Profibrotic monocyte-derived alveolar macrophages are expanded in patients with persistent respiratory symptoms and radiographic abnormalities after COVID-19.

Monocyte-derived alveolar macrophages drive lung injury and fibrosis in murine models and are associated with pulmonary fibrosis in humans. Monocyte-derived alveolar macrophages have been suggested to develop a phenotype that promotes lung repair as injury resolves. We compared single-cell and cytokine profiling of the alveolar space in a cohort of 35 patients with post-acute sequelae of COVID-19 who had persistent respiratory symptoms and abnormalities on a computed tomography scan of the chest that subsequently improved or progressed. The abundance of monocyte-derived alveolar macrophages, their gene expression programs, and the level of the monocyte chemokine CCL2 in bronchoalveolar lavage fluid positively associated with the severity of radiographic fibrosis. Monocyte-derived alveolar macrophages from patients with resolving or progressive fibrosis expressed the same set of profibrotic genes. Our findings argue against a distinct reparative phenotype in monocyte-derived alveolar macrophages, highlighting their utility as a biomarker of failed lung repair and a potential target for therapy.

Hyperpolarized 129Xe MRI and spectroscopy of gas exchange abnormalities in chronic hypersensitivity pneumonitis.

PURPOSE: To evaluate 3D gas-exchange functional imaging characteristics using 129Xe MRI in a group of study participants with chronic hypersensitivity pneumonitis (CHP) as compared with healthy control participants. METHODS: In this prospective study, 11 participants with clinical and CT findings of CHP (4M 7F, mean age 67 ± 6.1 years) as well as 41 healthy subjects (25M 16F, mean age 44 ± 18 years) were enrolled between 2017 and 2022 and underwent 129Xe MRI. Three-dimensional images of ventilation, interstitial membrane uptake, and RBC transfer were rendered into quantitative 3D maps relative to a healthy reference cohort. In addition, 129Xe spectroscopy was used to assess the RBC:membrane ratio (RBC:M), the oxygen-dependent RBC chemical shift, and cardiogenically-driven RBC oscillation amplitude. Differences between the CHP participants and healthy subjects were assessed using the two-sample t-test or Wilcoxon rank-sum test as appropriate. RESULTS: CHP participants demonstrated significant differences in 6 parameters (p < 0.001) including regions of reduced ventilation, increased membrane uptake, and reduced RBC transfer as compared to healthy subjects. Gas exchange abnormalities measured on spectroscopy included a reduced RBC:M, reduced RBC chemical shift, and increased RBC oscillation amplitude. CONCLUSION: In participants with CHP, 129Xe MRI demonstrated gas exchange abnormalities common to other fibrotic lung diseases including increased membrane uptake, deficits in RBC transfer, and reduced RBC:M. However, CHP participants also exhibited prominent ventilation abnormalities, which may be reflective of the airway-centric nature of the disease. Further, the high variability observed in the membrane uptake could suggest varying degrees of disease progression or activity.

Cellular and In Vivo Response to Industrial, Food Grade, and Photocatalytic TiO2 Nanoparticles.

We encounter titanium dioxide nanoparticles (TiO2 NPs) throughout our daily lives in the form of food coloring, cosmetics, and industrial materials. They are used on a massive industrial scale, with over 1 million metric tons in the global market. For the workers who process these materials, inhalation is a major concern. The goal of our current research is to provide a direct comparison of the three major types of TiO2 NPs (P25, E171, R101) in terms of surface characterization, cellular response, and in vivo response following introduction into the lungs of mice. In both cellular and in vivo experiments, we observe a pro-inflammatory response to the P25 TiO2 NPs that is not observed in the E171 or R101 TiO2 NPs at mass-matched concentrations. Cellular experiments measured a cytokine, TNF-α, as a marker of a pro-inflammatory response. In vivo experiments in mice measured the number of immune cells and four pro-inflammatory cytokines (IL-6, MIP-2, IP-10, and MCP-1) present in bronchoalveolar lavage fluid. A detailed physical and chemical characterization of the TiO2 NPs shows that the P25 TiO2 NPs are distinguished by smaller primary particles suggesting that samples matched by mass contain a larger number of P25 TiO2 NPs. Cellular dose-response measurements with the P25, E171, and R101 TiO2 NPs support this hypothesis showing increased TNF-α release by macrophages as a function of TiO2 NP dose. Overall, this direct comparison of the three major types of TiO2 NPs shows that the number of particles in a dose, which is dependent on the particle diameter, is a key parameter in TiO2 NP-induced inflammation.

Altered ontogeny and transcriptomic signatures of tissue-resident pulmonary interstitial macrophages ameliorate allergic airway hyperresponsiveness.

Introduction: Environmental exposures and experimental manipulations can alter the ontogenetic composition of tissue-resident macrophages. However, the impact of these alterations on subsequent immune responses, particularly in allergic airway diseases, remains poorly understood. This study aims to elucidate the significance of modified macrophage ontogeny resulting from environmental exposures on allergic airway responses to house dust mite (HDM) allergen. Methods: We utilized embryonic lineage labeling to delineate the ontogenetic profile of tissue-resident macrophages at baseline and following the resolution of repeated lipopolysaccharide (LPS)-induced lung injury. We investigated differences in house dust mite (HDM)-induced allergy to assess the influence of macrophage ontogeny on allergic airway responses. Additionally, we employed single-cell RNA sequencing (scRNAseq) and immunofluorescent staining to characterize the pulmonary macrophage composition, associated pathways, and tissue localization. Results: Our findings demonstrate that the ontogeny of homeostatic alveolar and interstitial macrophages is altered after the resolution from repeated LPS-induced lung injury, leading to the replacement of embryonic-derived by bone marrow-derived macrophages. This shift in macrophage ontogeny is associated with reduced HDM-induced allergic airway responses. Through scRNAseq and immunofluorescent staining, we identified a distinct subset of resident-derived interstitial macrophages expressing genes associated with allergic airway diseases, localized adjacent to terminal bronchi, and diminished by prior LPS exposure. Discussion: These results suggest a pivotal role for pulmonary macrophage ontogeny in modulating allergic airway responses. Moreover, our findings highlight the implications of prior environmental exposures in shaping future immune responses and influencing the development of allergies. By elucidating the mechanisms underlying these phenomena, this study provides valuable insights into potential therapeutic targets for allergic airway diseases and avenues for further research into immune modulation and allergic disease prevention.

House Dust Mite Extract Forms a Der p 2 Corona on Multi-Walled Carbon Nanotubes: Implications for Allergic Airway Disease.

Multi-walled carbons nanotubes (MWCNTs) are used in materials for the construction, automotive, and aerospace industries. Workers and consumers are exposed to these materials via inhalation. Existing recommended exposure limits are based on MWCNT exposures that do not take into account more realistic co-exposures. Our goal was to understand how a common allergen, house dust mites, interacts with pristine MWCNTs and lung fluid proteins. We used gel electrophoresis, western blotting, and proteomics to characterize the composition of the allergen corona formed from house dust mite extract on the surface of MWCNTs. We found that the corona is dominated by der p 2, a protein associated with human allergic responses to house dust mites. Der p 2 remains adsorbed on the surface of the MWCNTs following subsequent exposures to lung fluid proteins. The high concentration of der p 2, localized on surface of MWCNTs, has important implications for house dust mite-induced allergies and asthma. This research provides a detailed characterization of the complex house dust mite-lung fluid protein coronas for future cellular and in vivo studies. These studies will help to address the molecular and biochemical mechanisms underlying the exacerbation of allergic lung disease by nanomaterials.

Prolonged exposure to lung-derived cytokines is associated with activation of microglia in patients with COVID-19.

BACKGROUNDSurvivors of pneumonia, including SARS-CoV-2 pneumonia, are at increased risk for cognitive dysfunction and dementia. In rodent models, cognitive dysfunction following pneumonia has been linked to the systemic release of lung-derived pro-inflammatory cytokines. Microglia are poised to respond to inflammatory signals from the circulation, and their dysfunction has been linked to cognitive impairment in murine models of dementia and in humans.METHODSWe measured levels of 55 cytokines and chemokines in bronchoalveolar lavage fluid and plasma from 341 patients with respiratory failure and 13 healthy controls, including 93 unvaccinated patients with COVID-19 and 203 patients with other causes of pneumonia. We used flow cytometry to sort neuroimmune cells from postmortem brain tissue from 5 patients who died from COVID-19 and 3 patients who died from other causes for single-cell RNA-sequencing.RESULTSMicroglia from patients with COVID-19 exhibited a transcriptomic signature suggestive of their activation by circulating pro-inflammatory cytokines. Peak levels of pro-inflammatory cytokines were similar in patients with pneumonia irrespective of etiology, but cumulative cytokine exposure was higher in patients with COVID-19. Treatment with corticosteroids reduced expression of COVID-19-specific cytokines.CONCLUSIONProlonged lung inflammation results in sustained elevations in circulating cytokines in patients with SARS-CoV-2 pneumonia compared with those with pneumonia secondary to other pathogens. Microglia from patients with COVID-19 exhibit transcriptional responses to inflammatory cytokines. These findings support data from rodent models causally linking systemic inflammation with cognitive dysfunction in pneumonia and support further investigation into the role of microglia in pneumonia-related cognitive dysfunction.FUNDINGSCRIPT U19AI135964, UL1TR001422, P01AG049665, P01HL154998, R01HL149883, R01LM013337, R01HL153122, R01HL147290, R01HL147575, R01HL158139, R01ES034350, R01ES027574, I01CX001777, U01TR003528, R21AG075423, T32AG020506, F31AG071225, T32HL076139.

Soil exposure modulates the immune response to an influenza challenge in a mouse model.

There is increasing evidence that early life microbial exposure aids in immune system maturation, more recently known as the "old friends" hypothesis. To test this hypothesis, 4-week-old mice were exposed to soils of increasing microbial diversity for four weeks followed by an intranasal challenge with either live or heat inactivated influenza A virus and monitored for 7 additional days. Perturbations of the gut and lung microbiomes were explored through 16S rRNA amplicon sequencing. RNA-sequencing was used to examine the host response in the lung tissue through differential gene expression. We determined that compared to the gut microbiome, the lung microbiome is more susceptible to changes in beta diversity following soil exposure with Lachnospiraceae ASVs accounting for most of the differences between groups. While several immune system genes were found to be significantly differentially expressed in lung tissue due to soil exposures, there were no differences in viral load or weight loss. This study shows that exposure to diverse microbial communities through soil exposure alters the gut and lung microbiomes resulting in differential expression of specific immune system related genes within the lung following an influenza challenge.

Tissue-Resident Alveolar Macrophages Reduce Ozone-induced Inflammation via MerTK-mediated Efferocytosis.

Lung inflammation, caused by acute exposure to ozone (O3), one of the six criteria air pollutants, is a significant source of morbidity in susceptible individuals. Alveolar macrophages (AMØs) are the most abundant immune cells in the normal lung, and their number increases after O3 exposure. However, the role of AMØs in promoting or limiting O3-induced lung inflammation has not been clearly defined. In this study, we used a mouse model of acute O3 exposure, lineage tracing, genetic knockouts, and data from O3-exposed human volunteers to define the role and ontogeny of AMØs during acute O3 exposure. Lineage-tracing experiments showed that 12, 24, and 72 hours after exposure to O3 (2 ppm) for 3 hours, all AMØs were of tissue-resident origin. Similarly, in humans exposed to filtered air and O3 (200 ppb) for 135 minutes, we did not observe at ∼21 hours postexposure an increase in monocyte-derived AMØs by flow cytometry. Highlighting a role for tissue-resident AMØs, we demonstrate that depletion of tissue-resident AMØs with clodronate-loaded liposomes led to persistence of neutrophils in the alveolar space after O3 exposure, suggesting that impaired neutrophil clearance (i.e., efferocytosis) leads to prolonged lung inflammation. Moreover, depletion of tissue-resident AMØs demonstrated reduced clearance of intratracheally instilled apoptotic Jurkat cells, consistent with reduced efferocytosis. Genetic ablation of MerTK (MER proto-oncogene, tyrosine kinase), a key receptor involved in efferocytosis, also resulted in impaired clearance of apoptotic neutrophils after O3 exposure. Overall, these findings underscore the pivotal role of tissue-resident AMØs in resolving O3-induced inflammation via MerTK-mediated efferocytosis.

Biocidal products: Opportunities in risk assessment, management, and communication.

In the coronavirus disease 2019 era, biocidal products are increasingly used for controlling harmful organisms, including microorganisms. However, assuring safety against adverse health effects is a critical issue from a public health standpoint. This study aimed to provide an overview of key aspects of risk assessment, management, and communication that ensure the safety of biocidal active ingredients and products. The inherent characteristics of biocidal products make them effective against pests and pathogens; however, they also possess potential toxicities. Therefore, public awareness regarding both the beneficial and potential adverse effects of biocidal products needs to be increased. Biocidal active ingredients and products are regulated under specific laws: the Federal Insecticide, Fungicide, and Rodenticide Act for the United States; the European Union (EU) Biocidal Products Regulation for the EU; and the Consumer Chemical Products and Biocide Safety Management Act for the Republic of Korea. Risk management also needs to consider the evidence of enhanced sensitivity to toxicities in individuals with chronic diseases, given the increased prevalence of these conditions in the population. This is particularly important for post-marketing safety assessments of biocidal products. Risk communication conveys information, including potential risks and risk-reduction measures, aimed at managing or controlling health or environmental risks. Taken together, the collaborative effort of stakeholders in risk assessment, management, and communication strategies is critical to ensuring the safety of biocidal products sold in the market as these strategies are constantly evolving.

Interaction of TiO2 nanoparticles with lung fluid proteins and the resulting macrophage inflammatory response.

Inhalation is a major exposure route to nanoparticles. Following inhalation, nanoparticles first interact with the lung lining fluid, a complex mixture of proteins, lipids, and mucins. We measure the concentration and composition of lung fluid proteins adsorbed on the surface of titanium dioxide (TiO2) nanoparticles. Using proteomics, we find that lung fluid results in a unique protein corona on the surface of the TiO2 nanoparticles. We then measure the expression of three cytokines (interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and macrophage inflammatory protein 2 (MIP-2)) associated with lung inflammation. We find that the corona formed from lung fluid leads to elevated expression of these cytokines in comparison to bare TiO2 nanoparticles or coronas formed from serum or albumin. These experiments show that understanding the concentration and composition of the protein corona is essential for understanding the pulmonary response associated with human exposure to nanoparticles.

Functional enhancement of mesothelin-targeted TRuC-T cells by a PD1-CD28 chimeric switch receptor.

T cells expressing a mesothelin (MSLN)-specific T cell receptor fusion construct (TRuC®), called TC-210, have demonstrated robust antitumor activity in preclinical models of mesothelioma, ovarian cancer, and lung cancer. However, they are susceptible to suppression by the programmed cell death protein 1 (PD-1)/programmed cell death protein ligand 1 (PD-L1) axis and lack intrinsic costimulatory signaling elements. To enhance the function of anti-MSLN TRuC-T cells, chimeric switch receptors (CSRs) have been designed to co-opt the immunosuppressive PD-1/PD-L1 axis and to deliver a CD28-mediated costimulatory signal. Here, we report that coexpression of the PD1-CD28 CSR in TRuC-T cells enhanced T cell receptor signaling, increased proinflammatory effector cytokines, decreased anti-inflammatory cytokines, and sustained effector function in the presence of PD-L1 when compared with TC-210. Anti-MSLN TRuC-T cells engineered to coexpress PD1-CD28 CSRs comprising the ectodomain of PD-1 and the intracellular domain of CD28 linked by the transmembrane domain of PD-1 were selected for integration into an anti-MSLN TRuC-T cell therapy product called TC-510. In vitro, TC-510 showed significant improvements in persistence and resistance to exhaustion upon chronic stimulation by tumor cells expressing MSLN and PD-L1 when compared with TC-210. In vivo, TC-510 showed a superior ability to provide durable protection following tumor rechallenge, versus TC-210. These data demonstrate that integration of a PD1-CD28 CSR into TRuC-T cells improves effector function, resistance to exhaustion, and prolongs persistence. Based on these findings, TC-510 is currently being evaluated in patients with MSLN-expressing solid tumors.

Investigating sensitization activity of azobenzene disperse dyes via the Direct Peptide Reactivity Assay (DPRA).

Azobenzene disperse dyes are the fastest-growing category of commercial dyestuffs and have been found in indoor house dust and in children's polyester apparel. Azobenzene disperse dyes are implicated as potentially allergenic; however, little experimental data is available on allergenicity of these dyes. Here, we examine the binding of azobenzene disperse dyes to nucleophilic peptide residues as a proxy for their potential reactivity as electrophilic allergenic sensitizers. The Direct Peptide Reactivity Assay (DPRA) was utilized via both a spectrophotometric method and a high-performance liquid chromatography (HPLC) method. We tested dyes purified from commercial dyestuffs as well as several known transformation products. All dyes were found to react with nucleophilic peptides in a dose-dependent manner with pseudo-first order kinetics (rate constants as high as 0.04 h-1). Rates of binding reactivity were also found to correlate to electrophilic properties of dyes as measured by Hammett constants and electrophilicity indices. Reactivities of polyester shirt extracts were also tested for DPRA activity and the shirt extracts with high measured abundances of azobenzene disperse dyes were observed to induce greater peptide reactivity. Results suggest that azobenzene disperse dyes may function as immune sensitizers, and that clothing containing these dyes may pose risks for skin sensitization.

Linking Adiposity to Interstitial Lung Disease: The Role of the Dysfunctional Adipocyte and Inflammation.

Adipose tissue has functions beyond its principal functions in energy storage, including endocrine and immune functions. When faced with a surplus of energy, the functions of adipose tissue expand by mechanisms that can be both adaptive and detrimental. These detrimental adipose tissue functions can alter normal hormonal signaling and promote local and systemic inflammation with wide-ranging consequences. Although the mechanisms by which adipose tissue triggers metabolic dysfunction and local inflammation have been well described, little is known about the relationship between adiposity and the pathogenesis of chronic lung conditions, such as interstitial lung disease (ILD). In this review, we detail the conditions and mechanisms by which adipose tissue becomes dysfunctional and relate this dysfunction to inflammatory changes observed in various forms of ILD. Finally, we review the existing basic and clinical science literature linking adiposity to ILD, highlighting the need for additional research on the mechanisms of adipocyte-mediated inflammation in ILD and its clinical implications.

Prolonged exposure to lung-derived cytokines is associated with inflammatory activation of microglia in patients with COVID-19.

Neurological impairment is the most common finding in patients with post-acute sequelae of COVID-19. Furthermore, survivors of pneumonia from any cause have an elevated risk of dementia1-4. Dysfunction in microglia, the primary immune cell in the brain, has been linked to cognitive impairment in murine models of dementia and in humans5. Here, we report a transcriptional response in human microglia collected from patients who died following COVID-19 suggestive of their activation by TNF-α and other circulating pro-inflammatory cytokines. Consistent with these findings, the levels of 55 alveolar and plasma cytokines were elevated in a cohort of 341 patients with respiratory failure, including 93 unvaccinated patients with COVID-19 and 203 patients with other causes of pneumonia. While peak levels of pro-inflammatory cytokines were similar in patients with pneumonia irrespective of etiology, cumulative cytokine exposure was higher in patients with COVID-19. Corticosteroid treatment, which has been shown to be beneficial in patients with COVID-196, was associated with lower levels of CXCL10, CCL8, and CCL2-molecules that sustain inflammatory circuits between alveolar macrophages harboring SARS-CoV-2 and activated T cells7. These findings suggest that corticosteroids may break this cycle and decrease systemic exposure to lung-derived cytokines and inflammatory activation of microglia in patients with COVID-19.

Lethal eosinophilic crystalline pneumonia in mice expressing a stabilized Csf2 mRNA.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a cytokine that stimulates the proliferation and differentiation of granulocyte and macrophage precursors. The mouse gene-encoding GM-CSF, Csf2, is regulated at both transcriptional and post-transcriptional levels. An adenine-uridine-rich element (ARE) within the 3'-untranslated region of Csf2 mRNA was shown in cell transfection studies to confer instability on this transcript. To explore the physiological importance of this element in an intact animal, we generated mice with a knock-in deletion of the 75-nucleotide ARE. Mice heterozygous for this ARE deletion developed severe respiratory distress and death within about 12 weeks of age. There was dense infiltration of lung alveolar spaces by crystal-containing macrophages. Increased stability of Csf2 mRNA was confirmed in bone marrow-derived macrophages, and elevated GM-CSF levels were observed in serum and lung. These mice did not exhibit notable abnormalities in blood or bone marrow, and transplantation of bone marrow from mutant mice into lethally irradiated WT mice did not confer the pulmonary phenotype. Mice with a conditional deletion of the ARE restricted to lung type II alveolar cells exhibited an essentially identical lethal lung phenotype at the same ages as the mice with the whole-body deletion. In contrast, mice with the same conditional ARE deletion in myeloid cells, including macrophages, exhibited lesser degrees of macrophage infiltration into alveolar spaces much later in life, at approximately 9 months of age. Post-transcriptional Csf2 mRNA stability regulation in pulmonary alveolar epithelial cells appears to be essential for normal physiological GM-CSF secretion and pulmonary macrophage homeostasis.

Maternal exposure to ultrafine particles enhances influenza infection during pregnancy.

BACKGROUND: Interactions between air pollution and infectious agents are increasingly recognized and critical to identify, especially to protect vulnerable populations. Pregnancy represents a vulnerable period for influenza infection and air pollution exposure, yet interactions during pregnancy remain unclear. Maternal exposure to ultrafine particles (UFPs, [Formula: see text] 100 nm diameter), a class of particulate matter ubiquitous in urban environments, elicits unique pulmonary immune responses. We hypothesized that UFP exposure during pregnancy would lead to aberrant immune responses to influenza enhancing infection severity. RESULTS: Building from our well-characterized C57Bl/6N mouse model employing daily gestational UFP exposure from gestational day (GD) 0.5-13.5, we carried out a pilot study wherein pregnant dams were subsequently infected with Influenza A/Puerto Rico/8/1934 (PR8) on GD14.5. Findings indicate that PR8 infection caused decreased weight gain in filtered air (FA) and UFP-exposed groups. Co-exposure to UFPs and viral infection led to pronounced elevation in PR8 viral titer and reduced pulmonary inflammation, signifying potential suppression of innate and adaptive immune defenses. Pulmonary expression of the pro-viral factor sphingosine kinase 1 (Sphk1) and pro-inflammatory cytokine interleukin-1ß (IL-1 [Formula: see text]) was significantly increased in pregnant mice exposed to UFPs and infected with PR8; expression correlated with higher viral titer. CONCLUSIONS: Results from our model provide initial insight into how maternal UFP exposure during pregnancy enhances respiratory viral infection risk. This model is an important first step in establishing future regulatory and clinical strategies for protecting pregnant women exposed to UFPs.

Lung-gut axis of microbiome alterations following co-exposure to ultrafine carbon black and ozone.

BACKGROUND: Microbial dysbiosis is a potential mediator of air pollution-induced adverse outcomes. However, a systemic comparison of the lung and gut microbiome alterations and lung-gut axis following air pollution exposure is scant. In this study, we exposed male C57BL/6J mice to inhaled air, CB (10 mg/m3), O3 (2 ppm) or CB + O3 mixture for 3 h/day for either one day or four consecutive days and were euthanized 24 h post last exposure. The lung and gut microbiome were quantified by 16 s sequencing. RESULTS: Multiple CB + O3 exposures induced an increase in the lung inflammatory cells (neutrophils, eosinophils and B lymphocytes), reduced absolute bacterial load in the lungs and increased load in the gut. CB + O3 exposure was more potent as it decreased lung microbiome alpha diversity just after a single exposure. CB + O3 co-exposure uniquely increased Clostridiaceae and Prevotellaceae in the lungs. Serum short chain fatty acids (SCFA) (acetate and propionate) were increased significantly only after CB + O3 co-exposure. A significant increase in SCFA producing bacterial families (Ruminococcaceae, Lachnospiraceae, and Eubacterium) were also observed in the gut after multiple exposures. Co-exposure induced significant alterations in the gut derived metabolite receptors/mediator (Gcg, Glp-1r, Cck) mRNA expression. Oxidative stress related mRNA expression in lungs, and oxidant levels in the BALF, serum and gut significantly increased after CB + O3 exposures. CONCLUSION: Our study confirms distinct gut and lung microbiome alterations after CB + O3 inhalation co-exposure and indicate a potential homeostatic shift in the gut microbiome to counter deleterious impacts of environmental exposures on metabolic system.

Mesothelin-targeting T cells bearing a novel T cell receptor fusion construct (TRuC) exhibit potent antitumor efficacy against solid tumors.

T cell Receptor (TCR) Fusion Construct (TRuC®) T cells harness all signaling subunits of the TCR to activate T cells and eliminate tumor cells, with minimal release of cytokines. While adoptive cell therapy with chimeric antigen receptor (CAR)-T cells has shown unprecedented clinical efficacy against B-cell malignancies, monotherapy with CAR-T cells has suboptimal clinical efficacy against solid tumors, probably because of the artificial signaling properties of the CAR. TRuC-T cells may address the suboptimal efficacy of existing CAR-T therapies for solid tumors. Here, we report that mesothelin (MSLN)-specific TRuC-T cells (referred to as TC-210 T cells) potently kill MSLN+ tumor cells in vitro and efficiently eradicate MSLN+ mesothelioma, lung, and ovarian cancers in xenograft mouse tumor models. When benchmarked against MSLN-targeted BBζ CAR-T cells (MSLN-BBζ CAR-T cells), TC-210 T cells show an overall comparable level of efficacy; however, TC-210 T cells consistently show faster tumor rejection kinetics that are associated with earlier intratumoral accumulation and earlier signs of activation. Furthermore, in vitro and ex vivo metabolic profiling suggests TC-210 T cells have lower glycolytic activity and higher mitochondrial metabolism than MSLN-BBζ CAR-T cells. These data highlight TC-210 T cells as a promising cell therapy for treating MSLN-expressing cancers. The differentiated profile from CAR-T cells may translate into better efficacy and safety of TRuC-T cells for solid tumors.

Inhalation of an RNA aptamer that selectively binds extracellular histones protects from acute lung injury.

Acute lung injury (ALI) is a syndrome of acute inflammation, barrier disruption, and hypoxemic respiratory failure associated with high morbidity and mortality. Diverse conditions lead to ALI, including inhalation of toxic substances, aspiration of gastric contents, infection, and trauma. A shared mechanism of acute lung injury is cellular toxicity from damage-associated molecular patterns (DAMPs), including extracellular histones. We recently described the selection and efficacy of a histone-binding RNA aptamer (HBA7). The current study aimed to identify the effects of extracellular histones in the lung and determine if HBA7 protected mice from ALI. Histone proteins decreased metabolic activity, induced apoptosis, promoted proinflammatory cytokine production, and caused endothelial dysfunction and platelet activation in vitro. HBA7 prevented these effects. The oropharyngeal aspiration of histone proteins increased neutrophil and albumin levels in bronchoalveolar lavage fluid (BALF) and precipitated neutrophil infiltration, interstitial edema, and barrier disruption in alveoli in mice. Similarly, inhaling wood smoke particulate matter, as a clinically relevant model, increased lung inflammation and alveolar permeability. Treatment by HBA7 alleviated lung injury in both models of ALI. These findings demonstrate the pulmonary delivery of HBA7 as a nucleic acid-based therapeutic for ALI.