Explore the vast range of titles available.

Surfactant proteins A (SP-A) and D (SP-D) are soluble innate immune molecules which maintain lung homeostasis through their dual roles as anti-infectious and immunomodulatory agents. SP-A and SP-D bind numerous viruses including influenza A virus, respiratory syncytial virus (RSV) and human immunodeficiency virus (HIV), enhancing their clearance from mucosal points of entry and modulating the inflammatory response. They also have diverse roles in mediating innate and adaptive cell functions and in clearing apoptotic cells, allergens and other noxious particles. Here, we review how the properties of these first line defense molecules modulate inflammatory responses, as well as host-mediated immunopathology in response to viral infections. Since SP-A and SP-D are known to offer protection from viral and other infections, if their levels are decreased in some disease states as they are in severe asthma and chronic obstructive pulmonary disease (COPD), this may confer an increased risk of viral infection and exacerbations of disease. Recombinant molecules of SP-A and SP-D could be useful in both blocking respiratory viral infection while also modulating the immune system to prevent excessive inflammatory responses seen in, for example, RSV or coronavirus disease 2019 (COVID-19). Recombinant SP-A and SP-D could have therapeutic potential in neutralizing both current and future strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus as well as modulating the inflammation-mediated pathology associated with COVID-19. A recombinant fragment of human (rfh)SP-D has recently been shown to neutralize SARS-CoV-2. Further work investigating the potential therapeutic role of SP-A and SP-D in COVID-19 and other infectious and inflammatory diseases is indicated.

Background The amount of surfactant deposited in the lungs and its overall pulmonary distribution determine the therapeutic outcome of surfactant replacement therapy. Most of the currently available methods to determine the intrapulmonary distribution of surfactant are time-consuming and require surfactant labelling. Our aim was to assess the potential of Mass Spectrometry Imaging (MSI) as a label-free technique to qualitatively and quantitatively evaluate the distribution of surfactant to the premature lamb. Methods Twelve preterm lambs (gestational age 126-127d, term ~150d) were allocated in two experimental groups. Seven lambs were treated with an intratracheal bolus of the synthetic surfactant CHF5633 (200 mg/kg) and 5 lambs were managed with mechanical ventilation for 120 min, as controls. The right lung lobes of all lambs were gradually frozen while inflated to 20 cmH 2 O pressure for lung cryo-sections for MSI analysis. The intensity signals of SP-C analog and SP-B analog, the two synthetic peptides contained in the CHF5633 surfactant, were used to locate, map and quantify the intrapulmonary exogenous surfactant. Results Surfactant treatment was associated with a significant improvement of the mean arterial oxygenation and lung compliance ( p  < 0.05). Nevertheless, the physiological response to surfactant treatment was not uniform across all animals. SP-C analog and SP-B analog were successfully imaged and quantified by means of MSI in the peripheral lungs of all surfactant-treated animals. The intensity of the signal was remarkably low in untreated lambs, corresponding to background noise. The signal intensity of SP-B analog in each surfactant-treated animal, which represents the surfactant distributed to the peripheral right lung, correlated well with the physiologic response as assessed by the area under the curves of the individual arterial partial oxygen pressure and dynamic lung compliance curves of the lambs. Conclusions Applying MSI, we were able to detect, locate and quantify the amount of exogenous surfactant distributed to the lower right lung of surfactant-treated lambs. The distribution pattern of SP-B analog correlated well with the pulmonary physiological outcomes of the animals. MSI is a valuable label-free technique which is able to simultaneously evaluate qualitative and quantitative drug distribution in the lung.

ObjectiveCHF5633 (Chiesi Farmaceutici S.p.A., Parma, Italy) is the first fully synthetic surfactant enriched by peptide analogues of two human surfactant proteins. We planned to assess safety and tolerability of CHF5633 and explore preliminary efficacy.DesignMulticentre cohort study.PatientsForty infants from 27+0 to 33+6 weeks gestation with respiratory distress syndrome requiring fraction of inspired oxygen (FiO2) ≥0.35 were treated with a single dose of CHF5633 within 48 hours after birth. The first 20 received 100 mg/kg and the second 20 received 200 mg/kg.Outcome measuresAdverse events (AEs) and adverse drug reactions (ADRs) were monitored with complications of prematurity considered AEs if occurring after dosing. Systemic absorption and immunogenicity were assessed. Efficacy was assessed by change in FiO2 after dosing and need for poractant-alfa rescue.ResultsRapid and sustained improvements in FiO2 were observed in 39 (98%) infants. One responded neither to CHF5633 nor two poractant-alfa doses. A total of 79 AEs were experienced by 19 infants in the 100 mg/kg cohort and 53 AEs by 20 infants in the 200 mg/kg cohort. Most AEs were expected complications of prematurity. Two unrelated serious AEs occurred in the second cohort. One infant died of necrotising enterocolitis and another developed viral bronchiolitis after discharge. The single ADR was an episode of transient endotracheal tube obstruction following a 200 mg/kg dose. Neither systemic absorption, nor antibody development to either peptide was detected.ConclusionsBoth CHF5633 doses were well tolerated and showed promising clinical efficacy profile. These encouraging data provide a basis for ongoing randomised controlled trials.Trial registration numberClinicalTrials.gov NCT01651637.

Surfactant protein B (SP-B) deficiency is an autosomal recessive disorder that impairs surfactant homeostasis and manifests as lethal respiratory distress. A compelling argument exists for gene therapy to treat this disease, as de novo protein synthesis of SP-B in alveolar type 2 epithelial cells is required for proper surfactant production. Here we report a rationally designed adeno-associated virus (AAV) 6 capsid that demonstrates efficiency in lung epithelial cell transduction based on imaging and flow cytometry analysis. Intratracheal administration of this vector delivering murine or human proSFTPB cDNA into SP-B deficient mice restores surfactant homeostasis, prevents lung injury, and improves lung physiology. Untreated SP-B deficient mice develop fatal respiratory distress within two days. Gene therapy results in an improvement in median survival to greater than 200 days. This vector also transduces human lung tissue, demonstrating its potential for clinical translation against this lethal disease. Surfactant protein B (SP-B) deficiency is a genetic lung disease that results in lethal respiratory distress within months of birth. Here, the authors describe a gene therapy strategy using a rationally designed AAV6 capsid that restores surfactant homeostasis, prevents lung injury, and improves survival in a mouse model of SP-B deficiency.

Exposure to traffic-related air pollution (TRAP) has been associated with increased risks of respiratory diseases, but the biological mechanisms are not yet fully elucidated. Our aim was to evaluate the respiratory responses and explore potential biological mechanisms of TRAP exposure in a randomized crossover trial. We conducted a randomized crossover trial in 56 healthy adults. Each participant was exposed to high- and low-TRAP exposure sessions by walking in a park and down a road with high traffic volume for 4 h in random order. Respiratory symptoms and lung function, including forced expiratory volume in the first second ( ), forced vital capacity (FVC), the ratio of to FVC, and maximal mid-expiratory flow (MMEF), were measured before and after each exposure session. Markers of 8-isoprostane, tumor necrosis ( ), and ezrin in exhaled breath condensate (EBC), and surfactant proteins D (SP-D) in serum were also measured. We used linear mixed-effects models to estimate the associations, adjusted for age, sex, body mass index, meteorological condition, and batch (only for biomarkers). Liquid chromatography-mass spectrometry was used to profile the EBC metabolome. Untargeted metabolome-wide association study (MWAS) analysis and pathway enrichment analysis using mummichog were performed to identify critical metabolomic features and pathways associated with TRAP exposure. Participants had two to three times higher exposure to traffic-related air pollutants except for fine particulate matter while walking along the road compared with in the park. Compared with the low-TRAP exposure at the park, high-TRAP exposure at the road was associated with a higher score of respiratory symptoms [2.615 (95% CI: 0.605, 4.626), ] and relatively lower lung function indicators [ (95% CI: , ), ] for and (95% CI: , ; ) for MMEF]. Exposure to TRAP was significantly associated with changes in some, but not all, biomarkers, particularly with a (95% CI: 0.297, 0.691; ) increase for serum SP-D and a (95% CI: , ; ) decrease for EBC ezrin. Untargeted MWAS analysis revealed that elevated TRAP exposure was significantly associated with perturbations in 23 and 32 metabolic pathways under positive- and negative-ion modes, respectively. These pathways were most related to inflammatory response, oxidative stress, and energy use metabolism. This study suggests that TRAP exposure might lead to lung function impairment and respiratory symptoms. Possible underlying mechanisms include lung epithelial injury, inflammation, oxidative stress, and energy metabolism disorders. https://doi.org/10.1289/EHP11139.

Pulmonary surfactants consist of phospholipids and the hydrophobic proteins surfactant protein B and surfactant protein C. These surfactants keep the alveoli in the lung open to the atmosphere. Mutations in the genes encoding these proteins cause a variety of pulmonary syndromes. The pulmonary diseases associated with some of these mutations exemplify the consequences of the accumulation of misfolded proteins in tissue. The hydrophobic surfactant proteins B and C are essential for lung function and pulmonary homeostasis after birth. These proteins enhance the spreading, adsorption, and stability of surfactant lipids required for the reduction of surface tension in the alveolus. Surfactant proteins B and C also participate in the regulation of intracellular and extracellular processes critical for the maintenance of respiratory structure and function. Mutations in the genes encoding surfactant protein B and surfactant protein C ( SFTPB and SFTPC, respectively) are associated with acute respiratory failure and interstitial lung diseases. In this article, we review the current knowledge regarding the structure . . .

The acute respiratory distress syndrome (ARDS) results from a deficiency of functional surfactant in the airways. These investigators carried out a multicenter study in which patients with ARDS were treated with a recombinant human surfactant protein C–based surfactant. No clinical benefits were noted. A multicenter study in which patients with ARDS were treated with a recombinant human surfactant protein C–based surfactant. Although exogenous surfactant is of proven benefit in the prevention and treatment of the respiratory distress syndrome in infants, 1 its value in treating patients with the acute respiratory distress syndrome (ARDS) has not been established. Whereas infants with an immature lung have a deficit in surfactant production, patients with ARDS have decreased surfactant production as well as biochemical alterations of endogenous surfactant that impair surface-tension–lowering properties and decreased surfactant function in distal airways. 2 Normally, pulmonary surfactant phospholipids, acting in concert with surfactant proteins A, B, and C, cause alveolar surface tension to reach very low values at end expiration, thus . . .

Bronchopulmonary dysplasia (BPD) is an important complication of mechanical ventilation in preterm infants, and no definite therapy can eliminate this complication. Pulmonary inflammation plays a crucial role in its pathogenesis, and glucocorticoid is one potential therapy to prevent BPD. To compare the effect of intratracheal administration of surfactant/budesonide with that of surfactant alone on the incidence of death or BPD. A clinical trial was conducted in three tertiary neonatal centers in the United States and Taiwan, in which 265 very-low-birth-weight infants with severe respiratory distress syndrome who required mechanical ventilation and inspired oxygen (fraction of inspired oxygen, ≥50%) within 4 hours of birth were randomly assigned to one of two groups (131 intervention and 134 control). The intervention infants received surfactant (100 mg/kg) and budesonide (0.25 mg/kg), and the control infants received surfactant only (100 mg/kg), until each infant required inspired O2 at less than 30% or was extubated. The intervention group had a significantly lower incidence of BPD or death (55 of 131 [42.0%] vs. 89 of 134 [66%]; risk ratio, 0.58; 95% confidence interval, 0.44-0.77; P < 0.001; number needed to treat, 4.1; 95% confidence interval, 2.8-7.8). The intervention group required significantly fewer doses of surfactant than did the control group. The intervention group had significantly lower interleukin levels (IL-1, IL-6, IL-8) in tracheal aspirates at 12 hours and lower IL-8 at 3-5 and 7-8 days. In very-low-birth-weight infants with severe respiratory distress syndrome, intratracheal administration of surfactant/budesonide compared with surfactant alone significantly decreased the incidence of BPD or death without immediate adverse effect. Clinical trial registered with www.clinicaltrials.gov (NCT-00883532).

Pulmonary surfactant protein A (SP‑A) and pulmonary surfactant protein D (SP‑D) are associated with the pathogenesis of chronic obstructive pulmonary disease (COPD). The aim of the present study was to determine the correlation between SP‑A, SP‑D and lung function in patients with COPD. A total of 60 patients with lung cancer undergoing unilateral lobectomy were selected and divided into three groups, including a non‑COPD group (n=20), a COPD treatment group (n=20) and a COPD control group (n=20). The levels of SP‑A and SP‑D were detected in the exhaled breath condensate (EBC) using ELISA analysis. Tissue samples were obtained during lobectomy via resection of the adjacent lung tissues, located >5 cm from the nodule. Immunohistochemistry and reverse transcription‑quantitative polymerase chain reaction analysis was performed. The proportion of SP‑A+ alveolar type II (ATII) cells and the mRNA levels of SP‑A and SP‑D in lung tissue were measured. In addition, the correlation between SP‑A and SP‑D in EBC, SP‑A and SP‑D mRNA in lung tissue, forced expiratory volume in 1 sec (FEV1) and the ratio of SP‑A+ ATII, was evaluated. The expression levels of SP‑A and SP‑D were significantly increased in patients of the non‑COPD group compared with the other two groups (P<0.05). In addition, the expression levels of SP‑A were positively correlated with FEV1 and the ratio of SP‑A+ ATII (P<0.05). The expression levels of SP‑D exhibited no correlation with FEV1 and ratio of SP‑A+ ATII (P>0.05). The results of the present study indicated that the SP‑A and SP‑D levels in EBC were correlated with lung function, which contributed to COPD diagnosis. Future studies are required to further investigate the results of the present study.

Alveolar epithelial type II (AT2) cells secrete pulmonary surfactant via lamellar bodies (LBs). Abnormalities in LBs are associated with pulmonary disorders, including fibrosis. However, high-content screening (HCS) for LB abnormalities is limited by the lack of understanding of AT2 cell functions. In the present study, we have developed LB cells harboring LB-like organelles that secrete surfactant proteins. These cells were more similar to AT2 cells than to parental A549 cells. LB cells recapitulated amiodarone (AMD)-induced LB enlargement, similar to AT2 cells of patients exposed to AMD. To reverse AMD-induced LB abnormalities, we performed HCS of approved drugs and identified 2-hydroxypropyl-β-cyclodextrin (HPβCD), a cyclic oligosaccharide, as a potential therapeutic agent. A transcriptome analysis revealed that HPβCD modulates lipid homeostasis. In addition, HPβCD inhibited AMD-induced LB abnormalities in human induced pluripotent stem cell–derived AT2 cells. Our results demonstrate that LB cells are useful for HCS and suggest that HPβCD is a candidate therapeutic agent for AMD-induced interstitial pneumonia.