Background: DuoBody®-CD3xCD20 (GEN3013) is a full-length human IgG1 bispecific antibody (bsAb) recognizing CD3 and CD20, generated by controlled Fab-arm exchange. Its Fc domain was silenced by introduction of mutations L234F L235E D265A.
Methods: T-cell activation and T-cell-mediated cytotoxicity were measured by flow cytometry following co-culture with tumour cells.
Immunotherapy of cancer with CD3-targeting bispecific antibodies (CD3 bsAb) is a fast developing field, and multiple tumor-associated antigens (TAA) are evaluated for hematologic and solid malignancies. The efficacy of these CD3 bsAb is usually examined in xenograft mouse tumor models with human T cells or in genetically engineered mouse models, where human TAA are introduced. These models often fail to fully recapitulate the natural tumor environment, especially for solid cancers, because of interspecies differences.
View Article and Find Full Text PDFTissue factor (TF) is aberrantly expressed in solid cancers and is thought to contribute to disease progression through its procoagulant activity and its capacity to induce intracellular signaling in complex with factor VIIa (FVIIa). To explore the possibility of using tissue factor as a target for an antibody-drug conjugate (ADC), a panel of human tissue factor-specific antibodies (TF HuMab) was generated. Three tissue factor HuMab, that induced efficient inhibition of TF:FVIIa-dependent intracellular signaling, antibody-dependent cell-mediated cytotoxicity, and rapid target internalization, but had minimal impact on tissue factor procoagulant activity in vitro, were conjugated with the cytotoxic agents monomethyl auristatin E (MMAE) or monomethyl auristatin F (MMAF).
View Article and Find Full Text PDFTo evaluate the relevance of directing antigen-specific CD4(+) T helper cells as part of effective anticancer immunotherapy, we investigated the immunologic and clinical responses to vaccination with dendritic cells (DC) pulsed with either MHC class I (MHC-I)-restricted epitopes alone or both MHC class I and II (MHC-I/II)-restricted epitopes. We enrolled 33 stage III and IV HLA-A*02:01-positive patients with melanoma in this study, of whom 29 were evaluable for immunologic response. Patients received intranodal vaccinations with cytokine-matured DCs loaded with keyhole limpet hemocyanin and MHC-I alone or MHC-I/II-restricted tumor-associated antigens (TAA) of tyrosinase and gp100, depending on their HLA-DR4 status.
View Article and Find Full Text PDFPurpose: Electroporation of dendritic cells (DC) with mRNA encoding tumor-associated antigens (TAA) has multiple advantages compared to peptide loading. We investigated the immunologic and clinical responses to vaccination with mRNA-electroporated DC in stage III and IV melanoma patients.
Experimental Design: Twenty-six stage III HLA*02:01 melanoma patients scheduled for radical lymph node dissection (stage III) and 19 melanoma patients with irresectable locoregional or distant metastatic disease (referred to as stage IV) were included.
Epidermal growth factor receptor (EGFR) inhibitors are widely used in the treatment of cancer. EGFR-targeted treatment is known to be associated with a high incidence of dermatological adverse reactions, including papulopustular rash, which can be dose-limiting and may affect compliance to treatment. Currently, the pathways involved in EGFR inhibitor-induced rash are poorly understood and few treatment options for this adverse event are available.
View Article and Find Full Text PDFBackground: Dendritic cells (DCs) are the professional antigen-presenting cells of the immune system. We have demonstrated that vaccination of autologous ex vivo cultured DCs results in the induction of tumor-specific immune responses in cancer patients, which correlates with clinical response. Optimization of antigen loading is one of the possibilities for further improving the efficacy of DC vaccination.
View Article and Find Full Text PDFCurrently dendritic cell (DC)-based vaccines are explored in clinical trials, predominantly in cancer patients. Murine studies showed that only maturation with Toll-like receptor (TLR) ligands generates mature DCs that produce interleukin-12 and promote optimal T-cell help. Unfortunately, the limited availability of clinical-grade TLR ligands significantly hampers the translation of these findings into DC-based vaccines.
View Article and Find Full Text PDFCD4(+) T cells are important for CD8(+) T-cell priming by providing cognate signals for DC maturation. We analyzed the capacity of CD4(+) T cells to influence CD8(+) T-cell responses induced by activated DC. Surprisingly, mice depleted for CD4(+) cells were able to generate stronger antigen-specific CD8(+) T-cell responses after DC vaccination than non-depleted mice.
View Article and Find Full Text PDFElectroporation of dendritic cells (DC) with mRNA encoding tumor-associated antigens (TAA) for cancer immunotherapy has been proved efficient and clinically safe. It obviates prior knowledge of CTL and Th epitopes in the antigen and leads to the presentation of multiple epitopes for several HLA alleles. Here we studied the migration capacity and the antigen expression of mRNA-electroporated DC (mRNA-DC) in lymph nodes after vaccination in melanoma patients.
View Article and Find Full Text PDFTumor-derived peptides are used frequently as antigen (Ag) source in dendritic cell (DC) therapy in cancer patients. An alternative is to load DC with tumor-associated Ag (TAA)-encoding RNA. RNA-loading obviates prior knowledge of CTL and Th epitopes in the Ag.
View Article and Find Full Text PDFDendritic cells (DC) are professional antigen-presenting cells of the immune system that play a key role in regulating T cell-based immunity. In vivo, the capacity of DC to activate T cells depends on their ability to migrate to the T cell areas of lymph nodes as well as on their maturation state. Depending on their cytokine-secreting profile, DC are able to skew the immune response in a specific direction.
View Article and Find Full Text PDFAg-IgG immune complexes (IC) are efficiently taken up, and Ag-derived peptides are subsequently processed and presented by APC. In vitro experiments indicate that IgG Fc Receptors (FcgammaR) facilitate the efficient uptake of IC by dendritic cells. Previous experiments showed that the cross-presentation of Ag-derived peptides after s.
View Article and Find Full Text PDFProfessional antigen-presenting cells (APC) are able to process and present exogenous antigen leading to the activation of T cells. Antigen-immunoglobulin (Ig)G complexes (IC) are much more efficiently processed and presented than soluble antigen. Dendritic cells (DC) are known for their ability to take up and process immune complex (IC) via FcgammaR, and they have been shown to play a crucial role in IC-processing onto major histocompatibility complex (MHC) class I as they contain a specialized cross-presenting transport system required for MHC class I antigen-processing.
View Article and Find Full Text PDFDendritic cells (DCs) play an important role in the induction of T cell responses. Fc gammaRs, expressed on DCs, facilitate the uptake of complexed Ag, resulting in efficient MHC class I and MHC class II Ag presentation and DC maturation. In the present study, we show that prophylactic immunization with DCs loaded with Ag-IgG immune complexes (ICs) leads to efficient induction of tumor protection in mice.
View Article and Find Full Text PDFDendritic cells (DC) are professional antigen-presenting cells which are strategically positioned at the boundaries between the inner and the outside world, in this way bridging innate and adaptive immunity. DC can initiate T cell responses against microbial pathogens and tumors due to their capacity to stimulate naïve T cells. The development of DC occurs in distinct stages.
View Article and Find Full Text PDFAntigen(Ag)-immunoglobulin (Ig)G complexes (IC) are more efficiently processed and presented than soluble Ag. IC can bind to various cell types via different types of Fc-Receptors or, upon binding to complement factors, by complement receptors. Murine professional antigen-presenting cells (APC) express four types of FcgammaReceptors (FcgammaR) via which they are able to capture IC; three activating receptors (FcgammaRI, III and IV) and one inhibitory receptor (FcgammaRII).
View Article and Find Full Text PDFActivation of dendritic cells (DC) by Th-dependent (CD40) or -independent (LPS, CpG, or immune complexes) agonistic stimuli strongly enhances the expression of the proteasome activator PA28alphabeta complex. Upon activation of DC, increased MHC class I presentation occurred of the melanocyte-associated epitope tyrosinase-related protein 2(180-188) in a PA28alphabeta-dependent manner. In contrast to other cell types, regulation of PA28alphabeta expression in DC after maturation was found to be IFN-gamma independent.
View Article and Find Full Text PDFBackground: Activation of immature dendritic cells (DC) in the presence of the glucocorticoid hormone dexamethasone (DEX) results in alternatively matured DC that present antigen in the absence of a proper co-stimulatory context. This maturation process is irreversible, making these cells an attractive potential tool for the induction of antigen-specific T-cell tolerance in vivo. The authors explored the possibility of using these DC for the induction of transplantation tolerance in a fully allogeneic setting in mice.
View Article and Find Full Text PDFThe interaction between TNFR family member CD27 and its ligand CD70 promotes lymphocyte expansion and effector cell formation. In humans, control of CD27 function is partly regulated by the restricted expression of CD70. We used newly developed mAbs to characterize murine (m) CD70 expression in vitro and in vivo.
View Article and Find Full Text PDFDendritic cells (DCs) require a maturation signal to acquire efficient CTL-priming capacity. In vitro FcgammaR-mediated internalization of Ag-Ab immune complexes (ICs) can induce maturation of DCs. In this study, we show that IC-induced DC maturation in vitro enables DCs to prime peptide-specific CD8+ CTLs in vivo, independently of CD4+ Th cells.
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