Peripheral blood immune cell dynamics reflect antitumor immune responses and predict clinical response to immunotherapy.

BACKGROUND: Despite treatment advancements with immunotherapy, our understanding of response relies on tissue-based, static tumor features such as tumor mutation burden (TMB) and programmed death-ligand 1 (PD-L1) expression. These approaches are limited in capturing the plasticity of tumor-immune system interactions under selective pressure of immune checkpoint blockade and predicting therapeutic response and long-term outcomes. Here, we investigate the relationship between serial assessment of peripheral blood cell counts and tumor burden dynamics in the context of an evolving tumor ecosystem during immune checkpoint blockade. METHODS: Using machine learning, we integrated dynamics in peripheral blood immune cell subsets, including neutrophil-lymphocyte ratio (NLR), from 239 patients with metastatic non-small cell lung cancer (NSCLC) and predicted clinical outcome with immune checkpoint blockade. We then sought to interpret NLR dynamics in the context of transcriptomic and T cell repertoire trajectories for 26 patients with early stage NSCLC who received neoadjuvant immune checkpoint blockade. We further determined the relationship between NLR dynamics, pathologic response and circulating tumor DNA (ctDNA) clearance. RESULTS: Integrated dynamics of peripheral blood cell counts, predominantly NLR dynamics and changes in eosinophil levels, predicted clinical outcome, outperforming both TMB and PD-L1 expression. As early changes in NLR were a key predictor of response, we linked NLR dynamics with serial RNA sequencing deconvolution and T cell receptor sequencing to investigate differential tumor microenvironment reshaping during therapy for patients with reduction in peripheral NLR. Reductions in NLR were associated with induction of interferon-γ responses driving the expression of antigen presentation and proinflammatory gene sets coupled with reshaping of the intratumoral T cell repertoire. In addition, NLR dynamics reflected tumor regression assessed by pathological responses and complemented ctDNA kinetics in predicting long-term outcome. Elevated peripheral eosinophil levels during immune checkpoint blockade were correlated with therapeutic response in both metastatic and early stage cohorts. CONCLUSIONS: Our findings suggest that early dynamics in peripheral blood immune cell subsets reflect changes in the tumor microenvironment and capture antitumor immune responses, ultimately reflecting clinical outcomes with immune checkpoint blockade.

Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons.

A developmental program of epigenetic repression prepares each mammalian olfactory sensory neuron (OSN) to strongly express one allele from just one of hundreds of odorant receptor (OR) genes, but what completes this process of OR gene choice by driving the expression of this allele is incompletely understood. Conditional deletion experiments in mice demonstrate that Lhx2 is necessary for normal expression frequencies of nearly all ORs and all trace amine-associated receptors, irrespective of whether the deletion of Lhx2 is initiated in immature or mature OSNs. Given previous evidence that Lhx2 binds OR gene control elements, these findings indicate that Lhx2 is directly involved in driving OR expression. The data also support the conclusion that OR expression is necessary to allow immature OSNs to complete differentiation and become mature. In contrast to the robust effects of conditional deletion of Lhx2, the loss of Emx2 has much smaller effects and more often causes increased expression frequencies. Lhx2:Emx2 double mutants show opposing effects on Olfr15 expression that reveal independent effects of these two transcription factors. While Lhx2 is necessary for OR expression that supports OR gene choice, Emx2 can act differently; perhaps by helping to control the availability of OR genes for expression.

Decision support environment for medical product safety surveillance.

We have developed a Decision Support Environment (DSE) for medical experts at the US Food and Drug Administration (FDA). The DSE contains two integrated systems: The Event-based Text-mining of Health Electronic Records (ETHER) and the Pattern-based and Advanced Network Analyzer for Clinical Evaluation and Assessment (PANACEA). These systems assist medical experts in reviewing reports submitted to the Vaccine Adverse Event Reporting System (VAERS) and the FDA Adverse Event Reporting System (FAERS). In this manuscript, we describe the DSE architecture and key functionalities, and examine its potential contributions to the signal management process by focusing on four use cases: the identification of missing cases from a case series, the identification of duplicate case reports, retrieving cases for a case series analysis, and community detection for signal identification and characterization.

TPM: cloud-based tele-PTSD monitor using multi-dimensional information.

An automated system that can remotely and non-intrusively screen individuals at high risk for Post-Traumatic Stress Disorder (PTSD) and monitor their progress during treatment would be desired by many Veterans Affairs (VAs) as well as other PTSD treatment and research organizations. In this paper, we present an automated, cloud-based Tele-PTSD Monitor (TPM) system based on the fusion of multiple sources of information. The TPM system can be hosted in a cloud environment and accessed through landline or cell phones, or on the Internet through a web portal or mobile application (app).

A voice-based automated system for PTSD screening and monitoring.

Comprehensive evaluation of PTSD includes diagnostic interviews, self-report testing, and physiological reactivity measures. It is often difficult and costly to diagnose PTSD due to patient access and the variability in symptoms presented. Additionally, potential patients are often reluctant to seek help due to the stigma associated with the disorder. A voice-based automated system that is able to remotely screen individuals at high risk for PTSD and monitor their symptoms during treatment has the potential to make great strides in alleviating the barriers to cost effective PTSD assessment and progress monitoring. In this paper we present a voice-based automated Tele-PTSD Monitor (TPM) system currently in development, designed to remotely screen, and provide assistance to clinicians in diagnosing PTSD. The TPM system can be accessed via a Public Switched Telephone Network (PSTN) or the Internet. The acquired voice data is then sent to a secure server to invoke the PTSD Scoring Engine (PTSD-SE) where a PTSD mental health score is computed. If the score exceeds a predefined threshold, the system will notify clinicians (via email or short message service) for confirmation and/or an appropriate follow-up assessment and intervention. The TPM system requires only voice input and performs computer-based automated PTSD scoring, resulting in low cost and easy field-deployment. The concept of the TPM system was supported using a limited dataset with an average detection accuracy of up to 95.88%.

Altered expression of TRPV1 and sensitivity to capsaicin in pulmonary myelinated afferents following chronic airway inflammation in the rat.

Vagal pulmonary myelinated afferents are normally not activated by capsaicin, a selective agonist of transient receptor potential vanilloid type 1 (TRPV1) receptors. This study was carried out to investigate whether the expression of TRPV1 in these afferents is altered when chronic airway inflammation is induced by ovalbumin (Ova) sensitization. Two groups of Brown-Norway rats (sensitized and control) were exposed to aerosolized Ova and vehicle, respectively, 3 days per week for 3 weeks. After the C-fibre conduction in both vagus nerves was blocked, right-atrial injection of capsaicin elicited augmented breaths in sensitized rats breathing spontaneously, but not in control rats, indicating a stimulation of rapidly adapting receptors (RARs) by capsaicin. Single-unit fibre activities of RARs and slow adapting receptors (SARs), identified by their firing behaviour and adaptation indexes in response to lung inflation, were recorded in anaesthetized, vagotomized and artificially ventilated rats. Capsaicin injection evoked either negligible or no response in both RARs and SARs of control rats. However, in striking contrast, the same dose of capsaicin evoked an immediate stimulatory effect on these myelinated afferents in sensitized rats. Furthermore, the immunohistochemistry experiments showed that there was a significant increase in the proportion of TRPV1-expressing pulmonary neurones in nodose ganglia of sensitized rats; this increase in TRPV1 expression was found mainly in neurofilament-positive (myelinated) neurones. In conclusion, allergen-induced airway inflammation clearly elevated capsaicin sensitivity in myelinated pulmonary afferents, which probably resulted from an increased expression of TRPV1 in these sensory nerves.

Sensitizing effects of chronic exposure and acute inhalation of ovalbumin aerosol on pulmonary C fibers in rats.

The effect of ovalbumin (Ova) sensitization on pulmonary C-fiber sensitivity was investigated. Brown-Norway rats were sensitized by intraperitoneal injection of Ova followed by aerosolized Ova three times per week for 3 wk. Control rats received the vehicle. At the end of the third week, single-unit fiber activities (FA) of pulmonary C fibers were recorded in anesthetized, artificially ventilated rats. Our results showed the following: 1) Ova sensitization induced airway inflammation (infiltration of eosinophils and neutrophils) and airway hyperresponsiveness in rats; 2) baseline FA in sensitized rats was significantly higher than that in control ones; 3) similarly, the pulmonary C-fiber response to right atrial injection of capsaicin was markedly higher in sensitized rats, which were significantly amplified after the acute Ova inhalation challenge; and 4) similar patterns, but smaller magnitudes of the differences in C-fiber responses to adenosine and lung inflation, were also found between sensitized and control rats. In conclusion, Ova sensitization elevated the baseline FA and excitability of pulmonary C fibers, and the hypersensitivity was further potentiated after the acute Ova inhalation challenge in sensitized rats. Chronic allergic inflammatory reactions in the airway probably contributed to the sensitizing effect on these lung afferents.

Calcium transient evoked by nicotine in isolated rat vagal pulmonary sensory neurons.

It has been shown that inhaled cigarette smoke activates vagal pulmonary C fibers and rapidly adapting receptors (RARs) in the airways and that nicotine contained in the smoke is primarily responsible. This study was carried out to determine whether nicotine alone can activate pulmonary sensory neurons isolated from rat vagal ganglia; the response of these neurons was determined by fura-2-based ratiometric Ca(2+) imaging. The results showed: 1) Nicotine (10(-4) M, 20 s) evoked a transient increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) in 175 of the 522 neurons tested (Delta[Ca(2+)](i) = 142.2 +/- 12.3 nM); the response was reproducible, with a small reduction in peak amplitude in the same neurons when the challenge was repeated 20 min later. 2) A majority (59.7%) of these nicotine-sensitive neurons were also activated by capsaicin (10(-7) M). 3) 1,1-Dimethyl-4-phenylpiperazinium iodide (DMPP; 10(-4) M, 20 s), a selective agonist of the neuronal nicotinic acetylcholine receptors (NnAChRs), evoked a pattern of response similar to that of nicotine. 4) The responses to nicotine and DMPP were either totally abrogated or markedly attenuated by hexamethonium (10(-4) M). 5) In anesthetized rats, right atrial bolus injection of nicotine (75-200 mug/kg) evoked an immediate (latency <1-2 s) and intense burst of discharge in 47.8% of the pulmonary C-fiber endings and 28.6% of the RARs tested. In conclusion, nicotine exerts a direct stimulatory effect on vagal pulmonary sensory nerves, and the effect is probably mediated through an activation of the NnAChRs expressed on the membrane of these neurons.

Prostaglandin E2 enhances the sensitizing effect of hyperthermia on pulmonary C-fibers in rats.

This study was carried out to investigate whether the pulmonary C-fiber hypersensitivity induced by hyperthermia is altered by prostaglandin E(2) (PGE(2)). Single-unit afferent activities of pulmonary C-fibers were recorded in anesthetized, artificially ventilated rats when the intrathoracic temperature (T(it)) was maintained at normal (N; approximately 36 degrees C) and hyperthermia levels (H; approximately 41 degrees C) by perfusion of heated saline into the thoracic chamber for 3min. After approximately 20min of recovery, the fiber activities were recorded again during infusion of PGE(2) at both N and H levels of T(it). Our study showed: (1) The baseline fiber activity and responses to lung inflation, right-atrial injection of capsaicin and adenosine were all increased by increasing T(it) from N to H, and these hyperthermia-induced increases in sensitivities were also significantly augmented by PGE(2). (2) These enhanced sensitivities induced by PGE(2) were abolished by pretreatment with AH6809 and AH23848, selective antagonists of EP(2) and EP(4) prostanoid receptors, respectively. In conclusion, the hyperthermia-induced hypersensitivity of vagal pulmonary C-fibers is potentiated by PGE(2), and this effect is mediated through activation of EP(2) and EP(4) prostanoid receptors.