Clinical Efficacy among Patients with Chronic Rhinosinusitis with Nasal Polyps and Clinical Features of Obstructive Lung Disease: Post Hoc Analysis of the Phase III SINUS-24 and SINUS-52 Studies.

Purpose: To provide a descriptive summary of clinical efficacy and health-related quality of life (HRQoL) measures in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and clinical features of obstructive lung disease in the Phase III dupilumab studies SINUS-24 and SINUS-52 (NCT02912468, NCT02898454). Patients and Methods: Patients met a "broad" definition of having clinical features of obstructive lung disease with any of 3 criteria: (i) pre-bronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) <0.70 and smoking history; (ii) patient-reported medical history of chronic obstructive pulmonary disease (COPD); or (iii) asthma with >10 pack-years' smoking history. A "narrow" definition including criteria (i) or (ii) was also analyzed. CRSwNP and HRQoL measures were evaluated in all patients and lung function (FEV1; FEV1/FVC ratio) was captured and analyzed only in those patients who had a self-reported history of asthma. Results: Across both studies, 131 patients met the "broad" definition, of whom 90 also had asthma, and 115 patients met the "narrow" definition, of whom 74 had asthma. CRSwNP outcomes and HRQoL were improved with dupilumab vs placebo in both the broad and narrow subgroups. Among the 90 patients who met the broad definition and had asthma, dupilumab improved pre-bronchodilator FEV1 and FEV1/FVC ratio at Week 16 (least squares mean differences vs placebo: 0.38 L [95% confidence interval: 0.17, 0.59; p = 0.0004] and 4.8% [1.7%, 7.9%; p = 0.0024], respectively) sustained through Week 24. Similar results were seen in the "narrow" subgroup with asthma. Conclusion: In a population of patients with CRSwNP and clinical features of obstructive lung disease, dupilumab improved CRSwNP and HRQoL outcomes, and, among those with a history of asthma, also improved lung function. These results support further analyses of dupilumab in patients with evidence of type 2 inflammation and obstructive lung disease such as COPD.

Dupilumab efficacy in subgroups of type 2 asthma with high-dose inhaled corticosteroids at baseline.

BACKGROUND AND OBJECTIVE: Dupilumab blocks the shared receptor component for interleukin (IL)-4/IL-13, key and central drivers of type 2 inflammation in multiple diseases. In phase 3 QUEST (NCT02414854), add-on dupilumab 200 and 300 mg every 2 weeks reduced severe exacerbations, improved pre-bronchodilator forced expiratory volume in 1 s (FEV1), and was generally well tolerated in patients with uncontrolled moderate-to-severe asthma. This post hoc analysis assessed dupilumab efficacy in subpopulations of patients with type 2 asthma and high-dose inhaled corticosteroids (ICS). METHODS: Adjusted annualized severe exacerbation rates over the treatment period, least squares (LS) mean change from baseline at Week 12 in pre-bronchodilator FEV1, and LS mean change from baseline at Week 24 in 5-item Asthma Control Questionnaire (ACQ-5) scores were analyzed in subgroups of patients receiving high-dose (>500 µg) ICS with baseline blood eosinophils ≥150 cells/µL and/or fractional exhaled nitric oxide ≥25 ppb. Subgroups included allergic phenotype (with/without), comorbid chronic rhinosinusitis and/or nasal polyposis (with/without), pre-bronchodilator FEV1/forced vital capacity (<70%/≥70%), blood eosinophil level, exacerbation history, median baseline pre-bronchodilator FEV1, age at asthma onset (≤40/>40 years), median FEV1 reversibility, body mass index (<30/≥30 kg/m2), and sex. RESULTS: Dupilumab vs placebo reduced exacerbations and improved pre-bronchodilator FEV1 at Week 12 and ACQ-5 at Week 24 across subgroups of patients with type 2 asthma and high-dose ICS at baseline. Dupilumab was also effective in patients receiving medium-dose ICS. CONCLUSION: Dupilumab reduced severe exacerbations and improved lung function and asthma control in subgroups of patients with type 2 asthma and high-dose ICS at baseline. CLINICAL TRIAL REGISTRATION NUMBER: NCT02414854.

Effect of Dupilumab on Blood Eosinophil Counts in Patients With Asthma, Chronic Rhinosinusitis With Nasal Polyps, Atopic Dermatitis, or Eosinophilic Esophagitis.

BACKGROUND: Transient increases in blood eosinophil counts have been observed in dupilumab clinical trials. OBJECTIVE: To assess eosinophil counts and eosinophilia-related treatment-emergent adverse events (TEAEs) across 11 dupilumab clinical trials, comparing adult and adolescent patients with asthma and adult patients with chronic rhinosinusitis with nasal polyps (CRSwNP), atopic dermatitis, and eosinophilic esophagitis. METHODS: Eosinophil counts, rates of eosinophilia-related TEAEs or treatment-emergent eosinophilia (>1,500 cells/µL), discontinuations, clinical symptoms, and efficacy in patients with asthma or CRSwNP with treatment-emergent eosinophilia are presented. RESULTS: Transient increases in mean eosinophil counts were observed in dupilumab-treated patients with asthma (mean range across studies at baseline: 349-370 cells/µL; week 4: 515-578 cells/µL), CRSwNP (baseline: 440-448 cells/µL; week 16: 595 cells/µL), and atopic dermatitis (baseline: 434-600 cells/µL; week 4: 410-710 cells/µL), followed by a decline starting by week 24 to baseline or lower. No increases were seen in patients with eosinophilic esophagitis (baseline: 310 cells/µL; week 4: 230 cells/µL). In dupilumab-treated patients across all studies, rates of eosinophilia TEAEs were 0% to 13.6%. Clinical symptoms associated with increased eosinophils were rare (seven of 4,666 dupilumab-treated patients, including six cases of eosinophilic granulomatosis with polyangiitis) and occurred only in patients with asthma or CRSwNP. Eosinophilia was not associated with reduced dupilumab efficacy. CONCLUSIONS: Transient increases in eosinophil counts with dupilumab treatment did not affect efficacy and were rarely of clinical consequence. It remains important for physicians to base judgment on individual patient history and baseline eosinophil counts and to be alert to hypereosinophilic symptoms.

Dupilumab Demonstrates Rapid Onset of Response Across Three Type 2 Inflammatory Diseases.

BACKGROUND: Type 2 inflammatory diseases often coexist in patients. Dupilumab targets type 2 inflammation and has demonstrated treatment benefits in patients with atopic dermatitis (AD), asthma, and chronic rhinosinusitis with nasal polyps (CRSwNP) with an acceptable safety profile. OBJECTIVE: This post hoc analysis across five phase 3 studies in patients with moderate to severe AD or asthma, or severe CRSwNP, evaluated time of onset and duration of the treatment response. METHODS: Patients received subcutaneous dupilumab 200/300 mg or placebo. Assessments included the Eczema Area and Severity Index, Peak Pruritus Numerical Rating Scale, and Dermatology Life Quality Index in AD; pre-bronchodilator FEV1, daily morning peak expiratory flow, and symptom scores in asthma; and University of Pennsylvania Smell Identification Test, daily nasal congestion, and loss of smell scores in CRSwNP. RESULTS: At week 2 after the initiation of dupilumab versus placebo, 67.8% versus 36.5% of AD patients achieved a clinically meaningful benefit (Eczema Area and Severity Index: 50% or greater improvement; Peak Pruritus Numerical Rating Scale: 3 point or greater improvement; or Dermatology Life Quality Index: 4 point or greater improvement) (P < .001). Moreover, 61.6% versus 39.9% of asthma patients achieved improvements in pre-bronchodilator FEV1 of 100 mL or greater and 48.8% versus 26.3% achieved 200 mL or greater improvement (both P < .001); 33.2% versus 5.6% of CRSwNP patients regained a sense of smell (P < .001). Treatment effects further improved or were sustained to the end of treatment. CONCLUSIONS: Clinically meaningful responses were achieved rapidly after the first dupilumab dose in AD, asthma, or CRSwNP and were sustained throughout treatment (see Video in this article's Online Repository at www.jaci-inpractice.org).

Respiratory Infections and Anti-Infective Medication Use From Phase 3 Dupilumab Respiratory Studies.

BACKGROUND: Patients with asthma and/or chronic rhinosinusitis with nasal polyps (CRSwNP) experience recurrent respiratory tract infections. Dupilumab targets type 2 inflammation, a common underlying pathophysiology of both conditions, with proven efficacy. OBJECTIVE: To examine investigator-reported respiratory infection adverse events and anti-infective medication use with dupilumab versus placebo in patients with moderate-to-severe asthma or severe CRSwNP. METHODS: We performed a post hoc analysis of the pivotal phase 3 trials LIBERTY ASTHMA QUEST (NCT02414854) and LIBERTY NP SINUS-52 (NCT02898454) in moderate-to-severe asthma and severe CRSwNP, respectively. RESULTS: Investigator-reported respiratory infection events occurred at a significantly lower incidence in patients treated with dupilumab versus placebo, in both asthma (22% lower; P < .0001; 95% CI 0.71-0.85) and CRSwNP (38% lower; P <.0001; 95% CI 0.51-0.75). Reported upper and lower respiratory tract infection events were numerically or significantly lower in dupilumab-treated patients in both conditions, as were the number of patients experiencing investigator-reported infections. Significantly less systemic anti-infective medication use occurred in dupilumab versus placebo in asthma (24% lower; P < .0001; 95% CI 0.70-0.83) and CRSwNP patients (49% lower; P < .0001; 95% CI 0.43-0.61), and significantly fewer dupilumab-treated patients used anti-infective medications. When examined by season and month, the data indicated that investigator-reported respiratory infections and anti-infective medication use were less frequent in dupilumab- versus placebo-treated patients throughout the calendar year. CONCLUSIONS: Dupilumab treatment was associated with a reduced incidence of investigator-reported respiratory infections in patients with moderate-to-severe asthma or severe CRSwNP. Further studies are required to determine the mechanism behind this reduction.

Efficacy and safety of dupilumab in patients with uncontrolled severe chronic rhinosinusitis with nasal polyps and a clinical diagnosis of NSAID-ERD: Results from two randomized placebo-controlled phase 3 trials.

BACKGROUND: About one-tenth of patients with difficult-to-treat chronic rhinosinusitis with nasal polyps (CRSwNP) have comorbid non-steroidal anti-inflammatory drug-exacerbated respiratory disease (NSAID-ERD). Dupilumab, a fully human monoclonal antibody that blocks the shared interleukin (IL)-4/IL-13 receptor component, is an approved add-on treatment in severe CRSwNP. This post hoc analysis evaluated dupilumab efficacy and safety in patients with CRSwNP with/without NSAID-ERD. METHODS: Data were pooled from the phase 3 SINUS-24 and SINUS-52 studies in adults with uncontrolled severe CRSwNP who received dupilumab 300 mg or placebo every 2 weeks. CRSwNP, nasal airflow, lung function, and asthma control outcomes at Week 24 were evaluated, and treatment-subgroup interactions were assessed for patients with and without NSAID-ERD. RESULTS: Of 724 patients, 204 (28.2%) had a diagnosis of NSAID-ERD. At Week 24, least squares mean treatment differences demonstrated significant improvements in nasal polyp score, nasal congestion (NC), Lund-Mackay computed tomography, 22-item Sinonasal Outcome Test (SNOT-22), Total Symptom Score (TSS), rhinosinusitis severity visual analog scale, peak nasal inspiratory flow (PNIF), six-item Asthma Control Questionnaire score, and improvement in smell with dupilumab versus placebo (all p < .0001) in patients with NSAID-ERD. Treatment comparisons demonstrated significantly greater improvements with dupilumab in patients with versus without NSAID-ERD for NC (p = .0044), SNOT-22 (p = .0313), TSS (p = .0425), and PNIF (p = .0123). CONCLUSIONS: In patients with uncontrolled severe CRSwNP, dupilumab significantly improved objective measures and patient-reported symptoms to a greater extent in the presence of comorbid NSAID-ERD than without. Dupilumab was well tolerated in patients with/without NSAID-ERD.

Dupilumab efficacy in chronic rhinosinusitis with nasal polyps from SINUS-52 is unaffected by eosinophilic status.

BACKGROUND: The human monoclonal antibody dupilumab blocks interleukin (IL)-4 andIL-13, key and central drivers of type 2 inflammation. Dupilumab, on background mometasone furoate nasal spray (MFNS), improved outcomes in the phase III SINUS-52 study (NCT02898454) in patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP). This posthoc analysis of SINUS-52 examined whether eosinophilic status of CRSwNP was a predictor of dupilumab efficacy. METHODS: Patients were randomized 1:1:1 to dupilumab 300 mg every 2 weeks (q2w) until week 52; dupilumab 300 mg q2w until Week 24, then 300 mg every 4 weeks until week 52; or placebo (MFNS) until week 52. Coprimary endpoints were change from baseline in nasal polyps score (NPS), nasal congestion (NC), and Lund-Mackay score assessed by CT (LMK-CT) at week 24. Patients (n = 438) were stratified by eosinophilic chronic rhinosinusitis (ECRS) status according to the Japanese Epidemiological Survey of Refractory Eosinophilic Rhinosinusitis algorithm. RESULTS: Dupilumab significantly improved NPS, NC, and LMK-CT scores versus placebo at week 24 in all ECRS subgroups (p < 0.001), with improvements maintained or increased at week 52 (p < 0.001). There was no significant interaction between ECRS subgroup (non-/mild or moderate/severe) and dupilumab treatment effect for all endpoints at weeks 24 and 52 (p > 0.05), except LMK-CT at week 24 (p = 0.0275). Similar results were seen for the secondary endpoints. Dupilumab was well tolerated across all ECRS subgroups. CONCLUSION: Dupilumab produced consistent improvement in symptoms of severe CRSwNP irrespective of ECRS status. Therefore, blood eosinophil level may not be a suitable biomarker for dupilumab efficacy in CRSwNP.

Efficacy of dupilumab in patients with a history of prior sinus surgery for chronic rhinosinusitis with nasal polyps.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease treated with sinus surgery when refractory to medical intervention. However, recurrence postsurgery is common. Dupilumab, a fully human monoclonal antibody, blocks the shared receptor for interleukin 4 (IL-4) and IL-13, key and central drivers of type 2 inflammation. We report the efficacy of dupilumab in patients with CRSwNP from the SINUS-24/SINUS-52 trials (NCT02912468/NCT02898454), by number of prior surgeries and time since last surgery. METHODS: Patients were randomized to placebo or dupilumab 300 mg every 2 weeks. Post hoc subgroup analyses were performed for patients with 0, ≥1, 1/2, or ≥3 prior surgeries, and for patients who had surgery within <3, 3 to <5, 5 to <10, or ≥10 years. Efficacy outcomes at 24 weeks included co-primary endpoints nasal polyp score (NPS) and nasal congestion (NC), and Lund-Mackay (LMK), 22-item Sino-Nasal Outcome Test (SNOT-22), and smell scores. RESULTS: Of 724 patients randomized, 459 (63.4%) had ≥1 prior surgery. Baseline sinus disease (NPS, NC, LMK) and olfactory dysfunction (University of Pennsylvania Smell Identification Test [UPSIT] and loss of smell) scores were worse for patients with ≥3 prior surgeries vs no surgery. Baseline NPS and LMK were worse in patients with <3 years since last surgery than in patients with ≥5 years since last surgery. Dupilumab significantly improved all outcome measures vs placebo in all subgroups by number of surgeries and by time since last surgery. Improvements in NPS and LMK were greater in patients with <3 years since last surgery than patients with ≥5 years. Safety results were consistent with the known dupilumab safety profile. CONCLUSION: Dupilumab improved CRSwNP outcomes irrespective of surgery history, with greater improvements in endoscopic outcomes in patients with shorter duration since last surgery.

Impact of allergies on health-related quality of life in patients with asthma.

Objective: To estimate the health-related quality of life (HRQoL) and health utilities among asthma patients with and without comorbid allergies in a managed care population.Methods: This was a retrospective analysis of patient survey responses and pharmacy claims from the Observational Study of Asthma Control and Outcomes (OSACO). Patients ≥12 years-old with persistent asthma received four identical surveys between April-2011 and December-2012. The presence of allergy was identified by a positive response to a survey question about hay fever/seasonal allergies and ≥1 diagnosis-related ICD-9-CM code(s) for allergic conditions. HRQoL instruments included generic utility (EQ-5D-3L [including VAS]), asthma-specific utility (AQL-5D) and asthma-specific health status (Mini Asthma Quality of Life Questionnaire [MiniAQLQ]). Median regression was used for utility scores and Least Squares regression for MiniAQLQ, adjusting for sociodemographic characteristics and smoking.Results: Of the 2681 asthmatics who completed the first survey in the OSACO study, 971 had comorbid allergies. After adjusting for covariates, asthma patients with comorbid allergies had significantly lower MiniAQLQ scores than patients without allergies (-0.489 [95% CI -0.570, -0.409]; p < 0.01), with the greatest decrement/impairment observed for the environmental stimuli domain (-0.729 [95% CI -0.844, -0.613]; p < 0.01). Utility scores were also statistically significantly lower for asthma patients with comorbid allergies compared to those without allergies (EQ-5D, -0.031 [95% CI -0.047, -0.015]; AQL-5D, -0.036 [95% CI -0.042, -0.029]; p < 0.01 each).Conclusions: The presence of allergies with persistent asthma is associated with a significant deleterious impact on several different measures of HRQoL.

Retrospective Study on the Association of Biomarkers With Real-world Outcomes of Omalizumab-treated Patients With Allergic Asthma.

PURPOSE: Biomarkers, including blood eosinophils (EoS) and fractional exhaled nitric oxide (FeNO), may affect omalizumab outcomes in allergic asthma, but evidence in the literature remains mixed. This study assessed omalizumab outcomes in real-world patients with allergic asthma stratified by pretreatment biomarker levels. METHODS: Patients with allergic asthma aged ≥12 years initiated on omalizumab with ≥12 months of data after index were identified in the Allergy Partners electronic medical records (2007-2018). Patients with ≥1 diagnosis of chronic obstructive pulmonary disease in combination with ≥10 pack-years of smoking, cystic fibrosis, Alpha-1 antitrypsin deficiency, bronchiectasis, interstitial lung disease, and sarcoidosis in the 12 months before or after index were excluded. Patients were stratified by pretreatment EoS (≥/<300 cells/µL) and FeNO (≥/<25 parts per billion). Outcomes, including Asthma Control Test (ACT) scores, forced expiratory volume in 1 second (FEV1), and FEV1 as a percentage of predicted value (FEV1% predicted), were compared using generalized estimating equations at 6 and 12 months after versus before index date in stratified patients with outcome measures available at both time periods. FINDINGS: A total of 77 and 86 patients were stratified into the high and low EoS strata, respectively, and 56 patients into each of the intermediate-high and low FeNO strata. Compared with 6 months before index, mean difference (MD) in ACT scores at 6 months after index reached the minimally important difference of ≥3 points in high (MD = 3.75; 95% CI, 2.05-5.45) and low (MD = 4.56; 95% CI, 2.86-6.26) EoS, as well in the intermediate-high (MD = 3.75; 95% CI, 1.95-5.55) and low (MD = 3.55; 95% CI, 1.53-5.57) FeNO strata. Statistically significant improvements in mean FEV1 were observed in the high EoS (MD = 0.22 L/s; 95% CI, 0.08-0.35 L/s) and intermediate-high FeNO (MD = 0.13 L/s; 95% CI, 0.03-0.24 L/s) strata but not in the lower strata. In terms of mean FEV1% predicted, a statistically significant improvement was observed in high EoS stratum (MD = 4.95%; 95% CI, 0.60%-9.30%). Results that compared 12 months after versus before index date were similar. IMPLICATIONS: Omalizumab was associated with statistically significant improvements in ACT scores largely reaching or exceeding minimally important difference across biomarker levels and with a statistically significant improvement in lung function more evident in high biomarker strata. Although response varied by biomarkers for some outcomes, all strata indicated improvements on ≥1 measure. Real-world patients with allergic asthma could benefit from omalizumab regardless of pretreatment biomarker levels, suggesting that pretreatment biomarker levels might not inform response.

Layer-by-Layer Assembly of Amine-Reactive Multilayers Using an Azlactone-Functionalized Polymer and Small-Molecule Diamine Linkers.

We report the reactive layer-by-layer assembly of amine-reactive polymer multilayers using an azlactone-functionalized polymer and small-molecule diamine linkers. This approach yields cross-linked polymer/linker-type films that can be further functionalized, after fabrication, by treatment with functional primary amines, and provides opportunities to incorporate other useful functionality that can be difficult to introduce using other polyamine building blocks. Films fabricated using poly(2-vinyl-4,4-dimethylazlactone) (PVDMA) and three model nondegradable aliphatic diamine linkers yielded reactive thin films that were stable upon incubation in physiologically relevant media. By contrast, films fabricated using PVDMA and varying amounts of the model disulfide-containing diamine linker cystamine were stable in normal physiological media, but were unstable and eroded rapidly upon exposure to chemical reducing agents. We demonstrate that this approach can be used to fabricate functionalized polymer microcapsules that degrade in reducing environments, and that rates of erosion, extents of capsule swelling, and capsule degradation can be tuned by control over the relative concentration of cystamine linker used during fabrication. The polymer/linker approach used here expands the range of properties and functions that can be designed into reactive PVDMA-based coatings, including functionality that can degrade, erode, and undergo triggered destruction in aqueous environments. We therefore anticipate that these approaches will be useful for the functionalization, patterning, and customization of coatings, membranes, capsules, and interfaces of potential utility in biotechnical or biomedical contexts and other areas where degradation and transience are desired. The proof of concept strategies reported here are likely to be general, and should prove useful for the design of amine-reactive coatings containing other functional structures by judicious control of the structures of the linkers used during assembly.

Derivation of T cells in vitro from mouse embryonic stem cells.

The OP9/OP9-DL1 co-culture system has become a well-established method for deriving differentiated blood cell types from embryonic and hematopoietic progenitors of both mouse and human origin. It is now used to address a growing variety of complex genetic, cellular and molecular questions related to hematopoiesis, and is at the cutting edge of efforts to translate these basic findings to therapeutic applications. The procedures are straightforward and routinely yield robust results. However, achieving successful hematopoietic differentiation in vitro requires special attention to the details of reagent and cell culture maintenance. Furthermore, the protocol features technique sensitive steps that, while not difficult, take care and practice to master. Here we focus on the procedures for differentiation of T lymphocytes from mouse embryonic stem cells (mESC). We provide a detailed protocol with discussions of the critical steps and parameters that enable reproducibly robust cellular differentiation in vitro. It is in the interest of the field to consider wider adoption of this technology, as it has the potential to reduce animal use, lower the cost and shorten the timelines of both basic and translational experimentation.

Adapting in vitro embryonic stem cell differentiation to the study of locus control regions.

Numerous locus control region (LCR) activities have been discovered in gene loci important to immune cell development and function. LCRs are a distinct class of cis-acting gene regulatory elements that appear to contain all the DNA sequence information required to establish an independently and predictably regulated gene expression program at any genomic site in native chromatin of a whole animal. As such, LCR-regulated transgenic reporter systems provide invaluable opportunities to investigate the mechanisms of gene regulatory DNA action during development. Furthermore the qualities of LCR-driven gene expression, including spatiotemporal specificity and "integration site-independence" would be highly desirable to incorporate into vectors used in therapeutic genetic engineering. Thus, advancement in the methods used to investigate LCRs is of considerable basic and translational significance. We study the LCR present in the mouse T cell receptor (TCR)-α gene locus. Until recently, transgenic mice provided the only experimental model capable of supporting the entire spectrum of LCR activities. We have recently reported complete manifestation of TCRα LCR function in T cells derived in vitro from mouse embryonic stem cells (ESC), thus validating a complete cell culture model for the full range of LCR activities seen in transgenic mice. Here we discuss the critical parameters involved in studying LCR-regulated gene expression during in vitro hematopoietic differentiation from ESCs. This advance provides an approach to speed progress in the LCR field, and facilitate the clinical application of its findings, particularly to the genetic engineering of T cells.

A role for autophagic protein beclin 1 early in lymphocyte development.

Autophagy is a highly regulated and evolutionarily conserved process of cellular self-digestion. Recent evidence suggests that this process plays an important role in regulating T cell homeostasis. In this study, we used Rag1(-/-) (recombination activating gene 1(-/-)) blastocyst complementation and in vitro embryonic stem cell differentiation to address the role of Beclin 1, one of the key autophagic proteins, in lymphocyte development. Beclin 1-deficient Rag1(-/-) chimeras displayed a dramatic reduction in thymic cellularity compared with control mice. Using embryonic stem cell differentiation in vitro, we found that the inability to maintain normal thymic cellularity is likely caused by impaired maintenance of thymocyte progenitors. Interestingly, despite drastically reduced thymocyte numbers, the peripheral T cell compartment of Beclin 1-deficient Rag1(-/-) chimeras is largely normal. Peripheral T cells displayed normal in vitro proliferation despite significantly reduced numbers of autophagosomes. In addition, these chimeras had greatly reduced numbers of early B cells in the bone marrow compared with controls. However, the peripheral B cell compartment was not dramatically impacted by Beclin 1 deficiency. Collectively, our results suggest that Beclin 1 is required for maintenance of undifferentiated/early lymphocyte progenitor populations. In contrast, Beclin 1 is largely dispensable for the initial generation and function of the peripheral T and B cell compartments. This indicates that normal lymphocyte development involves Beclin 1-dependent, early-stage and distinct, Beclin 1-independent, late-stage processes.

A novel TCR transgenic model reveals that negative selection involves an immediate, Bim-dependent pathway and a delayed, Bim-independent pathway.

A complete understanding of negative selection has been elusive due to the rapid apoptosis and clearance of thymocytes in vivo. We report a TCR transgenic model in which expression of the TCR during differentiation occurs only after V(D)J-like recombination. TCR expression from this transgene closely mimics expression of the endogenous TCRalpha locus allowing for development that is similar to wild type thymocytes. This model allowed us to characterize the phenotypic changes that occurred after TCR-mediated signaling in self-reactive thymocytes prior to their deletion in a highly physiological setting. Self-reactive thymocytes were identified as being immature, activated and CD4(lo)CD8(lo). These cells had upregulated markers of negative selection and were apoptotic. Elimination of Bim reduced the apoptosis of self-reactive thymocytes, but it did not rescue their differentiation and the cells remained at the immature CD4(lo)CD8(lo) stage of development. These cells upregulate Nur77 and do not contribute to the peripheral T cell repertoire in vivo. Remarkably, development past the CD4(lo)CD8(lo) stage was possible once the cells were removed from the negatively selecting thymic environment. In vitro development of these cells occurred despite their maintenance of high intracellular levels of Nur77. Therefore, in vivo, negatively selected Bim-deficient thymocytes are eliminated after prolonged developmental arrest via a Bim-independent pathway that is dependent on the thymic microenvironment. These data newly reveal a layering of immediate, Bim-dependent, and delayed Bim-independent pathways that both contribute to elimination of self-reactive thymocytes in vivo.

Childhood asthma and extreme values of body mass index: the Harlem Children's Zone Asthma Initiative.

To examine the association between body mass index (BMI) percentile and asthma in children 2-11 years of age, we performed a cross-sectional analysis of 853 Black and Hispanic children from a community-based sample of 2- to 11-year olds with measured heights and weights screened for asthma by the Harlem Children's Zone Asthma Initiative. Current asthma was defined as parent/guardian-reported diagnosis of asthma and asthma-related symptoms or emergency care in the previous 12 months. Among girls, asthma prevalence increased approximately linearly with increasing body mass index (BMI) percentile, from a low of 12.0% among underweight girls (BMI 95th percentile). After adjusting for age, race/ethnicity, and household smoking, among girls, having asthma was associated with being at risk for overweight (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.4-5.0) and being overweight (OR, 2.1; 95% CI, 1.2-3.8) compared to normal weight; among boys, having asthma was associated both with overweight (OR, 2.4; 95% CI, 1.4-4.3) and with underweight (OR, 2.9; 95% CI, 1.1-7.7). Large, prospective studies that include very young children are needed to further explore the observed association between underweight and asthma among boys. Early interventions that concomitantly address asthma and weight gain are needed among pre-school and school-aged children.

Addressing the childhood asthma crisis in Harlem: the Harlem Children's Zone Asthma Initiative.

OBJECTIVES: We determined the prevalence of asthma and estimated baseline asthma symptoms and asthma management strategies among children aged 0-12 years in Central Harlem. METHODS: The Harlem Children's Zone Asthma Initiative is a longitudinal, community-based intervention designed for poor children with asthma. Children aged 0-12 years who live or go to school in the Harlem Children's Zone Project or who participate in any Harlem Children's Zone, Inc, program were screened for asthma. Children with asthma or asthma-like symptoms were invited to participate in an intensive intervention. RESULTS: Of the 1982 children currently screened, 28.5% have been told by a doctor or nurse that they have asthma, and 30.3% have asthma or asthma-like symptoms. To date, 229 children are enrolled in the Harlem Children's Zone Asthma Initiative; at baseline, 24.0% had missed school in the last 14 days because of asthma. CONCLUSION: The high prevalence of asthma among children in the Harlem Children's Zone Project is consistent with reports from other poor urban communities. Intensive efforts are under way to reduce children's asthma symptoms and improve their asthma management strategies.

Factors binding a non-classical Cis-element prevent heterochromatin effects on locus control region activity.

A locus control region (LCR) is a cis-acting gene-regulatory element capable of transferring the expression characteristics of its gene locus of origin to a linked transgene. Furthermore, it can do this independently of the site of integration in the genome of transgenic mice. Although most LCRs contain subelements with classical transcriptional enhancer function, key aspects of LCR activity are supported by cis-acting sequences devoid of the ability to act as direct transcriptional enhancers. Very few of these "non-enhancer" LCR components have been characterized. Consequently, the sequence requirements and molecular bases for their functions, as well as their roles in LCR activity, are poorly understood. We have investigated these questions using the LCR from the mouse T cell receptor (TCR) alpha/Dad1 gene locus. Here we focus on DNase hypersensitive site (HS) 6 of the TCRalpha LCR. HS6 does not support classical enhancer activity, yet has gene regulatory activity in an in vivo chromatin context. We have identified three in vivo occupied factor-binding sites within HS6, two of which interact with Runx1 and Elf-1 factors. Deletion of these sites from the LCR impairs its activity in vivo. This mutation renders the transgene locus abnormally inaccessible in chromatin, preventing the normal function of other LCR subelements and reducing transgene mRNA levels. These data show these factor-binding sites are required for preventing heterochromatin formation and indicate that they function to maintain an active TCRalpha LCR assembly in vivo.