| 1. |
- Clawson, Corbin, et al.
(författare)
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Delivery of a peptide via poly(D,L-lactic-co-glycolic) acid nanoparticles enhances its dendritic cell-stimulatory capacity
- 2010
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Ingår i: NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE. - : Future Medicine. - 1549-9634. ; 6:5, s. 651-661
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Tidskriftsartikel (refereegranskat)abstract
- Nanoparticles (NPs) are attractive carriers for vaccines. We have previously shown that a short peptide (Hp91) activates dendritic cells (DCs), which are critical for initiation of immune responses. In an effort to develop Hp91 as a vaccine adjuvant with NP carriers, we evaluated its activity when encapsulated in or conjugated to the surface of poly(D, L-lactic-co-glycolic) acid (PLGA) NPs. We found that Hp91, when encapsulated in or conjugated to the surface of PLGA-NPs, not only activates both human and mouse DCs, but is in fact more potent than free Hp91. Hp91 packaged within NPs was about fivefold more potent than the free peptide, and Hp91 conjugated to the surface of NPs was similar to 20-fold more potent than free Hp91. Because of their capacity to activate DCs, such NP-Hp91 systems are promising as delivery vehicles for subunit vaccines against infectious disease or cancer.
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| 2. |
- Tjomsland, Vegard, et al.
(författare)
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IL-1α Sustains the Inflammation in Human Pancreatic Cancer Microenvironment by Targeting Cancer Associated Fibroblasts
- 2010
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The tumor microenvironment in pancreatic ductal adenocarcinoma (PDAC) is dynamic with an extensive interaction between the stroma and tumor cells. Our aim for this study was to delineate the cross-talk between PDAC and cancer-associated fibroblasts (CAFs) with focus on the mechanism creating the chronic inflammatory tumor milieu. We assessed the effect cross talk between primary PDAC and CAF cell lines propagated from tumors had on the creation and sustenance of an inflammatory environment and what factors that were involved in establishing the inflammation. The coculture of PDAC and CAF cell lines, propagated from tumor tissues, enhanced the levels of inflammatory factors including IL-1α, IL-6, CXCL8, VEGFA, CCL20, and COX-2. The production of these factors correlated with the expression detected in vivo in PDAC tissues. The key producers of nearly all inflammatory factors were the CAFs and not the tumor cells. IL-1α was produced by the tumor cell lines, whereas almost all IL-1RI was expressed by CAFs thus corresponding to their in vivo expression profile in PDAC tissues, indicating a role for the IL-1 signaling cascade in a tumor favorable microenvironment. Neutralization of the IL-1α pathway efficiently diminished the cross talk induced production of inflammatory factors, both in stroma and tumor cells. These data suggest that the cross-talk between PDAC cells and the main stroma cell type, i.e. CAFs, is one contributing factor in the formation of the inflammatory tumor environment and we propose that the neutralization of IL-1α pathway might be a potential therapy for this cancer.
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| 3. |
- Tjomsland, Vegard, et al.
(författare)
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Pancreatic adenocarcinoma exerts systemic effects on the peripheral blood myeloid and plasmacytoid dendritic cells: an indicator of disease severity?
- 2010
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Ingår i: BMC CANCER. - : BioMed Central. - 1471-2407. ; 10:87
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Tidskriftsartikel (refereegranskat)abstract
- Background: Dendritic cells (DCs) isolated from tumor bearing animals or from individuals with solid tumors display functional abnormalities and the DC impairment has emerged as one mechanism for tumor evasion from the control of the immune system. Ductal pancreatic adenocarcinoma (PDAC), the most common pancreatic cancer, is recognized as a very aggressive cancer type with a mortality that almost matches the rate of incidence. Methods: We examined the systemic influence ductal pancreatic adenocarcinoma ( PDAC) exerted on levels of peripheral blood DCs and inflammatory mediators in comparison to the effects exerted by other pancreatic tumors, chronic pancreatitis, and age-matched controls. Results: All groups examined, including PDAC, had decreased levels of myeloid DCs (MDC) and plasmacytoid DCs (PDC) and enhanced apoptosis in these cells as compared to controls. We found elevated levels of PGE2 and CXCL8 in subjects with PDAC, and chronic pancreatitis. Levels of these inflammatory factors were in part restored in PDAC after tumor resection, whereas the levels of DCs were impaired in the majority of these patients similar to 12 weeks after tumor removal. Our results prove that solid pancreatic tumors, including PDAC, systemically affect blood DCs. The impairments do not seem to be tumor-specific, since similar results were obtained in subjects with chronic pancreatitis. Furthermore, we found that PDAC patients with a survival over 2 years had significant higher levels of blood DCs compared to patients with less than one year survival. Conclusions: Our findings points to the involvement of inflammation in the destruction of the blood MDCs and PDCs. Furthermore, the preservation of the blood DCs compartment in PDAC patients seems to benefit their ability to control the disease and survival.
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| 4. |
- Tjomsland, Vegard, et al.
(författare)
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Pancreatic cancer microenvironment has a high degree of inflammation and infiltrating immune cells in its stroma
- 2010
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Tumor microenvironment is composed of tumor cells, fibroblasts, and infiltrating immune cells, and other cellular components, which work together and create an inflammatory environment favoring tumor progression. The present study aimed to characterize the expression and location of immune cells and investigate inflammatory factors that influence pancreatic ductal adenocarcinoma (PDAC). Methods: qPCRs and immunohistological stainings were performed for inflammatory factors and immune cells localized in tumor tissues from patients with PDAC (N=30). Results: All PDAC tissues had significant increased levels of inflammatory and chemotactic factors such as IL-1α, COX-2, CXCL8, CCL2, and CCL20 as compared to controls. The PDAC stroma, i.e. the fibrosis surrounding the tumor, was the main producer of these factors with the exception of IL-1α, which was expressed by tumor cells and some infiltrating immune cells. The gene expression for immune cell specific markers CD163, CD1c, CD303, and CD8, corresponding to macrophages, myeloid dendritic cells (DCs), plasmacytoid DCs, and cytotoxic T lymphocytes (CTL), respectively, were all significantly increased in PDAC tissues. Immunostaining of the tumor tissue confirmed the elevated levels of infiltrating macrophages, DCs, mature DCs, and cytotoxic T lymphocytes (CTL). The different immune cells were in nearly all cases localized in the fibrotic tissue adjacent to tumor nests. Production of CXCL8 mRNA and protein by the stroma was dependent on the tumor expression of IL-1α. Of importance, we found a correlation in expression of the proinflammatory factor IL-1α and the PDAC patients’ survival time. Conclusion: PDAC cells seem to take advantage of IL-1α to create an inflammatory microenvironment with high degree of fibrosis and the ability to both recruit and activate immune cells and the level of inflammation in this environment influenced the clinical outcome for the patients. Therapies targeting the inflammation might be beneficial for the survival of patients with PDAC.
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| 5. |
- Tjomsland, Vegard, et al.
(författare)
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Semi Mature Blood Dendritic Cells Exist in Patients with Ductal Pancreatic Adenocarcinoma Owing to Inflammatory Factors Released from the Tumor
- 2010
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:10
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Tidskriftsartikel (refereegranskat)abstract
- Background: Much evidence exists regarding the fact that blood DCs, both myeloid DCs (MDCs) and plasmacytoid DCs (PDCs), are negatively affected in different types of cancer, with both reduced numbers and impaired functionality. Functional impairment of DCs in patients with pancreatic ductal adenocarcinoma (PDAC), may contribute to the poor clinical outcome. The aim of this study was to examine the effects PDAC had on blood DCs and elucidate the underlying mechanism responsible for the DC impairment. Methodology/Principal Findings: We examined the systemic influence PDAC exerted on blood DCs by ex vivo measuring numerous activation and maturation markers expressed on these cells. Furthermore, the effect patient plasma and the inflammatory factors CXCL8 and PGE(2) had on purified MDCs and PDCs from healthy donors was assessed and compared to the DCs existing in PDAC patients. We found a partial maturation of the blood MDCs and PDCs in PDAC patients with significantly enhanced expression of CD83, CD40, B7H3, PDL-1, CCR6, and CCR7 and decreased expression of ICOSL, and DCIR. These changes lead to impairment in their immunostimulatory function. Furthermore, chronic pancreatitis gave rise to DCs with similar semi-mature phenotype as seen in PDAC. Low expression of ICOSL was associated with poor prognosis. We found that the mechanism underlying this semi-maturation of DCs was inflammatory factors existing in the PDAC patients plasma. Of note, PGE2, which is elevated PDAC patient plasma, was one contributing factor to the changes seen in MDCs and PDCs phenotype. Conclusion/Significance: Our findings point to a role for the systemic inflammation in transforming blood MDCs and PDCs into semi-mature cells in PDAC patients and we show a correlation between maturation status and clinical outcome. Thus, means to preserve a functional blood DC compartment in PDAC patients by diminishing the inflammation could facilitate their ability to control the disease and improve survival.
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