Unleashing T cell anti-tumor immunity: new potential for 5-Nonloxytryptamine as an agent mediating MHC-I upregulation in tumors

BACKGROUND

New therapies are urgently needed in melanoma, particularly in late-stage patients not responsive to immunotherapies and kinase inhibitors. To uncover novel potentiators of T cell anti-tumor immunity, we carried out an ex vivo pharmacological screen and identified 5-Nonyloxytryptamine (5-NL), a serotonin agonist, as increasing the ability of T cells to target tumor cells.

METHODS

The pharmacological screen utilized lymphocytic choriomeningitis virus (LCMV)-primed splenic T cells and melanoma B16.F10 cells expressing the LCMV gp33 CTL epitope. In vivo tumor growth in C57BL/6 J and NSG mice, in vivo antibody depletion, flow cytometry, immunoblot, CRISPR/Cas9 knockout, histological and RNA-Seq analyses were used to decipher 5-NL's immunomodulatory effects in vitro and in vivo.

RESULTS

5-NL delayed tumor growth in vivo and the phenotype was dependent on the hosts' immune system, specifically CD8+ T cells. 5-NL's pro-immune effects were not directly consequential to T cells. Rather, 5-NL upregulated antigen presenting machinery in melanoma and other tumor cells in vitro and in vivo without increasing PD-L1 expression. Mechanistic studies indicated that 5-NL's induced MHC-I expression was inhibited by pharmacologically preventing cAMP Response Element-Binding Protein (CREB) phosphorylation. Importantly, 5-NL combined with anti-PD1 therapy showed significant improvement when compared to single anti-PD-1 treatment.

CONCLUSIONS

This study demonstrates novel therapeutic opportunities for augmenting immune responses in poorly immunogenic tumors.

Functional Analysis of a Novel, Non-Canonical RPGR Splice Variant Causing X-Linked Retinitis Pigmentosa

X-linked retinitis pigmentosa (XLRP) caused by mutations in the RPGR gene is one of the most severe forms of RP due to its early onset and intractable progression. Most cases have been associated with genetic variants within the purine-rich exon ORF15 region of this gene. RPGR retinal gene therapy is currently being investigated in several clinical trials. Therefore, it is crucial to report and functionally characterize (all novel) potentially pathogenic DNA sequence variants. Whole-exome sequencing (WES) was performed for the index patient. The splicing effects of a non-canonical splice variant were tested on cDNA from whole blood and a minigene assay. WES revealed a rare, non-canonical splice site variant predicted to disrupt the wildtype splice acceptor and create a novel acceptor site 8 nucleotides upstream of RPGR exon 12. Reverse-transcription PCR analyses confirmed the disruption of the correct splicing pattern, leading to the insertion of eight additional nucleotides in the variant transcript. Transcript analyses with minigene assays and cDNA from peripheral blood are useful tools for the characterization of splicing defects due to variants in the RPGR and may increase the diagnostic yield in RP. The functional analysis of non-canonical splice variants is required to classify those variants as pathogenic according to the ACMG's criteria.

An altered balance of plasma arginine metabolites is associated with increased thickness of the coronary intima-media complex in the adjacent to the culprit segment of an infarct-related artery

Background

The biomarkers of atherosclerosis remain insufficiently understood.

Purpose

We sought to investigate whether an altered balance of arginine metabolites in patients following myocardial infarction (MI) is associated with remodeling of the adjacent to the culprit segments of an infarct-related artery (IRA) and with clinical outcomes.

Methods

Arginine and its metabolites including ornithine, citrulline, proline and asymmetric dimethylarginine were measured using liquid chromatography and tandem mass spectrometry in 85 consecutive ST-segment elevation MI patients upon admission and at 6-month follow-up and were compared with morphology of the adjacent to the culprit proximal and distal 10-mm segments of IRA assessed with optical coherence tomography. A composite ischemic event was defined as death, recurrent MI, stroke, or unplanned percutaneous coronary intervention.

Results

The ratios of citrulline/ornithine and citrulline/arginine decreased 5.22 and 2.20 times (both P<0.001) respectively, while the ornithine/arginine index (I_O/A) increased 2.96 times (P<0.001) following ischemia compared with stable follow-up, indicating the enhanced arginase activity over nitric oxide synthase (NOS) in acute phase of STEMI. Follow-up I_O/A correlated with the mean intima-media (R=0.34, P=0.003, Figure 1A) and intima (R=0.30, P=0.008) diameter of an adjacent to the culprit IRA segment. By multivariate analysis, apart from male gender (P<0.001) and diabetes mellitus (P=0.02), a higher follow-up I_O/A was associated with the larger mean intima-media diameter of an adjacent to the culprit IRA segments (coefficient 0.218, 95% confidence interval 0.040–0.397, P=0.017, per 0.01). Within the median follow-up of 25 (19–35) months, ischemic composite endpoint was found in 13 (15.3%) patients. The follow-up I_O/A reached the area under the ROC curve of 0.78 (95% confidence interval 0.66–0.91, P=0.005) for prediction of composite ischemic endpoint with a cut-off value of ≥0.57, and a sensitivity of 72.3% and specificity of 80.0% (Figure !B).

Conclusions

Our findings provide arguments that during the acute phase of MI, arginine metabolism is shifted from NOS towards arginase, as compared to 6-month stable conditions. Simultaneously, the enhanced residual arginase activity over NOS in chronic phase was correlated with a higher thickness of intima or intima-media in the adjacent to the culprit segment within the IRA, and was also associated with unfavorable clinical outcomes.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grant of the National Science Center of Poland (Number 2016/21/B/NZ5/01378 to J.Z.)

The effects of Kaatsu training on an acute angiogenic response in post-interventional rehabilitation of peripheral arterial disease patients

Funding Acknowledgements

Type of funding sources: None.

Background

Atherosclerosis as the main cause of death in adults is one of the greatest challenges of modern medicine. Peripheral arterial disease (PAD) is a condition with worldwide increasing occurrence affecting more than 20% of Europeans and North Americans in the age group> 55 years, and in the group> 70 years of age affects as much as 60% of the population. Among many treatment forms the endovascular treatment remains the most common treatment method, however the most non-invasive, but still effective is rehabilitation by physical training. Recently, innovative solutions have been introduced concerning this form of treatment by combining anaerobic interval exercises with venous blood flow restriction (BFR) and cooling.

Purpose

The aim of the research is to evaluate the endothelial and angiogenic response to the aforementioned type of exercise.

Methods

Study was divided into 2 stages: with healthy volunteers and non-CLI patients. 35 healthy volunteers  were enrolled into the 1st stage. They performed a 21-minute interval training using a cross trainer with cooling liquid pressure cuffs (arms: 40 mmHg; legs: 65 mmHg) providing vein occlusion and cooling seat. Angiogenic processes and endothelial functions were monitored by laboratory parameters - vascular endothelial growth factor (VEGF), clusters of differentiation (CD31, CD34) as well as imaging examinations – flow mediated dilatation (FMD), stiffness index (SI), reflexion index (RI), reactive hyperaemia index (RHI) and augmentation index (AI). All measurements were performed before, as well as 20 to 30 minutes after the training.

Results

All of the laboratory parameters were significantly elevated after the BFRT- CD34 (ΔCD34: 0.13 vs 0.01 p < 0,001), CD31 (ΔCD31: 1.11 vs 0.37 p < 0,001) and VEGFR (ΔVEGFR: 6.35 vs 2.86 p < 0.001).Only FMD and RI of all endothelial imaging parametrs significantly changed after BFRT compared to regular training (FMD: 8.9% vs 7.41 p < 0,001 ΔFMD: 2.89 vs 1.33 p < 0,01; RI: 63.43 vs 69.49 p < 0,001, ΔRI: 4.0 vs 2.0, p > 0,001). RHI and AI weren’t significantly influenced by any exercise type.

Conclusions

BFR training successfully stimulates acute angiogenic response and moderately influences certain endothelial functions. This 1st stage results are being now implemented into the 2nd part of project involving PAD patients.

Whole Exome Sequencing in Coloboma/Microphthalmia: Identification of Novel and Recurrent Variants in Seven Genes

Coloboma and microphthalmia (C/M) are related congenital eye malformations, which can cause significant visual impairment. Molecular diagnosis is challenging as the genes associated to date with C/M account for only a small percentage of cases. Overall, the genetic cause remains unknown in up to 80% of patients. High throughput DNA sequencing technologies, including whole-exome sequencing (WES), are therefore a useful and efficient tool for genetic screening and identification of new mutations and novel genes in C/M. In this study, we analyzed the DNA of 19 patients with C/M from 15 unrelated families using singleton WES and data analysis for 307 genes of interest. We identified seven novel and one recurrent potentially disease-causing variants in CRIM1, CHD7, FAT1, PTCH1, PUF60, BRPF1, and TGFB2 in 47% of our families, three of which occurred de novo. The detection rate in patients with ocular and extraocular manifestations (67%) was higher than in patients with an isolated ocular phenotype (46%). Our study highlights the significant genetic heterogeneity in C/M cohorts and emphasizes the diagnostic power of WES for the screening of patients and families with C/M.

Dementia screening in elderly high-risk patients following heart failure decompensation may predict unfavorable long-term clinical outcomes

Background

Recently heart failure (HF) has been found to be a new dementia risk factor, nevertheless their relations in patients following HF decompensation remain unknown.

Purpose

We sought to investigate whether a screening diagnosis for dementia (SDD) in this high-risk population may predict unfavorable long-term clinical outcomes.

Methods

142 patients following HF decompensation requiring hospitalization were enrolled. Within a median time of 55 months all patients were screened for dementia with ALFI-MMSE scale whereas their compliance was assessed with the Morisky Medication Adherence Scale. Any incidents of myocardial infarction, coronary revascularization, stroke or transient ischemic attack (TIA), revascularization, HF hospitalization and bleedings during follow-up were collected.

Results

SDD was established in 37 patients (26%) based on the result of an ALFI-MMSE score of <17 points. By multivariate analysis the lower results of the ALFI-MMSE score were associated with a history of stroke/TIA (β=−0.29, P<0.001), peripheral arterial disease (PAD) (β=−0.20, P=0.011) and lower glomerular filtration rate (β=0.24, P=0.009). During the follow-up, patients with SDD were more often rehospitalized following HF decompensation (48.7% vs 28.6%, P=0.014) than patients without SDD, despite a similar level of compliance (P=0.25). Irrespective of stroke/TIA history, SDD independently increased the risk of rehospitalization due to HF decompensation (HR 2.22, 95% CI 1.23–4.01, P=0.007).

Conclusions

As shown for the first time in literature patients following decompensated HF, a history of stroke/TIA, PAD and impaired renal function independently influenced SDD. In this high-risk population, SDD was not associated with patients' compliance but irrespective of the stroke/TIA history it increased the risk of recurrent HF hospitalization.

The survival free of rehospitalization

Funding Acknowledgement

Type of funding source: None

The artificial intelligence system in prediction of the prevalence of acute coronary syndromes based on weather conditions

Background

It was shown that different individual weather conditions are associated with the incidence of acute coronary syndromes (ACS). Despite this, the prediction of the number of ACS depending on the weather conditions in the given place and time is not effective to date.

Purpose

We sought to investigate whether the artificial intelligence system might be useful in prediction of the prevalence of ACS based on weather conditions.

Methods

In this study, data of 159307 consecutive patients obtained from National Health Service registry, hospitalized due to ACS in Lesser Poland Province (province area of 15008 km2, population of 3.4 M in 2014) between 2008 and 2018 have been compared with meteorological conditions collected in the Institute of Meteorology and Water Management from five weather stations scattered across Lesser Poland Province. Because of small sample size in three of them, only data from two stations (Krakow-Balice, n=75565, Tarnow, n=30079) were used for further analysis. In four separate seasons, the number of ACS events in each day was compared with meteorological conditions on a given day and six days before. We analysed weather conditions such as: wind 10 metres above ground (W_10), temperature (T), dew point temperature (T_dp), relative humidity 2 metres above the ground (Hum_2), atmospheric pressure reduced to mean sea level (Pres), atmospheric precipitation (Prec), and 3 hours atmospheric pressure changes (Pres_3h). For all parameters extreme (maximum – max, minimum – min) values and ranges of these parameters in each day were analysed. All data were used in a system based on machine learning (Random Forest), which allowed to create a model that predicted the incidence of ACS and to determine importance of each inputted weather parameter in this prediction.

Results

All weather parameters were divided into machine learning data (70%) and test data (30%) to verify functioning of the model. The correlation between real number of ACS and predicted number of ACS for two meteorological stations for spring ranges from 0.69 to 0.71 with confidence intervals (CI) of 0.63–0.77, for summer the correlation was 0.66–0.75 with CI of 0.59–79, for autumn 0.69–0.74 with CI of 0.63–0.79 and for winter 0.69–0.72 with CI 0.63–0.77 (P<0.0001 for each prediction, example of prediction in the Figure 1A). Among all analysed meteorological parameters the most important in the machine learning were range of relative humidity, range of dew point temperature and maximal relative humidity (Figure 1B).

Conclusions

Artificial intelligence system seems to be useful in predicting the prevalence of ACS with model based on weather conditions.

Figure 1. ACS prediction for summer in Krakow

Funding Acknowledgement

Type of funding source: None

P2695ABSORB bioresorbable scaffold versus Xience metallic stent in acute coronary syndromes with treated with percutaneous coronary intervention. A subanalysis of the COMPARE-ABSORB trial

Background

The safety and efficacy of the ABSORB scaffold in ACS patients remain unclear. The COMPARE-ABSORB trial compares the ABSORB to the Xience stent in lesions and patients at high risk for restenosis Patients with STEMI and urgent PCI for non-STEMI were not excluded.

Methods

Patients included in the COMPARE-ABSORB trial undergoing PCI for ACS were eligible. Predefined implantation techniques for ABSORB was mandatory. Primary endpoint is target lesion failure (TLF) at 1 year, defined as a composite of cardiac death, target vessel myocardial infarction and clinically indicated target lesion revascularization.

Results

Of 1670 patients, 842 were treated for ACS. At 1-year, TLF occurred in 22 patients (5.0%) of the ABSORB group and in 14 patients (3.5%) of the Xience group (HR 1.44%; 95% CI 0.74%-2.82%, P=0.284). Definite device thrombosis occurred in 9 patients (2.0%) of the ABSORB group and in 2 patients (0.5%) of the Xience group (HR 4.10%; 95% CI 0.89%-18.9%, P=0.071).

Baseline characteristics ABSORB (n=442) XIENCE (n=400) Age, years (SD) 60.7 (9.6) 61.3 (9.1) Male 350/442 (79.2%) 313/400 (78.3%) Current smoker 159/439 (36.2%) 126/397 (31.7%) Diabetes mellitus 152/440 (34.5%) 138/399 (34.6%) Hypertension 298/442 (67.4%) 266/400 (66.5%) Hypercholesterolemia 255/442 (57.7%) 232/400 (58.0%) Family history of coronary artery disease 147/442 (33.3%) 103/400 (25.8%) Previous MI 61/442 (13.8%) 67/400 (16.8%) Established Peripheral Vascular Disease 27/442 (6.1%) 15/400 (3.8%) Previous PCI 83/442 (18.8%) 86/400 (21.5%) Previous CABG 1/442 (0.2%) 4/400 (1.0%) Previous stroke 15/442 (3.4%) 21/400 (5.3%) Renal Insufficiency 9/442 (2.0%) 13/400 (3.3%) Clinical presentation   Unstable angina 149/442 (33.7%) 141/400 (35.3%)   Non-ST elevation myocardial infarction 183/442 (41.4%) 156/400 (39.0%)   ST elevation myocardial infarction 110/442 (24.9%) 103/400 (25.7%)

KM plot for target lesion failure

Conclusion

The COMPARE-ABSORB trial showed no difference in the primary endpoint at one year for the ACS subgroup. The signal for increased thrombosis remained, even with the optimized implantation protocol

Acknowledgement/Funding

Maasstad Hospital, Rotterdam, the Netherlands

Thymic CCL2 influences induction of T-cell tolerance

Thymic epithelial cells (TEC) and dendritic cells (DC) play a role in T cell development by controlling the selection of the T cell receptor repertoire. DC have been described to take up antigens in the periphery and migrate into the thymus where they mediate tolerance via deletion of autoreactive T cells, or by induction of natural regulatory T cells. Migration of DC to thymus is driven by chemokine receptors. CCL2, a major ligand for the chemokine receptor CCR2, is an inflammation-associated chemokine that induces the recruitment of immune cells in tissues. CCL2 and CCR2 are implicated in promoting experimental autoimmune encephalomyelitis (EAE), a mouse model for multiple sclerosis. We here show that CCL2 is constitutively expressed by endothelial cells and TEC in the thymus. Transgenic mice overexpressing CCL2 in the thymus showed an increased number of thymic plasmacytoid DC and pronounced impairment of T cell development. Consequently, CCL2 transgenic mice were resistant to EAE. These findings demonstrate that expression of CCL2 in thymus regulates DC homeostasis and controls development of autoreactive T cells, thus preventing development of autoimmune diseases.

Apocynin reduces reactive oxygen species concentrations in exhaled breath condensate in asthmatics

Asthma is an inflammatory airway disease, and oxidative stress was proven to be involved in its pathogenesis. Apocynin effectively inhibits the main source of reactive oxygen species (ROS)-nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-by blocking its activation. The aim of this study was to investigate the effect of inhaled apocynin on ROS and RNS (reactive nitrogen species) concentration in 14 nonsmoking mild asthmatics. Effects of nebulized apocynin (0.5 mg/mL) were assessed in exhaled breath condensate (EBC) after 30, 60, and 120 minutes, and safety parameters have been analyzed. Apocynin significantly decreased H2O2 concentration in EBC in comparison with placebo after 60 and 120 minutes. Moreover, apocynin significantly reduced NO(-2) concentration 30 and 60 minutes after nebulization and caused a significant decrease of NO(-3) concentration in EBC 60 and 120 minutes after administration, comparing with placebo. No adverse events have been observed throughout the study. This research confirmed anti-inflammatory properties of nebulized apocynin, which might be an effective and safe drug in bronchial asthma.

Voltage sensitive dye imaging of transient neuronal assemblies in brain slices under hyperbaric conditions

We have developed a high pressure optical cell to study large-scale transient neuronal coalitions--"assemblies" using voltage sensitive dye (VSD) fluorescence combined with fast CCD imaging of brain slices under hyperbaric conditions. The new cell has been tested at pressures up to P = 150-200 atm, corresponding to the range over which effects such as "pressure-reversal" of anaesthesia have been described previously. Brain slices were maintained in a flow of artificial cerebrospinal fluid (aCSF) and hyperbaric conditions were controlled to within +/- 0.2 atm using a back-pressure regulator placed in the pumping system. Preliminary VSD imaging experiments were carried out on rat hippocampal slices at pressures up to P approximately 50 atm. An electrode placed in the CA3 region was used to stimulate a signal along the Schaffer collateral towards CA1. First results indicate that good VSD data can be obtained that can be analysed to provide a new view on how hydrostatic pressurisation affects the dynamic propagation of neuronal assemblies.

Inhibitory effect of furosemide on activation of human peripheral blood polymorphonuclear leukocytes stimulated with n-formyl-methionyl-leucyl-phenylalanine

The clinical efficacy of inhalatory furosemide (Fu) has been extensively studied in bronchial asthma patients but there are only a few studies addressing its action on cells participating in the underlying inflammatory process. Therefore, we investigated the effect of Fu on human peripheral blood polymorphonuclear leukocytes (PMNL) at concentrations that can be achieved in the bronchial lining fluid by inhalation, i.e. 10(-5), 10(-4) and 10(-3) M. The influence of Fu on the following PMNL parameters was investigated: intracellular calcium changes ([Ca2+]i) as a part of signal transduction and luminol dependent chemiluminescence (LCL) as an indirect measure of NADPH-oxidase activation upon n-formyl-methionyl-leucyl-phenylalanine (fMLP) stimulation; chemotaxis to fMLP, phagocytosis and intracellular killing of Staphylococcus aureus. Incubation with Fu resulted in a concentration dependent reduction of Ca2+ influx and Fu (10(-3) M) decreased the main Ca2+ parameters to one half of the control values and to the level obtained in calcium-free buffer. In contrast, Fu had no effect if preincubated with the cells and then removed by washing. The LCL signal was reduced by Fu (10(-3) M) from 2000 +/- 870 to 550 +/- 440 arbitrary units [aU] (p<0.05). In contrast to the [Ca2+]i measurements, a slightly diminished LCL was also observed following preincubation with Fu and washing. No effect of Fu was found on phagocytosis and intracellular killing of St. aureus. Fu diminished chemotaxis to fMLP but at 10(-3) M it also displayed weak chemoattractant properties. The differential action of Fu on human PMNL may add to the understanding of its topical and restricted efficacy in bronchial asthma.