A263 MICE CHALLENGED WITH DNBS FOUR DAYS AFTER INFECTION WITH THE RAT TAPEWORM HYMENOLEPIS DIMINUTA ARE PROTECTED FROM COLITIS

Background

Helminth therapy for colitis is supported by data from murine models, including infection with H. diminuta inhibiting dinitrobenzene sulphonic-acid (DNBS)-induced colitis. Considering H. diminuta as a candidate helminth therapy the kinetics of infection in the context of inflammation should be addressed. Reciprocally, it is important to know if colitis alters the immune response to the helminth.

Aims

1) Assess DNBS-colitis in mice infected 4-days previously with H. diminuta. 2) Determine in DNBS-induced colitis affects the outcome of infection with H. diminuta.

Methods

Male BALB/c mice were infected by gavage with five H. diminuta and four days later were challenged with DNBS (3 mg, ir.). Disease was assessed 3 days later (i.e. day 7-post H. diminuta) by colon length, disease activity score and histopathology (n=9–14 mice, 3 experiments). Alternatively, on day three post-DNBS, mice were infected with H. diminuta and worm infectivity and splenocyte Th2-cytokine production assessed at 8 days post-infection (n=5–9 mice, 1 experiment).

Results

Mice challenged with DNBS at 4-days post-infection were significantly protected from colitis, with 2/14 mice requiring humane euthanization for disease severity compared to 6/13 in the DNBS-only group. Splenocyte production of IL-4, IL-5 and IL-10 was increased in the H. diminuta-only group compared to control mice: DNBS-only treated mice showed reduced levels of all three cytokines and H. diminuta+DNBS mice had cytokine levels not different from H. diminuta-only infected mice. DNBS-colitis prior to infection did not affect the increase in systemic TH2 immunity evoked by H. diminuta, but did result in greater intestinal worm burdens.

Conclusions

The data suggest (1) the window of opportunity for H. diminuta to suppress colitis in a prophylactic regimen is at least 4–8 days post-infection, and (2) H. diminuta administered to mice at the peak of colitis severity mobilizes TH2 immunity that could promote quicker recovery from colitis.

Funding Agencies

CAG, CCC, NRCNSERC

A74 HELMINTH ANTIGENS OR REGULATORY MACROPHAGES REDUCE THE SEVERITY OF COLORECTAL CANCER

Background

Infection with helminth parasites is a potent stimulus of immunity, and murine model systems reveal that a bystander benefit of this response to helminths is suppression of colitis. Unraveling the mechanism of this inhibition of colitis, the regulatory macrophage has emerged as a cell of interest in ‘helminth therapy’. Given the relationship between inflammation and cancer – patients with inflammatory bowel disease (IBD) have a higher risk of colorectal cancer (CRC).

Aims

To test the hypothesis that intraperitoneal administration of excretory/secretory products from the tapeworm Taenia crassiceps (TcES) or IL-4-treated macrophages (M(IL-4)) (characteristic of the immune response to helminths) would affect the outcome of CRC.

Methods

CRC was induced in female BALB/c and male C57Bl/6 mice using azoxymethane (AOM) (10 mg, ip) and three cycles of Dextran sulfate sodium (DSS: 7 days, 1–2% wt./vol.) separated by 2 weeks of normal tap water. Following initiation of CRC, mice received TcES (200 μg, ip.) - or M(IL-4) (106, ip). On necropsy, CRC incidence, number, and size of the tumour were recorded and tumors assessed histologically.

Results

Mice receiving TcES or M(IL-4)s were substantially protected from AOM-DSS induced CRC, as shown by statistically significant reductions in tumor number and size, although the number of mice developing tumors was unchanged (n=4–8 mice). The suppression of CRC in TcES-treated mice correlated with reduced mobilization of STAT3 and NF-κB signaling cascades in the as determined by immunostaining and immunoblot of whole tissue extracts.

Conclusions

With the speculation that helminth-derived molecules or transfer of in vitro educated macrophages could be used to treat IBD comes the specter of the putative oncogenic effects of regulatory macrophages. Contrary to this, the data herein show that the TcES reduced CRC; and, that murine macrophages (M(IL4)) also actually limit the severity of inflammation-driven CRC by directly targeting the cancer cells or reducing the inflammatory stimulus. These findings add emphasis to the consideration of autologous regulatory macrophage transfer to treat IBD and CRC

Funding Agencies

CCCCONACYT (Mexico)

A47 ENTERIC TUFT CELL HYPERPLASIA FOLLOWING INFECTION WITH THE TAPEWORM HYMENOLEPIS DIMINUTA IS AFFECTED BY NEURONAL BUT NOT BACTERIAL FACTORS

Background

Tuft cells are a rare chemosensory population of the intestinal epithelium that detect intestinal parasitic nematodes and release IL-25 to mobilize innate lymphoid type 2 cells (ILC2), which then drive a Th2- dominant nematode expulsion response. Immunocompetent mice develop tuft cell hyperplasia in the small intestine during infection with Hymenolepis diminuta, a non-abrasive lumen dwelling small intestinal cestode parasite. Helminth infections are accompanied by alterations in sensory motor functions of the gut as well as the composition of the microbiota. It is poorly understood if tuft cell hyperplasia is regulated by these immunomodulatory influences.

Aims

To test if mice lacking (1) a functional adaptive immune system, (2) TRPV1+ gut-innervating sensory nerves and (3) a microbiome, display enteric tuft cell hyperplasia following infection with H. diminuta.

Methods

RAG-1-/- (male and female) and germ-free mice (n=3–6) were infected with 5 cysticercoids of H. diminuta and age matched non-infected mice served as control groups. Male C57BL/6j mice were treated with resiniferatoxin (RTX) to ablate TRPV1 +sensory neurons before infection. Mid-jejunum cryostat or paraffin embedded sections immunostained against doublecortin-like kinase -1 (DCLK-1) were blindly scored for tuft cell enumeration at 5–14 days post-infection.

Results

Tuft cell hyperplasia (~10-15-fold increase) was observed in the jejunum of wild-type mice at 11 days post infection with H. diminuta, by which time worms are expelled. Infected RAG-1-/- mice develop tuft cell hyperplasia of lesser magnitude than wild-type mice. Germ-free mice displayed tuft cell hyperplasia and kinetics of worm expulsion that were not different from wild-type mice. RTX-treated mice with confirmed loss of TRPV1+ nerve fibers in the gut and their cell soma in the dorsal root and nodose ganglia, had a greater increase (~2-fold) in tuft cell numbers compared to H. diminuta-only mice at 11 days post-infection.

Conclusions

Knowledge of how the host senses helminths in the gut lumen is central to the host-parasite interaction. Using the H. diminuta-mouse model system we find that tuft cell hyperplasia is largely, but not entirely dependent on adaptive immunity, occurs independent of the gut microbiota, and, intriguingly, TRPV1+ sensory nerves appear to act as a brake on the system, limiting the magnitude of the hyperplasia.

Funding Agencies

CIHRNSERC, Henry Koopman’s Memorial scholarship

A264 HELMINTH-INFECTION MOBILIZES HOST AND MICROBIAL FACTORS THAT CO-OPERATE TO SUPPRESS CHEMICAL-INDUCED COLITIS IN MICE

Background

Infection with helminth parasites suppresses inflammation in murine model systems; for example, IL-10 is important in Hymenolepis diminuta-inhibition of DNBS-induced colitis. Bacteria-derived products can have anti-inflammatory effects. Given that infection with H. diminuta, or other parasitic worms, results in perturbation of the gut microbiota, the present study tested a role for bacteria in helminth-suppression of colitis by assessing reciprocity between IL-10 and butyrate signaling in the amelioration of colitis.

Aims

To determine if a functional relationship exists between IL-10 and butyrate in the inhibition of colitis observed following infection with the lumen-dwelling tapeworm, Hymenolepis diminuta.

Methods

Colitis was induced in male BALB/c mice by intra-rectal dinitrobenzene sulphonic acid (DNBS) (3 mg/~22g mouse), with necropsy and assessment 3 days later. Mice received either infection with five H. diminuta cysticercoids by gavage or daily butyrate enemas or acetate in their drinking water. Immunostaining assessed IL-10R protein expression on formalin-fixed sections of colon. The murine IEC4.1 epithelial cell line and epithelial organoids were treated with butyrate and mRNA for the IL10Rα chain assessed, as was colonic tissue from mice.

Results

Mice infected with H. diminuta or receiving butyrate enemas (n=8–12) were protected from DNBS-induced colitis as gauged by colon length, and macroscopic disease and histopathology scores. Addition of acetate to the drinking water resulted in a more modest anti-colitic effect. Suppression of colitis was accompanied by increased epithelial expression of IL-10 in butyrate- and H. diminuta-treated mice, with the later also showing upregulation of the IL-10R on lamina propria cells; an effect negated by co-treating the mice with broad spectrum antibiotics. In vitro analyses revealed increased IL10Rα mRNA in butyrate-treated epithelia (n=4).

Conclusions

This study begins to tease apart the host (i.e. IL-10) and bacterial (i.e. butyrate) molecules that mediate H. diminuta-evoked suppression of colitis in a murine model. These proof-of-principle data suggest that knowledge of the individual patient (i.e. immunological basis of their disease and their microbiota) may be a critical determinant of the success or failure of helminth therapy.

Funding Agencies

CAG, CCCNSERC

Association of plasma C-reactive protein with ischaemic stroke: a Mendelian randomization study

BACKGROUND AND PURPOSE

Elevated C-reactive protein (CRP) is associated with an increased risk of ischaemic stroke (IS). However, the causality of this association is uncertain. The aim is to investigate whether genetically raised plasma CRP concentration levels are associated with IS on the basis of the Mendelian randomization method.

METHODS

Based on the National Center for Biotechnology Information single nucleotide polymorphism (SNP) database, the Chinese online genetic database as well as previously published studies, four CRP-associated SNP alleles (rs1130864, rs1205, rs876537 and rs3093059) with minor allele frequency ≥0.15 were selected and the concentration levels of CRP were measured in 378 first-ever IS patients and 613 healthy controls.

RESULTS

Three SNPs were chosen and used as instrumental variables. The adjusted odds ratios (ORs) [95% confidence interval (95% CI)] of IS per addition of the modelled allele were 1.07 (0.79-1.45) for rs876537, 0.99 (0.73-1.35) for rs1205 and 1.08 (0.71-1.65) for rs3093059. The OR (95% CI) of IS for plasma CRP ≥2.0 mg/l was 2.19 (1.06-4.53) compared with <2.0 mg/l. The adjusted OR (95% CI) of IS per genetically predicted 10% higher CRP concentration, based on the three SNPs as the instruments, was 1.02 (0.94-1.11). Furthermore, similar results were obtained with adjusted ORs (95% CI) of 1.00 (0.88-1.13) and 1.04 (0.93-1.16), respectively, for large-artery atherosclerosis and small-artery occlusion per genetically predicted 10% higher CRP concentration.

CONCLUSIONS

This Mendelian randomization study provides no clear support that elevated CRP concentration is causally associated with the risk of IS.

Cytology cell blocks are suitable for immunohistochemical testing for PD-L1 in lung cancer

Background

PD-L1 immunohistochemistry (IHC) testing is usually carried out on tissue blocks from core needle biopsy or surgical resections. In this study, we assessed the feasibility of using cytology cell blocks for PD-L1 IHC assay.

Methods

A total of 1419 consecutive cases of non-small-cell lung cancer (NSCLC), including 371 cytology cell blocks, 809 small biopsies, and 239 surgical specimens, were included in the study. The cytology cell blocks were prepared with formalin only, methanol/alcohol only or both. PD-L1 expression was examined by staining with Dako PD-L1 IHC 22C3 pharmDx kit. A Tumor Proportion Score (TPS) was categorized as <1%, 1%-49% and ≥50% tumor cells. A total of 100 viable tumor cells were required for adequacy.

Results

Of the cytology cell blocks, 92% of the specimens had an adequate number of tumor cells, not significantly different from small biopsies. The rate of TPS ≥50% differed between sample types and was observed in 42% of cytology cell blocks versus 36% of small biopsies (P = 0.04), and 29% of surgical resections (P = 0.001). The fixative methods did not affect the immunostaining, with overall PD-L1 high expression (TPS ≥50%) rates of 42% in formalin-fixed specimens versus 40% in specimens with combined fixation by methanol/alcohol and formalin (NS). The PD-L1 high expression rate was not associated with EGFR, ALK or KRAS molecular alterations. Higher stage (IV) was associated with higher PD-L1 TPS (P= 0.001).

Conclusion

Our results show that when the TPS ≥50% is used as the end point, PD-L1 IHC performs well with cytology cell blocks. Cell blocks should be considered as a valuable resource for PD-L1 testing in advanced NSCLC. The clinical significance of higher PD-L1 IHC scores in cytology specimens needs to be evaluated prospectively.

Proliferation effects of cinnamon extract on human HeLa and HL-60 tumor cell lines

OBJECTIVE

To investigate the possible anti-cancer properties of cinnamon extract on two human tumor cell lines, HeLa cells and HL-60 cells.

MATERIALS AND METHODS

Two human tumor cell lines, HeLa cells and HL-60 cells, were exposed to increased concentrations of an extract prepared from cinnamon. The cell proliferation and cell cycle distribution were evaluated using MTT assay and flow cytometry, respectively. The possible action mechanism was also investigated by Western blot.

RESULTS

The results showed that cinnamon extract strongly inhibited tumor cell proliferation in a dose-dependent manner and exhibited dramatic increases in the percentage of cells in G2/M in parallel with exposure to increasing concentration of cinnamon extract. The Western blot results showed that cinnamon extract reduced the cyclin A, cyclin B1, ERK2, and p-ERK proteins expression.

CONCLUSIONS

Our study suggested that cinnamon extract inhibit the tumor cell survival by both down-regulated their target cell cycle regulation molecules and mitosis regulation molecules.

HMGA1-mediated miR-671-5p targets APC to promote metastasis of clear cell renal cell carcinoma through Wnt signaling

This study aimed to investigate the effect of miR-671-5p on metastasis of clear cell renal cell carcinoma (ccRCC) and underlying mechanism involved. The migration and invasion of ccRCC cells were determined by transwell and boyden assays in vitro and in vivo. Genes mRNA and protein expression were detected by quantitative polymerase chain reaction (qPCR) and western blot analysis, respectively. The target gene of miRNA was confirmed by luciferase reporter assays. Transcriptional regulation of miRNA by transcription factor was detected by chromatin immunoprecipitation assay (ChIP). The expression of miRNA in clinical specimens were detected by in situ hybridization (ISH). miR-671-5p promoted migration and invasion of ccRCC in vivo and in vitro. Moreover, miR-671-5p directly targeted APC to activate Wnt signaling, thus inducing the epithelial-mesenchymal transition (EMT) in ccRCC. Intriguingly, miR-671-5p expression was transcriptionally enhanced by HMGA1. Consistently, bioinformatics analysis suggested that HMGA1 was positively correlated with miR-671 expression, however, miR-671 was negatively correlated with APC. In situ hybridization analysis showed that miR-671-5p was upregulated in ccRCC compared with paracarcinoma and correlated with poor prognosis of ccRCC patients. In addition, univariate and multivariate analysis indicated that miR-671-5p expression was an independent prognostic factor for overall survival in ccRCC patients. Our data suggest that miR-671-5p is a tumor enhancer in regulating of ccRCC metastasis, and miR-671-5p may be utilized as a factor for the clinical diagnosis and prognosis of ccRCC.

228Long-term safety and effectiveness of mavacamten in symptomatic obstructive hypertrophic cardiomyopathy (oHCM) patients (pts): update from PIONEER open-label extension (PIONEER-OLE) study

Background

In a phase 2 PIONEER-HCM study, pts with symptomatic, obstructive hypertrophic cardiomyopathy (oHCM) showed improvement in left ventricular outflow tract (LVOT) obstruction, exercise capacity, and symptoms after 12 wk of treatment with the novel myosin modulator, mavacamten (Mava).

Purpose

To examine the long-term safety and effectiveness of Mava in PIONEER-OLE study

Methods

PIONEER-OLE (NCT03496168) is an ongoing 2-y multicenter study for adults with symptomatic oHCM who completed PIONEER-HCM (NCT02842242). The starting dose of Mava is 5 mg/d with titration at wk 6 to an individualized therapeutic dose (5, 10, or 15 mg). Evaluations are at wk 4, 6, 8, 12 and every 12 wk thereafter to monitor LV ejection fraction (LVEF), LVOT gradient, New York Heart Association (NYHA) class, NT-proBNP, drug concentration, and safety.

Results

13 pts (mean age, 57.8 y; 9 male; 12 on beta-blockers) were enrolled. Mean baseline LVOT obstruction and LVEF, and wk 12 changes from baseline, were similar to those in PIONEER-HCM (Table). Mava significantly reduced resting and provoked LVOT gradients and NT-proBNP at wk 12 and 24 compared with baseline (P<0.004). Of 10 pts who reached wk 24, 8 reported improvement in NYHA class (1 improved Class III to II; 7 improved Class II to I), and 2 pts remained Class II. Mava has been well tolerated up to 40 wk; 31 adverse events (AEs; 22 mild, 5 moderate) were reported in 8 pts; 1 pt had 3 severe and 1 serious AE (cholangiocarcinoma); all AEs were unrelated to study drug.

Results from PIONEER-OLE Parameter PIONEER-HCMa PIONEER-OLE Baseline Wk 12 Baselineb Wk 12 Change at Wk 12 Wilcoxon Signed Wk 24 Change at Wk 24 Wilcoxon Signed Mean ± SD Mean ± SD Mean ± SD Mean ± SD Mean ± SD Rank Mean ± SD Mean ± SD Rank (n=13) (n=13) (n=13)c (n=12)c (n=12)c P value (n=10)c (n=10)c P value LVOT Rest gradient, mmHg 69.7±53.9 27.8±31.3 67.3±42.8 12.0±5.4 −57.9±43.2 0.0005 10.5±4.8 −66.6±42.4 0.0020 LVOT Valsalva gradient, mmHg 93.7±55.6 36.8±37.5 89.9±30.7 (n=12) 23.6±20.0 −66.4±35.3 (n=11) 0.0020 21.1±11.5 −67.3±33.5 (n=9) 0.0039 LVEF, % 73.0±5.6 64.6±10.5 72.0±4.9 67.6±7.2 −4.4±5.5 0.0269 68.2±6.5 −3.2±3.3 0.0195 NT-proBNP, pg/mL 1601.3±2782 (n=12) 684±980 1836±2886 181±211 −1759±2789 0.0005 170±225 −2128±3104 0.0039 Data extraction date January 24, 2019. aCombined results shown for pts from PIONEER-HCM originally in cohort A (n=5) and cohort B (n=8). bBaseline in PIONEER-OLE occurred 6–18 months after completion of PIONEER-HCM. cNumber of pts with data available for analysis, unless otherwise specified.

Conclusion

Despite management with current therapies, pts enrolled in PIONEER-OLE with similar levels of obstruction and hypercontractility as in PIONEER-HCM. In this longest observation period, Mava significantly reduced obstruction (LVOT gradient) in pts with oHCM beyond standard HCM therapy, while maintaining normal LVEF and improving symptoms.

Acknowledgement/Funding

MyoKardia

Microbial community responses reduce soil carbon loss in Tibetan alpine grasslands under short-term warming

Changes in labile carbon (LC) pools and microbial communities are the primary factors controlling soil heterotrophic respiration (R_h ) in warming experiments. Warming is expected to initially increase R_h but studies show this increase may not be continuous or sustained. Specifically, LC and soil microbiome have been shown to contribute to the effect of extended warming on R_h . However, their relative contribution is unclear and this gap in knowledge causes considerable uncertainty in the prediction of carbon cycle feedbacks to climate change. In this study, we used a two-step incubation approach to reveal the relative contribution of LC limitation and soil microbial community responses in attenuating the effect that extended warming has on R_h . Soil samples from three Tibetan ecosystems-an alpine meadow (AM), alpine steppe (AS), and desert steppe (DS)-were exposed to a temperature gradient of 5-25°C. After an initial incubation period, soils were processed in one of two methods: (a) soils were sterilized then inoculated with parent soil microbes to assess the LC limitation effects, while controlling for microbial community responses; or (b) soil microbes from the incubations were used to inoculate sterilized parent soils to assess the microbial community effects, while controlling for LC limitation. We found both LC limitation and microbial community responses led to significant declines in R_h by 37% and 30%, respectively, but their relative contributions were ecosystem specific. LC limitation alone caused a greater R_h decrease for DS soils than AMs or ASs. Our study demonstrates that soil carbon loss due to R_h in Tibetan alpine soils-especially in copiotrophic soils-will be weakened by microbial community responses under short-term warming.

P14.33 Adult brainstem gliomas in neurofibromatosis type 1 (NF1)

BACKGROUND

The brainstem is the second location of brain tumors after optic pathways in NF1. In NF1 children, brainstem gliomas are usually indolent and have a better prognosis than their counterparts in non NF1 children. In contrast, the natural history and prognosis of adult brainstem gliomas in NF1 are nearly unknown.

MATERIAL AND METHODS

We conducted a retrospective analysis of medical records and MRI of adult NF1 patients followed for a brainstem glioma in 8 centers over a 17 years period (2000–2017). Clinical and imaging characteristics, management and outcome were analyzed.

RESULTS

Twenty five patients were included in the study (13 males and 12 females) with a median age of 32 (range 17–58). The epicenter of the tumor was located into the pons n=13 (52%), the mesencephalon n=7 (28%), the medulla oblongata n=5 (20%). On MRI, contrast enhancement was seen in 19 tumors (76%). Pathological examination was available in 13 tumors (52%) and showed a high grade astrocytoma (III or IV) in 9 tumors. Five patients were asymptomatic, 3 remained asymptomatic during the follow-up (median follow-up: 86 months, range 22–124). Twenty patients were symptomatic with a median duration of symptom of 2.5 months (range 1–10) before diagnosis. Among these symptomatic patients, 15 died from tumor progression despite treatment with radiation therapy and or chemotherapy. The median overall survival of symptomatic patients was 36 months.

CONCLUSION

Brainstem gliomas are rare tumors in adults with NF1. Unlike children, adult brainstem gliomas seem to have an unexpected poor prognosis, suggesting the disease may be different in adulthood.

Discoidin domain receptor 1 interactions with myosin motors contribute to collagen remodeling and tissue fibrosis

Discoidin Domain Receptor (DDR) genes and their homologues have been identified in sponges, worms and flies. These genes code for proteins that are implicated in cell adhesion to matrix proteins. DDRs are now recognized as playing central regulatory roles in several high prevalence human diseases, including invasive cancers, atherosclerosis, and organ fibrosis. While the mechanisms by which DDRs contribute to these diseases are just now being delineated, one of the common themes involves cell adhesion to collagen and the assembly and organization of collagen fibers in the extracellular matrix. In mammals, the multi-functional roles of DDRs in promoting cell adhesion to collagen fibers and in mediating collagen-dependent signaling, suggest that DDRs contribute to multiple pathways of extracellular matrix remodeling, which are centrally important processes in health and disease. In this review we consider that interactions of the cytoplasmic domains of DDR1 with cytoskeletal motor proteins may contribute to matrix remodeling by promoting collagen fiber alignment and compaction. Poorly controlled collagen remodeling with excessive compaction of matrix proteins is a hallmark of fibrotic lesions in many organs and tissues that are affected by infectious, traumatic or chemical-mediated injury. An improved understanding of the mechanisms by which DDRs mediate collagen remodeling and collagen-dependent signaling could suggest new drug targets for treatment of fibrotic diseases.