Cold Atmospheric Plasma Is a Promising Alternative Treatment Option in Case of Split Skin Graft Failure.

Cold atmospheric plasma (CAP) has shown promising potential in promoting wound healing. This case report presents the successful application of CAP in a 42-year-old female patient with extensive wound healing disorders and superinfections following the excision of an abscess in the left thoracic region. After several failed split skin graft attempts, the implementation of CAP led to significant improvements in wound healing. This report highlights the wound healing-promoting effects of CAP and discusses its potential mechanisms of action.

CCR4 Blockade Diminishes Intratumoral Macrophage Recruitment and Augments Survival of Syngeneic Pancreatic Cancer-Bearing Mice.

Pancreatic cancer is known for its tumor microenvironment (TME), which is rich in stromal and immune cells supporting cancer growth and therapy resistance. In particular, tumor-associated macrophages (TAMs) are known for their angiogenesis- and metastasis-promoting properties, which lead to the failure of conventional therapies for pancreatic cancer. Hence, treatment options targeting TAMs are needed. The C-C chemokine receptor type 4 (CCR4) is critical for immune cell recruitment into the TME, and in this paper we explore the effects of its genetic or immunotherapeutic blockade in pancreatic-cancer-bearing mice. Murine PDA6606 pancreatic cancer cells and murine peritoneal macrophages were used for in vitro migration assays. In vivo, a syngeneic, orthotropic pancreatic cancer model was established. Tumor growth and survival were monitored under prophylactic and therapeutic application of a CCR4 antagonist (AF-399/420/18025) in wildtype (CCR4wt) and CCR4-knockout (CCR4-/-) mice. Immune infiltration was monitored in tumor tissue sections and via flow cytometry of lysed tumors. PDA6606 cells induced less migration in CCR4-/- than in CCR4wt macrophages in vitro. Pancreatic TAM infiltration was higher, and survival was reduced in CCR4wt mice compared to CCR4-/- mice. Antagonizing CCR4 in wildtype mice revealed similar results as in CCR4-/- mice without antagonization. Prophylactic CCR4 antagonist application in wildtype mice was more efficient than therapeutic antagonization. CCR4 seems to be critically involved in TAM generation and tumor progression in pancreatic cancer. CCR4 blockade may help prolong the relapse-free period after curative surgery in pancreatic cancer and improve prognosis.

S1PR4 deficiency results in reduced germinal center formation but only marginally affects antibody production.

Introduction: Splenic B cells exhibit a high expression of the G protein-coupled sphingosine-1-phosphate (S1P) receptor type 4 (S1PR4). Little is known about the functional relevance of S1PR4 expression on those cells. Methods: In this study, S1PR4-deficient mice were used to study the role of S1PR4-mediated S1P signaling in B cell motility in vitro and for the maintenance of the splenic architecture under steady state conditions as well as in polymicrobial abdominal sepsis in vivo. Finally, the impact of S1PR4 deficiency on antibody production after immunization with T cell dependent antigens was assessed. Results: Loss of S1PR4 resulted in minor alterations of the splenic architecture concerning the presence of B cell follicles. After sepsis induction, the germinal center response was severely impaired in S1PR4-deficient animals. Splenic B cells showed reduced motility in the absence of S1PR4. However, titres of specific antibodies showed only minor reductions in S1PR4-deficient animals. Discussion: These observations suggest that S1P signaling mediated by S1PR4 modifies chemokine-induced splenic B cell chemotaxis, thus modulating splenic microarchitecture, GC formation and T-cell dependent antibody production.

Murine Macrophages Modulate Their Inflammatory Profile in Response to Gas Plasma-Inactivated Pancreatic Cancer Cells.

Macrophages and immuno-modulation play a dominant role in the pathology of pancreatic cancer. Gas plasma is a technology recently suggested to demonstrate anticancer efficacy. To this end, two murine cell lines were employed to analyze the inflammatory consequences of plasma-treated pancreatic cancer cells (PDA) on macrophages using the kINPen plasma jet. Plasma treatment decreased the metabolic activity, viability, and migratory activity in an ROS- and treatment time-dependent manner in PDA cells in vitro. These results were confirmed in pancreatic tumors grown on chicken embryos in the TUM-CAM model (in ovo). PDA cells promote tumor-supporting M2 macrophage polarization and cluster formation. Plasma treatment of PDA cells abrogated this cluster formation with a mixed M1/M2 phenotype observed in such co-cultured macrophages. Multiplex chemokine and cytokine quantification showed a marked decrease of the neutrophil chemoattractant CXCL1, IL6, and the tumor growth supporting TGFß and VEGF in plasma-treated compared to untreated co-culture settings. At the same time, macrophage-attractant CCL4 and MCP1 release were profoundly enhanced. These cellular and secretome data suggest that the plasma-inactivated PDA6606 cells modulate the inflammatory profile of murine RAW 264.7 macrophages favorably, which may support plasma cancer therapy.

RAW 264.7 Macrophage Polarization by Pancreatic Cancer Cells - A Model for Studying Tumour-promoting Macrophages.

BACKGROUND/AIM: Tumour-associated macrophages (TAMs) are highjacked M2-polarized macrophages that especially promote pancreatic cancer growth. The aim of this study was to identify an easy-to-use cell culture model suitable for studying this interaction and macrophage polarization. MATERIALS AND METHODS: Co-cultures of two cell lines, PDA6606 cells with RAW macrophages cells were used in vitro and in ovo. Macrophages were analyzed by microscopy, magnetic resonance imaging (MRI), and flow cytometry. RESULTS: By comparing chemically-induced M1 and M2 macrophages, a clear induction of the M2 phenotype of RAW macrophages by PDA6606 pancreatic cancer cells was observed in vitro. In ovo, PDA6606 cells and conditioned media polarized macrophages to the M2 phenotype, which in turn promoted tumour growth and angiogenesis via their surface marker profiles and VEGF production. CONCLUSION: PDA6606 pancreatic cancer cells expectantly and potently induced M2 polarization of RAW264.7 macrophages. This model may be used to study pancreatic cancer-macrophage plasticity in e.g. drug research in vitro and in ovo.