT cell numbers are decreased in a broad variety of disorders with (auto)immune-mediated pathology, affecting the skin, bowel, central nervous system, and joints, regardless of disease duration or activity. Remarkably, normal circulating V(alpha24+) Vbeta11+ NKT cell numbers were found in Graves disease and coeliac disease. Since earlier studies noted a rise in NKT cells in myasthenia gravis, the picture emerges in which a defective NKT cell population is associated with autoreactive tissue damage rather than with the propensity to develop autoimmune disease. The present data support the idea that therapies aiming at the in vivo expansion of regulatory NKT cells might help to control immune-mediated damage in autoimmune disease.

Research paper thumbnail of Local Administration of PF-3512676 CpG-B Instigates Tumor-Specific CD8+ T-Cell Reactivity in Melanoma Patients

Clinical Cancer Research, 2008

Purpose: Impaired immune effector functions in the melanoma sentinel lymph node (SLN) may allow f... more Purpose: Impaired immune effector functions in the melanoma sentinel lymph node (SLN) may allow for early metastatic events. Local administration of PF-3512676 (formerly known as CpG 7909) has shown immunostimulatory effects of both dendritic cell and T-cell subsets in the melanoma SLN. Here, we set out to ascertain whether these PF-3512676-induced immunostimulatory effects translate into higher frequencies of melanoma-specific CD8+ T cells. Experimental Design: Twenty-four stage I to III melanoma patients were randomized to preoperative local administration of either PF-3512676 or saline. CD8+ T cells from SLN and peripheral blood were tested for reactivity by IFN-γ ELISPOT assay against several HLA-A1/A2/A3-restricted epitopes derived from various melanoma-associated antigens (MAA) in 21 of 24 enrolled patients. Frequencies of natural killer (NK) cells and frequencies and maturation state of dendritic cell subsets in the SLN were determined by flow cytometry. Results: Melanoma-spe...

Research paper thumbnail of Intradermal CpG-B Activates Both Plasmacytoid and Myeloid Dendritic Cells in the Sentinel Lymph Node of Melanoma Patients

Clinical Cancer Research, 2007

Purpose: A decrease in the frequency and activation state of dendritic cells in the sentinel lymp... more Purpose: A decrease in the frequency and activation state of dendritic cells in the sentinel lymph node (SLN) has been observed in early stages of melanoma development. This may hinder the generation of effective antitumor T-cell responses and increase the likelihood of metastatic spread. Immunopotentiation of the melanoma SLN may therefore be a valuable adjuvant treatment option. One way to achieve this is through the use of bacterially derived unmethylated cytosine-phosphate-guanine (CpG) DNA sequences that bind Toll-like receptor 9 and activate plasmacytoid dendritic cells (PDC). CpG-activated PDC, in turn, release IFNα and may thus boost T-cell and natural killer cell responses as well as activate conventional myeloid dendritic cells (MDC). Experimental Design: We studied the effects of preoperative local administration of the CpG B-type oligodeoxynucleotide (ODN) PF-3512676 (formerly known as CPG 7909) on dendritic cell and T-cell subsets in the SLN of 23 stage I to III melanom...

Research paper thumbnail of Sunitinib-Induced Myeloid Lineage Redistribution in Renal Cell Cancer Patients: CD1c+ Dendritic Cell Frequency Predicts Progression-Free Survival

Clinical Cancer Research, 2008

Purpose: A disturbed myeloid lineage development with abnormally abundant neutrophils and impaire... more Purpose: A disturbed myeloid lineage development with abnormally abundant neutrophils and impaired dendritic cell (DC) differentiation may contribute to tumor immune escape. We investigated the effect of sunitinib, a tyrosine kinase inhibitor of fms-like tyrosine kinase-3, KIT, and vascular endothelial growth factor receptors, on myeloid differentiation in renal cell cancer (RCC) patients. Experimental Design: Twenty-six advanced RCC patients were treated with sunitinib in a 4-week on/2-week off schedule. Enumeration and extensive phenotyping of myeloid subsets in the blood was done at baseline and at weeks 4 and 6 of the first treatment cycle. Baseline patient data were compared with sex- and age-matched healthy donor data. Results: Baseline frequencies of DC subsets were lower in RCC patients than in healthy donors. After 4 weeks of sunitinib treatment, a generalized decrease in myeloid frequencies was observed. Whereas neutrophils and monocytes, which were both abnormally high at...

Research paper thumbnail of Defective Differentiation of Myeloid and Plasmacytoid Dendritic Cells in Advanced Cancer Patients is not Normalized by Tyrosine Kinase Inhibition of the Vascular Endothelial Growth Factor Receptor

Clinical and Developmental Immunology, 2007

Tumor-derived vascular endothelial growth factor (VEGF) has previously been identified as a causa... more Tumor-derived vascular endothelial growth factor (VEGF) has previously been identified as a causative factor in the disturbed differentiation of myeloid dendritic cells (DC) in advanced cancer patients. Here, we investigated the potential of vascular endothelial growth factor receptor (VEGFR) tyrosine kinase (TK) inhibition to overcome this defective DC differentiation. To this end, peripheral blood DC (PBDC) precursor and subset frequencies were measured in 13 patients with advanced cancer before and after treatment with AZD2171, a TK inhibitor (TKI) of VEGFR, coadministered with gefitinib, and an epidermal growth factor receptor (EGFR) TKI. Of note, not only myeloid DC but also plasmacytoid DC frequencies were significantly reduced in the blood of the cancer patients prior to treatment, as compared to healthy controls. Moreover, besides an accumulated population of immature myeloid cells (ImC), a population of myeloid suppressor cells (MSC) was significantly increased. Upon system...

Research paper thumbnail of Potent Antitumor Immunity Generated by a CD40-Targeted Adenoviral Vaccine

Cancer Research, 2011

In situ delivery of tumor-associated antigen (TAA) genes into dendritic cells (DC) has great pote... more In situ delivery of tumor-associated antigen (TAA) genes into dendritic cells (DC) has great potential as a generally applicable tumor vaccination approach. Although adenoviruses (Ad) are an attractive vaccine vehicle in this regard, Ad-mediated transduction of DCs is hampered by the lack of expression of the Ad receptor CAR on the DC surface. DC activation also requires interaction of CD40 with its ligand CD40L to generate protective T-cell–mediated tumor immunity. Therefore, to create a strategy to target Ads to DCs in vivo, we constructed a bispecific adaptor molecule with the CAR ectodomain linked to the CD40L extracellular domain via a trimerization motif (CFm40L). By targeting Ad to CD40 with the use of CFm40L, we enhanced both transduction and maturation of cultured bone marrow–derived DCs. Moreover, we improved transduction efficiency of DCs in lymph node and splenic cell suspensions in vitro and in skin and vaccination site–draining lymph nodes in vivo. Furthermore, CD40 ta...