Using a new human milk fortifier to optimize human milk feeding among very preterm and/or very low birth weight infants: a multicenter study in China.

BACKGROUND: Human milk fortifier (HMF) composition has been optimized recently. But clinical evidence of its safety and efficacy is limited in Chinese population. The aim of this study was to evaluate effects of a new HMF in growth, nutritional status, feeding intolerance, and major morbidities among very preterm (VPT) or very low birth weight (VLBW) infants in China. METHODS: VPT/VLBW infants admitted from March 2020 to April 2021 were prospectively included in the experimental (new HMF, nHMF) group, who received a new powdered HMF as a breast milk feeding supplement during hospitalization. Infants in the control group (cHMF) admitted from January 2018 to December 2019, were retrospective included, and matched with nHMF group infants for gestational age and birth weight. They received other kinds of commercially available HMFs. Weight gain velocity, concentrations of nutritional biomarkers, incidence of major morbidities, and measures of feeding intolerance were compared between the two groups. RESULTS: Demographic and clinical characteristics of infants in nHMF and cHMF groups were comparable. Weight gain velocity had no significant difference between the nHMF (14.0 ± 3.5 g/kg/d) and the cHMF group (14.2 ± 3.8 g/kg/d; P = 0.46). Incidence of morbidities, including necrotizing enterocolitis, bronchopulmonary dysplasia, retinopathy of prematurity, culture-confirmed sepsis, and feeding intolerance during hospitalization between nHMF and cHMF, were similar (all P-values > 0.05). The time to achieve full enteral feeding [13.5 (10, 21) days] in the nHMF group was significantly shorter than that in the cHMF group [17 (12, 23) days, HR = 0.67, 95%CI: 0.49, 0.92; P = 0.01]. Compared with cHMF group, the decrease of blood urea nitrogen level over time in nHMF group was smaller (ß = 0.6, 95%CI:0.1, 1.0; P = 0.01). CONCLUSIONS: The new HMF can promote growth of preterm infants effectively without increasing the incidence of major morbidity and feeding intolerance. It can be used feasible in Chinese VPT/VLBW infants. TRIAL REGISTRATION: This study was registered on ClinicalTrials.gov (NCT04283799).

Soluble ST2 predicts continuous renal replacement therapy in patients receiving venoarterial extracorporeal membrane oxygenation.

OBJECTIVE: This study aimed to evaluate the relationship between plasma soluble ST2 (sST2) levels 24 h after extracorporeal membrane oxygenation (ECMO) initiation and continuous renal replacement therapy (CRRT) in patients receiving venoarterial ECMO (V-A ECMO) support. METHODS AND RESULTS: Data of patients who received ECMO support for postcardiotomy cardiogenic shock between January 2017 and July 2019 were retrospectively collected from Beijing Anzhen Hospital, Capital Medical University. Ultimately, 116 patients were included in the present study for analysis. The concentration of sST2 was determined by enzyme-linked immunosorbent assay (ELISA). The log10 sST2 levels were higher in patients undergoing CRRT than those who did not (6.06 vs. 6.22, p = 0.019). Patients undergoing CRRT had a lower survival rate than those who did not (32.8% vs. 67.3%, p < 0.001). In the univariate logistic regression analysis, sST2, HCO3-, lactate, and creatinine levels 24 h after ECMO initiation were related to CRRT (p < 0.05). In the multivariate logistic regression analysis, HCO3- and sST2 were identified as independent risk factors for CRRT use in patients undergoing ECMO (p < 0.05). The area under receiver operator characteristic curve (AUC) for sST2 and HCO3- together was 0.72 (95% confidence interval (CI), 0.79-0.91), which was better than those of sST2 or HCO3- alone (0.63 vs. 0.67). CONCLUSIONS: sST2 and HCO3-levels at 24 h after ECMO initiation were associated with CRRT and could predict CRRT use in postcardiotomy cardiogenic shock patients undergoing ECMO.

[Congenital pulmonary alveolar proteinosis in a neonate]. / æ–°ç”Ÿå„¿å ˆå¤©æ€§è‚ºæ³¡è›‹ç™½æ²‰ç§¯ç—‡1例.

The male patient was referred to the hospital at 44 days old due to dyspnea after birth and inability to wean off oxygen. His brother died three days after birth due to respiratory failure. The main symptoms observed were respiratory failure, dyspnea, and hypoxemia. A chest CT scan revealed characteristic reduced opacity in both lungs with a "crazy-paving" appearance. The bronchoalveolar lavage fluid (BALF) showed periodic acid-Schiff positive proteinaceous deposits. Genetic testing indicated a compound heterozygous mutation in the ABCA3 gene. The diagnosis for the infant was congenital pulmonary alveolar proteinosis (PAP). Congenital PAP is a significant cause of challenging-to-treat respiratory failure in full-term infants. Therefore, congenital PAP should be considered in infants experiencing persistently difficult-to-treat dyspnea shortly after birth. Early utilization of chest CT scans, BALF pathological examination, and genetic testing may aid in early diagnosis.

Assessment of Clinical Features in HIV-Infected Patients with Acute Coronary Syndromes Undergoing Percutaneous Coronary Intervention in China.

Objectives: We aimed to compare coronary risk factors, burden of coronary artery disease (CAD), and 1-year prognosis of people living with HIV (PLWH) and HIV-negative controls who underwent percutaneous coronary intervention (PCI) for acute coronary syndromes (ACSs). Background: Cardiovascular disease is drawing more and more attention in PLWH since effective antiretroviral therapy (ART) has been available. Clinical characteristics and outcomes of PLWH undergoing PCI for ACS in China remain unknown. Methods: We compared demographic characteristics, angiographic features, and 1-year outcomes of 48 PLWH versus 48 HIV-negative controls matched for age (±2 years), sex, diabetes mellitus, and year of PCI (±2 years) in Beijing Ditan Hospital, Capital Medical University from January 2008 to November 2020. Results: In PLWH (mean age: 53.6 ± 10.6 years, 95.8% male, and 79.2% on ART), high-density lipoprotein cholesterol was lower than in HIV-negative controls; however, the statin use was more common, the incidence of hypertension was lower, and low-density lipoprotein cholesterol, and the body mass index were significantly lower than in controls. Two groups had a similar extent of coronary atherosclerosis as measured by the presence of multivessel diseases and the median Gensini score; however, lesions of PLWH were longer and were more likely to locate at the proximal segment of the coronary artery. In addition, the risk of major adverse cardiac and cerebrovascular events at 1 year was similar in both groups. Conclusion: PLWH undergoing PCI displayed similar CAD burden and 1-year prognosis compared with HIV-negative patients. Early detection of cardiovascular risk factors and appropriate secondary prevention of CAD in PLWH might alleviate the risk of severe adverse cardiovascular events.

Anxiety, depression, and sleep disturbances among people on long-term efavirenz-based treatment for HIV: a cross-sectional study in Beijing, China.

BACKGROUND: Efavirenz (EFV)-induced neuropsychiatric toxicity bothers people living with HIV (PLHIV). Neuropsychiatric adverse effects of EFV may differ by length of time on EFV-based antiretroviral treatment (ART). METHODS: A cross-sectional, single-center study was conducted at Beijing Ditan Hospital in China from June-August 2020 among ART-experienced PLHIV who were on long-term EFV-based ART. 424 eligible virological suppressed participants were enrolled and divided into four groups according to time on EFV-based ART: group A (0.5 ≤ ART < 2 year), B (2 ≤ ART < 4 year), C (4 ≤ ART < 6 year), and D (ART ≥ 6 year). The questionnaires about 12-item Short Form Health Survey (SF-12), Hospital Anxiety and Depression Scale (HADS) and Pittsburgh Sleep Quality Index (PSQI) were administered to assess neuropsychiatric adverse events of EFV among different groups. RESULTS: Overall mental component summary scores (MCS) of SF-12 in PLHIV was 50.2, which was lower than general population. Overall prevalence of anxiety, depression and sleep disturbances was 15.6%, 15.3% and 58%, respectively. Prevalence of anxiety, depression and sleep disturbances did not vary significantly between the time-on-ART groups. Anxiety, depression, sleep disturbances had no correlation with time on EFV-based ART or CD4+ T cells counts. CONCLUSIONS: In ART-experienced PLHIV in China, neuropsychiatric adverse events exist persistently and prevalence do not significantly change with prolonged time on EFV-based ART. The prevalence of sleep disturbances was high, suggesting that clinicians should pay more attention to long-standing psychiatric health to perform early and effective interventions.

Phenotypic and functional alterations of monocyte subsets with aging.

BACKGROUND: It has been widely accepted that monocytes are one of the central mediators contributing to inflammaging. However, it remains unclear whether aged monocytes, similar to aged T cells, have characteristics of hyperactivation and increased expression of co-inhibitory molecules. METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from young (21-40 years old), middle-aged (41-60 years old), and older human subjects (> 60 years old). Flow cytometry was used to monitor changes in the expression of surface molecules of monocyte subsets and cytokine-producing capacity. RESULTS: We observed increased tumor necrosis factor-α: TNF-α and decreased interleukin-6 (IL-6) production in monocytes from older adults compared with young and middle-aged adults. Older adults had a greater percentage of intermediate and non-classical monocyte subsets, along with increased levels of the immune activation markers human leukocyte antigen-DR (HLA-DR), and adhesion molecules cluster of differentiation molecule 11b (CD11b) and L-selectin (CD62L). Furthermore, we observed increased C-C motif chemokine receptor 2 (CCR2) expression on classical monocytes and decreased C-X3-C motif chemokine receptor 1 (CX3CR1) expression on non-classical monocytes in older adult subjects. The expression of co-inhibitory receptors was reduced on monocyte subsets in older adults. CONCLUSIONS: Circulating monocytes in older adults exhibit increased expression of activation, adhesion, and migration markers, but decreased expression of co-inhibitory molecules.

A Real-Time Recognition System of Driving Propensity Based on AutoNavi Navigation Data.

Driving propensity is the driver's attitude towards the actual traffic situation and the corresponding decision-making or behavior during the driving process. It is of great significance to improve the accuracy of safety early warning and reduce traffic accidents. In this paper, a real-time identification system of driving propensity based on AutoNavi navigation data is proposed. The main work includes: (1) A dynamic data acquisition method of AutoNavi navigation is proposed to obtain the time, speed and acceleration of the driver during the navigation process. (2) The dynamic data collection method of AutoNavi navigation is analyzed and verified through the dynamic data obtained in the real vehicle experiment. The principal component analysis method is used to process the experimental data to extract the driving propensity characteristics variables. (3) The fruit fly optimization algorithm combined with GRNN (generalized neural network) and the feature variable set are used to build a FOA-GRNN-based model. The results show that the overall accuracy of the model can reach 94.17%. (4) A driving propensity identification system is constructed. The system has been verified through real vehicle test experiments. This paper provides a novel and convenient method for building personalized intelligent driver assistance systems in practical applications.

A Recognition Method of Aggressive Driving Behavior Based on Ensemble Learning.

Aggressive driving behavior (ADB) is one of the main causes of traffic accidents. The accurate recognition of ADB is the premise to timely and effectively conduct warning or intervention to the driver. There are some disadvantages, such as high miss rate and low accuracy, in the previous data-driven recognition methods of ADB, which are caused by the problems such as the improper processing of the dataset with imbalanced class distribution and one single classifier utilized. Aiming to deal with these disadvantages, an ensemble learning-based recognition method of ADB is proposed in this paper. First, the majority class in the dataset is grouped employing the self-organizing map (SOM) and then are combined with the minority class to construct multiple class balance datasets. Second, three deep learning methods, including convolutional neural networks (CNN), long short-term memory (LSTM), and gated recurrent unit (GRU), are employed to build the base classifiers for the class balance datasets. Finally, the ensemble classifiers are combined by the base classifiers according to 10 different rules, and then trained and verified using a multi-source naturalistic driving dataset acquired by the integrated experiment vehicle. The results suggest that in terms of the recognition of ADB, the ensemble learning method proposed in this research achieves better performance in accuracy, recall, and F1-score than the aforementioned typical deep learning methods. Among the ensemble classifiers, the one based on the LSTM and the Product Rule has the optimal performance, and the other one based on the LSTM and the Sum Rule has the suboptimal performance.

Specific Redistribution of Severe Acute Respiratory Syndrome Coronavirus 2 Variants in the Respiratory System and Intestinal Tract.

Intrahost analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomic sequences identified 2 viral haplotypes comprised of 3 genetically linked mutations from the respiratory and intestinal tracts of a patient with coronavirus disease 2019. Spatiotemporal data suggest that this patient initially had dual infection of 2 SARS-CoV-2 variants, which subsequently redistributed into the 2 systems.

Antibiotic Use in Neonatal Intensive Care Units in China: A Multicenter Cohort Study.

OBJECTIVE: To provide national-level antibiotic use data from Chinese neonatal intensive care units to inform future antimicrobial stewardship using a large contemporary cohort of preterm infants in China. STUDY DESIGN: This retrospective cohort study enrolled all infants less than 340/7 weeks of gestation admitted to 25 tertiary neonatal intensive care units across China between May 1, 2015, and April 30, 2018. The antibiotic use rate (AUR) was defined as the number of days an infant was prescribed with 1 or more antibiotics divided by the total length of hospital stay. RESULTS: Among 24 597 eligible infants, 21 736 (88.4%) infants received antibiotics. The median AUR was 441 per 1000 patient-days (IQR, 242-692 per 1000 patient-days). The median duration of each antibiotic course was 9 days (IQR, 6-14 days). Overall, 64.6% infants received broad-spectrum antibiotics, with a median broad-spectrum AUR of 250 per 1000 patient-days (IQR, 0-500 per 1000 patient-days), accounting for 70.7% of all antibiotic use days. Overall, 68.7% of all antibiotic use occurred among infants without infection-related morbidities, with a median duration of 8 days (IQR, 6-13 days) for each course. Only 22.9% episodes of culture-negative sepsis were prescribed with antibiotics for 7 or fewer days, and 34.7% were treated with antibiotics for more than 14 days. For early antibiotic use, the median duration of antibiotic therapy within 7 days after birth was 7 days (IQR, 4-7 days). CONCLUSIONS: A high AUR among infants without infections, prolonged antibiotic durations, and excessive use of broad-spectrum antibiotics were the main problems of antibiotic use in Chinese neonatal intensive care units and should be high-impact focuses for future stewardship interventions.

PDK1/mTOR Signaling in Myeloid Cells Differentially Regulates the Early and Late Stages of Sepsis.

The cecal ligation and perforation (CLP) model is the gold standard for the polymicrobial sepsis. In the CLP mice, the myeloid cells play an important role in septic shock. The phenotypes and the activation state of the macrophage and neutrophil correlate with their metabolism. In the present study, we generated the specific myeloid deletion of PDK1 and mTOR mice, which was the important regulator of metabolic signaling. We found that the deletion of PDK1 in the myeloid cells could aggravate the early septic shock in the CLP mice, as well as the deletion of mTORC1 and mTORC2. Moreover, PDK1 deletion attenuated the inflammation induced by LPS in the late stage on CLP mice, which was exacerbated in mTORC1 and mTORC2 knockout mice. Both PDK1 and mTORC1/2 could not only regulate the cellular metabolism but also play important roles on the myeloid cells in the secondary stimulation of sepsis. The present study will provide a theoretical prospect for the therapy of the septic shock in different stages.

The effect of methylprednisolone prophylaxis on inflammatory monocyte subsets and suppressive regulatory T cells of patients undergoing cardiopulmonary bypass.

BACKGROUND: Cardiopulmonary bypass (CPB) during open-heart surgery triggers an inflammatory response that can cause significant morbidity and mortality. Human monocytes and regulatory T (Treg) cells are phenotypically and functionally heterogeneous and have been shown to play a significant role in the inflammatory dysfunction triggered by CPB. Glucocorticoids (GCs) have been widely administered for decades in patients undergoing CPB to reduce this inflammatory response. However, it has not been clearly established how routine prophylactic administration of glucocorticoids (GCs) affects monocyte and Treg subsets. METHODS: Thirty-six patient who underwent heart surgery with CPB were randomly assigned to a methylprednisolone group (MG, N = 18; 500 mg in the CPB priming) and a non-methylprednisolone group (NMG, N = 18). The circulating monocyte and Treg subsets were analyzed by flow cytometry. RESULTS: The MG and NMG groups had comparable percentages of monocyte subsets and similar expression levels of HLA-DR, CD86, CD64 and toll-like receptor 4 (TLR4). Remarkably, methylprednisolone increased the percentage of CD4+CD25+ Treg cells among CD4+ T cells in patients undergoing CPB, but did not increase the proportion of suppressive Treg cells, either resting or activated, in these patients undergoing CPB. CONCLUSIONS: Our results showed that prophylactic administration of methylprednisolone neither decreased the percentages and counts of inflammatory monocyte subsets nor did it induce the expansion of suppressive Treg cells in patients undergoing CPB. These results clarified the effects of GCs on cell-mediated immune responses and provided additional evidence in practice. TRIAL REGISTRATION: Clinicaltrials.gov : NCT01296074. Registered 14 February 2011.

High Level of Neutrophil Extracellular Traps Correlates With Poor Prognosis of Severe Influenza A Infection.

Background: Most patients with severe infection with influenza A virus (IAV) progress to acute respiratory distress syndrome and even multiple organ dysfunction syndrome (MODS). Neutrophil extracellular traps (NETs) can be induced by pathogens and are responsible for immune tissue damage. We conducted a prospective study on the production and effects of NETs in H7N9 and H1N1 patients. Methods: We investigated NET production in plasma and supernatant of cultured neutrophils by measuring cell-free deoxyribonucleic acid (DNA) and myeloperoxidase (MPO)-DNA complexes with PicoGreen dye and enzyme-linked immunosorbent assay methods, respectively. We also observed NET structure by immunofluorescence staining. Results: We found that patients with severe influenza showed elevated plasma NET level on the day of admission. Neutrophils from these patients showed higher capacity to release MPO-DNA complex in response to interleukin-8 or lipopolysaccharide stimulation. We also found that NETs from H7N9 and H1N1 patients increased the permeability of alveolar epithelial cells, and, consequently, NET production was positively correlated with acute physiology and chronic health evaluation (APACHE) II score and MODS. Conclusions: These data indicate that high level of NETs contributes to lung injury and is correlated with severity of disease. Thus, NETs might be a key factor to predict the poor prognosis in IAV patients.

Immature monocytes contribute to cardiopulmonary bypass-induced acute lung injury by generating inflammatory descendants.

BACKGROUND: As immune regulatory and effector cells, monocytes play an important role in the blood-extracorporeal circuit contact-related acute lung injury in patients undergoing cardiopulmonary bypass (CPB). However, circulating monocytes are phenotypically and functionally heterogeneous, so we characterised how immature monocytes affect acute lung injury induced by CPB. METHODS: The identification and dynamic changes in monocyte subsets were monitored by flow cytometry in patients undergoing CPB and in a rat model of CPB. The differentiation and migration of monocyte subsets were explored by in vitro cultures and adoptive transfer in the CPB rat model. RESULTS: We observed a dramatic increase of two monocyte subsets in the peripheral blood of patients undergoing CPB, involving tumour necrosis factor (TNF)-α-producing, mature intermediate CD14highCD16+ monocytes and a novel immature CD14lowCD16- subset. The immature CD14lowCD16- monocytes possessed limited ability for TNF-α production, and failed to suppress T-cell proliferation mediated by T-cell receptor signalling. However, these immature cells were highly proliferative and could differentiate into TNF-α producing, mature CD14highCD16+ monocytes. In the rat model of CPB, we further demonstrated that CPB induced migration of immature monocytes into the lungs, either from the bone marrow or from the spleen. Moreover, we confirmed the hypothesis that immature subsets could contribute to CPB-induced acute lung injury by giving rise to TNF-α producing descendants. CONCLUSIONS: The immature CD14lowCD16- monocytes might contribute to blood-circuit contact-induced acute lung injury by generating TNF-α-producing, mature monocytes. New strategies based on monocyte manipulation could be a promising therapeutic approach for minimising CPB-related lung injury.

Sepsis-Induced Thymic Atrophy Is Associated with Defects in Early Lymphopoiesis.

Impaired T lymphopoiesis is associated with immunosuppression of the adaptive immune response and plays a role in the morbidity and mortality of patients and animal models of sepsis. Although previous studies examined several intrathymic mechanisms that negatively affect T lymphopoiesis, the extrathymic mechanisms remain poorly understood. Here, we report a dramatic decrease in the percentage of early T lineage progenitors (ETPs) in three models of sepsis in mice (cecal ligation and puncture, lipopolysaccharide continuous injection, and poly I:C continuous injection). However, septic mice did not show a decrease in the number of bone marrow (BM) precursor cells. Instead, the BM progenitors for ETPs expressed reduced mRNA levels of CC chemokine receptor (CCR) 7, CCR9 and P-selectin glycoprotein ligand 1, and exhibited impaired homing capacity in vitro and in vivo. Furthermore, RNA-Seq analysis and real-time PCR showed a marked downregulation of several lymphoid-related genes in hematopoietic stem and progenitor cells. Hematopoietic stem and progenitor cells differentiated into myeloid cells but failed to generate T lymphocytes in vitro and in vivo. Our results indicate that the depletion of ETPs in septic mice might be a consequence of an impaired migration of BM progenitors to the thymus, as well as a defect in lymphoid lineage commitment. Stem Cells 2016;34:2902-2915.

Increased activated regulatory T cells proportion correlate with the severity of idiopathic pulmonary fibrosis.

BACKGROUND: Regulatory T cells (Tregs) are crucial in maintaining immune tolerance and immune homeostasis, but their role in idiopathic pulmonary fibrosis (IPF) is unclear. This study was designed to explore the role of Tregs in IPF. METHODS: Percentages of Tregs and their subpopulations in peripheral blood (PB) and bronchoalveolar lavage (BAL) samples were determined by flow cytometry in 29 patients with IPF, 19 patients with primary Sjögren's syndrome-related interstitial pneumonia (pSS-IP), and 23 healthy controls (HCs). RESULTS: In peripheral blood, no difference was found in CD4+CD25+Foxp3+ Treg percentages among patients with IPF, pSS-IP, or HCs. However, activated Treg (aTreg) fractions among CD4+ T cells increased significantly in IPF compared with pSS-IP or HCs. Being consistent with the result from the PB, aTreg fractions among CD4+ T cells in IPF also increased significantly compared with pSS-IP or HCs, accompanied by increased fraction III compared with HCs in BAL. IPF patients had lower levels of resting Tregs (rTregs) from the thymus than did HCs, whereas aTreg levels originating from the thymus did not significantly differ from HCs. Both rTregs and aTregs proliferated in IPF, with aTregs being more proliferative than rTregs. Both rTregs and aTregs significantly inhibited proliferation of CD4+ T lymphocytes in vitro. The percentage of aTregs was correlated negatively with predicted diffusing capacity values for carbon monoxide and positively with GAP index in IPF. CONCLUSIONS: Our study showed the imbalance between subpopulations of Tregs in IPF. Increased aTregs proportion in the peripheral blood correlated inversely with disease severity.

Total Synthesis and Biological Evaluation of Tubulysin Analogues.

We report a second-generation synthesis of the exceedingly potent antimitotic agent N14-desacetoxytubulysin H (1) as well as the preparation of nine analogues of this lead structure. Highlights of our synthetic efforts include an efficient late-stage functionalization that allows for the preparation of new side-chain- and backbone-modified analogues. We also discovered C-terminal modifications that preserve the exquisite biological activity of acid 1 and offer the opportunity for effective conjugation to cell type-targeting moieties. All analogues had antiproliferative activities in the high picomolar to low nanomolar range and caused apoptosis and mitotic arrest as measured in a high content nuclear morphology assay. The ten synthetic agents described herein spanned a range of almost 4 orders of magnitude in biological activity and illustrate the continued potential to discover extraordinarily potent antiproliferative compounds based on natural product leads.

Cu2+-labeled dansyl compounds as fluorescent and PET probes for imaging apoptosis.

Compound DNSTT-Cu2+, a novel chelate of Cu2+ with DOTA conjugated to a fluorescent dansyl fragment, is developed for imaging cell apoptosis. Apoptotic U-87MG cells could be selectively visualized by the fluorescence of DNSTT-Cu2+ from cytoplasm of cells, confirmed by the fluorescence of apoptosis cells co-labeled with Alexa Fluor 568-labeled annexin V, a conventional probe for selectively labeling membranes of apoptosis cells. A radioactive 64Cu2+ analog, DNSTT-64Cu2+, was easily synthesized, providing a potential PET probe for imaging apoptosis in vivo.

Steroidogenic enzyme Cyp11a1 regulates Type 2 CD8+ T cell skewing in allergic lung disease.

Allergic asthma is a heterogeneous inflammatory disorder of the airways characterized by chronic airway inflammation and airway hyperresponsiveness. Numbers of CD8(+)IL-13(+) T cells are increased in asthmatics and during the development of experimental asthma in mice. In an atopic environment rich in IL-4, these CD8(+) T cells mediate asthmatic responses, but the mechanisms regulating the conversion of CD8(+) effector T cells from IFN-γ- to pathogenic IL-13-producing effector cells that contribute to an asthma phenotype have not been defined. Here, we show that cholesterol side-chain cleavage P450 enzyme, Cyp11a1, is a key regulator of CD8(+) T-cell conversion. Expression of the gene, protein, and enzymatic activity of Cyp11a1 were markedly increased in CD8(+) T cells differentiated in the presence of IL-2 plus IL-4 compared with cells differentiated in IL-2 alone. Inhibition of Cyp11a1 enzymatic activity with aminoglutethimide or reduction in the expression of Cyp11a1 using short hairpin RNA prevented the IL-4-induced conversion of IFN-γ- to IL-13-producing cells without affecting expression of the lineage-specific transcription factors T-box expressed in T cells (T-bet) or GATA binding protein 3 (GATA3). Adoptive transfer of aminoglutethimide-treated CD8(+) T cells into sensitized and challenged CD8-deficient recipients failed to restore airway hyperresponsiveness and inflammation. We demonstrate that Cyp11a1 controls the phenotypic conversion of CD8(+) T cells from IFN-γ to IL-13 production, linking steroidogenesis in CD8(+) T cells, a nonclassical steroidogenic tissue, to a proallergic differentiation pathway.

Eosinophils contribute to the resolution of lung-allergic responses following repeated allergen challenge.

BACKGROUND: Eosinophils accumulate at the site of allergic inflammation and are critical effector cells in allergic diseases. Recent studies have also suggested a role for eosinophils in the resolution of inflammation. OBJECTIVE: To determine the role of eosinophils in the resolution phase of the response to repeated allergen challenge. METHODS: Eosinophil-deficient (PHIL) and wild-type (WT) littermates were sensitized and challenged to ovalbumin (OVA) 7 or 11 times. Airway inflammation, airway hyperresponsiveness (AHR) to inhaled methacholine, bronchoalveolar lavage (BAL) cytokine levels, and lung histology were monitored. Intracellular cytokine levels in BAL leukocytes were analyzed by flow cytometry. Groups of OVA-sensitized PHIL mice received bone marrow from WT or IL-10(-/-) donors 30 days before the OVA challenge. RESULTS: PHIL and WT mice developed similar levels of AHR and numbers of leukocytes and cytokine levels in BAL fluid after OVA sensitization and 7 airway challenges; no eosinophils were detected in the PHIL mice. Unlike WT mice, sensitized PHIL mice maintained AHR, lung inflammation, and increased levels of IL-4, IL-5, and IL-13 in BAL fluid after 11 challenges whereas IL-10 and TGF-ß levels were decreased. Restoration of eosinophil numbers after injection of bone marrow from WT but not IL-10-deficient mice restored levels of IL-10 and TGF-ß in BAL fluid as well as suppressed AHR and inflammation. Intracellular staining of BAL leukocytes revealed the capacity of eosinophils to produce IL-10. CONCLUSIONS: After repeated allergen challenge, eosinophils appeared not essential for the development of AHR and lung inflammation but contributed to the resolution of AHR and inflammation by producing IL-10.