Citations

Abstract MUC1 (MUC1 in human and Muc1 in nonhumans) is a membrane-tethered mucin that interacts with Pseudomonas aeruginosa (PA) through flagellin. In this study, we compared PA pulmonary clearance and proinflammatory responses by Muc1−/− mice with Muc1+/+ littermates following intranasal instillation of PA or flagellin. Compared with Muc1+/+ mice, Muc1−/− mice showed increased PA clearance, greater airway recruitment of neutrophils, higher levels of TNF-α and KC in bronchoalveolar lavage fluid, higher levels of TNF-α in media of flagellin-stimulated alveolar macrophages, and higher levels of KC in media of tracheal epithelial cells. Knockdown of MUC1 enhanced flagellin-induced IL-8 production by primary human bronchial epithelial cells. Expression of MUC1 in HEK293T cells attenuated TLR5-dependent IL-8 release in response to flagellin, which was completely ablated when its cytoplasmic tail was deleted. We conclude that MUC1/Muc1 suppresses pulmonary innate immunity and speculate its anti-inflammatory activity may play an important modulatory role during microbial infection.

Abstract Pancreatic cancer is a highly aggressive, treatment refractory cancer and is the fourth leading cause of death in the United States. In humans, 90% of pancreatic adenocarcinomas overexpress altered forms of a tumor-specific Ag, mucin 1 (MUC1; an epithelial mucin glycoprotein), which is a potential target for immunotherapy. We have established a clinically relevant animal model for pancreatic cancer by developing a double transgenic mouse model (called MET) that expresses human MUC1 as self molecule and develops spontaneous tumors of the pancreas. These mice exhibit acinar cell dysplasia at birth, which progresses to microadenomas and acinar cell carcinomas. The tumors express large amounts of underglycosylated MUC1 similar to humans. Tumor-bearing MET mice develop low affinity MUC1-specific CTLs that have no effect on the spontaneously occurring pancreatic tumors in vivo. However, adoptive transfer of these CTLs was able to completely eradicate MUC1-expressing injectable tumors in MUC1 transgenic mice, and these mice developed long-term immunity. These CTLs were MHC class I restricted and recognized peptide epitopes in the immunodominant tandem repeat region of MUC1. The MET mice appropriately mimic the human condition and are an excellent model with which to elucidate the native immune responses that develop during tumor progression and to develop effective antitumor vaccine strategies.

Abstract Cancer-associated inflammation is a molecular key feature in pancreatic ductal adenocarcinoma. Oncogenic KRAS in conjunction with persistent inflammation is known to accelerate carcinogenesis, although the underlying mechanisms remain poorly understood. Here, we outline a novel pathway whereby the transcription factors NFATc1 and STAT3 cooperate in pancreatic epithelial cells to promote KrasG12D-driven carcinogenesis. NFATc1 activation is induced by inflammation and itself accelerates inflammation-induced carcinogenesis in KrasG12D mice, whereas genetic or pharmacologic ablation of NFATc1 attenuates this effect. Mechanistically, NFATc1 complexes with STAT3 for enhancer–promoter communications at jointly regulated genes involved in oncogenesis, for example, Cyclin, EGFR and WNT family members. The NFATc1–STAT3 cooperativity is operative in pancreatitis-mediated carcinogenesis as well as in established human pancreatic cancer. Together, these studies unravel new mechanisms of inflammatory-driven pancreatic carcinogenesis and suggest beneficial effects of chemopreventive strategies using drugs that are currently available for targeting these factors in clinical trials. Significance: Our study points to the existence of an oncogenic NFATc1–STAT3 cooperativity that mechanistically links inflammation with pancreatic cancer initiation and progression. Because NFATc1–STAT3 nucleoprotein complexes control the expression of gene networks at the intersection of inflammation and cancer, our study has significant relevance for potentially managing pancreatic cancer and other inflammatory-driven malignancies. Cancer Discov; 4(6); 688–701. ©2014 AACR. This article is highlighted in the In This Issue feature, p. 621

AbstractGene regulation resulting from glucocorticoid receptor and glucocorticoid response element interactions is a hallmark feature of stress response signaling. Imbalanced glucocorticoid production and glucocorticoid receptor activity have been linked to socioeconomically crippling neuropsychiatric disorders, and accordingly there is a need to developin vivomodels to help understand disease progression and management. Therefore, we developed the transgenicSR4Gzebrafish reporter line with six glucocorticoid response elements used to promote expression of a short half‐life green fluorescent protein following glucocorticoid receptor activation. Herein, we document the ability of this reporter line to respond to both chronic and acute exogenous glucocorticoid treatment. The green fluorescent protein expression in response to transgene activation was high in a variety of tissues including the brain, and provided single‐cell resolution in the effected regions. The specificity of these responses is demonstrated using the partial agonist mifepristone and mutation of the glucocorticoid receptor. Importantly, the reporter line also modeled the temporal dynamics of endogenous stress response signaling, including the increased production of the glucocorticoid cortisol following hyperosmotic stress and the fluctuations of basal cortisol concentrations with the circadian rhythm. Taken together, these results characterize our newly developed reporter line for elucidating environmental or genetic modifiers of stress response signaling, which may provide insights to the neuronal mechanisms underlying neuropsychiatric disorders such as major depressive disorder.

BackgroundThe use of hematopoietic progenitor cell (HPC) transplant has risen over the past two decades. A variety of adverse events (AEs) of varying severity have been noted during HPC infusions. These AEs have been associated with several factors such as the amount of dimethyl sulfoxide and white blood cells in the HPC product. We performed a single‐institution retrospective analysis to determine the effect of two different HPC infusion techniques, manual push with syringes versus infusion from bags with the aid of gravity, on the occurrence of infusion‐related AEs.Study Design and MethodsInfusions between December 2008 and November 2010 involving peripheral blood HPCs were reviewed. Pertinent clinical and HPC product–related information was recorded. Data were analyzed to determine the incidence of infusion‐related AEs and its association with patient and product‐related variables.ResultsWe found 461 AEs in 645 patients during the study period. A total of 325 (50%) experienced at least one AE. Flushing was the most common type of AE followed by nausea and hypertension. The use of syringe infusion was more commonly associated with AEs (odds ratio, 1.82 [95% confidence interval, 1.32‐2.50]; p = 0.002). Other independent risk factors were cryopreserved products and the amount of polymorphonuclear leukocytes in the product.ConclusionTo our knowledge, this is the first study examining the effect of two different infusion techniques on infusion‐related AEs. Our findings suggest that the use of bags for infusion protected the patients from AEs.

ABSTRACT There has been controversy as to whether there is an underlying neurodegenerative process of the cerebellum in essential tremor (ET). The aim of this study was to examine whether ET is associated with Purkinje cell (PC) loss. Prospectively categorized ET and control subjects who were longitudinally examined in the Arizona Study for Aging and Neurodegenerative Disorders and came to autopsy between 1998 and 2013 underwent standardized neuropathological assessment of the brain. PC linear density of the cerebellar hemisphere was calculated in a blinded manner. There were 56 ET cases and 62 age‐matched controls free of dementia and other neurodegenerative disorders included in the study. Mean PC linear density was 3.80 ± 0.81 cells per mm for tremor cases and 3.82 ± 0.91 cells per mm for controls ( Δ 0.02; 95% confidence interval [CI]: −0.30‐0.34). PC counts were not associated with tremor duration (r = 0.06; 95% CI: −0.21‐0.32). These data demonstrate that ET is not associated with cerebellar PC loss. © 2014 International Parkinson and Movement Disorder Society

Mitogenic stimulation of lymphocytes involves alkalinization of intracellular pH (pHi). Subsequent pHi regulation may involve HCO3− extrusion through Cl−/HCO3− exchangers and/or Na+‐HCO3− co‐transporters with acid‐loading capability. Abnormalities in these mechanisms could result in immune dysfunctions, as suggested by the CD8+ T‐cell expansion encountered in mice lacking Ae2 (a widely expressed acid loader with electroneutral and Na+‐independent Cl−/HCO3− anion‐exchange activity). Here we report that CD8+ T cells but not CD4+ T cells or other lymphocyte populations, are crucially dependent on Ae2 for pHi regulation. While total lymphocytes (including isolated CD4+ T cells) exhibit Ae1 expression and Na+‐HCO3− co‐transport with acidifying potential, CD8+ T cells lack these acid‐loading mechanisms. In Ae2‐KO mice, CD4+ but not CD8+ T cells upregulate these potential Ae2 surrogates. As a consequence, Ae2‐KO CD8+ T cells exhibit alkalinized pHi, and dramatically increase their pHi upon CD3 stimulation. Moreover, stimulated Ae2‐deficient CD8+ T cells show enhanced intracellular production of IL‐2 and membrane expression of its receptor IL‐2Rα, together with increased cell proliferation and activation. These findings demonstrate that CD8+ T cells are critically dependent on Ae2 for pHi homeostasis and tuning of cell proliferation and activation. Ae2 thus constitutes a novel target to modulate CD8+ T‐cell responses.