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Purpose/Objective(s) Primary tumor failure is common in patients treated with chemoradiation (CRT) for unresectable LA-NSCLC. Stereotactic body radiation therapy (SBRT) yields high rates of primary tumor control in Stage I NSCLC. This trial tested an SBRT boost to the primary tumor prior to the start of CRT to improve primary tumor control (PTC). Materials/Methods Patients with LA-NSCLC with primary tumor ≤10 cm were enrolled on a prospective phase II trial testing an SBRT boost in 2 fractions (central 6 Gy x 2, peripheral 8 Gy x 2) immediately followed by standard concurrent CRT (60 Gy in 30 fractions). Patients were staged with PET-CT, brain MRI, and underwent 4D-CT simulation for radiation planning using a customized immobilization device that enabled radiation planning for the sequential delivery of the SBRT boost and conventionally-fractionated radiation from the same CT dataset. Chemotherapy was carboplatin/paclitaxel (C/P) or cisplatin/etoposide. For patients receiving C/P, consolidation C/P for 2 cycles was given at the discretion of the medical oncologist. The trial was later amended to allow for consolidation durvalumab. The primary objective was to estimate PTC rate at 1-year with a hypothesis that the 1-year PTC rate is ≥90%. Secondary objectives were to establish the safety, feasibility, objective response rate (ORR; RECISTv1.1), and rates of regional & distant control, disease-free survival (DFS), and overall survival (OS). Exploratory functional MRI (fMRI) scans before and within the first 30 hrs of the first SBRT fraction were performed in 11 patients. Results The study enrolled 21 patients (10 male, 11 female), with median age 62 years (range 52-78). 16 patients received 6 Gy x 2 SBRT boost, while 5 patients received 8 Gy x 2 SBRT boost. 18 patients received C/P chemotherapy, of whom 9 patients received consolidation C/P. Six patients received consolidation durvalumab. Median pre-treatment primary tumor size was 5.0 cm (range 1.0-8.3). Median and mean follow-up were17.9 and 20.2 months, respectively. The most common toxicities were fatigue, neutropenia, leukopenia, lymphopenia, anemia, pneumonitis, fibrosis, dyspnea and esophagitis. Five grade 4 toxicities related to treatment occurred [lymphopenia (3), neutropenia (1), and leukopenia (1)], but no grade 5 toxicities related to treatment occurred. ORR at 3 and 6 months was 72.7% and 80.0%. The PTC rate was 100% and 92.3% at 1 and 2 years, respectively. The 2-year regional and distant control were 81.6% and 70.3%, respectively. Disease-free survival and overall survival at 2 yrs were 46.1% and 50.3%, respectively. Median survival was 37.8 months. fMRI detected a mean relative decrease in BOLD signal of -87.1% (P = 0.05). Conclusion Dose escalation to the primary tumor utilizing upfront SBRT appears feasible and safe. PTC was high and other oncologic endpoints compared favorably with the literature. Through the use of 1 CT simulation dataset, accurate calculation of the planned dose through the 2 sequentially-delivered plans is achievable.

There are numerous mechanisms by which mammals respond to hypoxia. These include acute changes in pulmonary arterial tone due to smooth muscle cell contraction, acute increases in respiration triggered by the carotid body chemosensory cells, and chronic changes such as induction of red blood cell proliferation and angiogenesis by hypoxia inducible factor targets erythropoietin and vascular endothelial growth factor, respectively. Mitochondria account for the majority of oxygen consumption in the cell and have recently been appreciated to serve as signaling organelles required for the initiation or propagation of numerous homeostatic mechanisms. Mitochondria can influence cell signaling by production of reactive oxygen species and metabolites. Here we review recent evidence that mitochondrial signals can imitate acute and chronic hypoxia responses.

Mitochondrial complex I regenerates NAD+ and proton pumps for TCA cycle function and ATP production, respectively. Mitochondrial complex I dysfunction has been implicated in many brain pathologies including Leigh Syndrome and Parkinson’s disease. We sought to determine whether NAD+ regeneration or proton pumping is the dominant function of mitochondrial complex I in protection from brain pathology. We generated a mouse that conditionally expresses the yeast NDI1 protein, a single enzyme that can replace the NAD+ regeneration capability of the 45-subunit mammalian mitochondrial complex I without proton pumping. NDI1 expression was sufficient to dramatically prolong lifespan without significantly improving motor function in a mouse model of Leigh Syndrome. Therefore, complex I activity in the brain supports organismal survival through its NAD+ regeneration capacity while optimal motor control requires the bioenergetic function of mitochondrial complex I.

The continuing horrors of military conflicts and terrorism often involve the use of chemical warfare agents (CWAs) and toxic industrial chemicals (TICs). Many CWA and TIC exposures are difficult to treat due to the danger they pose to first responders and their rapid onset that can produce death shortly after exposure. While the specific mechanism(s) of toxicity of these agents are diverse, many are associated either directly or indirectly with increased oxidative stress in affected tissues. This has led to the exploration of various antioxidants as potential medical countermeasures for CWA/TIC exposures. Studies have been performed across a wide array of agents, model organisms, exposure systems, and antioxidants, looking at an almost equally diverse set of endpoints. Attempts at treating CWAs/TICs with antioxidants have met with mixed results, ranging from no effect to nearly complete protection. The aim of this commentary is to summarize the literature in each category for evidence of oxidative stress and antioxidant efficacy against CWAs and TICs. While there is great disparity in the data concerning methods, models, and remedies, the outlook on antioxidants as medical countermeasures for CWA/TIC management appears promising.

Although RNA interference (RNAi) has become a ubiquitous laboratory tool since its discovery 12 years ago, in vivo delivery to selected cell types remains a major technical challenge. Here, we report the use of lentiviral vectors for long-term in vivo delivery of RNAi selectively to resident alveolar macrophages (AMs), key immune effector cells in the lung. We demonstrate the therapeutic potential of this approach by RNAi-based downregulation of p65 (RelA), a component of the pro-inflammatory transcriptional regulator, nuclear factor κB (NF-κB) and a key participant in lung disease pathogenesis. In vivo RNAi delivery results in decreased induction of NF-κB and downstream neutrophilic chemokines in transduced AMs as well as attenuated lung neutrophilia following stimulation with lipopolysaccharide (LPS). Through concurrent delivery of a novel lentiviral reporter vector (lenti-NF-κB-luc-GFP) we track in vivo expression of NF-κB target genes in real time, a critical step towards extending RNAi-based therapy to longstanding lung diseases. Application of this system reveals that resident AMs persist in the airspaces of mice following the resolution of LPS-induced inflammation, thus allowing these localized cells to be used as effective vehicles for prolonged RNAi delivery in disease settings.

It is widely reported that Listeria monocytogenes can infect virtually all cell types, however, the degree to which this facultative intracellular pathogen can infect lymphocytes has not been well characterized. Previous studies have shown that a subset of lymphocytes, including activated T cells, are susceptible to apoptosis following exposure to L. monocytogenes, but the ability of the bacteria to replicate in the cytosol of lymphocytes prior to cell death was not examined. In this report, we demonstrate that intracellular L. monocytogenes can survive and multiply in vitro in a variety of transformed cell lines of lymphocytic origin. Intracellular L. monocytogenes were also recovered from splenic B cells, T cells, and NK cells following intravenous infection of mice. In fact, lymphocyte-associated L. monocytogenes comprised a substantial portion of the total bacterial burden in the spleen throughout the course of murine infection and B cell-deficient mice had significantly lower titers of bacteria present in the spleen following intravenous infection. These results suggest that lymphocytes can be a reservoir for L. monocytogenes growth in vivo.

Detection of cytotoxic activity by pathogen-specific T cells of unknown antigenic specificity is difficult due to the limitations of using infected cells, instead of peptide-pulsed cells, as targets. We report here that the recently described CD107 mobilization assay readily allowed for the ex vivo detection of cytotoxic T lymphocytes (CTL) with a novel MHC-Ib restriction that specifically recognized Listeria monocytogenes-infected macrophages. The CD107 mobilization assay is likely to be a useful tool for detection of CD8(+) T cells that recognize a wide variety of intracellular pathogens.