Biomedical subjects

Barbara Wollenberg

Publications and source records attributed to Barbara Wollenberg.

16 recordsLinked to original sources

PubMed2006

Analysis of plasmacytoid and myeloid dendritic cells in nasal epithelium.

The role of plasmacytoid dendritic cells (PDC), the major producers of alpha interferon upon viral infection, in the nasal mucosa is largely unknown. Here we examined the presence of PDC together with myeloid dendritic cells (MDC) in the nasal epithelia of healthy individuals, of asymptomatic patients with chronic nasal allergy, of patients undergoing steroid therapy, and of patients with infectious rhinitis or rhinosinusitis. Considerable numbers of PDC and MDC could be detected in the nasal epithelium. Furthermore, we demonstrate the expression of SDF-1, the major chemoattractant for PDC, in the nasal epithelium. PDC levels were significantly lower for patients with allergies than for healthy individuals. Interestingly, PDC and MDC were almost absent from patients who received treatment with glucocorticoids, while very high numbers of PDC were found for patients with recent upper respiratory tract infections. Our results demonstrate for the first time a quantitative analysis of PDC and MDC in the healthy nasal epithelium and in nasal epithelia from patients with different pathological conditions. With the identification of PDC, the major target cell for CpG DNA or immunostimulatory RNA, in the nasal epithelium, this study forms the basis for a local nasal application of such oligonucleotides for the treatment of viral infection and allergy.

Adolescent↗

PubMed2006

Cytokines in head and neck cancer.

Head and neck squamous cell carcinoma (HNSCC) is one of the most frequent cancers in the world. Standard treatment has only marginally improved the 5-year survival rate of patients with HNSCC in the last 40 years. Alterations in immune, inflammatory as well as angiogenetic responses within the HNSCC microenvironment play a critical role in tumor aggressiveness and its response to chemo- and radiation therapies as well as its influence on the immune system. Therefore, the better understanding of secretion and regulation pathways of immune suppressive and proangiogenic cytokines in HNSCC is essential to increase the clinical perspective of this tumor type with respect to an immunomodulatory intervention in patients with HNSCC.

Carcinoma, Squamous Cell↗

PubMed2006

Role of cytokines in head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma is one of the most frequent cancers and standard treatment has only marginally improved the 5-year survival rate of patients with this disease in the last few decades. It is supposed that cytokine alterations in immune, inflammatory and angiogenetic regulatory routes within the head and neck squamous cell carcinoma microenvironment play a critical role in tumor aggressiveness, its response to chemo- and radiation therapies, as well as the development of immune escape mechanisms.

Carcinoma, Squamous Cell↗

PubMed2003

Identification and functional analysis of tumor-infiltrating plasmacytoid dendritic cells in head and neck cancer.

The antitumor activity of IFN-alpha is well established. However, the role of the plasmacytoid dendritic cell (PDC), the major producer of IFN-alpha upon viral infection, in tumor biology is unknown. We sought to study the presence and function of PDC in a human solid tumor. Here, we demonstrate that PDCs infiltrate tumor tissue of patients with head and neck squamous cell carcinoma (HNSCC). Functional activity of PDC was examined by using CpG motif containing oligonucleotides, a defined microbial stimulus for PDCs (recognized via toll-like receptor 9). We found that HNSCC diminished the ability of PDC to produce IFN-alpha in response to CpG motif containing oligonucleotide. Tumor-induced down-regulation of toll-like receptor 9 was identified as one mechanism likely contributing to impaired PDC function within the tumor environment. In tumor-draining lymph nodes, suppression of CpG-induced IFN-alpha production was less pronounced than in single-cell suspensions of primary tumor tissue. In these lymph nodes, CpG-induced IFN-alpha production was associated with increased levels of interferon-induced protein 10 and IFN-gamma and activation of CD4 and CD8 T cells. These results show for the first time the presence of PDCs in human solid tumor tissue and that tumors suppress the capacity of PDCs to produce IFN-alpha. PDCs, which in the absence of appropriate stimulation are reported to promote regulatory CD8 T cells, may contribute to an impaired T-cell-mediated immune response in HNSCC.

Adolescent↗

PubMed2003

Tumor-specific glycosylation of the carcinoma-associated epithelial cell adhesion molecule EpCAM in head and neck carcinomas.

The tissue-specific glycosylation of the carcinoma (CA)-associated antigen epithelial cell adhesion molecule (EpCAM) was studied in 60 patients suffering from head and neck CAs, and 26 pairs of autologous healthy thyroid and CA biopsies. EpCAM was glycosylated in all tumor samples in which its expression was detectable (73%). Additionally, in 80.7% of patients, tumor-derived EpCAM was heavily glycosylated while EpCAM derived from autologous thyroid was not (76.2%) or weakly (23.8%). Four cases showed a similar glycosylation pattern (15.3%) and one case displayed a reverse pattern (3.8%). Additionally, the expression and glycosylation of EpCAM were assessed in tumor adjacent and distant tissue. EpCAM was glycosylated in tumor-adjacent while it was not or only weakly expressed in tumor distant tissue where it was unglycosylated. Thus, EpCAM is differentially glycosylated in healthy tissue and tumor cells of the head and neck area.

Adult↗

PubMed2002

Impaired monocyte function in cancer patients: restoration with a cyclooxygenase-2 inhibitor.

Epidemiological data and animal models have provided evidence that nonsteroidal antiinflammatory drugs (NSAIDs) have an anticancer effect. However, the molecular mechanisms underlying these antineoplastic effects are not well understood. We described previously that expression levels of the chemokine receptor, CCR5, and the beta2-integrin, Mac-1, were down-regulated on primary monocytes after incubation in supernatants from human carcinoma cell lines, and that this down-regulation resulted in impaired monocyte function with respect to migration and adhesion. We now demonstrate that these impairments are also present in vivo. Monocytes from cancer patients displayed significantly reduced CCR5 levels and migration capacities in comparison to cells from healthy donors. Because migration is necessary for the antitumor activity of monocytes/macrophages, these deficits may contribute to the suppressed immune system seen in cancer patients. In a clinical study, we analyzed the effect of a selective COX-2 inhibitor, Rofecoxib, on the migration of monocytes derived from cancer patients. The results revealed significant improvement in migration equal to those levels seen in healthy donors. We conclude that in patients with cancer, the intake of Rofecoxib for 3 wk leads to significant restoration of monocyte function. These data may, at least in part, help explain the anticancer effects of NSAIDs.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2002

B cells immortalized by a mini-Epstein-Barr virus encoding a foreign antigen efficiently reactivate specific cytotoxic T cells.

Lymphoblastoid cell lines (LCLs) are human B cells latently infected and immortalized by Epstein-Barr virus (EBV). Presenting viral antigens, they efficiently induce EBV-specific T-cell responses in vitro. Analogous ways to generate T-cell cultures specific for other antigens of interest are highly desirable. Previously, we constructed a mini-EBV plasmid that consists of less than half the EBV genome, is unable to cause virus production, but still immortalizes B cells in vitro. Mini-EBV-immortalized B-cell lines (mini-LCLs) are efficiently produced by infection of B cells with viruslike particles carrying only mini-EBV DNA. Mini-EBV plasmids can be engineered to express an additional gene in immortalized B cells. Here we present a mini-EBV coding for a potent CD8(+) T-cell antigen, the matrix phosphoprotein pp65 of human cytomegalovirus (CMV). By means of this pp65 mini-EBV, pp65-expressing mini-LCLs could be readily established from healthy donors in a one-step procedure. We used these pp65 mini-LCLs to reactivate and expand effector T cells from autologous peripheral blood cells in vitro. When generated from cytomegalovirus (CMV)-seropositive donors, these effector T-cell cultures displayed strong pp65-specific HLA-restricted cytotoxicity. A large fraction of CD8(+) T cells with pp65 epitope specificity was present in such cultures, as demonstrated by direct staining with HLA/peptide tetramers. We conclude that the pp65 mini-EBV is an attractive tool for CMV-specific adoptive immunotherapy. Mini-EBVs could also facilitate the generation of T cells specific for various other antigens of interest.

Antigens, Viral↗

PubMedDate not supplied

Antitumour effects of a bispecific trivalent antibody in multicellular tumour spheroids.

BACKGROUND: New adjuvant immunological therapies that selectively redirect effector cells towards tumour cells are currently under development. These strategies include the use of bispecific antibodies as promising tools for the elimination of disseminated tumour cells and micrometastases. At present, bispecific molecules have demonstrated their antitumour potential in investigations in vitro using monolayer cell cultures. However, their effectiveness in vivo is less clear and expressive in vitro tumour models are in high demand. MATERIALS AND METHODS: Three-dimensional multicellular tumour spheroids (MTS) are of intermediate complexity between monolayer cell cultures and solid tumours in patients and therefore represent a particularly promising in vitro system. RESULTS: We show, here, the antitumour potential of a bispecific antibody, BiUII, in three-dimensional multicellular tumour spheroids and furthermore demonstrate that BiUII triggers peripheral blood mononuclear cells to invade MTSs and elicit the production of TNFalpha, resulting in the efficient destruction of tumour cells. CONCLUSION: These results demonstrate that bispecific antibodies are capable of activating immune effector cells, resulting in the elimination of three-dimensional structures of tumour cells. The therapeutic potential of these antibodies in the clinical setting merits further investigations.

Antibodies, Bispecific↗

PubMedDate not supplied

Soluble CD44v6 is not a sensitive tumor marker in patients with head and neck squamous cell cancer.

BACKGROUND: In some epithelial tumors, isoforms of CD44 are overexpressed and soluble isoforms detectable in serum samples are elevated. In squamous cell cancer of the head and neck (SCCHN) the alteration of CD44 isoforms could be associated with poor prognosis. A comprehensive study was undertaken to examine the value of CD44v6 as a tumor marker for SCCHN. PATIENTS AND METHODS: Serum samples of SCCHN and healthy smokers were analyzed for soluble CD44v6 by ELISA. The expression of CD44 isoforms was determined by immunohistochemical staining of healthy and dysplastic tissue. RESULTS: There was no significant difference between the serum levels of sCD44v6 in SCCHN and healthy smokers. Nor was there a correlation between the serum level of sCD44v6 and UICC stage, TNM stage or histological grading. In tissue of primary SCCHN, expression of CD44v6 was found as a strong, specific staining of the lower epithelial layers. Similar amounts of CD44v6-positive-labelled tumor cells were found in invasive carcinoma. CONCLUSION: Soluble CD44v6 is not a valuable tumor marker for SCCHN since the soluble form appears to be present in healthy smokers and does not reflect the stage of the disease.

Biomarkers, Tumor↗

PubMedDate not supplied

Liposomal transfection of squamous carcinoma cells of the head and neck with IL-2 and B7 plasmids inducing an autologous immune response in vitro.

New treatment strategies need to be developed to face the increasing incidence and mortality of squamous cell carcinoma of the head and neck (SCCHN), as the overall survival rate remains poor, with minor therapeutic progress having been achieved over the past forty years. One major goal could be to restore a damaged immune system by intratumoral injection of IL-2-genes that permanently provide non-toxic IL-2-protein concentrations at the tumor site, sufficient to activate cellular immunity in vivo. We showed that the transfection of SCCHN cell lines with IL-2-plasmids, encapsulated in DOTMA/Col, in vitro resulted in the synthesis of bioactive IL-2-protein for up to 30 days by the tumor cells themselves. The transcription of secondary cytokines (IL-6, IL-8, GM-CSF, TNF-alpha) and the expression of immunomodulatory surface molecules (MHC Class II, ICAM1) were enhanced. The IL-2-modified tumor cells were effectively lysed by autologous peripheral blood lymphocytes (PBLs). The immune response was enhanced by B7.1-gene-cotransfection and/or preactivation of PBLs with exogenous IL-2. We demonstrated that in vitro liposome-mediated IL-2-gene-transfection of SCCHN cells is an effective method to stimulate an autologous immune response and is, therefore, promising for clinical application.

B7-1 Antigen↗

PubMedDate not supplied

Generation of an autologous cell system for immunotherapy of squamous cell carcinoma of the head and neck.

BACKGROUND: To date, there is no tumor antigen known to be sufficiently specific for diagnosis, therapy monitoring and immunotherapy of squamous cell carcinoma of the head and neck (SCCHN). The aim of our study was to generate an autologous immune response against SCCHN in vitro for further characterization of SCCHN-specific tumor markers and adoptive immunotherapy. MATERIALS AND METHODS: As sources for tumor antigens (Ags) for the restimulation of autologous immune cells, cell lines from solid SCCHN were established and characterized. Forty-five percent of 40 tumors of different SCCHN specimens were maintained for more than 20 cell generations in culture. RESULTS: One primary cell line, SCCHN-GHD, newly established from a hypopharynx carcinoma, was further characterized as a telomerase-positive, immortalized cell line with epithelial cell characteristics. It was found to be tumorigenic in SCID mice. CONCLUSION: This new SCCHN-GHD cell line is competent as a target for lysis by autologous immune cells and for the restimulation of autologous tumor-specific immune cells. Subsequent characterization of tumor antigens will be performed.

Animals↗

PubMedDate not supplied

Prednisolone reduces TNF-alpha release by PBMCs activated with a trifunctional bispecific antibody but not their anti-tumor activity.

BACKGROUND: New adjuvant immunological therapies, that selectively redirect effector cells towards tumors, are currently under development. These strategies include trifunctional bispecific antibodies (trAb) as promising tools for the elimination of disseminated tumor cells and micrometastases. To date, these chimeric molecules have demonstrated their antitumor potential mainly in vitro. Here, trAb-activated peripheral blood mononuclear cells (PBMCs) displayed considerable antitumor activity, accompanied by the release of cytokines, which contributed to the antitumor activity but, on the other hand, may evoke serious limiting side-effects in vivo, demanding therapeutic interventions. MATERIALS AND METHODS: The antitumor activity and cytokine release by trAb-activated PBMCs were studied in co-cultures with multicellular tumor spheroids (MTS), which represent a three-dimensional in vitro model for solid tumors, especially non-vascularized micrometastases. The glucocorticoid prednisolone was tested for its influence on the release of TNF-alpha and the activity of PBMCs. RESULTS: It was shown that PBMCs, which were stimulated with a trifunctional bispecific antibody, BiUII, displayed an excellent antitumor activity, resulting in complete disintegration of the MTS. Also, it was demonstrated that prednisolone significantly reduced the release of TNF-alpha, without impairing the antitumor activity of BiUII-activated PBMCs. In contrast, unspecific killing was reduced, as demonstrated with an identical trAb (Bi48), which recognizes an antigen absent from the target cells. CONCLUSION: The in vivo application of bispecific antibodies for adjuvant tumor therapies may be limited by the manifest activation of immune effectors, accompanied by overwhelming cytokine release. Glucocorticoids, like prednisolone, may effectively reduce cytokine release without impairing the antitumor activity of trAb-activated immune cells.

Animals↗

PubMedDate not supplied

Secretion of tumor-promoting and immune suppressive cytokines by cell lines of head and neck squamous cell carcinoma.

BACKGROUND: Cytokine profiles of permanent cell lines of head and neck squamous cell carcinoma (HNSCC) were analyzed to define the cytokine levels secreted in the absence of immune cells. MATERIALS AND METHODS: Cytokine profiles of IL-4, IL-6, IL-8 and IL-10 were analyzed in the supematants of 4 different permanent HNSCC cell lines using the Bio-Plex human cytokine assay system. RESULTS: In HNSCC, IL-6 and IL-8 are involved in oncogenic processes, while IL-4 and IL-10 suppress proper immune responses in the tumor microenvironment. Our data indicate that, in the absence of tumor-infiltrating immune cells, HNSCC secretes high levels of the proto-oncogenic cytokines IL-6 and IL-8, but no significant levels of the immune suppressors IL-4 and IL-10. CONCLUSION: The data strongly suggest that the intercellular crosstalk between cells of HNSCC and tumor-infiltrating immune cells in vivo is required to stimulate an increased production of immune suppressive mediators in head and neck cancer.

Carcinoma, Squamous Cell↗

PubMedDate not supplied

Limited suitability of EpCAM for molecular staging of tumor borders in head and neck cancer.

BACKGROUND: The epithelial cell adhesion molecule (EpCAM) is expressed in most normal epithelia, but is absent from squamous stratified epithelia. However, a de novo expression can be observed in squamous epithelia during carcinogenesis. MATERIALS AND METHODS: In order to evaluate EpCAM as a molecular marker to indicate borders of high risk for the development of local recurrences, its expression was examined in the marginal zone of malignancies. Specimens of squamous cell carcinoma of the head and neck (SCCHN), of the histologically tumor-free defined resection margin and of healthy epithelia of 20 patients were examined by RT-PCR in order to identify the expression of EpCAM in these three different areas. Additionally, immunohistochemistry was perfonned on biopsies from 10 patients in order to confirm these findings and to investigate a potential correlation between EpCAM expression and the degree of dysplasia. RESULTS: By RT-PCR, high expression of EpCAM was found in the tumor. An inverse correlation was observed between EpCAM expression and the distance from the tumor, with no expression being detectable in healthy oral mucosa. In 70% of the cases, EpCAM was expressed in the marginal zone, which had been defined as tumor-free by routine histopathological assessment. Additional immunohistology revealed no correlation between EpCAM expression and the grade of dysplasia. CONCLUSION: Our data provide evidence that EpCAM is restricted as a marker for redefining the real tumor margin by RT-PCR. To complement routine histology, immunohistochemical staining with EpCAM is limited due to its expression in hyperplastic tissue without dysplastic changes. Both observations limit the reliable use of EpCAM for the molecular definition of the critical tumor border and resection margins.

Aged↗

PubMedDate not supplied

Isolation of human myeloid dendritic cells from tumor tissue and peripheral blood.

BACKGROUND: Human myeloid dendritic cells (MDC) have been identified in human solid tumor tissue of head and neck squamous cell carcinoma (HNSCC), their cellular functions being strongly affected in this environment. The characterization of MDC differentiation and functions requires the establishment of highly efficient isolation procedures. MATERIALS AND METHODS: Human MDC were isolated from peripheral blood and solid HNSCC using density gradient centrifugation or preparation of single cell suspensions, respectively. The cells were isolated by "magnetic bead separation" using magnetically-labelled antibodies and were analyzed by flow cytometry. RESULTS: The isolation of human MDC from peripheral blood or solid HNSCC tissue resulted in highly enriched cell populations and revealed cell purities of about 90%. CONCLUSION: The scale of molecular investigations on human myeloid dendritic cells is restricted by the limited proportion of this cell type. Thus, highly efficient and gentle MDC isolation procedures are essential to characterize in vivo matured MDC.

Adolescent↗

PubMedDate not supplied

Toll-like receptor interference in myeloid dendritic cells through head and neck cancer.

BACKGROUND: In head and neck squamous cell carcinoma (HNSCC) the secretion of various immunosuppressive mediators contributes to large-scale effects on the immune functions. The influence of HNSCC on the Toll-like receptor (TLR) expression profiles of human myeloid dendritic cells (MDCs), which have been identified in human solid tumor tissue of the head and neck, was analysed. MATERIALS AND METHODS: MDCs were isolated from peripheral blood by 'magnetic bead separation' and subsequently incubated with supernatants of HNSCC permanent cell lines. TLR expression profiles were investigated using Af cytometry and SDS-PAGE. RESULTS: Human MDC from peripheral blood were found to express all human TLRs except TLR4 and TLR9. Incubation of MDC with supernatants of HNSCC resulted in an increased expression of TLR7. CONCLUSION: The data suggest an interference of TLR7 expression through HNSCC and provide novel evidence of TLR alterations as a potential tumor promoting event in head and neck cancer.

Adolescent↗