Publications by authors named "Stamova S"

IL-32 expression is important for pathogen clearance but detrimental in chronic inflammation, autoimmunity, and cancer. T cells are major IL-32 producers in these diseases and key mediators of pathogen and tumor elimination but also autoimmune destruction. However, their contribution to IL-32 biology during immune responses is hardly understood due to several isoforms with divergent inflammatory properties.

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Cancer immunotherapy is a pillar of clinical oncology but only achieves long-term remissions in a minority of cases. In this issue, van Elsas et al. show that effective immunotherapy requires a series of processes orchestrated by CD8 T cells that result in the recruitment and local activation of M1-like macrophages.

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Article Synopsis
  • Glioblastoma (GB) IDH-wildtype is a highly aggressive brain tumor that shows significant resistance to immunotherapy, with the translocator protein 18 kDa (TSPO) playing a key role in this process.* -
  • TSPO expression in GB cells correlates with immune infiltration and resistance to T cell-mediated killing, as it regulates apoptosis pathways and is upregulated in response to cytokines from T cells.* -
  • Targeting TSPO may enhance the effectiveness of immunotherapy for GB by overcoming intrinsic resistance mechanisms and improving the sensitivity of cancer cells to immune attacks.*
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Background: Cancer immunotherapeutic strategies showed unprecedented results in the clinic. However, many patients do not respond to immuno-oncological treatments due to the occurrence of a plethora of immunological obstacles, including tumor intrinsic mechanisms of resistance to cytotoxic T-cell (TC) attack. Thus, a deeper understanding of these mechanisms is needed to develop successful immunotherapies.

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Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6), a cell surface receptor, is expressed on normal epithelial tissue and highly expressed in cancers of high unmet medical need, such as non-small cell lung, pancreatic, and colorectal cancer. CEACAM receptors undergo homo- and heterophilic interactions thereby regulating normal tissue homeostasis and angiogenesis, and in cancer, tumor invasion and metastasis. CEACAM6 expression on malignant plasma cells inhibits antitumor activity of T cells, and we hypothesize a similar function on epithelial cancer cells.

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Rare subpopulations of tumor antigen-reactive memory T cells, which actively secrete type-1 effector cytokines, particularly TNF-α in situ, possess anti-tumor activity and prognostic relevance. These cells are relevant for cancer immunotherapy; however, their low frequencies make them difficult to study and novel protocols for their culture and expansion ex vivo are needed. Here, we studied the presence of T cells secreting type-1 cytokines (CyT cells) in the blood and tumors of 24 patients with oral squamous cell carcinomas (OSCC) and explored possibilities for their isolation and expansion.

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The efficacy of cancer immunotherapy may be improved by increasing the number of circulating tumor-reactive T cells. The bone marrow is a priming site and reservoir for such T cells. The characteristics of bone marrow-derived tumor-reactive T cells are poorly understood in patients with non-small-cell lung cancer (NSCLC).

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Successful immunotherapies for IDH gliomas require better knowledge of T-cell target antigens. Here, we elucidated their antigen repertoire recognized by spontaneous T-cell responses using an unbiased proteomic approach. Protein fractionations of tissue lysates from IDH gliomas ( = 4) were performed.

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In this prospective study, we examined postoperative follow-up and preoperative IFN-γ T cell responses against 14 non-small cell lung cancer (NSCLC)-associated antigens in the blood of 51 patients with NSCLC, 7 patients with benign pulmonary tumors, and 10 tumor-free patients by enzyme-linked immunospot assay. The phenotype and function of T cells specific for tumor-associated antigens (TAAs) in the blood or tumor tissue of 9 NSCLC patients were characterized in detail using TNF-α, IL-2, and IFN-γ cytokine capture assays. We found that circulating TAA-specific T cells were significantly enriched in NSCLC compared with tumor-free patients.

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Glioblastoma (GBM) is a highly aggressive brain tumor and still remains incurable. Among others, an immature subpopulation of self-renewing and therapy-resistant tumor cells-often referred to as glioblastoma stem-like cells (GSCs)-has been shown to contribute to disease recurrence. To target these cells personalized immunotherapy has gained a lot of interest, e.

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VEGFR-2 is expressed on tumor vasculature and a target for anti-angiogenic intervention. VXM01 is a first in kind orally applied tumor vaccine based on live, attenuated Salmonella bacteria carrying an expression plasmid, encoding VEGFR-2. We here studied the safety, tolerability, T effector (Teff), T regulatory (Treg) and humoral responses to VEGFR2 and anti-angiogenic effects in advanced pancreatic cancer patients in a randomized, dose escalation phase I clinical trial.

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The composition of tumor-targeted T cell infiltrates is a major prognostic factor in colorectal cancer (CRC) outcome; however, the functional role of these populations in prolonging patient survival remains unclear. Here, we evaluated 190 patients with CRC for the presence of functionally active tumor-infiltrating lymphocytes (TILs), the tumor specificity of these TILs, and the correlation between patient TILs and long-term survival. Using intracytoplasmic cytokine staining in conjunction with HLA multimers loaded with tumor peptide and antigen-specific cytokine secretion assays, we determined that TNF-α expression delineates a population of tumor antigen-specific (TA-specific) cytotoxic T lymphocytes (CTLs) present within tumors from patients with CRC.

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Genetically engineered T lymphocytes are a promising option for cancer therapy. Prior to adoptive transfer they have to be expanded in vitro to reach therapeutically sufficient numbers. So far, no universal method exists for selective in vitro expansion of engineered T lymphocytes.

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We have recently described a novel modular targeting platform for T cell recruitment that not only efficiently replaces but also is superior to conventional T cell-engaging bispecific antibodies as it allows for the flexible targeting of several antigens and the delivery of co-stimulatory ligands to malignant lesions, thereby enhancing the antitumor potential of redirected T cells.

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Owing to their clinical success, there is growing interest in novel bispecific antibodies (bsAbs) for retargeting of T cells to tumor cells including for the treatment of acute myeloid leukemia (AML). One potential target for retargeting of T cells to AML blasts is the surface molecule CD33. Here we describe a novel modular targeting platform that consists of a universal effector module (EM) and individual target modules (TMs).

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The nuclear autoantigen La can be detected on the surface of dying cells. Here we present an assay which enables us to show that La protein is not limited to the surface of dying cells but will be released upon stress-induced cell death. As released La protein tightly binds to the surface of neighboring intact cells we asked the question whether or not La protein could serve as a stress-inducible target e.

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Prostate cancer is the most common noncutaneous malignancy in men. The prostate stem cell Ag (PSCA) is a promising target for immunotherapy of advanced disease. Based on a novel mAb directed to PSCA, we established and compared a series of murine and humanized anti-CD3-anti-PSCA single-chain bispecific Abs.

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For some instances, protein gels need to be dried after SDS-PAGE, for example, if autoradiography should be performed from radioactive-labeled proteins after their separation on SDS-polyacrylamide gels. Another reason may be to simply store the gel in the laboratory book. Aside from expensive commercial solutions, especially for storage of the dried gel in the lab book, the simple and cheap drying protocol here presented may be sufficient.

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There is growing interest in the development of novel single-chain bispecific antibodies for retargeting of immune effector T cells to tumor cells. Until today, functional fusion constructs consisting of a single-chain bispecific antibody and a fluorescent protein were not reported. Such molecules could be useful for an in vivo visualization of this retargeting process.

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Bispecific Abs hold great potential for immunotherapy of malignant diseases. Because the first components of this new drug class are now entering clinical trials, all aspects of their mode of action should be well understood. Several studies proved that CD8(+) and CD4(+) effector T cells can be successfully redirected and activated against tumor cells by bispecific Abs both in vitro and in vivo.

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CD33 is an attractive immunotarget on the surface of tumor cells from patients with acute myeloid leukemia (AML). In a first attempt for immunotargeting of AML blasts we constructed two bispecific antibodies in the single chain bispecific diabody (scBsDb) format by fusing the variable domains of monoclonal antibodies directed against CD3 and CD33. Unfortunately, protein expression of both scBsDbs resulted in varying mixtures of fragmented and full length proteins.

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Background: Prostate cancer (PCa) is the most common malignant disease in men. Novel treatment options are needed for patients after development of metastatic, hormone-refractory disease or for those who have failed a local treatment. The prostate stem cell antigen (PSCA) is expressed in >80% of primary PCa samples and bone metastases.

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