Comprehensive Assessment of the Intrinsic Pancreatic Microbiome.

OBJECTIVE: We sought to comprehensively profile tissue and cyst fluid in patients with benign, precancerous, and cancerous conditions of the pancreas to characterize the intrinsic pancreatic microbiome. SUMMARY BACKGROUND DATA: Small studies in pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasm (IPMN) have suggested that intra-pancreatic microbial dysbiosis may drive malignant transformation. METHODS: Pancreatic samples were collected at the time of resection from 109 patients. Samples included tumor tissue (control, n=20; IPMN, n=20; PDAC, n=19) and pancreatic cyst fluid (IPMN, n=30; SCA, n=10; MCN, n=10). Assessment of bacterial DNA by quantitative PCR and 16S ribosomal RNA gene sequencing was performed. Downstream analyses determined the relative abundances of individual taxa between groups and compared intergroup diversity. Whole-genome sequencing data from 140 patients with PDAC in the National Cancer Institute's Clinical Proteomic Tumor Analysis Consortium (CPTAC) were analyzed to validate findings. RESULTS: Sequencing of pancreatic tissue yielded few microbial reads regardless of diagnosis, and analysis of pancreatic tissue showed no difference in the abundance and composition of bacterial taxa between normal pancreas, IPMN, or PDAC groups. Low-grade dysplasia (LGD) and high-grade dysplasia (HGD) IPMN were characterized by low bacterial abundances with no difference in tissue composition and a slight increase in Pseudomonas and Sediminibacterium in HGD cyst fluid. Decontamination analysis using the CPTAC database confirmed a low-biomass, low-diversity intrinsic pancreatic microbiome that did not differ by pathology. CONCLUSIONS: Our analysis of the pancreatic microbiome demonstrated very low intrinsic biomass that is relatively conserved across diverse neoplastic conditions and thus unlikely to drive malignant transformation.

Initial Report: Personalized Circulating Tumor DNA and Survival in Patients with Resectable Pancreatic Cancer.

ABSTRACT: BACKGROUND: Pancreatic adenocarcinoma (PDAC) is highly lethal with up to 80% of resected patients experiencing disease recurrence within 2 years (Watanabe, Nakamura, Kimura et al in Int J Mol Sci 23(19):11521, 2022). Cross-sectional imaging and serum tumor markers are used for monitoring post-operative recurrence; however, both have significant limitations (Edland, Tjensvoll, Oltedal et al in Mol Oncol 17:1857-1870, 2023). Circulating tumor DNA (ctDNA) has emerged as a valuable prognostic tool to measure molecular residual disease (MRD) and predict recurrence in solid tumors (Watanabe, Nakamura, Kimura et al in Int J Mol Sci 23(19):11521, 2022). In this study, we evaluated the feasibility of a personalized, tumor-informed ctDNA assay to detect recurrence prior to standard surveillance tools in patients with PDAC. PATIENTS AND METHODS: After Institutional Review Board (IRB) approval (Pro00106870), we assessed serial ctDNA measurements (n = 177) from 35 patients with resectable PDAC treated by either upfront resection or neoadjuvant chemotherapy. Plasma samples (median 4 ml, interquartile range 0.6-5.9 ml) were isolated from blood collected in EDTA tubes and banked at diagnosis, during neoadjuvant therapy if applicable, on the day of surgery, and every 2-3 months postoperatively. A tumor-informed assay (Signatera™, Natera, Inc.) that tracks up to 16 individual-specific, somatic single nucleotide variants in the corresponding patient's plasma samples were used for ctDNA detection. Survival was calculated using Kaplan-Meier curves, and significance was determined with the log-rank test. RESULTS: Personalized ctDNA assays were successfully designed for all patients (with 32/35 patients having 16-plex assays). Median follow-up from initial treatment was 13 months (range 1-26 months; Table 1). ctDNA-positivity at any time point was observed in 40% (14/35) of patients. During the follow-up period, 18 patients (51%) developed radiographic evidence of recurrence after a median of 9 months of follow-up (range 1-26 months). At the time of radiographic recurrence, 50% (9/18) of patients were ctDNA-positive. During the immediate postoperative period (up to 9 weeks post-surgery), RFS and OS were significantly inferior in patients who were ctDNA-positive versus ctDNA-negative (RFS 97 versus 297 days, p < 0.001; OS 110 versus 381 days, p < 0.001; Fig. 1). Table 1 Cohort demographics (N = 35); patient demographics, tumor characteristics, and survival Gender (%) Female 17 (49%) Male 18 (51%) Median age (IQR) 70 years (65-75 years) Neoadjuvant treatment (%) 11 (31%) Median sample plasma volume (IQR) 4.0 mL (0.6-5.9 mL) Median follow-up (range) 13 months (1-26 months) Median initial CA 19-9 in U/mL (IQR) 56 (18-160) Median tumor size in cm (IQR) 2.5 (1.8-3.3) Median number of positive lymph nodes (IQR) 1 (0-3) Median recurrence-free survival 9.4 months Median overall survival N/A (not reached) Fig. 1 a Overview plot showing longitudinal ctDNA status, treatment regimen, and clinical outcomes for each patient (N = 35); median follow-up from the start of the neoadjuvant therapy/surgery was 13 months (range 1-26 months); ctDNA at any time point was 40% (14/35); out of the 35 patients, 18 (51%) developed radiographic evidence of recurrence (median RFS: 9 months), and of these 18 patients with clinical recurrence, 9 (50%) were ctDNA-positive and the remaining ctDNA-negative; notably, all ctDNA-negative patients with recurrence had suboptimal plasma volume available for ctDNA analysis; b, c Kaplan-Meier estimates representing the association of ctDNA status with (b) RFS and (c) OS, at MRD time point (9 weeks post-surgery) DISCUSSION: Our study demonstrates the feasibility of tumor-informed ctDNA-based MRD testing in resectable PDAC and shows that MRD detected by ctDNA within the immediate postoperative period portends a dismal prognosis. This information is valuable for both patients and clinicians in setting prognostic expectations.

Functional reprogramming of peripheral blood monocytes by soluble mediators in patients with pancreatic cancer and intraductal papillary mucinous neoplasms.

Background: Monocytes and monocyte-derived tumor infiltrating cells have been implicated in the immunosuppression and immune evasion associated with pancreatic adenocarcinoma (PDAC). Yet, precisely how monocytes in the periphery and tumor microenvironment in patients with intraductal papillary mucinous neoplasm (IPMN), a precursor lesion to PDAC, change during disease progression has not been defined. Here we functionally profiled the peripheral immune system and characterized the tumor microenvironment of patients with both IPMN and PDAC. We also tested if sera from patients with IPMN and PDAC functionally reprogram monocytes relative to that of healthy donors. Methods: Pancreatic tissue and peripheral blood were collected at the time of resection from 16 patients with IPMN and 32 patients with PDAC. Peripheral blood and pancreatic tissue/tumor were immunophenotyped using flow cytometry. Whole blood was plated and incubated with R848 (a TLR 7/8 agonist) or LPS (a TLR4 agonist) for 6 hours and TNF expression in monocytes was measured by flow cytometry to measure monocyte activation. To test if TLR sensitivity is determined by factors in patient sera, we preconditioned healthy donor monocytes in serum from PDAC (n=23), IPMN (n=15), or age-matched healthy donors (n=10) followed by in vitro stimulation with R848 or LPS and multiplex cytokine measurements in the supernatant. Results: TNF expression in R848-stimulated peripheral blood monocytes was higher in patients with low grade vs high grade IPMN (65% vs 32%, p = 0.03) and stage 1 vs stage 2/3 PDAC (58% vs 42%, p = 0.03), this was not observed after LPS stimulation. TLR activation correlated with increasing grade of dysplasia from low grade IPMN to high grade IPMN. Serum from patients with IPMN and PDAC recapitulated suppression of TNF induction after R848 stimulation in naïve, healthy donor monocytes. Conclusion: Peripheral blood monocyte TNF secretion inversely correlates with the degree of dysplasia in IPMN and cancer stage in PDAC, suggesting innate immune reprogramming as IPMNs progress to invasive disease. These effects are, at least in part, mediated by soluble mediators in sera.

Digital spatial profiling of intraductal papillary mucinous neoplasms: Toward a molecular framework for risk stratification.

The histopathologic heterogeneity of intraductal papillary mucinous neoplasms (IPMN) complicates the prediction of pancreatic ductal adenocarcinoma (PDAC) risk. Intratumoral regions of pancreaticobiliary (PB), intestinal (INT), and gastric foveolar (GF) epithelium may occur with either low-grade dysplasia (LGD) or high-grade dysplasia (HGD). We used digital spatial RNA profiling of dysplastic epithelium (83 regions) from surgically resected IPMN tissues (12 patients) to differentiate subtypes and predict genes associated with malignancy. The expression patterns of PB and GF lesions diverged from INT, suggesting that PB and GF arise from a common lineage. Transcriptional dysregulation within PB lesions mirrored that of PDAC, whereas INT and GF foci did not. Tumor necrosis factor/nuclear factor κB (TNF-NFκB) and cell cycle (cycling S and cycling G2-M) programs occurred with relative prominence in PB and INT subtypes, respectively. Together, this study delineates markers of high-risk IPMN and insights into malignant progression.

COVID-19 vaccine hesitancy in inflammatory arthritis patients: serial surveys from a large longitudinal national Australian cohort.

OBJECTIVES: To determine COVID-19 vaccine hesitancy rates in inflammatory arthritis patients and identify factors associated with changing vaccine hesitancy over time. METHODS: This investigation was a prospective cohort study of inflammatory arthritis patients from community and public hospital outpatient rheumatology clinics enrolled in the Australian Rheumatology Association Database (ARAD). Two surveys were conducted, one immediately prior to (pre-pandemic) and another approximately 1 year after the start of the pandemic (follow-up). Coronavirus disease 2019 (COVID-19) vaccine hesitancy was measured at follow-up, and general vaccine hesitancy was inferred pre-pandemic; these were used to identify factors associated with fixed and changing vaccine beliefs, including sources of information and broader beliefs about medication. RESULTS: Of the 594 participants who completed both surveys, 74 (12%) were COVID-19 vaccine hesitant. This was associated with pre-pandemic beliefs about medications being harmful (P < 0.001) and overused (P = 0.002), with stronger beliefs resulting in vaccine hesitancy persistent over two time points (P = 0.008, P = 0.005). For those not vaccine hesitant pre-pandemic, the development of COVID-19 vaccine hesitancy was associated with a lower likelihood of seeking out vaccine information from health-care professionals (P < 0.001). COVID-19 vaccine hesitancy was not associated with new influenza vaccine hesitancy (P = 0.138). CONCLUSION: In this study of vaccine beliefs before and during the COVID-19 pandemic, factors associated with COVID-19 vaccine hesitancy in inflammatory arthritis patients varied, depending on vaccine attitudes immediately prior to the start of the pandemic. Fixed beliefs reflected broader views about medications, while fluid beliefs were highly influenced by whether they sought out information from health-care professionals, including rheumatologists.

Multidimensional Immunophenotyping of Intraductal Papillary Mucinous Neoplasms Reveals Novel T Cell and Macrophage Signature.

BACKGROUND: Intraductal papillary mucinous neoplasms (IPMN) are the only radiographically identifiable precursor to pancreatic adenocarcinoma, yet little is known about how these lesions progress to cancer. Inflammation has been associated with dysplastic progression; however, the cause and composition of this inflammation remains poorly characterized. We sought to comprehensively profile immune cell infiltration using parallel spatial transcriptomic and flow cytometric techniques. METHODS: Twelve patients with resected IPMN exhibiting both high-grade dysplasia (HGD) and low-grade dysplasia (LGD) were selected for spatial transcriptomics (NanoString GeoMx). Immune (CD45+), epithelial (PanCK+), and stromal (SMA+) compartments were analyzed separately using the GeoMx NGS Pipeline. An additional 11 patients resected for IPMN of varying degrees of dysplasia underwent immunophenotyping using flow cytometry (DURAClone IM). RESULTS: Spatial transcriptomics revealed that T cells represent the dominant immune cell within IPMN stroma, which was confirmed by flow cytometry (56%). Spatial profiling found that the T-cell infiltrate was significantly higher in regions of LGD compared with HGD (62% vs. 50%, p = 0.038). Macrophages were the only other immune cell type with > 10% abundance, yet conversely, were generally more abundant in regions of HGD compared to LGD (19% vs. 11%, p = 0.058). Correspondingly, immune cells within regions of HGD demonstrated transcriptional upregulation of genes associated with macrophage activity including secretion (CXCL1) and phagocytosis (C1QA, C1S, C4B). CONCLUSIONS: IPMN immune infiltrate is primarily composed of T cells and macrophages. Regions of HGD appear to be relatively deplete of T cells and show a trend toward macrophage enrichment compared with regions of LGD.

Patterns of biologic and targeted-synthetic disease-modifying antirheumatic drug use in rheumatoid arthritis in Australia.

OBJECTIVE: The aim of this study was to describe treatment patterns in RA, including the frequency and reasons for switching or stopping biologic and targeted synthetic DMARDs (b/tsDMARDs). METHODS: The reasons for switching or stopping b/tsDMARDs were extracted from the Australian Rheumatology Association Database (ARAD) from 2003 to 2018 for RA participants. Switching patterns for each b/tsDMARD and time on first-, second- and third-line b/tsDMARDs were evaluated using Sankey diagrams and survival methods. RESULTS: A total of 2839 participants were included in the analysis. The first-line b/tsDMARDs were etanercept (n = 1414), adalimumab (n = 1024), infliximab (n = 155), golimumab (n = 98), abatacept (n = 66), certolizumab (n = 38), tocilizumab (n = 21) and tofacitinib (n = 23). Of those starting first-, second- and third-line biologic therapy, 24.0%, 31.8% and 24.4% switched to another b/tsDMARD within 12 months, respectively. Inefficacy or adverse effects were the most common reasons for stopping therapy, irrespective of line of treatment. Compared with first-line etanercept, participants were more likely to stop adalimumab [Hazard ratio (HR) 1.16, 95% CI: 1.04, 1.29] and infliximab (HR 1.77, 95% CI: 1.46, 2.16). No differences were seen for other b/tsDMARDs. For second-line therapies compared with etanercept, the risk of stopping was lower for tocilizumab (HR 0.41, 95% CI: 0.25, 0.70), rituximab (HR 0.51, 95% CI: 0.30, 0.85) and tofacitinib (HR 0.29, 95% CI: 0.15, 0.57). Participants taking rituximab, tocilizumab and tofacitinib were also less likely to stop third-line therapy in comparison with participants taking etanercept. CONCLUSIONS: Switching between b/tsDMARDs was common among ARAD participants with RA, most commonly due to inefficacy or adverse effects. Durability of exposure and reasons for switching varied between b/tsDMARDs.

Pediatric Emergency Department Return Visits Within 72 Hours: Caregivers' Motives and Analysis of Ethnic and Primary Language Disparities.

OBJECTIVES: In the United States, approximately 2.2% to 5% of children discharged from the emergency department (ED) return within 72 hours. There is limited literature examining caregivers' reasons for return to the ED, and none among Hispanics and Spanish-speaking caregivers. We sought to examine why caregivers of pediatric patients return to the ED within 72 hours of a prior ED visit, and assess roles of ethnicity and primary language. METHODS: A previously validated survey was prospectively administered to caregivers returning to the ED within 72 hours of discharge at a freestanding, tertiary care, children's hospital over a 7-month period. Reasons for return to the ED, previous ED discharge processes, and events since discharge were summarized according to Hispanic ethnicity, and English or Spanish language preference, and compared using the Fisher exact test. RESULTS: Among 499 caregiver surveys analyzed, caregivers returned mostly because of no symptom improvement (57.5%) and worsening condition (35.5%), with no statistically significant differences between Hispanic/non-Hispanic ethnicity, or English/Spanish preference. Most (85.2%) caregivers recalled reasons to return to the ED. Recall of expected duration until symptom improvement was significantly higher among Hispanic (60.4%) versus non-Hispanic (52.1%) (P = 0.003), and for Spanish- (68.9%) versus English-speaking (54.6%) (P = 0.04), caregivers. CONCLUSIONS: Most caregivers returned to the ED because their child's condition was not better or had worsened. Ethnicity and language were not associated with variations in reasons for return. Non-Hispanic and English-speaking caregivers were less likely to recall being informed of time to improvement and may require additional intervention.

Healthcare access and attitudes towards telehealth during the early phase of the COVID-19 pandemic among an Australian cohort with inflammatory arthritis.

Community restrictions due to COVID-19 have changed healthcare, including increased telehealth use. During the early pandemic phase, a cohort of Australian patients with inflammatory arthritis was surveyed. Self-reported access to healthcare was maintained and physical health was more likely to be self-rated poorly than mental health. There was a high level of support for telehealth during and after the pandemic.

Oral Complementary Medicine Use among People with Inflammatory Arthritis: An Australian Rheumatology Association Database Analysis.

OBJECTIVES: To describe oral complementary medicine (CM) use in people with inflammatory arthritis, associations with use, and changes in use over time. METHODS: Demographic, clinical, and patient-reported outcome data from 5,630 participants with rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PsA), and juvenile idiopathic arthritis (JIA) were extracted from the Australian Rheumatology Association Database (ARAD), a national observational database. CM use at entry into ARAD was ascertained for participants recruited between 2002 and 2018. CM was categorised according to the NIH/Cochrane schema (fatty acids, herbs, or supplements). Logistic regression was used to assess associations between demographic characteristics and CM use. Change in CM use between 2006 and 2016 was investigated using a nonparametric test for trend of rate by year. RESULTS: 2,156 (38.3%) ARAD participants were taking CM at enrolment (RA: 1,502/3,960 (37.9%), AS: 281/736 (38.2%), PsA: 334/749 (44.6%), and JIA: 39/185 (21.1%)). CM use was more prevalent in women (OR 1.3; 95% CI: 1.13-1.50), those with tertiary education (OR 1.32; 95% CI: 1.13-1.55), private health insurance (OR 1.26; (95% CI: 1.10-1.44), drinking alcohol sometimes (OR 1.22; 95% CI: 1.05-1.43), poorer function (HAQ) (OR 1.13; 95% CI: 1.02-1.24), use of NSAID (OR 1.32; 95% CI 1.17-1.50), weak (OR 1.21; 95% CI 1.05-1.41) but not strong opioids, and less prevalent in current smokers (OR 0.76; 95%: CI 0.63-0.91). CM use was not associated with pain, disease activity, or quality of life. The most common CMs were fish oils (N = 1,489 users) followed by glucosamine (N = 605). Both declined in use over time between 2006 and 2016 (27.5% to 21.4%, trend p = 0.85 and 15.5% to 6.4%, trend p < 0.01), respectively. CONCLUSION: Oral CM use is common among Australians with inflammatory arthritis. Its use is greater among women and those with tertiary education. Fish oil and glucosamine, the most common CMs, both declined in use over time.

In vivo assessment of respiratory burst inhibition by xenobiotic exposure using larval zebrafish.

Currently, assessment of the potential immunotoxicity of a given agent involves a tiered approach for hazard identification and mechanistic studies, including observational studies, evaluation of immune function, and measurement of susceptibility to infectious and neoplastic diseases. These studies generally use costly low-throughput mammalian models. Zebrafish, however, offer an excellent alternative due to their rapid development, ease of maintenance, and homology to mammalian immune system function and development. Larval zebrafish also are a convenient model to study the innate immune system with no interference from the adaptive immune system. In this study, a respiratory burst assay (RBA) was utilized to measure reactive oxygen species (ROS) production after developmental xenobiotic exposure. Embryos were exposed to non-teratogenic doses of chemicals and at 96 h post-fertilization, the ability to produce ROS was measured. Using the RBA, 12 compounds with varying immune-suppressive properties were screened. Seven compounds neither suppressed nor enhanced the respiratory burst; five reproducibly suppressed global ROS production, but with varying potencies: benzo[a]pyrene, 17ß-estradiol, lead acetate, methoxychlor, and phenanthrene. These five compounds have all previously been reported as immunosuppressive in mammalian innate immunity assays. To evaluate whether the suppression of ROS by these compounds was a result of decreased immune cell numbers, flow cytometry with transgenic zebrafish larvae was used to count the numbers of neutrophils and macrophages after chemical exposure. With this assay, benzo[a]pyrene was found to be the only chemical that induced a change in the number of immune cells by increasing macrophage but not neutrophil numbers. Taken together, this work demonstrates the utility of zebrafish larvae as a vertebrate model for identifying compounds that impact innate immune function at non-teratogenic levels and validates measuring ROS production and phagocyte numbers as metrics for monitoring how xenobiotic exposure alters the innate immune system.

Disruption of Trim9 function abrogates macrophage motility in vivo.

The vertebrate immune response comprises multiple molecular and cellular components that interface to provide defense against pathogens. Because of the dynamic complexity of the immune system and its interdependent innate and adaptive functionality, an understanding of the whole-organism response to pathogen exposure remains unresolved. Zebrafish larvae provide a unique model for overcoming this obstacle, because larvae are protected against pathogens while lacking a functional adaptive immune system during the first few weeks of life. Zebrafish larvae were exposed to immune agonists for various lengths of time, and a microarray transcriptome analysis was executed. This strategy identified known immune response genes, as well as genes with unknown immune function, including the E3 ubiquitin ligase tripartite motif-9 (Trim9). Although trim9 expression was originally described as "brain specific," its expression has been reported in stimulated human Mϕs. In this study, we found elevated levels of trim9 transcripts in vivo in zebrafish Mϕs after immune stimulation. Trim9 has been implicated in axonal migration, and we therefore investigated the impact of Trim9 disruption on Mϕ motility and found that Mϕ chemotaxis and cellular architecture are subsequently impaired in vivo. These results demonstrate that Trim9 mediates cellular movement and migration in Mϕs as well as neurons.

Neutrophil transfer of miR-223 to lung epithelial cells dampens acute lung injury in mice.

Intercellular transfer of microRNAs can mediate communication between critical effector cells. We hypothesized that transfer of neutrophil-derived microRNAs to pulmonary epithelial cells could alter mucosal gene expression during acute lung injury. Pulmonary-epithelial microRNA profiling during coculture of alveolar epithelial cells with polymorphonuclear neutrophils (PMNs) revealed a selective increase in lung epithelial cell expression of microRNA-223 (miR-223). Analysis of PMN-derived supernatants showed activation-dependent release of miR-223 and subsequent transfer to alveolar epithelial cells during coculture in vitro or after ventilator-induced acute lung injury in mice. Genetic studies indicated that miR-223 deficiency was associated with severe lung inflammation, whereas pulmonary overexpression of miR-223 in mice resulted in protection during acute lung injury induced by mechanical ventilation or by infection with Staphylococcus aureus Studies of putative miR-223 gene targets implicated repression of poly(adenosine diphosphate-ribose) polymerase-1 (PARP-1) in the miR-223-dependent attenuation of lung inflammation. Together, these findings suggest that intercellular transfer of miR-223 from neutrophils to pulmonary epithelial cells may dampen acute lung injury through repression of PARP-1.

Mucins and Their Sugars. Critical Mediators of Hyperreactivity and Inflammation.

Excessive mucus causes severe airflow obstruction in fatal asthma. It is also present in mild to moderate disease, but is poorly understood and treated. Mucus overproduction is associated with dysregulated expression of the mucins MUC5AC and MUC5B. Whereas increased MUC5AC is a consistent finding, MUC5B varies-remaining stably produced in some patients but strongly repressed in others (>90%). Patients with lower MUC5B display worsened asthma phenotypes including airway hyperreactivity (AHR) to methacholine (MCh) and eosinophilic inflammation. To better understand the roles of mucins in asthma, we generated Muc5ac and Muc5b knockout ((-/-)) mice. AHR to MCh was abolished in antigen-challenged Muc5ac(-/-) mice, due to prevention of heterogeneous mucous plugging that occurred in allergic wild-type mice during MCh-induced bronchoconstriction. Thus, in addition to the established role of smooth muscle-mediated airway narrowing, Muc5ac is an essential noncontractile AHR component. We also found that, unlike Muc5ac(-/-) mice, Muc5b-deficient mice were not protected from asthma phenotypes. Furthermore, whereas inflammation was unaffected by Muc5ac deficiency, it was exaggerated in the absence of Muc5b. On the basis of these differential effects, we are now determining how asthma phenotypes are regulated by mucin isoform specificity. Glycosylation is dramatically different: Muc5ac is heavily fucosylated whereas Muc5b is mainly sialylated. Fucosylation increases mucus viscoelasticity, and FUT2, the enzyme that catalyzes mucin α1,2-fucosylation, is associated with severe asthma exacerbation risk. Sialylation is required for binding to siglec (sialic acid-binding immunoglobulin-like lectin) receptors on leukocytes. Eosinophils express Siglec-F (mouse) or Siglec-8 (human). Engagement by sialoside ligands induces eosinophil apoptosis, and Muc5b via sialylated termini that require the α2,3-sialyltransferase ST3Gal3 for synthesis binds Siglec-F and induces apoptosis in mouse eosinophils. Because Muc5b is required for host defense in mouse lungs, inhibiting MUC5AC while preserving or enhancing MUC5B functions may be effective for treating asthma.

The polymeric mucin Muc5ac is required for allergic airway hyperreactivity.

In asthma, airflow obstruction is thought to result primarily from inflammation-triggered airway smooth muscle (ASM) contraction. However, anti-inflammatory and smooth muscle-relaxing treatments are often temporary or ineffective. Overproduction of the mucin MUC5AC is an additional disease feature that, while strongly associated pathologically, is poorly understood functionally. Here we show that Muc5ac is a central effector of allergic inflammation that is required for airway hyperreactivity (AHR) to methacholine (MCh). In mice bred on two well-characterized strain backgrounds (C57BL/6 and BALB/c) and exposed to two separate allergic stimuli (ovalbumin and Aspergillus extract), genetic removal of Muc5ac abolishes AHR. Residual MCh responses are identical to unchallenged controls, and although inflammation remains intact, heterogeneous mucous occlusion decreases by 74%. Thus, whereas inflammatory effects on ASM alone are insufficient for AHR, Muc5ac-mediated plugging is an essential mechanism. Inhibiting MUC5AC may be effective for treating asthma and other lung diseases where it is also overproduced.

Asking about human papillomavirus vaccination and the usefulness of registry validation: a study of young women recruited using Facebook.

BACKGROUND: Australia was the first country to implement a government-funded National Human Papillomavirus (HPV) Vaccination Programme. We assessed HPV vaccine uptake comparing self-reported and Register validated estimates, and the knowledge and attitudes of young women with regards to HPV vaccination post-implementation of the programme. METHODS: Females, aged 16-25 years living in Victoria, Australia, were recruited using targeted advertising on Facebook from May to September 2010, to complete a web-based questionnaire. RESULTS: Geographic distribution, Indigenous and socio-economic status of the 278 participants were representative of the target population. Overall, 210/278 (76%) had heard of HPV vaccines, with 162/278 (58%) reporting receipt of at least one dose of vaccine, and 54 (19%) unsure. Verification of HPV vaccination status of 142 consenting participants (51%) showed 71% had received at least one dose. Main reasons for vaccination were for protection against HPV infection and cervical cancer (96%) and because it was free (87%), whereas unvaccinated women were uncertain of their eligibility (50%), concerned about adverse reactions (32%), or perceived that vaccination was not needed if they were monogamous (32%). CONCLUSION: The potential utility of a vaccination register in the context of a national programme is apparent from the large proportion of young women who were unsure of their vaccine status. HPV vaccine knowledge among participants was relatively high suggesting the national programme has successfully communicated to the majority of eligible women, the purpose and limitations of the vaccine. Vigilance is needed to ensure that young women follow through with Pap testing in vaccine eligible cohorts. The ongoing vaccination programme for pre-adolescent girls and boys should communicate to parents that those with one sexual partner can still acquire HPV and that the safety of the vaccine is now well demonstrated.

Antiinflammatory and Antimicrobial Effects of Thiocyanate in a Cystic Fibrosis Mouse Model.

Thiocyanate (SCN) is used by the innate immune system, but less is known about its impact on inflammation and oxidative stress. Granulocytes oxidize SCN to evolve the bactericidal hypothiocyanous acid, which we previously demonstrated is metabolized by mammalian, but not bacterial, thioredoxin reductase (TrxR). There is also evidence that SCN is dysregulated in cystic fibrosis (CF), a disease marked by chronic infection and airway inflammation. To investigate antiinflammatory effects of SCN, we administered nebulized SCN or saline to ß epithelial sodium channel (ßENaC) mice, a phenotypic CF model. SCN significantly decreased airway neutrophil infiltrate and restored the redox ratio of glutathione in lung tissue and airway epithelial lining fluid to levels comparable to wild type. Furthermore, in Pseudomonas aeruginosa-infected ßENaC and wild-type mice, SCN decreased inflammation, proinflammatory cytokines, and bacterial load. SCN also decreased airway neutrophil chemokine keratinocyte chemoattractant (also known as C-X-C motif chemokine ligand 1) and glutathione sulfonamide, a biomarker of granulocyte oxidative activity, in uninfected ßENaC mice. Lung tissue TrxR activity and expression increased in inflamed lung tissue, providing in vivo evidence for the link between hypothiocyanous acid metabolism by TrxR and the promotion of selective biocide of pathogens. SCN treatment both suppressed inflammation and improved host defense, suggesting that nebulized SCN may have important therapeutic utility in diseases of both chronic airway inflammation and persistent bacterial infection, such as CF.