Etonogestrel promotes respiratory recovery in an in vivo rat model of central chemoreflex impairment.

AIM: The central CO2 chemoreflex is a vital component of respiratory control networks, providing excitatory drive during resting conditions and challenges to blood gas homeostasis. The retrotrapezoid nucleus is a crucial hub for CO2 chemosensitivity; its ablation or inhibition attenuates CO2 chemoreflexes and diminishes restful breathing. Similar phenotypes characterize certain hypoventilation syndromes, suggesting underlying retrotrapezoid nucleus impairment in these disorders. Progesterone stimulates restful breathing and CO2 chemoreflexes. However, its mechanisms and sites of actions remain unknown and the experimental use of synthetic progestins in patients and animal models have been met with mixed respiratory outcomes. METHODS: We investigated whether acute or chronic administration of the progestinic drug, etonogestrel, could rescue respiratory chemoreflexes following selective lesion of the retrotrapezoid nucleus with saporin toxin. Adult female Sprague Dawley rats were grouped based on lesion size determined by the number of surviving chemosensitive neurons, and ventilatory responses were measured by whole body plethysmography. RESULTS: Ventilatory responses to hypercapnia (but not hypoxia) were compromised in a lesion-dependent manner. Chronic etonogestrel treatment improved CO2 chemosensitivity selectively in rats with moderate lesion, suggesting that a residual number of chemosensitive neurons are required for etonogestrel-induced CO2 chemoreflex recovery. CONCLUSION: This study provides new evidence for the use of progestins as respiratory stimulants under conditions of central hypoventilation and provides a new testable model for assessing the mechanism of action of progestins in the respiratory network.

Tumor-Targeted Nonablative Radiation Promotes Solid Tumor CAR T-cell Therapy Efficacy.

Infiltration of tumor by T cells is a prerequisite for successful immunotherapy of solid tumors. In this study, we investigate the influence of tumor-targeted radiation on chimeric antigen receptor (CAR) T-cell therapy tumor infiltration, accumulation, and efficacy in clinically relevant models of pleural mesothelioma and non-small cell lung cancers. We use a nonablative dose of tumor-targeted radiation prior to systemic administration of mesothelin-targeted CAR T cells to assess infiltration, proliferation, antitumor efficacy, and functional persistence of CAR T cells at primary and distant sites of tumor. A tumor-targeted, nonablative dose of radiation promotes early and high infiltration, proliferation, and functional persistence of CAR T cells. Tumor-targeted radiation promotes tumor-chemokine expression and chemokine-receptor expression in infiltrating T cells and results in a subpopulation of higher-intensity CAR-expressing T cells with high coexpression of chemokine receptors that further infiltrate distant sites of disease, enhancing CAR T-cell antitumor efficacy. Enhanced CAR T-cell efficacy is evident in models of both high-mesothelin-expressing mesothelioma and mixed-mesothelin-expressing lung cancer-two thoracic cancers for which radiotherapy is part of the standard of care. Our results strongly suggest that the use of tumor-targeted radiation prior to systemic administration of CAR T cells may substantially improve CAR T-cell therapy efficacy for solid tumors. Building on our observations, we describe a translational strategy of "sandwich" cell therapy for solid tumors that combines sequential metastatic site-targeted radiation and CAR T cells-a regional solution to overcome barriers to systemic delivery of CAR T cells.

Correlative analysis from a phase I clinical trial of intrapleural administration of oncolytic vaccinia virus (Olvi-vec) in patients with malignant pleural mesothelioma.

Background: The attenuated, genetically engineered vaccinia virus has been shown to be a promising oncolytic virus for the treatment of patients with solid tumors, through both direct cytotoxic and immune-activating effects. Whereas systemically administered oncolytic viruses can be neutralized by pre-existing antibodies, locoregionally administered viruses can infect tumor cells and generate immune responses. We conducted a phase I clinical trial to investigate the safety, feasibility and immune activating effects of intrapleural administration of oncolytic vaccinia virus (NCT01766739). Methods: Eighteen patients with malignant pleural effusion due to either malignant pleural mesothelioma or metastatic disease (non-small cell lung cancer or breast cancer) underwent intrapleural administration of the oncolytic vaccinia virus using a dose-escalating method, following drainage of malignant pleural effusion. The primary objective of this trial was to determine a recommended dose of attenuated vaccinia virus. The secondary objectives were to assess feasibility, safety and tolerability; evaluate viral presence in the tumor and serum as well as viral shedding in pleural fluid, sputum, and urine; and evaluate anti-vaccinia virus immune response. Correlative analyses were performed on body fluids, peripheral blood, and tumor specimens obtained from pre- and post-treatment timepoints. Results: Treatment with attenuated vaccinia virus at the dose of 1.00E+07 plaque-forming units (PFU) to 6.00E+09 PFU was feasible and safe, with no treatment-associated mortalities or dose-limiting toxicities. Vaccinia virus was detectable in tumor cells 2-5 days post-treatment, and treatment was associated with a decrease in tumor cell density and an increase in immune cell density as assessed by a pathologist blinded to the clinical observations. An increase in both effector (CD8+, NK, cytotoxic cells) and suppressor (Tregs) immune cell populations was observed following treatment. Dendritic cell and neutrophil populations were also increased, and immune effector and immune checkpoint proteins (granzyme B, perforin, PD-1, PD-L1, and PD-L2) and cytokines (IFN-γ, TNF-α, TGFß1 and RANTES) were upregulated. Conclusion: The intrapleural administration of oncolytic vaccinia viral therapy is safe and feasible and generates regional immune response without overt systemic symptoms. Clinical trial registration: https://clinicaltrials.gov/ct2/show/NCT01766739, identifier NCT01766739.

Micropapillary and Solid Histologic Patterns in N1 and N2 Lymph Node Metastases Are Independent Factors of Poor Prognosis in Patients With Stages II to III Lung Adenocarcinoma.

INTRODUCTION: High-grade histologic patterns are associated with poor prognosis in patients with primary nonmucinous lung adenocarcinoma (ADC). We investigated whether the presence of micropapillary (MIP), solid (SOL), or both patterns in lymph node (LN) metastases has prognostic value. METHODS: Patients who underwent lobectomy for pathologic stages II to III lung ADC with N1 or N2 LN metastases (N = 360; 2000-2012) were analyzed. We assessed overall survival (OS), lung cancer-specific cumulative incidence of death (LC-CID), and cumulative incidence of recurrence (CIR) between patients with and without MIP/SOL patterns in LN metastases. Multivariable Cox regression analysis was used to quantify the association between MIP/SOL patterns and outcomes. RESULTS: MIP and SOL in LN metastases were associated with a higher incidence of smoking history (p = 0.004), tumor necrosis (p = 0.013), and spread of tumor through air spaces (p < 0.0001), a higher prevalence of MIP or SOL in the primary tumor (p < 0.0001), shorter OS (5-y OS, 40% [95% confidence interval or CI: 29%-56%] versus 63% [48%-83%] for no MIP/SOL in LNs, p = 0.03), higher LC-CID (5-y, 43% [29%-56%] versus 14% [4%-29%], p = 0.013), and higher CIR (5-y, 65% [50%-77%] versus 43% [25%-60%], p = 0.057). MIP and SOL in LN metastases were independently associated with poor outcomes: OS (hazard ratio [HR] = 1.81 [95% CI: 1.00-3.29], p = 0.05), LC-CID (HR = 3.10 [1.30-7.37], p = 0.01), and CIR (HR = 2.06 [1.09-3.90], p = 0.026). CONCLUSIONS: MIP/SOL histologic patterns in N1 or N2 LN metastases are associated with worse outcomes in patients with stages II to III lung ADC. MIP/SOL histologic patterns in LN metastases can stratify patients with high-risk stages II to III lung ADC.

Next-generation immunotherapy for solid tumors: combination immunotherapy with crosstalk blockade of TGFß and PD-1/PD-L1.

INTRODUCTION: In solid tumor immunotherapy, less than 20% of patients respond to anti-programmed cell death 1 (PD-1)/programmed cell death 1 ligand 1 (PD-L1) agents. The role of transforming growth factor ß (TGFß) in diverse immunity is well-established; however, systemic blockade of TGFß is associated with toxicity. Accumulating evidence suggests the role of crosstalk between TGFß and PD-1/PD-L1 pathways. AREAS COVERED: We focus on TGFß and PD-1/PD-L1 signaling pathway crosstalk and the determinant role of TGFß in the resistance of immune checkpoint blockade. We provide the rationale for combination anti-TGFß and anti-PD-1/PD-L1 therapies for solid tumors and discuss the current status of dual blockade therapy in preclinical and clinical studies. EXPERT OPINION: The heterogeneity of tumor microenvironment across solid tumors complicates patient selection, treatment regimens, and response and toxicity assessment for investigation of dual blockade agents. However, clinical knowledge from single-agent studies provides infrastructure to translate dual blockade therapies. Dual TGFß and PD-1/PD-L1 blockade results in enhanced T-cell infiltration into tumors, a primary requisite for successful immunotherapy. A bifunctional fusion protein specifically targets TGFß in the tumor microenvironment, avoiding systemic toxicity, and prevents interaction of PD-1+ cytotoxic cells with PD-L1+ tumor cells.

Etonogestrel Administration Reduces the Expression of PHOX2B and Its Target Genes in the Solitary Tract Nucleus.

Heterozygous mutations of the transcription factor PHOX2B are responsible for Congenital Central Hypoventilation Syndrome, a neurological disorder characterized by inadequate respiratory response to hypercapnia and life-threatening hypoventilation during sleep. Although no cure is currently available, it was suggested that a potent progestin drug provides partial recovery of chemoreflex response. Previous in vitro data show a direct molecular link between progestins and PHOX2B expression. However, the mechanism through which these drugs ameliorate breathing in vivo remains unknown. Here, we investigated the effects of chronic administration of the potent progestin drug Etonogestrel (ETO) on respiratory function and transcriptional activity in adult female rats. We assessed respiratory function with whole-body plethysmography and measured genomic changes in brain regions important for respiratory control. Our results show that ETO reduced metabolic activity, leading to an enhanced chemoreflex response and concurrent increased breathing cycle variability at rest. Furthermore, ETO-treated brains showed reduced mRNA and protein expression of PHOX2B and its target genes selectively in the dorsal vagal complex, while other areas were unaffected. Histological analysis suggests that changes occurred in the solitary tract nucleus (NTS). Thus, we propose that the NTS, rich in both progesterone receptors and PHOX2B, is a good candidate for ETO-induced respiratory modulation.

Expiratory activity during sleep in children.

Sleep irregularities and respiratory events (apnea, O2 desaturation or a combination thereof) are often present in the infant population. While inspiration is the main active process in the act of breathing, expiration is generally thought to occur passively. Although commonly considered as quiet during sleep, expiratory abdominal muscles have been proposed to be recruited to promote ventilation, facilitate gas exchange, and reduce the work of breathing during conditions of increased respiratory drive, exercise, or airway obstruction. In this study, we investigated the occurrence of expiratory abdominal muscle activity in polysomnographic studies of subjects (aged 0-2 years) suspected of sleep disordered breathing. Our results indicate that abdominal muscle activation occurs during sleep, most frequently during non-rapid eye movement and rapid-eye movement states compared to slow-wave sleep. Furthermore, abdominal muscle activity was present during regular breathing or associated with respiratory events (apneas or O2 desaturation). In the latter case, abdominal muscle recruitment more frequently followed the onset of respiratory events and terminated with recovery from blood O2 desaturation events. We conclude that expiratory abdominal muscle activity contributes to the pattern of respiratory muscle recruitment during sleep in infants and given its temporal relationship with respiratory events, we propose that its recruitment could facilitate proper ventilation by counteracting airway resistance and O2 desaturation in infancy across different stages of sleep.

Imaging CAR T-cell kinetics in solid tumors: Translational implications.

Success in solid tumor chimeric antigen receptor (CAR) T-cell therapy requires overcoming several barriers, including lung sequestration, inefficient accumulation within the tumor, and target-antigen heterogeneity. Understanding CAR T-cell kinetics can assist in the interpretation of therapy response and limitations and thereby facilitate developing successful strategies to treat solid tumors. As T-cell therapy response varies across metastatic sites, the assessment of CAR T-cell kinetics by peripheral blood analysis or a single-site tumor biopsy is inadequate for interpretation of therapy response. The use of tumor imaging alone has also proven to be insufficient to interpret response to therapy. To address these limitations, we conducted dual tumor and T-cell imaging by use of a bioluminescent reporter and positron emission tomography in clinically relevant mouse models of pleural mesothelioma and non-small cell lung cancer. We observed that the mode of delivery of T cells (systemic versus regional), T-cell activation status (presence or absence of antigen-expressing tumor), and tumor-antigen expression heterogeneity influence T-cell kinetics. The observations from our study underscore the need to identify and develop a T-cell reporter-in addition to standard parameters of tumor imaging and antitumor efficacy-that can be used for repeat imaging without compromising the efficacy of CAR T cells in vivo.

CAR T-cell therapy for pleural mesothelioma: Rationale, preclinical development, and clinical trials.

The aim of adoptive T-cell therapy is to promote tumor-infiltrating immune cells following the transfer of either tumor-harvested or genetically engineered T lymphocytes. A new chapter in adoptive T-cell therapy began with the success of chimeric antigen receptor (CAR) T-cell therapy. T cells harvested from peripheral blood are transduced with genetically engineered CARs that render the ability to recognize cancer cell-surface antigen and lyse cancer cells. The successes in CAR T-cell therapy for B-cell leukemia and lymphoma have led to efforts to expand this therapy to solid tumors. Herein, we discuss the rationale behind the preclinical development and clinical trials of T-cell therapies in patients with malignant pleural mesothelioma. Furthermore, we highlight the ongoing investigation of combination immunotherapy strategies to synergistically potentiate endogenous as well as adoptively transferred immunity.

Generation of recombinant hyperimmune globulins from diverse B-cell repertoires.

Plasma-derived polyclonal antibody therapeutics, such as intravenous immunoglobulin, have multiple drawbacks, including low potency, impurities, insufficient supply and batch-to-batch variation. Here we describe a microfluidics and molecular genomics strategy for capturing diverse mammalian antibody repertoires to create recombinant multivalent hyperimmune globulins. Our method generates of diverse mixtures of thousands of recombinant antibodies, enriched for specificity and activity against therapeutic targets. Each hyperimmune globulin product comprised thousands to tens of thousands of antibodies derived from convalescent or vaccinated human donors or from immunized mice. Using this approach, we generated hyperimmune globulins with potent neutralizing activity against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in under 3 months, Fc-engineered hyperimmune globulins specific for Zika virus that lacked antibody-dependent enhancement of disease, and hyperimmune globulins specific for lung pathogens present in patients with primary immune deficiency. To address the limitations of rabbit-derived anti-thymocyte globulin, we generated a recombinant human version and demonstrated its efficacy in mice against graft-versus-host disease.

Biodistribution and toxicity of epitope-functionalized dextran iron oxide nanoparticles in a pregnant murine model.

In pursuit of a preventive therapeutic for maternal autoantibody-related (MAR) autism, we assessed the toxicity, biodistribution, and clearance of a MAR specific peptide-functionalized dextran iron oxide nanoparticle system in pregnant murine dams. We previously synthesized ~15 nm citrate-coated dextran iron oxide nanoparticles (DIONPs), surface-modified with polyethylene glycol and MAR peptides to produce systems for nanoparticle-based autoantibody reception and entrapments (SNAREs). First, we investigated their immunogenicity and MAR lactate dehydrogenase B antibody uptake in murine serum in vitro. To assess biodistribution and toxicity, as well as systemic effects, we performed in vivo clinical and post mortem pathological evaluations. We observed minimal production of inflammatory cytokines-interleukin 10 (IL-10) and IL-12 following in vitro exposure of macrophages to SNAREs. We established the maximum tolerated dose of SNAREs to be 150 mg/kg at which deposition of iron was evident in the liver and lungs by histology and magnetic resonance imaging but no concurrent evidence of liver toxicity or lung infarction was detected. Further, SNAREs exhibited slower clearance from the maternal blood in pregnant dams compared to DIONPs based on serum total iron concentration. These findings demonstrated that the SNAREs have a prolonged presence in the blood and are safe for use in pregnant mice as evidenced by no associated organ damage, failure, inflammation, and fetal mortality. Determination of the MTD dose sets the basis for future studies investigating the efficacy of our nanoparticle formulation in a MAR autism mouse model.

Breathing During Sleep in the Postnatal Period of Rats: The Contribution of Active Expiration.

Breathing is most vulnerable to apneas and other disturbances during sleep in both humans and rodents, especially in the newborn period. We recently demonstrated in adult rats that, in contrast to the atonia typical of skeletal muscles during rapid eye movement sleep, the normally passive expiratory muscles become active, and their activity is associated with stabilization of breathing and increased ventilation. In this study, we investigated the relationship between respiration and expiratory muscle recruitment across sleep states during the first 2 weeks of rat postnatal development. We instrumented rats with electromyography electrodes in neck and abdominal muscles while sleep states (active and quiet sleep) were classified based on nuchal muscle tone and overt behavior inside a whole-body plethysmograph. Our results indicate that breathing was most irregular in active sleep (AS) and that rats displayed frequent recruitment of expiratory muscle activity, which occurred in both active and quiet sleep states. While the occurrence of active expiration in quiet sleep did not affect ventilation and its frequency decreased with age, the recruitment of expiratory muscles during AS was present across development and it was associated with a reduction in respiratory variability across development and an increase in ventilation at most age groups considered. We conclude that the occurrence of active expiration is a common feature of respiration in the postnatal period, and it significantly contributes to ventilation, in particular in AS.