Proton radiation boosts the efficacy of mesothelin-targeting chimeric antigen receptor T cell therapy in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) represents a challenge in oncology, with limited treatment options for advanced-stage patients. Chimeric antigen receptor T cell (CAR T) therapy targeting mesothelin (MSLN) shows promise, but challenges such as the hostile immunosuppressive tumor microenvironment (TME) hinder its efficacy. This study explores the synergistic potential of combining proton radiation therapy (RT) with MSLN-targeting CAR T therapy in a syngeneic PDAC model. Proton RT significantly increased MSLN expression in tumor cells and caused a significant increase in CAR T cell infiltration into tumors. The combination therapy reshaped the immunosuppressive TME, promoting antitumorigenic M1 polarized macrophages and reducing myeloid-derived suppressor cells (MDSC). In a flank PDAC model, the combination therapy demonstrated superior attenuation of tumor growth and improved survival compared to individual treatments alone. In an orthotopic PDAC model treated with image-guided proton RT, tumor growth was significantly reduced in the combination group compared to the RT treatment alone. Further, the combination therapy induced an abscopal effect in a dual-flank tumor model, with increased serum interferon-γ levels and enhanced proliferation of extratumoral CAR T cells. In conclusion, combining proton RT with MSLN-targeting CAR T therapy proves effective in modulating the TME, enhancing CAR T cell trafficking, and exerting systemic antitumor effects. Thus, this combinatorial approach could present a promising strategy for improving outcomes in unresectable PDAC.

In vitro multitarget activity of sulfadiazine substituted triazenes as antimicrobial, cytotoxic, and larvicidal agents.

Multidrug resistance (MDR) causes difficulties in the treatment of infections and cancer. Research and development studies have become increasingly important for the strategy of preventing MDR. There is a need for new multitarget drug research and advancement to reduce the development of drug resistance in drug-drug interactions and reduce cost and toxic effects. This study aimed to determine the effects of multi-target triazene compounds on antibacterial, antifungal, antiviral, cytotoxic, and larvicidal activities were investigated in vitro. A series of 12 novel of 1,3-diaryltriazene-substituted sulfadiazine (SDZ) derivatives were synthesized, and the obtained pure products characterized in detail by spectroscopic and analytic methods (FT-IR, 1 H-NMR, 13 C-NMR, and melting points). The antibacterial and antifungal activities of these derivatives (AH1-12) were determined by broth microdilution method. All derivatives have been evaluated in cell-based assays for cytotoxic and antiviral activities against Modified Vaccinia Virus Ankara. The larvicidal efficacy of these chemical compounds was also investigated by using Lucilia sericata (L. sericata) larvae. Twelve 1,3-diaryltriazene-substituted SDZ derivatives (AH1-12) were designed and developed as potent multitargeted compounds. Among them, the AH1 derivative showed the most antibacterial and antifungal activity. Besides, synthesized derivatives AH2, AH3, AH5, and AH7 showed higher antiviral activity than SDZ. All synthesized derivatives showed higher cytotoxic activity than SDZ. Also, they showed larvicidal activity at 72 h of the experiment. As a result, these compounds might be great leads for the development of next-generation multitargeted agents.

Evaluation of cytotoxic, antifungal, and larvicidal activities of different bis-sulfonamide Schiff base compounds.

Schiff bases (imines or azomethines) are versatile ligands synthesized from the condensation of amino compounds with active carbonyl groups and used for many pharmaceutical and medicinal applications. In our study, we aimed to determine the cytotoxic, antifungal and larvicidal activities of biologically potent bis-sulfonamide Schiff base derivatives that were re-synthesized by us. For this aim, 16 compounds were re-synthesized and tested for their cytotoxic, antifungal and larvicidal properties. Among this series, compounds A1B2, A1B4, A4B2, A4B3, and A4B4 were shown to have cytotoxic activity against tested cancer lung cell line (A549). The most potent antifungal activity was observed in compounds A2B1 and A2B2 against all fungi. A1B1 showed the strongest larvicidal effect at all concentrations at the 72nd h (100% mortality). These obtained results demonstrate that these type of bis-substituted compounds might be used as biologically potent pharmacophores against different types of diseases.

Prevalence of Demodex folliculorum and Demodex brevis in patients with blepharitis and chalazion.

PURPOSE: Demodex folliculorum and Demodex brevis are common ectoparasites on skin that also can lead to blepharitis and chalazion. The aim of our study is to determine the prevalence of Demodex spp. in eyelashes of patients diagnosed with chronic blepharitis and chalazion. METHODS: This study included 330 patients diagnosed with chronic blepharitis, 70 patients diagnosed with chalazion and 130 volunteers without any ocular problems. Patient eyelashes were examined under a light microscope at magnifications of × 40, × 100 and × 400. Demodex spp. were determined. RESULTS: Parasite prevalence was significantly higher in blepharitis (75.5%) and chalazion groups (70%) compared to the control group (16.2%) (p < 0.001). The prevalence of D. folliculorum in the blepharitis group and D. brevis in the chalazion group was found to be significantly higher compared to other groups (p < 0.05). The average number of mites per eyelash was found to be significantly higher in patients with Demodex positive blepharitis (p = 0.001) and in chalazion patients (p = 0.047) than in the control group. It has been determined that mite positivity increases with age in blepharitis and control groups (p < 0.05). In the group with blepharitis, it was found that mite positivity was significant in the presence of symptoms (p = 0.0001) and Demodex positivity decreased as the education level of individuals increased (p = 0.039). CONCLUSION: The results of the study show that Demodex spp infestations should be considered in chronic blepharitis and chalazion.

Driving CAR T cells towards dermatologic oncology.

Whereas approximately half of metastatic melanoma patients benefit from combined immune checkpoint inhibition targeting cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and Programmed cell death protein 1 (PD-1), for those who do not respond, further strategies and treatment options need to be developed. Thus, focus is turning to the use of chimeric antigen receptor (CAR) T cells, a novel therapy that has not yet achieved a major breakthrough in solid tumors despite the impressive response rates reported for their use in hematologic malignancies. In melanoma and other solid tumor entities, different problems still need to be addressed to improve this therapy, with mechanisms to counteract tumor escape being one of them. In this context, we could show the feasibility of combining two different transfection methods - lentiviral transduction and RNA-electroporation - for equipping the same T lymphocyte with two different tumor antigen-specific receptors. While further analysis is required to transfer this novel strategy from bench to bedside, appropriate target antigens that avoid on-target/off-tumor toxicities and additional optimization to increase CAR T cell power are also needed to maximize their potential use in dermatologic oncology.

Fasten the seat belt: Increasing safety of CAR T-cell therapy.

After the recent success and approvals of chimeric antigen receptor (CAR) T cells in haematological malignancies, its efficacy is currently evaluated in a broad spectrum of tumor entities including melanoma. However, severe and potentially life-threatening side effects like cytokine release syndrome, neurologic toxicities, and the competing risk of morbidity and mortality from the treatment itself are still a major limiting factor in the current CAR T-cell landscape. In addition, especially in solid tumors, the lack of ideal target antigens to avoid on-target/off-tumor toxicities also restricts its use. While various groups are working on strategies to boost CAR T-cell efficacy, mechanisms to increase engineered T-cell safety should not move out of focus. Thus, the aim of this article is to summarize and to discuss current and potential future strategies and mechanisms to increase CAR T-cell safety in order to enable the wide use of this promising approach in melanoma and other tumor entities.

Automated Good Manufacturing Practice-compliant generation of human monocyte-derived dendritic cells from a complete apheresis product using a hollow-fiber bioreactor system overcomes a major hurdle in the manufacture of dendritic cells for cancer vaccines.

BACKGROUND: Although dendritic cell (DC)-based cancer vaccines represent a promising treatment strategy, its exploration in the clinic is hampered due to the need for Good Manufacturing Practice (GMP) facilities and associated trained staff for the generation of large numbers of DCs. The Quantum bioreactor system offered by Terumo BCT represents a hollow-fiber platform integrating GMP-compliant manufacturing steps in a closed system for automated cultivation of cellular products. In the respective established protocols, the hollow fibers are coated with fibronectin and trypsin is used to harvest the final cell product, which in the case of DCs allows processing of only one tenth of an apheresis product. MATERIALS AND RESULTS: We successfully developed a new protocol that circumvents the need for fibronectin coating and trypsin digestion, and makes the Quantum bioreactor system now suitable for generating large numbers of mature human monocyte-derived DCs (Mo-DCs) by processing a complete apheresis product at once. To achieve that, it needed a step-by-step optimization of DC-differentiation, e.g., the varying of media exchange rates and cytokine concentration until the total yield (% of input CD14+ monocytes), as well as the phenotype and functionality of mature Mo-DCs, became equivalent to those generated by our established standard production of Mo-DCs in cell culture bags. CONCLUSIONS: By using this new protocol for the Food and Drug Administration-approved Quantum system, it is now possible for the first time to process one complete apheresis to automatically generate large numbers of human Mo-DCs, making it much more feasible to exploit the potential of individualized DC-based immunotherapy.

Skin and Soft Tissue Infections Caused by Mycobacterium chelonae: More Common Than Expected?

Mycobacterium chelonae is a rapidly growing non-tuberculous mycobacterium, which causes infections of the human skin and soft tissue. Despite an increasing incidence of such infections, patients are often misdiagnosed. We report here 5 patients with cutaneous and/or soft tissue infection due to M. chelonae who were diagnosed and treated at our centre. Two of the 5 patients were on immunosuppressive treatment. While clinical presentations differed in each patient, all had a long history of skin lesions. In addition to careful history-taking, tissue biopsies were obtained for mycobacterial culture and histopathological examination. Culture-directed antibiotic therapy was initiated, which resulted in a slow, but continuous, healing of the lesions. In summary, M. chelonae infections are still relatively rare, but should be considered in both immunocompromised and immunocompetent patients with prolonged skin lesions resistant to standard antibiotic treatment. For diagnosis, tissue analysis for mycobacterial culture and histopathological examination, and once diagnosed, adequate antibiotic treatment, is needed.

CAR-T cell therapy in melanoma: A future success story?

Chimeric antigen receptor (CAR)-T cells are one of the impressive recent success stories of anti-cancer immunotherapy. Especially in haematological malignancies, this treatment strategy has shown promising results leading to the recent approval of two CAR-T cell constructs targeting CD19 in the United States and the European Union. After the huge success in haematological cancers, the next step will be the evaluation of its efficacy in different solid tumors, which is currently investigated in preclinical as well as clinical settings. A commonly examined tumor model in the context of immunotherapy is melanoma, since it is known for its immunogenic features. However, the first results of CAR-T cell therapy in solid tumors did not reveal the same impressive outcomes that were observed in haematological malignancies, as engineered cells need to cope with several challenges. Obstacles include the lack of migration of CAR-T cells from blood vessels to the tumor site as well as the immunosuppressive tumor microenvironment within solid tumors. Another hurdle is posed by the identification of an ideal target antigen to avoid on-target/off-tumor toxicities. Regarding immune escape mechanisms, which can be developed by tumor cells to bypass immune recognition, the observation of antigen loss should also be considered. This article gives an overview of the challenges displayed in CAR-T cell therapy for the use in solid tumors and discusses different new strategies and approaches that deal with these problems in order to improve CAR-T cell therapy, particularly for its use in melanoma.

The siRNA-mediated downregulation of PD-1 alone or simultaneously with CTLA-4 shows enhanced in vitro CAR-T-cell functionality for further clinical development towards the potential use in immunotherapy of melanoma.

Chimeric antigen receptor (CAR)-T cells have been used successfully for cancer immunotherapy. While substantial tumor regression was observed in leukaemia and lymphoma, CAR therapy of solid tumors needs further improvement. A major obstacle to the efficiency of engineered T cells is posed by triggering of inhibitory receptors, for example programmed cell death protein 1 (PD-1) and cytotoxic T lymphocyte-associated protein 4 (CTLA-4), leading to an impaired antitumor activity. To boost CAR-T-cell function, we co-electroporated T cells with both, mRNA encoding a CAR specific for chondroitin sulphate proteoglycan 4 (CSPG4) and small-interfering RNAs (siRNAs) to downregulate PD-1 (siPD-1) and CTLA-4 (siCTLA-4). Flow cytometry revealed that activation-induced upregulation of both PD-1 and CTLA-4 was suppressed when compared to CAR-T cells electroporated with negative control siRNA. The siRNA transfection showed no influence on CAR expression of engineered T cells. Functionality assays were performed using PD-L1- and CD80-transfected melanoma cells endogenously expressing CSPG4. CAR-T cells transfected with siPD-1 alone showed improvement in cytokine secretion. Additionally, CAR-T cells transfected with either siPD-1 alone or together with siCTLA-4 exhibited a significantly increased cytotoxicity. No or only little effects were observed when CAR-T cells were co-transfected with siCTLA-4 only. Taken together, it is feasible to optimize CAR-T cells by co-transfection of CAR-encoding mRNA and siRNAs to downregulate inhibitory receptors. Our in vitro data indicate an improvement of the functionality of these CAR-T cells, suggesting that this strategy could represent a novel method to enhance CAR-T-cell immunotherapy of cancer.