Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal malignancies. Cancer stem cells (CSCs), which are not targeted by current therapies, may be the reason for pronounced therapy resistance. A new treatment option in phase II trials is cabozantinib that inhibits the pancreatic CSC surface marker and tyrosine kinase receptor c-Met. The purpose of this study was to evaluate the effect of cabozantinib to stem-like features and therapy resistance. Established PDA cell lines, a gemcitabine-resistant subclone, non-malignant pancreatic ductal cells and primary spheroidal cultures from patient tumors were analyzed by MTT-assay, flow cytometry, colony and spheroid formation assays, western blotting, qRT-PCR, antibody protein array, immunohistochemistry and morphological features. Cabozantinib inhibited viability and spheroid formation and induced apoptosis in malignant cells with minor effects in non-malignant cells. After long-term cabozantinib treatment, PDA cells had altered anti- and pro-apoptotic signaling, but still responded to cabozantinib, as apoptosis only slightly decreased and viability only slightly increased suggesting a low resistance-inducing potential of cabozantinib. In parallel, c-Met expression and the pluripotency transcription factor SOX2 were downregulated, which might counteract development of full therapy resistance in long-term treated subclones. In single-treatment studies, cabozantinib increased efficacy of gemcitabine. Most importantly, cabozantinib strongly induced apoptosis and reduced viability in PDA cell lines, which are completely resistant toward gemcitabine. In primary, CSC-enriched spheroidal cultures cabozantinib downregulated CSC markers SOX2, c-Met and CD133 and induced apoptosis. These findings suggest that the clinical use of cabozantinib may be more effective than current chemotherapeutics.
Abstract The arginine-hydrolyzing enzyme arginase is constitutively expressed by human polymorphonuclear granulocytes (PMN). Upon PMN cell death arginase is liberated and depletes arginine in the microenvironment. This amino acid depletion suppresses T cell proliferation and cytokine secretion and emerges as a key mechanism of immunosuppression during chronic inflammation and tumor growth. Here we show that PMN arginase also severely impairs key functions of primary human NK cells as well as IL-2-activated NK cells. In the absence of arginine, NK cell proliferation and IL-12/IL-18-induced secretion of IFN-γ are severely diminished. In contrast, NK cell viability, granule exocytosis, and cytotoxicity are independent of extracellular arginine. The mechanism of NK cell suppression by arginine depletion is posttranscriptional since mRNA transcript frequency is unaffected upon NK cell activation in the absence of arginine. Finally, we demonstrate that human purulent exudate ex vivo inhibits NK cell functions exclusively due to liberated arginase. Arginase inhibitors are therefore promising pharmacological agents to treat unwanted suppression of the innate (NK cell) as well as the adaptive (T cell) immune system.
GATA2 deficiency is characterized by monocytopenia, deficiency of dendritic cells, and a variable degree of lymphocytopenia affecting B cells and NK cells, leading to an enhanced risk of mycobacterial, viral, and fungal infections. Here we present a patient with a heterozygous intronic GATA2 mutation who acquired a fatal disseminated mycosis due to the black yeast-like fungus Arthrocladium fulminans following an infection with Mycobacterium sherrisii. This case illustrates that in patients with severe uncommon infections, immunodeficiency syndromes must be ruled out.
Einleitung: Die jährliche Inzidenz des Kolorektalen Karzinoms beträgt 60.000 Neuerkrankungen pro Jahr. Das opportunistische Vorsorgeprogramm ermöglicht allen Versicherten ab dem 50. Lebensjahr die Teilnahme am Screening mittels FOBT und ab 55 alle 2 Jahre einen FOBT oder eine Koloskopie mit Wiederholung nach 10 Jahren. Die Maßnahmen erreichen nicht alle Berechtigten. Die jährliche Teilnahmerate der Berechtigten an der Vorsorgekoloskopie sind 2,8% bei Frauen und 2,8% bei Männer (Pox, Altenhofen et al. 2012). Die Umstellung des opportunistischen Systems auf ein Einladungsverfahren soll die Teilnahme steigern.
Hintergrund/Einleitung: Nach Anlage eines ileoanalen Pouches (IAP) entwickeln im weiteren Verlauf ca. 10–40% der Pat. mit Colitis ulcerosa (CU), aber weniger als 5% der Patienten mit Polyposis coli (FAP) eine Pouchitis. Ungeklärt ist die Frage, ob es sich bei der Pouchitis um ein Wiederauftreten der Grunderkrankung im Pouch oder aber um eine eigene CED-Entität handelt. Wir charakterisierten daher die Zytokin- und Chemokin-Transkriptprofile in entzündeten und nicht-entzündeten Pouches von Patienten mit CU, M. Crohn (MC) und FAP.
Treatment with the anti-tumour necrosis factor alpha chimeric monoclonal antibody infliximab is highly effective in the treatment of refractory and fistulising Crohn's disease. Infliximab has been tolerated well, with minimal and short-lived adverse effects. The likelihood of severe reactions to infliximab, such as acute and delayed hypersensitivity infusion reactions, is small; nevertheless, if they do occur, they are life-threatening. We report a case of an anaphylaxis-like reaction in a 22-year-old female with long-standing Crohn's disease. The patient was treated successfully with adalimumab, a fully human anti-tumour necrosis factor alpha monoclonal antibody. Follow-up demonstrated mucosal healing and normalisation of elevated pro-inflammatory cytokine transcripts.
Type 1 diabetes (T1D) results from autoimmune destruction of insulin-producing beta cells in pancreatic islets. Various immune cell populations are involved in disease development and natural course. However, to our knowledge, so far there are no comprehensive comparative investigations of all main immune cell populations and their most important subsets at the onset of disease. Therefore, in the current study, we analyzed 51 peripheral blood immune cell populations in 22 young T1D patients and in 25 age-matched controls using a comprehensive polychromatic flow cytometry panel developed for whole blood by the COST Action no. BM0907 ENTIRE (European Network for Translational Immunology Research and Education: From Immunomonitoring to Personalized Immunotherapy) consortium. We found that in T1D patients, frequencies and absolute counts of natural killer (NK) cells, dendritic cells (DC) and T cells, as well as their respective subsets, were significantly altered compared to controls. Further, we observed that changes in several cell populations (e.g. CD14+ CD16+ non-classical monocytes, plasmablasts) were dependent on the age of the patient. In addition to age-related changes, we also found that alterations in immune cell patterns were associated with parameters such as the presence of ketoacidosis and C-peptide serum levels. Our study provides a foundation for future studies investigating different cell lineages and their role in T1D and illustrates the value of polychromatic flow cytometry for evaluating all main peripheral immune cells and their subsets in whole blood samples.
