ABSTRACT
RATIONALE: Lymphocytic alveolitis in HIV-1-infected individuals is associated with multiple pulmonary complications and a poor prognosis. Although lymphocytic alveolitis has been associated with viremia and an increased number of CD8(+) T cells in the lung, its exact cause is unknown. OBJECTIVES: To determine if HIV-1-specific T cells are associated with lymphocytic alveolitis in HIV-1-infected individuals. METHODS: Using blood and bronchoalveolar lavage (BAL) cells from normal control subjects and untreated HIV-1-infected individuals, we examined the frequency and functional capacity of HIV-1-specific T cells. MEASUREMENTS AND MAIN RESULTS: We found that HIV-1-specific T cells were significantly elevated in the BAL compared with blood of HIV-1-infected individuals and strongly correlated with T-cell alveolitis. Expression of Ki67, a marker of in vivo proliferation, was significantly reduced on HIV-1-specific T cells in BAL compared with blood, suggesting a diminished proliferative capacity. In addition, HIV-1-specific CD4(+) and CD8(+) T cells in BAL had higher expression of programmed death 1 (PD-1) and lower cytotoxic T-lymphocyte antigen 4 (CTLA-4) expression than those in the blood. A strong correlation between PD-1, but not CTLA-4, and HIV-1-specific T-cell proliferation was seen, and blockade of the PD-1/PD-L1 pathway augmented HIV-1-specific T-cell proliferation, suggesting that the PD-1 pathway was the main cause of reduced proliferation in the lung. CONCLUSIONS: These findings suggest that alveolitis associated with HIV-1 infection is caused by the recruitment of HIV-1-specific CD4(+) and CD8(+) T cells to the lung. These antigen-specific T cells display an impaired proliferative capacity that is caused by increased expression of PD-1.
Subject(s)
CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/metabolism , HIV Infections/immunology , HIV-1/immunology , Lung Diseases/virology , Biomarkers/metabolism , Bronchoalveolar Lavage Fluid/immunology , Bronchoalveolar Lavage Fluid/virology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/virology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/virology , Case-Control Studies , Flow Cytometry , Fluorescent Antibody Technique , HIV Antigens/immunology , HIV Infections/complications , HIV Infections/virology , Humans , Lung/immunology , Lung/virology , Lung Diseases/immunology , Lymphocyte Activation/immunology , Programmed Cell Death 1 Receptor/metabolismABSTRACT
RATIONALE: Lung infections caused by opportunistic or virulent pathogens are a principal cause of morbidity and mortality in HIV infection. It is unknown whether HIV infection leads to changes in basal lung microflora, which may contribute to chronic pulmonary complications that increasingly are being recognized in individuals infected with HIV. OBJECTIVES: To determine whether the immunodeficiency associated with HIV infection resulted in alteration of the lung microbiota. METHODS: We used 16S ribosomal RNA targeted pyrosequencing and shotgun metagenomic sequencing to analyze bacterial gene sequences in bronchoalveolar lavage (BAL) and mouths of 82 HIV-positive and 77 HIV-negative subjects. MEASUREMENTS AND MAIN RESULTS: Sequences representing Tropheryma whipplei, the etiologic agent of Whipple's disease, were significantly more frequent in BAL of HIV-positive compared with HIV-negative individuals. T. whipplei dominated the community (>50% of sequence reads) in 11 HIV-positive subjects, but only 1 HIV-negative individual (13.4 versus 1.3%; P = 0.0018). In 30 HIV-positive individuals sampled longitudinally, antiretroviral therapy resulted in a significantly reduced relative abundance of T. whipplei in the lung. Shotgun metagenomic sequencing was performed on eight BAL samples dominated by T. whipplei 16S ribosomal RNA. Whole genome assembly of pooled reads showed that uncultured lung-derived T. whipplei had similar gene content to two isolates obtained from subjects with Whipple's disease. CONCLUSIONS: Asymptomatic subjects with HIV infection have unexpected colonization of the lung by T. whipplei, which is reduced by effective antiretroviral therapy and merits further study for a potential pathogenic role in chronic pulmonary complications of HIV infection.
Subject(s)
HIV Infections/complications , Lung/microbiology , Tropheryma , Whipple Disease/complications , Whipple Disease/microbiology , Cohort Studies , Humans , Longitudinal StudiesABSTRACT
BACKGROUND: Up to 50% of chronic obstructive pulmonary disease (COPD) patients do not receive recommended care for COPD. To address this issue, we developed Proactive Integrated Care (Proactive iCare), a health care delivery model that couples integrated care with remote monitoring. METHODS: We conducted a prospective, quasi-randomized clinical trial in 511 patients with advanced COPD or a recent COPD exacerbation, to test whether Proactive iCare impacts patient-centered outcomes and health care utilization. Patients were allocated to Proactive iCare (n=352) or Usual Care ( =159) and were examined for changes in quality of life using the St George's Respiratory Questionnaire (SGRQ), symptoms, guideline-based care, and health care utilization. FINDINGS: Proactive iCare improved total SGRQ by 7-9 units (p < 0.0001), symptom SGRQ by 9 units (p<0.0001), activity SGRQ by 6-7 units (p<0.001) and impact SGRQ by 7-11 units (p<0.0001) at 3, 6 and 9 months compared with Usual Care. Proactive iCare increased the 6-minute walk distance by 40 m (p<0.001), reduced annual COPD-related urgent office visits by 76 visits per 100 participants (p<0.0001), identified unreported exacerbations, and decreased smoking (p=0.01). Proactive iCare also improved symptoms, the body mass index-airway obstruction-dyspnea-exercise tolerance (BODE) index and oxygen titration (p<0.05). Mortality in the Proactive iCare group (1.1%) was not significantly different than mortality in the Usual Care group (3.8%; p=0.08). INTERPRETATION: Linking integrated care with remote monitoring improves the lives of people with advanced COPD, findings that may have been made more relevant by the coronavirus 2019 (COVID-19) pandemic.
ABSTRACT
RATIONALE: Cigarette smoke (CS) is the primary cause of chronic obstructive pulmonary disease (COPD), an effect that is, in part, due to intense oxidant stress. Clearance of apoptotic cells (efferocytosis) is a critical regulator of lung homeostasis, which is defective in smokers and in patients with COPD, suggesting a role in disease pathogenesis. OBJECTIVES: We hypothesized that CS would impair efferocytosis through oxidant-dependent activation of RhoA, a known inhibitor of this process. METHODS: We investigated the effect of CS on efferocytosis in vivo and ex vivo, using acute, subacute, and long-term mouse exposure models. MEASUREMENTS AND MAIN RESULTS: Acute and subacute CS exposure suppressed efferocytosis by alveolar macrophages in a dose-dependent, reversible, and cell type-independent manner, whereas more intense CS exposure had an irreversible effect. In contrast, CS did not alter ingestion through the Fc gamma receptor. The inhibitory effect of CS on apoptotic cell clearance depended on oxidants, because the effect was blunted in oxidant-resistant ICR mice, and was prevented by either genetic or pharmacologic antioxidant strategies in vivo and ex vivo. CS inhibited efferocytosis through oxidant-dependent activation of the RhoA-Rho kinase pathway because (1) CS activated RhoA, (2) antioxidants prevented RhoA activation by CS, and (3) inhibitors of the RhoA-Rho kinase pathway reversed the suppressive effect of CS on apoptotic cell clearance in vivo and ex vivo. CONCLUSIONS: These findings advance the hypothesis that impaired efferocytosis may contribute to the pathogenesis of COPD and suggest the therapeutic potential of drugs targeting the RhoA-Rho kinase pathway.
Subject(s)
Apoptosis , Macrophages, Alveolar/drug effects , Phagocytosis/drug effects , Smoking/physiopathology , rho GTP-Binding Proteins/drug effects , Animals , Cell Line, Tumor , Humans , Macrophages, Alveolar/immunology , Male , Mice , Mice, Inbred ICR , Mice, Knockout , Neutrophils , Oxidative Stress/drug effects , Oxidative Stress/immunology , Pulmonary Disease, Chronic Obstructive/physiopathology , Signal Transduction/drug effects , Smoking/immunology , Tumor Necrosis Factor-alpha , rho GTP-Binding Proteins/metabolism , rho-Associated Kinases/drug effects , rhoA GTP-Binding ProteinABSTRACT
RATIONALE: Efficient removal of apoptotic cells is essential for the resolution of acute pulmonary inflammation. Alveolar macrophages ingest apoptotic cells less avidly than other professional phagocytes at rest but overcome this defect during acute inflammation. Surfactant protein (SP)-A and SP-D are potent modulators of macrophage function and may suppress clearance of apoptotic cells through activation of the transmembrane receptor signal inhibitory regulatory protein alpha (SIRP alpha). OBJECTIVES: To investigate whether binding of SP-A and SP-D to SIRP alpha on alveolar macrophages suppresses apoptotic cell clearance. METHODS: Phagocytosis of apoptotic cells was assessed using macrophages pretreated with SP-A, SP-D, or the collectin-like molecule C1q. Binding of SP-A and SP-D to SIRP alpha was confirmed in vitro using blocking antibodies and fibroblasts transfected with active and mutant SIRP alpha. The effects of downstream molecules SHP-1 and RhoA on phagocytosis were studied using SHP-1-deficient mice, sodium stibogluconate, and a Rho kinase inhibitor. Lipopolysaccharide was given to chimeric mice to study the effects of SP-A and SP-D binding on inflammatory macrophages. MEASUREMENTS AND MAIN RESULTS: Preincubation of macrophages with SP-A or SP-D suppressed apoptotic cell clearance. Surfactant suppression of macrophage phagocytosis was reversed by blocking SIRP alpha and inhibiting downstream molecules SHP-1 and RhoA. Macrophages from inflamed lungs ingested apoptotic cells more efficiently than resting alveolar macrophages. Recruited mononuclear phagocytes with low levels of SP-A and SP-D mediated this effect. CONCLUSIONS: SP-A and SP-D tonically inhibit alveolar macrophage phagocytosis by binding SIRP alpha. During acute pulmonary inflammation, defects in apoptotic cell clearance are overcome by recruited mononuclear phagocytes.
Subject(s)
Antigens, Differentiation/immunology , Inflammation/physiopathology , Macrophages, Alveolar/immunology , Phagocytosis/immunology , Pulmonary Surfactant-Associated Protein A/immunology , Pulmonary Surfactant-Associated Protein D/immunology , Receptors, Immunologic/immunology , Animals , Apoptosis/immunology , Binding, Competitive , Cells, Cultured , Humans , Inflammation/immunology , Lung/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, TransgenicABSTRACT
The aim of this article is to review some of the important topics in critical care medicine, including the latest management recommendations for sepsis, the use of noninvasive ventilation in respiratory failure, and practice guidelines for transfusion in critically ill patients.
Subject(s)
Critical Care/organization & administration , Critical Illness/therapy , Hospitalists/methods , Intensive Care Units , Humans , Outcome Assessment, Health Care , United StatesABSTRACT
Context .- In an era in which testing of patient tumor material for molecular and other ancillary studies is of increasing clinical importance for selection of therapy, the ability to test on small samplings becomes critical. Often, small samplings are rapidly depleted in the diagnostic workup or are insufficient for multiple ancillary testing approaches. Objective .- To describe technical methodologies that can be implemented to preserve and maximize tissue for molecular and other ancillary testing. Data Sources .- Retrospective analysis of a case cohort from the University of Colorado, description of techniques used at the University of Colorado, and published literature. Conclusions .- Numerous techniques can be deployed to maximize molecular and other ancillary testing, even when specimens are from small samplings. A dedicated process for molecular prioritization has a high success rate, but also increases workload, which must be factored into establishing such a process. Additionally, establishing high-fidelity communication strings is critical for success of dedicated molecular prioritization of samples. Numerous approaches can be deployed for alternative specimen types, and several technical approaches can also aid in maximizing small specimens.
ABSTRACT
PURPOSE: Patients with anaplastic lymphoma kinase (ALK) gene rearrangements often manifest dramatic responses to crizotinib, a small-molecule ALK inhibitor. Unfortunately, not every patient responds and acquired drug resistance inevitably develops in those who do respond. This study aimed to define molecular mechanisms of resistance to crizotinib in patients with ALK(+) non-small cell lung cancer (NSCLC). EXPERIMENTAL DESIGN: We analyzed tissue obtained from 14 patients with ALK(+) NSCLC showing evidence of radiologic progression while on crizotinib to define mechanisms of intrinsic and acquired resistance to crizotinib. RESULTS: Eleven patients had material evaluable for molecular analysis. Four patients (36%) developed secondary mutations in the tyrosine kinase domain of ALK. A novel mutation in the ALK domain, encoding a G1269A amino acid substitution that confers resistance to crizotinib in vitro, was identified in two of these cases. Two patients, one with a resistance mutation, exhibited new onset ALK copy number gain (CNG). One patient showed outgrowth of epidermal growth factor receptor (EGFR) mutant NSCLC without evidence of a persistent ALK gene rearrangement. Two patients exhibited a KRAS mutation, one of which occurred without evidence of a persisting ALK gene rearrangement. One patient showed the emergence of an ALK gene fusion-negative tumor compared with the baseline sample but with no identifiable alternate driver. Two patients retained ALK positivity with no identifiable resistance mechanism. CONCLUSIONS: Crizotinib resistance in ALK(+) NSCLC occurs through somatic kinase domain mutations, ALK gene fusion CNG, and emergence of separate oncogenic drivers.
Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , Lung Neoplasms/genetics , Protein Kinase Inhibitors/pharmacology , Pyrazoles/pharmacology , Pyridines/pharmacology , Receptor Protein-Tyrosine Kinases/genetics , Translocation, Genetic , Anaplastic Lymphoma Kinase , Carcinoma, Non-Small-Cell Lung/drug therapy , Cell Line , Crizotinib , DNA Copy Number Variations , Disease Progression , Drug Resistance, Neoplasm/genetics , ErbB Receptors/genetics , Humans , Lung Neoplasms/drug therapy , Models, Molecular , Mutation , Oncogene Proteins, Fusion/genetics , Protein Kinase Inhibitors/therapeutic use , Protein Structure, Tertiary , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins p21(ras) , Pyrazoles/therapeutic use , Pyridines/therapeutic use , Receptor Protein-Tyrosine Kinases/chemistry , ras Proteins/geneticsSubject(s)
Delivery of Health Care, Integrated , Pulmonary Disease, Chronic Obstructive/mortality , Pulmonary Disease, Chronic Obstructive/therapy , Aged , Colorado , Female , Health Care Surveys , Humans , Longitudinal Studies , Male , Middle Aged , Oxygen Consumption/physiology , Quality of Life , Rural Health ServicesABSTRACT
Apoptotic cells must be cleared to resolve inflammation, but few resident alveolar macrophages (AMo) from normal lungs ingest apoptotic cells. We examined how Mo ingestion of apoptotic cells is altered during immune inflammation induced by intratracheal challenge of primed C57BL/6 mice using sheep red blood cells. Resident AMo were labeled in situ before challenge using intravenous PKH26 to distinguish them from recruited monocytes. Using flow cytometry, we identified phagocytosis of fluorescently-labeled apoptotic thymocytes by alveolar mononuclear phagocytes in vitro and in vivo, and measured surface molecule expression. Intratracheal challenge induced rapid recruitment of monocytes, peaking at Day 3 and decreasing thereafter, whereas numbers of resident AMo did not change significantly. At all times, the percentage of phagocytes ingesting apoptotic thymocytes in vitro was greater among resident AMo (28-45%) than among recruited monocytes (9-19%), but was low in both cell types relative to ingestion of immunoglobulin-opsonized targets. There was also a nonsignificant trend toward lower ingestion by monocytes in vivo. MerTK, a receptor tyrosine kinase crucial for apoptotic cell phagocytosis, was expressed by resident AMo, but not by recruited monocytes. Relative to resident AMo, monocytes recruited to the alveolus ingest apoptotic cells meagerly, possibly due to absence of MerTK expression.