Effect of music-based interventions on physiologic stability of hospitalized preterm infants. A pilot study

BACKGROUND AND OBJECTIVE

Hospitalized preterm infants experience reduced meaningful auditory exposures during a critical period of brain development. Music-based interventions (MBI) may be beneficial, though it remains unclear which stimuli optimally enhance infant stabilization. We investigated the relationship between three conceptually-different MBIs and short-term responses in hospitalized preterm infants.

STUDY DESIGN

This is a case-crossover pilot study including 21 preterm infants between 30 and 35 weeks postmenstrual age. Participants listened to three MBIs and 'no music'; each condition was provided three times in random order. We monitored physiologic and behavioral parameters around each exposure and analyzed results using linear mixed models.

RESULTS

Respiratory rates decreased after each MBI compared with 'no music' (p = 0.02). The most notable decrease occurred following exposure to a low, repetitive musical pattern resembling a lullaby (p = 0.01). We noted no significant changes for the remaining parameters.

CONCLUSION

Specific MBI characteristics may preferentially enhance physiologic stabilization in hospitalized preterm infants.

Quantitative EEG and prediction of outcome in neonatal encephalopathy: a review

Electroencephalogram (EEG) is an important biomarker for neonatal encephalopathy (NE) and has significant predictive value for brain injury and neurodevelopmental outcomes. Quantitative analysis of EEG involves the representation of complex EEG data in an objective, reproducible and scalable manner. Quantitative EEG (qEEG) can be derived from both a limited channel EEG (as available during amplitude integrated EEG) and multi-channel conventional EEG. It has the potential to enable bedside clinicians to monitor and evaluate details of cortical function without the necessity of continuous expert input. This is particularly useful in NE, a dynamic and evolving condition. In these infants, continuous, detailed evaluation of cortical function at the bedside is a valuable aide to management especially in the current era of therapeutic hypothermia and possible upcoming neuroprotective therapies. This review discusses the role of qEEG in newborns with NE and its use in informing monitoring and therapy, along with its ability to predict imaging changes and short and long-term neurodevelopmental outcomes. IMPACT: Quantitative representation of EEG data brings the evaluation of continuous brain function, from the neurophysiology lab to the NICU bedside and has a potential role as a biomarker for neonatal encephalopathy. Clinical and research applications of quantitative EEG in the newborn are rapidly evolving and a wider understanding of its utility is valuable. This overview summarizes the role of quantitative EEG at different timepoints, its relevance to management and its predictive value for short- and long-term outcomes in neonatal encephalopathy.

Multi-wavelength multi-distance diffuse correlation spectroscopy system for assessment of premature infants' cerebral hemodynamics

Infants born at an extremely low gestational age (ELGA, < 29 weeks) are at an increased risk of intraventricular hemorrhage (IVH), and there is a need for standalone, safe, easy-to-use tools for monitoring cerebral hemodynamics. We have built a multi-wavelength multi-distance diffuse correlation spectroscopy device (MW-MD-DCS), which utilizes time-multiplexed, long-coherence lasers at 785, 808, and 853 nm, to simultaneously quantify the index of cerebral blood flow (CBFi) and the hemoglobin oxygen saturation (SO2). We show characterization data on liquid phantoms and demonstrate the system performance on the forearm of healthy adults, as well as clinical data obtained on two preterm infants.

Integrating Multiplexed Imaging and Multiscale Modeling Identifies Tumor Phenotype Transformation as a Critical Component of Therapeutic T Cell Efficacy

Cancer progression is a complex process involving interactions that unfold across molecular, cellular, and tissue scales. These multiscale interactions have been difficult to measure and to simulate. Here we integrated CODEX multiplexed tissue imaging with multiscale modeling software, to model key action points that influence the outcome of T cell therapies with cancer. The initial phenotype of therapeutic T cells influences the ability of T cells to convert tumor cells to an inflammatory, anti-proliferative phenotype. This T cell phenotype could be preserved by structural reprogramming to facilitate continual tumor phenotype conversion and killing. One takeaway is that controlling the rate of cancer phenotype conversion is critical for control of tumor growth. The results suggest new design criteria and patient selection metrics for T cell therapies, call for a rethinking of T cell therapeutic implementation, and provide a foundation for synergistically integrating multiplexed imaging data with multiscale modeling of the cancer-immune interface.

Functional near-infrared spectroscopy-based prefrontal cortex oxygenation during working memory tasks in sickle cell disease

Significance

Sickle cell disease (SCD), characterized by painful vaso-occlusive crises, is associated with cognitive decline. However, objective quantification of cognitive decline in SCD remains a challenge, and the associated hemodynamics are unknown.

Aim

To address this, we utilized functional near-infrared spectroscopy (fNIRS) to measure prefrontal cortex (PFC) oxygenation responses to N -back working memory tasks in SCD patients and compared them with healthy controls.

Approach

We quantified the PFC oxygenation rate as an index of cognitive activity in each group and compared them. In half of the participants, a Stroop test was administered before they started N -back to elevate their baseline stress level.

Results

In SCD compared to healthy controls, we found that (1) under a high baseline stress level, there were significantly greater oxygenation responses during the 2-back task, further elevated with histories of stroke; (2) there was a marginally slower N -back response time, and it was even slower with a history of stroke; and (3) the task accuracy was not different.

Conclusions

Additional requirements for processing time, PFC resources, and PFC oxygenation in SCD patients offer an important basis for understanding their cognitive decline and highlight the potential of fNIRS for evaluating cognitive functions.

7-UP: Generating in silico CODEX from a small set of immunofluorescence markers

Multiplex immunofluorescence (mIF) assays multiple protein biomarkers on a single tissue section. Recently, high-plex CODEX (co-detection by indexing) systems enable simultaneous imaging of 40+ protein biomarkers, unlocking more detailed molecular phenotyping, leading to richer insights into cellular interactions and disease. However, high-plex data can be slower and more costly to collect, limiting its applications, especially in clinical settings. We propose a machine learning framework, 7-UP, that can computationally generate in silico 40-plex CODEX at single-cell resolution from a standard 7-plex mIF panel by leveraging cellular morphology. We demonstrate the usefulness of the imputed biomarkers in accurately classifying cell types and predicting patient survival outcomes. Furthermore, 7-UP's imputations generalize well across samples from different clinical sites and cancer types. 7-UP opens the possibility of in silico CODEX, making insights from high-plex mIF more widely available.

Towards multiomic analysis of oral mucosal pathologies

Oral mucosal pathologies comprise an array of diseases with worldwide prevalence and medical relevance. Affecting a confined space with crucial physiological and social functions, oral pathologies can be mutilating and drastically reduce quality of life. Despite their relevance, treatment for these diseases is often far from curative and remains vastly understudied. While multiple factors are involved in the pathogenesis of oral mucosal pathologies, the host's immune system plays a major role in the development, maintenance, and resolution of these diseases. Consequently, a precise understanding of immunological mechanisms implicated in oral mucosal pathologies is critical (1) to identify accurate, mechanistic biomarkers of clinical outcomes; (2) to develop targeted immunotherapeutic strategies; and (3) to individualize prevention and treatment approaches. Here, we review key elements of the immune system's role in oral mucosal pathologies that hold promise to overcome limitations in current diagnostic and therapeutic approaches. We emphasize recent and ongoing multiomic and single-cell approaches that enable an integrative view of these pathophysiological processes and thereby provide unifying and clinically relevant biological signatures.

Intraoperative Cerebral Hemodynamic Monitoring during Carotid Endarterectomy via Diffuse Correlation Spectroscopy and Near-Infrared Spectroscopy

Objective: This pilot study aims to show the feasibility of noninvasive and real-time cerebral hemodynamic monitoring during carotid endarterectomy (CEA) via diffuse correlation spectroscopy (DCS) and near-infrared spectroscopy (NIRS). Methods: Cerebral blood flow index (CBFi) was measured unilaterally in seven patients and bilaterally in seventeen patients via DCS. In fourteen patients, hemoglobin oxygenation changes were measured bilaterally and simultaneously via NIRS. Cerebral autoregulation (CAR) and cerebrovascular resistance (CVR) were estimated using CBFi and arterial blood pressure data. Further, compensatory responses to the ipsilateral hemisphere were investigated at different contralateral stenosis levels. Results: Clamping of carotid arteries caused a sharp increase of CVR (~70%) and a marked decrease of ipsilateral CBFi (57%). From the initial drop, we observed partial recovery in CBFi, an increase of blood volume, and a reduction in CVR in the ipsilateral hemisphere. There were no significant changes in compensatory responses between different contralateral stenosis levels as CAR was intact in both hemispheres throughout the CEA phase. A comparison between hemispheric CBFi showed lower ipsilateral levels during the CEA and post-CEA phases (p < 0.001, 0.03). Conclusion: DCS alone or combined with NIRS is a useful monitoring technique for real-time assessment of cerebral hemodynamic changes and allows individualized strategies to improve cerebral perfusion during CEA by identifying different hemodynamic metrics.

Diffuse correlation spectroscopy blood flow monitoring for intraventricular hemorrhage vulnerability in extremely low gestational age newborns

In premature infants with an extremely low gestational age (ELGA, < 29 weeks GA), dysregulated changes in cerebral blood flow (CBF) are among the major pathogenic factors leading to germinal matrix/intraventricular hemorrhage (GM/IVH). Continuous monitoring of CBF can guide interventions to minimize the risk of brain injury, but there are no clinically standard techniques or tools for its measurement. We report the feasibility of the continuous monitoring of CBF, including measures of autoregulation, via diffuse correlation spectroscopy (DCS) in ELGA infants using CBF variability and correlation with scalp blood flow (SBF, served as a surrogate measure of systemic perturbations). In nineteen ELGA infants (with 9 cases of GM/IVH) monitored for 6–24 h between days 2–5 of life, we found a strong correlation between CBF and SBF in severe IVH (Grade III or IV) and IVH diagnosed within 72 h of life, while CBF variability alone was not associated with IVH. The proposed method is potentially useful at the bedside for the prompt assessment of cerebral autoregulation and early identification of infants vulnerable to GM/IVH.

A Contact-Sensitive Probe for Biomedical Optics

Capacitive proximity sensing is widespread in our everyday life, but no sensor for biomedical optics takes advantage of this technology to monitor the probe attachment to the subject’s skin. In particular, when using optical monitoring devices, the capability to quantitatively measure the probe contact can significantly improve data quality and ensure the subject’s safety. We present a custom novel optical probe based on a flexible printed circuit board which integrates a capacitive contact sensor, 3D-printed optic fiber holders and an accelerometer sensor. The device can be effectively adopted during continuous monitoring optical measurements to detect contact quality, motion artifacts, probe detachment and ensure optimal signal quality.

Vasoconstriction Response to Mental Stress in Sickle Cell Disease: The Role of the Cardiac and Vascular Baroreflexes

Recent studies have shown that individuals with sickle cell disease (SCD) exhibit greater vasoconstriction responses to physical autonomic stressors, such as heat pain and cold pain than normal individuals, but this is not the case for mental stress (MTS). We sought to determine whether this anomalous finding for MTS is related to inter-group differences in baseline cardiac and vascular autonomic function. Fifteen subjects with SCD and 15 healthy volunteers participated in three MTS tasks: N-back, Stroop, and pain anticipation (PA). R-R interval (RRI), arterial blood pressure and finger photoplethysmogram (PPG) were continuously monitored before and during these MTS tasks. The magnitude of vasoconstriction was quantified using change in PPG amplitude (PPGa) from the baseline period. To represent basal autonomic function, we assessed both cardiac and vascular arms of the baroreflex during the baseline period. Cardiac baroreflex sensitivity (BRSc) was estimated by applying both the "sequence" and "spectral" techniques to beat-to-beat measurements of systolic blood pressure and RRIs. The vascular baroreflex sensitivity (BRSv) was quantified using the same approaches, modified for application to beat-to-beat diastolic blood pressure and PPGa measurements. Baseline BRSc was not different between SCD and non-SCD subjects, was not correlated with BRSv, and was not associated with the vasoconstriction responses to MTS tasks. BRSv in both groups was correlated with mean PPGa, and since both baseline PPGa and BRSv were lower in SCD, these results suggested that the SCD subjects were in a basal state of higher sympathetically mediated vascular tone. In both groups, baseline BRSv was positively correlated with the vasoconstriction responses to N-back, Stroop, and PA. After adjusting for differences in BRSv within and between groups, we found no difference in the vasoconstriction responses to all three mental tasks between SCD and non-SCD subjects. The implications of these findings are significant in subjects with SCD since vasoconstriction reduces microvascular flow and prolongs capillary transit time, increasing the likelihood for vaso-occlusive crisis (VOC) to be triggered by exposure to stressful events.

45 AI-assisted whole-body assessment of immunotherapy response using [18F]F-AraG, a PET agent for activated T cells

Background

Patterns of response to immunotherapy differ from traditional cytotoxic drugs, making clinical decisions concerning response evaluation more challenging. Radiological response criteria, such as iRECIST, updated to address response patterns unique to immunotherapeutics, focus only on changes in the tumor burden.1 An 18F labeled nucleoside analog, [18F]F-AraG was developed as a PET agent for imaging activated T cells,2–5 critical components of immune response and the common target of immunotherapies. Whole body assessment of [18F]F-AraG uptake that indicates presence of activated T cells might allow for analysis of complex immunologic processes and provide early indication of treatment response as well as off-target side effects. Here, we employ AIQ Solutions’ TRAQinform IQ software to analyze [18F]F-AraG scans and assess activation of T cells in head and neck squamous cell carcinoma (HNSCC) patients undergoing anti-PD-1 therapy.

Methods

Four treatment-naïve HNSCC patients were imaged using [18F]F-AraG before and 2–3 weeks after a single dose of anti-PD-1 antibody. [18F]F-AraG PET scans of six healthy subjects were used to define areas of increased [18F]F-AraG uptake in patients. The regions of uptake in the baseline and on-treatment scans were registered and matched using articulated registration.6 7 Standardized uptake values, SUVmax, SUVmean and SUVtotal were extracted from all areas of tracer uptake in both scans and changes in signal calculated to assess therapy effects. The change in signal was analyzed in the context of the patient‘s clinical status and changes in T cell infiltration in the primary lesion when biopsy specimens were available.

Results

TRAQinform IQ whole body evaluation of [18F]F-AraG PET revealed heterogeneity in the signal range and extent of signal change both between different patients and between different areas of tracer uptake within the same patient (figure 1). The post-therapy whole-body [18F]F-AraG signal change trended with patients‘ outcome. The patients with areas where the signal disappeared or decreased post therapy, indicative of the lack of T cell activation, had shorter overall survival than the patients with areas with stable and increasing signal. The change in infiltration of activated T cells in the primary lesion tissue did not correspond to the patient survival, reflecting limitations of serial biopsy in evaluating therapy response.

Abstract 45 Figure 1

TRAQinform IQ assessment of the SUVmean [18F]F-AraG signal change in a HNSCC patient two weeks after a single dose of anti-PD-1 antibody. Quantification of the differences in the [18F]F-AraG uptake in the baseline and on-treatment scan revealed 17 hotspots with disappearing or decreasing signal, 22 hotpots with the stable signal and 11 hotspots with increasing or new signal post therapy.

Conclusions

TRAQinform IQ analysis and quantification of [18F]F-AraG PET provides patient-level assessment of tracer uptake and may allow for better understanding of heterogeneity of T cell activation and potentially offer a more comprehensive evaluation of response to immunotherapy than the standard, tumor-centric, radiologic methods.

References

Nishino M, et al. Monitoring immune-checkpoint blockade: response evaluation and biomarker development. Nat Rev Clin Oncol, 2017.

Namavari M, et al. Synthesis of 2’-deoxy-2’-[18F]fluoro-9-beta-D-arabinofuranosylguanine: a novel agent for imaging T-cell activation with PET. Mol Imaging Biol 2011; 13(5):812–8.

Ronald JA, et al. A PET imaging strategy to visualize activated T cells in acute graft-versus-host disease elicited by allogenic hematopoietic cell transplant. Cancer Res 2017; 77(11):2893–2902.

Levi J, et al. Imaging of activated T cells as an early predictor of immune response to anti-PD-1 Therapy. Cancer Research 2019; 79(13):3455–3465.

Levi J, et al. (18)F-AraG PET for CD8 profiling of tumors and assessment of immunomodulation by chemotherapy. J Nucl Med 2021; 62(6):802–807.

Yip S, T Perk, and R Jeraj, Development and evaluation of an articulated registration algorithm for human skeleton registration. Phys Med Biol 2014; 59(6):1485–99.

Yip S. and R Jeraj. Use of articulated registration for response assessment of individual metastatic bone lesions. Phys Med Biol 2014; 59(6): 1501–14.

Ethics Approval

The study was approved by Stanford University Ethics Board, approval number 40425.

180 T cell phenotype drives restructuring of tumor microenvironment to balance T cell longevity and tumor control: insights from multiplexed imaging and multi-scale agent based modeling

Background

Immune cell therapies continue to have success in treatment of cancers yet face challenges of complexity, cost, toxicity, and low solid-tumor efficacy. Much work has focused on the phenotype characterization and control of ex vivo expanded cells; however, little is known about its relationship to changes in the tumor microenvironment in vivo. Thus, we imaged tumors treated with different phenotype tumor-specific CD8+ T cells with CODEX multiplexed imaging1–4 that is able to visualize 42 antibodies at the same tissue in the tissue (figure 1A). To further probe this data in a systems immunology approach we created a multiscale agent-based model including critical circuits from the T cell-tumor microenvironment interactions (figure 1B).

Methods

We initialized our agent-based models various percentages of either PD1+, PD1-, PDL1+, or PDL1- phenotypes and ran simulations for 72 hours. We also treated PMEL CD8+ T cells with or without 2 hydroxycitrate as a metabolic inhibitor during activation to achieve different input phenotypes of CD8+ T cells for therapeutic adoptive transfer on day 10 following B16-F10 tumors had been established. We performed neighborhood analysis on CODEX multiplexed imaging data by clustering neighboring cell types using a sliding window for neighborhood analysis.

Results

Interestingly, the agent-based modeling indicated that the tumor phenotype switch to decrease proliferation was more effective than direct T cell killing. We observed spatially restricted inflammatory immune fronts when simulating with different initial percentages of PD1+ T cells and also from our CODEX multiplexed imaging. Quantitatively we observe that there is a drastic increase in the PDL1+, MHCI+, Ki67- tumor phenotype that increases with metabolically inhibited T cells. Neighborhood analysis indicated that metabolically treated T cells were able to create distinct immune cell environments that supported productive T cell-tumor interactions and also helped maintain T cell phenotype.

Conclusions

This indicates there is a balance for therapeutic T cell to mitigate chronic tumor exposure while controlling tumor growth through killing and by changing tumor phenotype. We observe T cells create distinct tumor microenvironments that differs significantly based on the starting T cell phenotype. Controlling T cell phenotype to promote productive immune-tumor structures will be critical to maintain T cell functionality and efficacy. In the future we will investigate T cell recruitment of immune structures by similar systems biology technologies.

Acknowledgements

J.W.H. is funded by an ACS Postdoctoral Fellowship (PF-20-032-01-CSM).

References

Goltsev Y, Samusik N, Kennedy-Darling J, Bhate S, Hale M, Vazquez G, Black S and Nolan GP, Deep profiling of mouse splenic architecture with CODEX multiplexed imaging. Cell, 174(4):968–981.

Schürch CM, Bhate SS, Barlow GL, Phillips DJ, Noti L, Zlobec I, Chu P, Black S, Demeter J, McIlwain DR and Samusik N. Coordinated cellular neighborhoods orchestrate antitumoral immunity at the colorectal cancer invasive front. Cell 182(5):1341–1359.

Black S, Phillips D, Hickey JW, Kennedy-Darling J, Venkataraaman VG, Samusik N, Goltsev Y, Schürch CM. and Nolan GP. CODEX multiplexed tissue imaging with DNA-conjugated antibodies. Nature Protocols 1–36.

Kennedy-Darling J, Bhate SS, Hickey JW, Black S, Barlow GL, Vazquez G, Venkataraaman VG, Samusik N, Goltsev Y, Schürch CM and Nolan GP. Highly multiplexed tissue imaging using repeated oligonucleotide exchange reaction. European Journal of Immunology 51(5):1262–1277.

Ethics Approval

All studies involving mice were approved under Stanford’s APLAC protocol 33502.

20 Tumor-informed liquid biopsy monitoring of evolving therapeutic resistance mechanisms in head and neck squamous cell carcinoma patients receiving anti-PD-1 therapy

Background

Typical liquid biopsy panels offer a limited understanding of tumor biology, potentially under-representing the heterogeneity of resistance in late-stage cancers. Here, diminished scope can result in undetected, therapeutically-relevant biomarkers which respond dynamically to treatment, as well as potentially missed resistance mechanisms and pathway-level events. To address the challenges associated with identifying multiple concurrent heterogeneous resistance mechanisms in individual patients, we evaluated longitudinal exome-scale tumor-informed cell-free DNA (cfDNA) data from head and neck squamous cell carcinoma (HNSCC) patients receiving anti-PD1 therapy.

Methods

Pre- and post-intervention matched tumor, normal and plasma samples were retrospectively obtained from 15 stage II-IV HNSCC patients. Following baseline sample collection, all patients received a single dose of nivolumab or pembrolizumab. The primary tumor was then resected approximately one month later when possible, or a second biopsy collected where resection was impractical. Paired tumor and normal samples were then profiled using ImmunoID NeXT Platform®, an augmented exome/transcriptome platform and analysis pipeline. Exome-scale cfDNA profiling of matched plasma samples was performed using the NeXT Liquid BiopsyTM platform to detect somatic variants.

Results

Patient neoantigen presentation score (NEOPSTM) rapidly and significantly contracted following therapy (p=.00098). Novel neoantigens arising post-treatment which were predicted to be presented on lost HLA alleles were significantly higher in patients with longer overall survival (p=.019). Variant detection across same-patient serial cfDNA samples revealed significantly correlated VAFs (R=.62, p<.0001) despite significant contraction of mutational burden in solid tumor (p=.0039), suggesting complex clonal/subclonal dynamics. Investigation of the evolving tumor and cfDNA subclonal architecture revealed significant association between decreasing cellular prevalence and NOTCH signaling (q=.001) and the innate immune system (q=.002), while increasing cellular prevalence was associated with p53 signalling (q=.02) and hypoxia (q=.02). These findings were complimented by transcriptomic data which showed significant enrichment of multiple immune pathways across treatment.

Conclusions

We found that immune checkpoint blockade precipitates rapid evolution of the HNSCC tumor microenvironment. By leveraging comprehensive, tumor-informed liquid biopsy data we were able to identify contracting cellular populations enriched for NOTCH pathway mutations. Longer OS following either intervention was associated with an expansion of novel neoantigens predicted to be presented by lost HLA alleles. Our results suggest that tumor-informed liquid biopsy provides a more robust understanding of therapeutic response and resistance mechanisms than that attainable with typical liquid biopsy panels alone.

Ethics Approval

This study obtained ethics approval from Human Subjects Research at Stanford University. ID number is 40425. All participants gave informed consent prior to enrollment.

181 Intraepithelial group 1 innate lymphoid cells generated in vitro exhibit enhanced cytotoxicity and infiltration into solid tumoroids

Background

Immunotherapy approaches have shown striking success in the liquid tumor setting but have been unable to demonstrate similar efficacy against solid tumors. Cell-based therapies, in particular, struggle to overcome the harshly immunosuppressive tumor microenvironment. Additionally, cells for adoptive therapy are often generated from immune cells circulating in the peripheral blood of patients or healthy donors, rather than isolating them from solid tissues. Designing immunotherapies using insights from tissue-resident cells represents a novel method for enhancing trafficking into and retention within solid tumors.1 To this end, we developed methodology for differentiating peripheral blood natural killer cells (pbNKs) into cells resembling intraepithelial group 1 innate lymphoid cells (ieILC1s) in vitro and assessed their potential for immunotherapy.

Methods

We co-cultured irradiated squamous cell carcinoma (SCC) cells and pbNKs, isolated from blood of healthy human donors, to generate cells exhibiting an ieILC1 phenotype. We assessed the differentiation using traditional flow cytometry and further profiled the cells using cytometry by time of flight (CyTOF)2 to obtain higher-dimensional data about their surface and intracellular phenotypes. We then tested the cells for their cytotoxicity against a variety of target cell lines using the xCELLigence platform. Next, we grew three-dimensional tumoroids from single-cell suspensions of SCC cell lines in basement membrane extracts and added fluorescently labeled pbNKs and ieILC1s to them. We assessed their infiltration capacity into the tumoroids using confocal microscopy.

Results

The ieILC1-like cells generated in vitro had a comparable surface and intracellular phenotype to ieILC1s in healthy tissue. These cells exhibited significantly increased cytotoxicity against multiple SCC cell lines and were also capable of antibody-dependent cellular cytotoxicity, which we tested using anti-epidermal growth factor receptor (EGFR) antibody (figure 1). Importantly, the ieILC1-like cells efficiently infiltrated the tumoroids in a manner consistent with their tissue-resident phenotype (figure 2A) and at higher rates than the conventional pbNKs (figure 2B).

Abstract 181 Figure 1

Cytolysis of pbNKs and ieILC1-like cells was compared using the xCELLigence platform to monitor killing of adherent SCC target cells over 36 hours. Cells were cultured at a 1:4 E:T ratio with or without 10 ug/mL cetuximab.

Abstract 181 Figure 2

Tumoroid infiltration rates of pbNKs and ieILC1-like cells were compared using confocal microscopy. A: Representative cross-sections of tumoroids, with nuclei labeled with DAPI (blue) and infiltrating cells labeled with CellTrace Far Red (pink). B: Infiltrating cells within each tumoroid were counted and then normalized to the area of the tumoroid.

Conclusions

Our data show that ieILC1-like cells can be generated from pbNKs using a co-culture system with irradiated epithelial tumor cells. These ieILC1-like cells provide a novel platform for adoptive cell therapy, as they exhibit strong natural cytotoxicity and ADCC against multiple cell lines. Finally, the ieILC1-like cells have an enhanced capacity for infiltration into solid tumoroids. Future work will include in vivo modeling of tumor infiltration and efficacy as well as optimization of the co-culture platform to maximize expansion and cytotoxicity of the cells as they differentiate.

Acknowledgements

N.B.H. is funded by the Stanford Bio-X Fellowship. The laboratory of J.B.S. is funded by NIH R35 DE030054.

References

Milner J, Toma C, Yu B, Zhang K, Omilusik K, Phan A, Wang D, Getzler A, Nguyen T, Crotty S, Wang W, Pipkin M, Goldrath A. Runx3 programs CD8+ T cell residency in non-lymphoid tissues and tumours. Nature 2017;552:253–257.

Bendall S, Simonds E, Qiu P, Amir E, Krutzik P, Finck R, Bruggner R, Melamed R, Trejo A, Ornatsky O, Balderas R, Plevritis S, Sachs K, Pe’er D, Tanner S, Nolan G. Single-Cell mass cytometry of differential immune and drug responses across a human hematopoietic continuum. Science 2011;332:687–696.

Ethics Approval

The studies reported here were approved by the Stanford Institutional Review Board (IRB 11402) and the Stanford Administrative Panel on Laboratory Animal Care (APLAC 20547).

215 Tissue-resident natural killer cells resembling intraepithelial ILC1 have potent anti-tumor activity in human head and neck cancer and represent a novel class of effector cells for immunotherapy

Background

Natural killer (NK) cells comprise a subset of the innate lymphoid cell (ILC) family. Although NK cells have been observed to be present in most solid tumors, their role in the protection against tumor formation in humans has been unclear. Studies have been hampered by the heterogeneity of NK cells within the tumor microenvironment (TME) and lack of information about the broader ILC subsets found in tumors. Further, there is an increasing recognition of plasticity between NK cells and other ILC family members in various disease contexts, calling for a broader examination of ILCs within solid tumors. We previously analyzed the ILC population in primary samples from human head and neck squamous cell carcinoma (HNSCC) and matched blood by single-cell RNA sequencing (scRNA-seq).1 Those studies revealed that peripheral NK cells differentiate along two divergent trajectories in the TME, resulting in different end-states: one with a hyporesponsive phenotype and another possessing potent anti-tumor activity and resembling intraepithelial ILC1s (ieILC1s).

Methods

In vitro co-culture approaches and in vivo mouse models were used to investigate the ability of peripheral NK cells to differentiate into alternate ILC states with heterogeneous functions. Cytotoxicity assays were used to assess functional activity of in vitro derived ieILC1-like cells. Adoptive cell transfer of ieILC1-like cells into tumor-bearing mice was also used to assess anti-tumor function.

Results

Peripheral human NK cells could be efficiently differentiated into ieILC1-like cells using an in vitro co-culture system. These ieILC1-like cells had enhanced natural cytotoxicity against target cells compared to conventional IL-15-activated and K562-expanded NK cells. In addition, they infiltrated the TME efficiently and were a more effective means of adoptive cell therapy against HNSCC solid tumor xenografts in vivo compared to conventional NK cells.

Conclusions

Our data indicate that peripheral NK cells change cell states within the TME of HNSCC. The heterogeneity in the relative proportion of the cell states may influence host response to tumors. We identified the ieILC1-like cell state to be the phenotype with the most potent anti-tumor activity within the TME. Importantly, this cell state can be induced from peripheral donor NK cells ex vivo for differentiation into and expansion of highly active ieILC1-like cells, providing a platform for a novel class of effector cells for adoptive cell immunotherapy.

Acknowledgements

These studies were supported by the Lokey Stem Cell Research Building (SIM1) Flow Cytometry core facility for cell sorting and flow cytometric analysis and the Stanford Cancer Institute Tissue Bank for procurement of tumor samples and blood. This work was supported by funding from the National Institutes of Health (R01CA158516; R35DE030054; U54CA209971) to J.B.S.

Reference

Moreno-Nieves UY, Tay JK, Saumyaa S, Shin JH, Horowitz NB, Mohammad IA, Luca B, Mundy DC, Gulati GS, Bedi N, Chang S, Chen C, Kaplan MJ, Rosenthal EL, Holsinger FC, Divi V, Baik FM, Sirjani DB, Gentles AJ, Newman AM, Freud AG, Sunwoo JB. Landscape of ILCs in human head and neck cancer reveals divergent NK cell states in the tumor microenvironment. Proc Natl Acad Sci U S A 2021;118(28):e2101169118.

Ethics Approval

The studies reported here were approved by the Stanford Institutional Review Board (IRB 11402) and the Stanford Administrative Panel on Laboratory Animal Care (APLAC 20547).

Chromatin accessibility associates with protein-RNA correlation in human cancer

Although alterations in chromatin structure are known to exist in tumors, how these alterations relate to molecular phenotypes in cancer remains to be demonstrated. Multi-omics profiling of human tumors can provide insight into how alterations in chromatin structure are propagated through the pathway of gene expression to result in malignant protein expression. We applied multi-omics profiling of chromatin accessibility, RNA abundance, and protein abundance to 36 human thyroid cancer primary tumors, metastases, and patient-match normal tissue. Through quantification of chromatin accessibility associated with active transcription units and global protein expression, we identify a local chromatin structure that is highly correlated with coordinated RNA and protein expression. In particular, we identify enhancers located within gene-bodies as predictive of correlated RNA and protein expression, that is independent of overall transcriptional activity. To demonstrate the generalizability of these findings we also identify similar results in an independent cohort of human breast cancers. Taken together, these analyses suggest that local enhancers, rather than distal enhancers, are likely most predictive of cancer gene expression phenotypes. This allows for identification of potential targets for cancer therapeutic approaches and reinforces the utility of multi-omics profiling as a methodology to understand human disease.

Abstract 399: Pan-cancer survey of HLA loss of heterozygosity using a robustly validated NGS-based machine learning algorithm

HLA loss of heterozygosity (LOH) is increasingly being recognized as an important immune escape mechanism in response to checkpoint inhibitor therapy. HLA LOH reduces the repertoire of neoantigens displayed on the cell surface of cancer cells, limiting the efficacy of the immune system to detect and eliminate them. Though highly accurate HLA LOH detection algorithms are needed to allow clinical utility, the field lacks robust, allele-specific validation approaches. Moreover, algorithms of unknown sensitivity and specificity have led to significant discrepancies in the estimated occurrence of HLA LOH as an immune escape mechanism across tumor types. To address these challenges, we have developed a machine learning algorithm to detect HLA LOH (DASH - Deletion of Allele-Specific HLAs), established the accuracy of the algorithm with an allele-specific PCR validation strategy, investigated the frequencies of HLA LOH across 14 tumor types in a cohort of over 800 patients and observed allele-specific neoantigen expansion in response to immunotherapy. To build DASH, we profiled 279 patients on the ImmunoID NeXT Platform to create a training dataset. Our novel features, which account for allele-specific differences in exome probe capture and capitalize on our whole exome platform by including information about copy number alterations in the regions flanking the HLA genes, were used to train an XGBoost model. Orthogonal, allele-specific validation was required to accurately assess sensitivity and specificity for clinical utility. Thus, we profiled over 30 paired tumor-normal cell lines on the ImmunoID NeXT Platform® and identified cell lines with HLA LOH. Using in silico mixtures, we found 100% sensitivity and specificity for tumors with at least 36% tumor purity. Next, we designed a digital PCR (dPCR) assay using patient-specific, allele-specific primers that target a single HLA allele while avoiding all other HLA alleles and tested the limit of detection of the assay in the same cell lines. Then, we performed dPCR with patient-specific primers on 20 tumor and normal sample pairs and found 94% sensitivity. After establishing the high sensitivity and specificity of DASH, we profiled over 800 patients spanning 14 tumor types on the ImmunoID NeXT Platform. We found that over 25% of patients in the majority of tumor types had at least one HLA LOH event. Further, we observed that novel neoantigens that arose during checkpoint treatment were significantly more likely to bind to deleted HLA alleles as compared to the remaining HLA alleles in a head and neck carcinoma cohort treated with anti-PD-1 therapy, shedding light on the mechanism of immune escape in response to checkpoint inhibitors. In summary, we introduced an HLA LOH detection method, performed allele-specific validation, exposed widespread HLA across tumor types and observed the mechanism of immune escape in response to immunotherapy.

Citation Format: Rachel Marty Pyke, Datta Mellacheruvu, Charles Abbott, Steven Dea, Eric Levy, Simo V. Zhang, Nikita Bedi, A. Dimitrios Colevas, Devayani Bhave, Manju Chinnappa, Gabor Bartha, John Lyle, John West, Michael Snyder, John Sunwoo, Richard Chen, Sean Michael Boyle. Pan-cancer survey of HLA loss of heterozygosity using a robustly validated NGS-based machine learning algorithm [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 399.

Loss of alpha-globin genes in human subjects is associated with improved nitric oxide-mediated vascular perfusion

Alpha thalassemia is a hemoglobinopathy due to decreased production of the α-globin protein from loss of up to four α-globin genes, with one or two missing in the trait phenotype. Individuals with sickle cell disease who co-inherit the loss of one or two α-globin genes have been known to have reduced risk of morbid outcomes, but the underlying mechanism is unknown. While α-globin gene deletions affect sickle red cell deformability, the α-globin genes and protein are also present in the endothelial wall of human arterioles and participate in nitric oxide scavenging during vasoconstriction. Decreased production of α-globin due to α-thalassemia trait may thereby limit nitric oxide scavenging and promote vasodilation. To evaluate this potential mechanism, we performed flow-mediated dilation and microvascular post-occlusive reactive hyperemia in 27 human subjects (15 missing one or two α-globin genes and 12 healthy controls). Flow-mediated dilation was significantly higher in subjects with α-trait after controlling for age (P = .0357), but microvascular perfusion was not different between groups. As none of the subjects had anemia or hemolysis, the improvement in vascular function could be attributed to the difference in α-globin gene status. This may explain the beneficial effect of α-globin gene loss in sickle cell disease and suggests that α-globin gene status may play a role in other vascular diseases.

Validation of diffuse correlation spectroscopy measures of critical closing pressure against transcranial Doppler ultrasound in stroke patients

SIGNIFICANCE

Intracranial pressure (ICP), variability in perfusion, and resulting ischemia are leading causes of secondary brain injury in patients treated in the neurointensive care unit. Continuous, accurate monitoring of cerebral blood flow (CBF) and ICP guide intervention and ultimately reduce morbidity and mortality. Currently, only invasive tools are used to monitor patients at high risk for intracranial hypertension.

AIM

Diffuse correlation spectroscopy (DCS), a noninvasive near-infrared optical technique, is emerging as a possible method for continuous monitoring of CBF and critical closing pressure (CrCP or zero-flow pressure), a parameter directly related to ICP.

APPROACH

We optimized DCS hardware and algorithms for the quantification of CrCP. Toward its clinical translation, we validated the DCS estimates of cerebral blood flow index (CBFi) and CrCP in ischemic stroke patients with respect to simultaneously acquired transcranial Doppler ultrasound (TCD) cerebral blood flow velocity (CBFV) and CrCP.

RESULTS

We found CrCP derived from DCS and TCD were highly linearly correlated (ipsilateral R2  =  0.77, p  =  9  ×  10  -  7; contralateral R2  =  0.83, p  =  7  ×  10  -  8). We found weaker correlations between CBFi and CBFV (ipsilateral R2  =  0.25, p  =  0.03; contralateral R2  =  0.48, p  =  1  ×  10  -  3) probably due to the different vasculature measured.

CONCLUSION

Our results suggest DCS is a valid alternative to TCD for continuous monitoring of CrCP.

The role of diffuse correlation spectroscopy and frequency-domain near-infrared spectroscopy in monitoring cerebral hemodynamics during hypothermic circulatory arrests

Objectives

Real-time noninvasive monitoring of cerebral blood flow (CBF) during surgery is key to reducing mortality rates associated with adult cardiac surgeries requiring hypothermic circulatory arrest (HCA). We explored a method to monitor cerebral blood flow during different brain protection techniques using diffuse correlation spectroscopy (DCS), a noninvasive optical technique which, combined with frequency-domain near-infrared spectroscopy (FDNIRS), also provides a measure of oxygen metabolism.

Methods

We used DCS in combination with FDNIRS to simultaneously measure hemoglobin oxygen saturation (SO₂), an index of cerebral blood flow (CBF_i), and an index of cerebral metabolic rate of oxygen (CMRO_2i) in 12 patients undergoing cardiac surgery with HCA.

Results

Our measurements revealed that a negligible amount of blood is delivered to the cerebral cortex during HCA with retrograde cerebral perfusion, indistinguishable from HCA-only cases (median CBF_i drops of 93% and 95%, respectively) with consequent similar decreases in SO₂ (mean decrease of 0.6 ± 0.1% and 0.9 ± 0.2% per minute, respectively); CBF_i and SO₂ are mostly maintained with antegrade cerebral perfusion; the relationship of CMRO_2i to temperature is given by CMRO_2i = 0.052e^0.079T.

Conclusions

FDNIRS-DCS is able to detect changes in CBF_i, SO₂, and CMRO_2i with intervention and can become a valuable tool for optimizing cerebral protection during HCA.

Progressive vasoconstriction with sequential thermal stimulation indicates vascular dysautonomia in sickle cell disease

Persons with sickle cell disease (SCD) exhibit subjective hypersensitivity to cold and heat perception in experimental settings, and triggers such as cold exposure are known to precipitate vaso-occlusive crises by still unclear mechanisms. Decreased microvascular blood flow (MBF) increases the likelihood of vaso-occlusion by increasing entrapment of sickled red blood cells in the microvasculature. Because those with SCD have dysautonomia, we anticipated that thermal exposure would induce autonomic hypersensitivity of their microvasculature with an increased propensity toward vasoconstriction. We exposed 17 patients with SCD and 16 control participants to a sequence of predetermined threshold temperatures for cold and heat detection and cold and heat pain via a thermode placed on the right hand. MBF was measured on the contralateral hand by photoplethysmography, and cardiac autonomic balance was assessed by determining heart rate variability. Thermal stimuli at both detection and pain thresholds caused a significant decrease in MBF in the contralateral hand within seconds of stimulus application, with patients with SCD showing significantly stronger vasoconstriction (P = .019). Furthermore, patients with SCD showed a greater progressive decrease in blood flow than did the controls, with poor recovery between episodes of thermal stimulation (P = .042). They had faster vasoconstriction than the controls (P = .033), especially with cold detection stimulus. Individuals with higher anxiety also experienced more rapid vasoconstriction (P = .007). Augmented vasoconstriction responses and progressive decreases in perfusion with repeated thermal stimulation in SCD are indicative of autonomic hypersensitivity in the microvasculature. These effects are likely to increase red cell entrapment in response to clinical triggers such as cold or stress, which have been associated with vaso-occlusive crises in SCD.

Abstract 6678: Sensitive HLA loss of heterozygosity detection reveals allele-specific neoantigen expansion as resistance mechanism to anti-PD-1 therapy

Loss of heterozygosity (LOH) in the HLA locus is increasingly being recognized as an important mechanism of immune escape and a proposed biomarker for immunotherapy response. Neoantigens that bind to a deleted HLA allele will no longer be presented to the immune system, potentially allowing subclones with these deletions to escape immune surveillance. Despite interest in the field, few methods exist to detect HLA LOH, and their sensitivity is not well understood. Moreover, the mechanistic impact of HLA LOH in response to immune checkpoint inhibitors (ICI) remains unexplored. Here, using a novel tool to detect HLA LOH, DASH (Deletion of Allele-Specific HLAs), we reveal allele-specific neoantigen expansion in response to ICIs in a head and neck carcinoma cohort and the widespread occurrence of HLA LOH across several tumor types.

We performed exome sequencing with ImmunoID NeXT, which enhances coverage of the HLA locus, on tumor and normal samples from 260 patients to create a training dataset for our model. For each patient, we mapped reads to each of their allele-specific HLAs and manually annotated LOH. Then, using purity, ploidy and two novel features (normalized b-allele frequency and allele-specific coverage ratios), we trained an XGBoost model.

To evaluate our tool, we compared DASH predictions on held out tumor samples to deletion calls from a standard copy number tool in the regions flanking each HLA gene (91% concordance, 0.73 F1-score), ascertained our sensitivity by diluting cell line data with known HLA LOH to imitate variable purity (100% accuracy in samples above 17% purity) and confirmed the functional impact of HLA LOH using immunopeptidomics data of tumor samples (average of 47% fewer unique peptides binding to lost alleles than kept). To explore the mechanistic impact of HLA LOH in response to ICIs, we studied a cohort of nine head and neck carcinoma patients who received a single dose of nivolumab, and sequenced pre- and posttreatment tumor biopsies for each patient. With DASH, we detected HLA LOH in four of the patients, pretreatment. For these patients, we found a significant posttreatment expansion of neoantigens predicted to bind to the deleted HLA alleles in comparison to the pretreatment biopsy (p=0.046, Wilcoxon signed-rank), revealing the evolutionary force of HLA LOH as a resistance mechanism during ICI therapy. To assess the pervasiveness of HLA LOH across tumor types, we applied DASH to over 500 pretreatment tumors across 13 tumor types and found highly variable frequencies of HLA LOH across the tumor types.

In summary, we developed a sensitive method to detect HLA LOH and exposed neoantigen expansion to deleted HLA alleles in response to ICI therapy, emphasizing the limitations of deleted alleles to ignite an immune response. Moreover, we found widespread occurrences of HLA LOH across tumor types, highlighting the importance of accurate HLA LOH detection as a pan-cancer biomarker.

Citation Format: Rachel Marty Pyke, Charles Abbott, Dattatreya Mellacheruvu, Simo V. Zhang, Nikita Bedi, A. Dimitrios Colevas, John Sunwoo, John West, Richard Chen, Sean Michael Boyle. Sensitive HLA loss of heterozygosity detection reveals allele-specific neoantigen expansion as resistance mechanism to anti-PD-1 therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6678.

Abstract B08: High-resolution positron emission microscopy of patient-derived tumor organoids

Tumor organoids are self-organizing three-dimensional tumor models grown in vitro from patient-derived tumor tissue. They closely recapitulate the structural and functional microenvironment of solid tumors. Rapid translation of biomedical information from preclinical models to patients requires imaging biomarkers that span the full scale of tumor models. However, a key limitation is that, unlike human patients or preclinical mouse models, the tiny organoids are incompatible with the suite of radiologic tools used in oncology clinics. Here, we present 18F-fluorodeoxyglucose positron-emission microscopy (FDG-PEM), a radioluminescence-based technique for imaging glucose metabolism in patient-derived tumor organoids with spatial resolution 100-fold better than that of clinical positron emission tomography (PET). Tumor organoids derived from head-and-neck cancer patients were imaged to reveal metabolic maps that, in combination with brightfield imaging, functionally mirror the PET/CT images from the clinic. Tumor organoids were fed with FDG and mounted on a thin CdWO4 scintillator plate. Scintillator flashes were directly imaged by a single-photon-sensitivity electron-multiplying charge-coupled devices (EMCCD) camera. The EMCCD signal was calibrated with known radioactivity of FDG for accurate quantification of PEM images. Dual-modality PEM/fluorescence imaging found that FDG uptake occurred mainly in the viable region of tumor organoids and was more specific than staining by 2-NBDG, a fluorescent glucose mimetic. The influx rate constant (Ki) of FDG into the tumor organoids was calculated and found to be similar to the patient tumor from which the organoids were grown. This positive correlation of FDG influx between patient and organoid tumor suggests that PEM can be a preclinical tool to bridge the gap between laboratory and clinical cancer imaging. Finally, organoids treated with cisplatin displayed a dose-dependent decrease in the metabolic activity, while organoids derived from cisplatin-resistant patients retained high metabolic activity despite cisplatin treatment. Our results suggest that PEM imaging of patient-derived organoids could be used to predict individual patient response to different treatments to provide a more personalized approach to cancer care.

Citation Format: Syamantak Khan, June Ho Shin, Ning Cheng, Calvin Kuo, John Sunwoo, Guillem Pratx. High-resolution positron emission microscopy of patient-derived tumor organoids [abstract]. In: Proceedings of the AACR Special Conference on the Evolving Landscape of Cancer Modeling; 2020 Mar 2-5; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2020;80(11 Suppl):Abstract nr B08.

0935 Association Between Chronotype, Sleep Duration, Weekend Catch-Up Sleep, and Depression Among Korean High School Students

Introduction

The present study aimed to examine the association between chronotype, sleep duration, weekend catch-up sleep (CUS) duration, and depression among Korean high school students.

Methods

A total of 8,565 high school students who were analyzed from 15 nationwide districts in South Korea completed an online self-report questionnaire. Depressive mood was assessed using the Korean version of the Beck Depression Inventory. The following sleep characteristics were assessed: weekday and weekend sleep durations, weekend CUS duration, chronotype, perceived sufficiency of sleep, self-reported snoring and sleep apnea, daytime sleepiness, and sleep environment. Age, sex, body mass index, number of private classes, and proneness to internet addiction were also measured. Logistic regression analysis was conducted to compute odds ratios for the association between depression and sleep characteristics, after controlling for relevant covariates.

Results

The prevalence of depression (BDI ≥ 16) was 1,794 (20.9%). In the analyses of multivariate logistic regression, the late chronotype (odds ratio [OR], 1.71; 95% CI, 1.47-1.99), female (OR, 2.24; 95% CI, 1.99-2.53), underweight (OR, 1.27; 95% CI, 1.02-1.57) and obesity (OR, 1.41; 95% CI, 1.13-1.75), weekday sleep duration (OR, 0.86; 95% CI, 0.81-0.91), weekend CUS duration ≥ 2 hours (OR, 0.68; 95% CI, 0.55-0.85), ESS (OR, 1.08; 95% CI, 1.07-1.10), much (OR, 2.15; 95% CI, 1.63-2.84) and insufficient (OR, 1.71; 95% CI, 1.46-2.01) perceived sleep, snoring (OR, 1.27; 95% CI, 1.11-1.46) and witnessed apnea (OR, 2.10; 95% CI, 1.75-2.52), increased internet addiction (OR, 1.06; 95% CI, 1.05-1.06), high number of private education (OR, 0.76; 95% CI, 0.60-0.95), and poor sleep environment (OR, 1.86; 95% CI, 1.56-2.21) were associated with depression.

Conclusion

Eveningness preference, insufficient weekday sleep duration, short weekend CUS duration, and self-reported snoring and sleep apnea were associated with an increased risk for depression.

Support

 

Mental stress causes vasoconstriction in subjects with sickle cell disease and in normal controls

Vaso-occlusive crisis (VOC) is a hallmark of sickle cell disease (SCD) and occurs when deoxygenated sickled red blood cells occlude the microvasculature. Any stimulus, such as mental stress, which decreases microvascular blood flow will increase the likelihood of red cell entrapment resulting in local vaso-occlusion and progression to VOC. Neurally mediated vasoconstriction might be the physiological link between crisis triggers and vaso-occlusion. In this study, we determined the effect of mental stress on microvascular blood flow and autonomic nervous system reactivity. Sickle cell patients and controls performed mentally stressful tasks, including a memory task, conflict test and pain anticipation test. Blood flow was measured using photoplethysmography, autonomic reactivity was derived from electrocardiography and perceived stress was measured by the State-Trait Anxiety Inventory questionnaire. Stress tasks induced a significant decrease in microvascular blood flow, parasympathetic withdrawal and sympathetic activation in all subjects. Of the various tests, pain anticipation caused the highest degree of vasoconstriction. The magnitude of vasoconstriction, sympathetic activation and perceived stress was greater during the Stroop conflict test than during the N-back memory test, indicating the relationship between magnitude of experimental stress and degree of regional vasoconstriction. Baseline anxiety had a significant effect on the vasoconstrictive response in sickle cell subjects but not in controls. In conclusion, mental stress caused vasoconstriction and autonomic nervous system reactivity in all subjects. Although the pattern of responses was not significantly different between the two groups, the consequences of vasoconstriction can be quite significant in SCD because of the resultant entrapment of sickle cells in the microvasculature. This suggests that mental stress can precipitate a VOC in SCD by causing neural-mediated vasoconstriction.

Sickle Cell Disease Subjects Have a Distinct Abnormal Autonomic Phenotype Characterized by Peripheral Vasoconstriction With Blunted Cardiac Response to Head-Up Tilt

In sickle cell disease (SCD), prolonged capillary transit times, resulting from reduced peripheral blood flow, increase the likelihood of rigid red cells entrapment in the microvasculature, predisposing to vaso-occlusive crisis. Since changes in peripheral flow are mediated by the autonomic nervous system (ANS), we tested the hypothesis that the cardiac and peripheral vascular responses to head-up tilt (HUT) are abnormal in SCD. Heart rate, respiration, non-invasive continuous blood pressure and finger photoplethysmogram (PPG) were monitored before, during, and after HUT in SCD, anemic controls and healthy subjects. Percent increase in heart rate from baseline was used to quantify cardiac ANS response, while percent decrease in PPG amplitude represented degree of peripheral vasoconstriction. After employing cluster analysis to determine threshold levels, the HUT responses were classified into four phenotypes: (CP) increased heart rate and peripheral vasoconstriction; (C) increased heart rate only; (P) peripheral vasoconstriction only; and (ST) subthreshold cardiac and peripheral vascular responses. Multinomial logistic regression (MLR) was used to relate these phenotypic responses to various parameters representing blood properties and baseline cardiovascular activity. The most common phenotypic response, CP, was found in 82% of non-SCD subjects, including those with chronic anemia. In contrast, 70% of SCD subjects responded abnormally to HUT: C-phenotype = 22%, P-phenotype = 37%, or ST-phenotype = 11%. MLR revealed that the HUT phenotypes were significantly associated with baseline cardiac parasympathetic activity, baseline peripheral vascular variability, hemoglobin level and SCD diagnosis. Low parasympathetic activity at baseline dramatically increased the probability of belonging to the P-phenotype in SCD subjects, even after adjusting for hemoglobin level, suggesting a characteristic autonomic dysfunction that is independent of anemia. Further analysis using a mathematical model of heart rate variability revealed that the low parasympathetic activity in P-phenotype SCD subjects was due to impaired respiratory-cardiac coupling rather than reduced cardiac baroreflex sensitivity. By having strong peripheral vasoconstriction without compensatory cardiac responses, P-phenotype subjects may be at increased risk for vaso-occlusive crisis. The classification of autonomic phenotypes based on HUT response may have potential use for guiding therapeutic interventions to alleviate the risk of adverse outcomes in SCD.

A novel cross-correlation methodology for assessing biophysical responses associated with pain

Purpose

The purpose of this work was to noninvasively detect and quantify microvascular blood flow changes in response to externally applied pain in humans. The responsiveness of the microvasculature to pain stimulation might serve as an objective biomarker in diseases associated with altered pain perception and dysregulated vascular functions. The availability of such a biomarker may be useful as a tool for predicting outcome and response to treatments, particularly in diseases like sickle cell anemia where clinical manifestations are directly linked to microvascular perfusion. We, therefore, developed a method to distinguish the blood flow response due to the test stimulus from the blood flow measurement that also includes concurrent flow changes from unknown origins.

Subjects and methods

We measured the microvascular blood flow response in 24 healthy subjects in response to a train of randomly spaced and scaled heat pulses on the anterior forearm. The fingertip microvascular perfusion was measured using laser Doppler flowmetry. The cross-correlation between the heat pulses and the blood flow response was computed and tested for significance against the null distribution obtained from the baseline recording using bootstrapping method.

Results

We estimated correlation coefficients, response time, response significance, and the magnitude of vasoreactivity from microvascular blood flow responses. Based on these pain response indices, we identified strong responders and subjects who did not show significant responses.

Conclusion

The cross-correlation of a random pattern of painful stimuli with directly measured microvascular flow can detect vasoconstriction responses in a noisy blood flow signal, determine the time between stimulus and response, and quantify the magnitude of this response. This approach provided an objective measurement of vascular response to pain that may be an inherent characteristic of individual human subjects, and may also be related to the severity of vascular disorders.

Safety, tolerability, pharmacodynamics and pharmacokinetics of DWP14012, a novel potassium-competitive acid blocker, in healthy male subjects

BACKGROUND

A novel potassium-competitive acid blocker, DWP14012, is in clinical development as a potential alternative to proton pump inhibitors for the treatment of acid-related diseases.

AIMS

To evaluate the safety, tolerability, pharmacodynamics and pharmacokinetics of DWP14012 in humans.

METHODS

A randomised, double-blind, double-dummy, placebo- and active-controlled, single- and multiple-ascending dose (SAD and MAD, respectively) study was conducted in healthy male subjects without Helicobacter pylori infection. Subjects randomly received a single oral dose of 10-320 mg DWP14012, esomeprazole (active comparator) or placebo in the SAD study (n = 72) and once daily doses of 20-160 mg DWP14012, esomeprazole or placebo for 7 days in the MAD study (n = 48; 8:2:2). Tolerability was evaluated using a microRNA-122 assay. Pharmacodynamics were evaluated through 24-hour gastric pH monitoring, and pharmacokinetics were evaluated plasma and urine DWP14012 concentrations.

RESULTS

DWP14012 was generally well tolerated. The liver toxicity of DWP14012 was not higher than that of placebo after multiple oral administrations. DWP14012 showed rapid and sustained suppression of gastric acid secretion for 24 hours after dosing. Clear dose-response and exposure-response relationships were observed. Plasma concentrations of DWP14012 increased in a dose-proportional manner in the MAD study, whereas in the SAD study, DWP14012 did not significantly accumulate in the plasma.

CONCLUSIONS

DWP14012 was well tolerated, and showed a rapid and long-lasting gastric acid suppression effect in healthy subjects. These results justify further investigation of DWP14012 in patients with acid-related disorders.

Abstract 3411: Biological subtypes of nasopharyngeal carcinoma by genomic profiling

Objective:

Nasopharyngeal carcinoma (NPC) is a common Epstein-barr virus-associated epithelial malignancy in several parts of the world including Southeast Asia. While the majority of patients are treated uniformly with a combination of chemo and radiation therapy, 20% of patients experience recurrence, most commonly in the form of distant metastasis. NPC subtypes based on underlying differences in biology are unexplored and are likely responsible for the heterogeneous clinical response. As NPC biopsies are small and have significant stromal infiltrate, obtaining pure epithelial cells for genomic profiling is a challenge. We aim to overcome these limitations to identify biological subtypes and dysregulated molecular pathways in NPC.

Methods:

We first evaluated 217 whole exomes sequences, including 102 microdissected tumors, from three previous studies for single nucleotide variants and copy number changes, following GATK standards and using next generation sequencing copy number callers. We then applied a novel method for gene expression profiling developed in our lab to a new cohort of EBV-positive primary NPC cases from our institution. We performed laser capture microdissection, separately dissecting tumor, normal and microenvironment for each case. We applied Smart-3SEQ, a novel 3' end RNA-Seq technique which allows for the accurate quantification of transcript abundance in dissected FFPE samples comprising only a few hundred cells.

Results:

We achieved a per-base concordance of 80.4% between copy number profiles by SNP array and whole exome sequencing. Unsupervised clustering identified three distinct copy-number groups of NPC tumors, with a low copy-number group demonstrating an 18.7% better 5-year disease-specific survival, not attributable to stage. Apart from broad cytogenetic changes, narrow regions of amplifications (e.g. 1q21, 11q13) and deletions (e.g. 9p21, 11q22) were important for defining copy-number subtypes.

Preliminary differential gene expression analysis showed that genes involved in cell cycle and cellular differentiation were significantly dysregulated in tumor cells (p &lt; 0.001 and p = 0.03 respectively), while genes involved in cilia assembly and flagella transport were upregulated in normal cells (p &lt; 0.001 for both). Our further analysis includes defining tumor subtypes based on gene expression, identifying key driver pathways, and correlating with EBV-latent gene expression, the immune environment, as well as clinical outcome.

Conclusion:

NPC tumors are biologically heterogeneous and can be classified based on their mutational and gene expression profiles. This provides an important basis for the consideration of escalation and de-escalation of therapy in selected patient groups.

Citation Format: Kai Xun Joshua Tay, Chunfang Zhu, Sujay Vennam, Sushama Varma, Quynh-Thu Le, John Sunwoo, Robert West. Biological subtypes of nasopharyngeal carcinoma by genomic profiling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3411.

Experimentally constrained circuit model of cortical arteriole networks for understanding flow redistribution due to occlusion and neural activation

Computations are described which estimate flows in all branches of the cortical surface arteriole network from two-photon excited fluorescence (2PEF) microscopy images which provide the network topology and, in selected branches red blood cell (RBC) speeds and lumen diameters. Validation is done by comparing the flow predicted by the model with experimentally measured flows and by comparing the predicted flow redistribution in the network due to single-vessel strokes with experimental observations. The model predicts that tissue is protected from RBC flow decreases caused by multiple occlusions of surface arterioles but not penetrating arterioles. The model can also be used to study flow rerouting due to vessel dilations and constrictions.

Individuals with sickle cell disease have a significantly greater vasoconstriction response to thermal pain than controls and have significant vasoconstriction in response to anticipation of pain

The painful vaso-occlusive crises (VOC) that characterize sickle cell disease (SCD) progress over hours from the asymptomatic steady-state. SCD patients report that VOC can be triggered by stress, cold exposure, and, pain itself. We anticipated that pain could cause neural-mediated vasoconstriction, decreasing regional blood flow and promoting entrapment of sickle cells in the microvasculature. Therefore, we measured microvascular blood flow in the fingers of both hands using plethysmography and laser-Doppler flowmetry while applying a series of painful thermal stimuli on the right forearm in 23 SCD patients and 25 controls. Heat pain applied to one arm caused bilateral decrease in microvascular perfusion. The vasoconstriction response started before administration of the thermal pain stimulus in all subjects, suggesting that pain anticipation also causes significant vasoconstriction. The time delay between thermal pain application and global vasoconstriction ranged from 5 to 15.5 seconds and increased with age (P < .01). Although subjective measures, pain threshold and pain tolerance were not different between SCD subjects and controls, but the vaso-reactivity index characterizing the microvascular blood flow response to painful stimuli was significantly higher in SCD patients (P = .0028). This global vasoconstriction increases microvascular transit time, and may promote entrapment of sickle cells in the microvasculature, making vaso-occlusion more likely. The rapidity of the global vasoconstriction response indicates a neural origin that may play a part in the transition from steady-state to VOC, and may also contribute to the variability in VOC frequency observed in SCD patients.

Biophysical markers of the peripheral vasoconstriction response to pain in sickle cell disease

Painful vaso-occlusive crisis (VOC), a complication of sickle cell disease (SCD), occurs when sickled red blood cells obstruct flow in the microvasculature. We postulated that exaggerated sympathetically mediated vasoconstriction, endothelial dysfunction and the synergistic interaction between these two factors act together to reduce microvascular flow, promoting regional vaso-occlusions, setting the stage for VOC. We previously found that SCD subjects had stronger vasoconstriction response to pulses of heat-induced pain compared to controls but the relative degrees to which autonomic dysregulation, peripheral vascular dysfunction and their interaction are present in SCD remain unknown. In the present study, we employed a mathematical model to decompose the total vasoconstriction response to pain into: 1) the neurogenic component, 2) the vascular response to blood pressure, 3) respiratory coupling and 4) neurogenic-vascular interaction. The model allowed us to quantify the contribution of each component to the total vasoconstriction response. The most salient features of the components were extracted to represent biophysical markers of autonomic and vascular impairment in SCD and controls. These markers provide a means of phenotyping severity of disease in sickle-cell anemia that is based more on underlying physiology than on genotype. The marker of the vascular component (BM_v) showed stronger contribution to vasoconstriction in SCD than controls (p = 0.0409), suggesting a dominant myogenic response in the SCD subjects as a consequence of endothelial dysfunction. The marker of neurogenic-vascular interaction (BM_n-v) revealed that the interaction reinforced vasoconstriction in SCD but produced vasodilatory response in controls (p = 0.0167). This marked difference in BM_n-v suggests that it is the most sensitive marker for quantifying combined alterations in autonomic and vascular function in SCD in response to heat-induced pain.

Targeting CD137 enhances the efficacy of cetuximab

Treatment with cetuximab, an EGFR-targeting IgG1 mAb, results in beneficial, yet limited, clinical improvement for patients with head and neck (HN) cancer as well as colorectal cancer (CRC) patients with WT KRAS tumors. Antibody-dependent cell-mediated cytotoxicity (ADCC) by NK cells contributes to the efficacy of cetuximab. The costimulatory molecule CD137 (4-1BB) is expressed following NK and memory T cell activation. We found that isolated human NK cells substantially increased expression of CD137 when exposed to cetuximab-coated, EGFR-expressing HN and CRC cell lines. Furthermore, activation of CD137 with an agonistic mAb enhanced NK cell degranulation and cytotoxicity. In multiple murine xenograft models, including EGFR-expressing cancer cells, HN cells, and KRAS-WT and KRAS-mutant CRC, combined cetuximab and anti-CD137 mAb administration was synergistic and led to complete tumor resolution and prolonged survival, which was dependent on the presence of NK cells. In patients receiving cetuximab, the level of CD137 on circulating and intratumoral NK cells was dependent on postcetuximab time and host FcyRIIIa polymorphism. Interestingly, the increase in CD137-expressing NK cells directly correlated to an increase in EGFR-specific CD8+ T cells. These results support development of a sequential antibody approach against EGFR-expressing malignancies that first targets the tumor and then the host immune system.