IL-4 and IL-13 are closely related cytokines that are produced by Th2 cells. However, IL-4 and IL-13 have different effects on the development of asthma phenotypes. Here, we evaluated downstream molecular mechanisms involved in the development of Th2 type asthma phenotypes. A murine model of Th2 asthma was used that involved intraperitoneal sensitization with an allergen (ovalbumin) plus alum and then challenge with ovalbumin alone. Asthma phenotypes, including airway-hyperresponsiveness (AHR), lung inflammation, and immunologic parameters were evaluated after allergen challenge in mice deficient in candidate genes. The present study showed that methacholine AHR and lung inflammation developed in allergen-challenged IL-4-deficient mice but not in allergen-challenged IL-13-deficient mice. In addition, the production of OVA-specific IgG2a and IFN-gamma-inducible protein (IP)-10 was also impaired in the absence of IL-13, but not of IL-4. Lung-targeted IFN-gamma over-expression in the airways enhanced methacholine AHR and non-eosinophilic inflammation; in addition, these asthma phenotypes were impaired in allergen-challenged IFN-gamma-deficient mice. Moreover, AHR, non-eosinophilic inflammation, and IFN-gamma expression were impaired in allergen-challenged IL-12Rbeta2- and STAT4-deficient mice; however, AHR and non-eosinophilic inflammation were not impaired in allergen-challenged IL-4Ralpha-deficient mice, and these phenomena were accompanied by the enhanced expression of IL-12 and IFN-gamma. The present data suggest that IL-13-mediated asthma phenotypes, such as AHR and non-eosinophilic inflammation, in the Th2 type asthma are dependent on the IL-12-STAT4-IFN-gamma axis, and that these asthma phenotypes are independent of IL-4Ralpha-mediated signaling.
Allergens/immunology ; Animals ; Asthma/complications/*immunology/pathology/physiopathology ; Bronchial Hyperreactivity/complications/immunology/pathology ; Disease Models, Animal ; Interferon-gamma/*immunology ; Interleukin-12/*immunology ; Interleukin-12 Receptor beta 2 Subunit/metabolism ; Interleukin-13/deficiency/*immunology ; Interleukin-4/deficiency ; Methacholine Chloride ; Mice ; Mice, Transgenic ; Models, Immunological ; Organ Specificity ; Pneumonia/complications/immunology/pathology ; Receptors, Cell Surface/metabolism ; STAT4 Transcription Factor/*metabolism ; Signal Transduction/*immunology ; Th2 Cells/*immunology

A case of inflammatory pseudotumor of the lung occurring in a six-year-old boy is reported with clinicopathologic findings, including its ultrastructure. The patient had had frequent upper respiratory tract infections, and one and half year before the discovery of the lung mass, he suffered from pneumonia of the right lung, which was serologically proven to be a mycoplasma pneumoniae infection. Exploratory thoracotomy revealed a large mediastinal mass that was removed together with the right middle and lower lobes of the lung. The mass arose from the lung with an endobronchial element. Microscopically, the mass was composed of a variety of inflammatory and mesenchymal cells, including plasma cells, histiocytes, lymphocytes, and fibroblast-like spindle cells. Ultrastructurally, the spindle-shaped mesenchymal cells were either fibroblasts or myofibroblasts. At the time of diagnosis of the inflammatory pseudotumor of the lung, the serum titer of antimycoplasma antibody rose again, and the lung parenchyma adjacent to the mass showed interstitial pneumonia with features of bronchiolitis obliterans. The present case suggests that the inflammatory pseudotumor of the lung could be a postinflammatory lesion associated with mycoplasma pneumoniae infection.
Antibodies, Bacterial/blood ; Bronchiolitis Obliterans/complications ; Child ; Diagnosis, Differential ; Fibroma/etiology/*pathology/surgery ; Humans ; Lung Neoplasms/etiology/*pathology/surgery ; Male ; Mycoplasma pneumoniae/immunology/*pathogenicity ; Pneumonia, Mycoplasma/complications/microbiology/*pathology ; Tomography, X-Ray Computed

The 2019 novel coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has occurred in China and around the world. SARS-CoV-2-infected patients with severe pneumonia rapidly develop acute respiratory distress syndrome (ARDS) and die of multiple organ failure. Despite advances in supportive care approaches, ARDS is still associated with high mortality and morbidity. Mesenchymal stem cell (MSC)-based therapy may be an potential alternative strategy for treating ARDS by targeting the various pathophysiological events of ARDS. By releasing a variety of paracrine factors and extracellular vesicles, MSC can exert anti-inflammatory, anti-apoptotic, anti-microbial, and pro-angiogenic effects, promote bacterial and alveolar fluid clearance, disrupt the pulmonary endothelial and epithelial cell damage, eventually avoiding the lung and distal organ injuries to rescue patients with ARDS. An increasing number of experimental animal studies and early clinical studies verify the safety and efficacy of MSC therapy in ARDS. Since low cell engraftment and survival in lung limit MSC therapeutic potentials, several strategies have been developed to enhance their engraftment in the lung and their intrinsic, therapeutic properties. Here, we provide a comprehensive review of the mechanisms and optimization of MSC therapy in ARDS and highlighted the potentials and possible barriers of MSC therapy for COVID-19 patients with ARDS.
Adoptive Transfer ; Alveolar Epithelial Cells ; pathology ; Animals ; Apoptosis ; Betacoronavirus ; Body Fluids ; metabolism ; CD4-Positive T-Lymphocytes ; immunology ; Clinical Trials as Topic ; Coinfection ; prevention & control ; therapy ; Coronavirus Infections ; complications ; immunology ; Disease Models, Animal ; Endothelial Cells ; pathology ; Extracorporeal Membrane Oxygenation ; Genetic Therapy ; methods ; Genetic Vectors ; administration & dosage ; therapeutic use ; Humans ; Immunity, Innate ; Inflammation Mediators ; metabolism ; Lung ; pathology ; physiopathology ; Mesenchymal Stem Cell Transplantation ; methods ; Mesenchymal Stem Cells ; physiology ; Multiple Organ Failure ; etiology ; prevention & control ; Pandemics ; Pneumonia, Viral ; complications ; immunology ; Respiratory Distress Syndrome, Adult ; immunology ; pathology ; therapy ; Translational Medical Research

OBJECTIVETo analyze the safety and efficacy of anti-CD20 monoclonal antibody in treatment of severe pediatric systemic lupus erythematosus (PSLE).

METHODThe diagnosis of PSLE was made according to the criteria for the classification of systemic lupus erythematosus revised by the American College of Rheumatology in 1997. Severe cases with PSLE was selected by the following criteria: age ≤ 16 years, number of important organs involved > 1, SLEDAI score > 10 points and poor response to conventional immunosuppressive treatment. These patients received 2 doses of 375 mg/m(2) rituximab (RTX), 2 weeks apart. Clinical, laboratory findings and drug side effects were recorded at RTX initiation, 2 weeks, 1 month, 3, 6 and 12 months after infusion.

RESULTA total of 20 patients. Male to female ratio was 1:3, were enrolled. They were 5-16 years old. The course of disease was (3.0 ± 2.5) years (range: 1 month-7 years), patients were followed up for 12 - 36 months [median: (27.0 ± 7.8) months]. Delirium and cognitive disorders were significantly improved in 10 cases of lupus encephalopathy after 1 month. Lupus nephritis in children were eased slowly, 14/15 patients with lupus nephritis were improved after 2-3 months. Four cases of lupus pneumonia were significantly improved within 1 month. Decreased blood cells counts were relieved at 1 month in 16/18 cases. Cellular immune function was assessed 2 weeks after application of anti-CD20 monoclonal antibody; we found B-cell clearance in 19 patients (95%). B lymphocyte count of 18 patients (90%) was restored within one year. SLEDAI score was reduced obviously. Dose of corticosteroid ranged from (45.0 ± 4.7) mg/m(2) before drug use to (12.0 ± 2.7) mg/m(2) 12 months later (P < 0.001). After the drug use, 5 patients had pneumonia within 6 months; 2 cases who suffered from aspergillus pneumonia and Pneumocystis carinii pneumonia respectively were severe. They accepted mechanical ventilation and anti-inflammatory support after being transferred to the intensive care unit, and their conditions improved at last. No death occurred. In 2 patients the disease recurred with B-cell recovery after 15 months and 18 months. Administration of another cycle of rituximab resulted in remission again in one case but not in the other.

CONCLUSIONAnti-CD20 monoclonal antibody is effective and safe in treatment of severe PSLE. But severe infections may occur in some cases. Focusing on prevention and early treatment can reduce the probability of adverse reactions.

Adolescent ; Antibodies, Monoclonal, Murine-Derived ; administration & dosage ; adverse effects ; therapeutic use ; B-Lymphocytes ; drug effects ; immunology ; Biomarkers ; blood ; Child ; Child, Preschool ; Cyclophosphamide ; administration & dosage ; Female ; Follow-Up Studies ; Glucocorticoids ; administration & dosage ; therapeutic use ; Humans ; Immunologic Factors ; administration & dosage ; adverse effects ; therapeutic use ; Lupus Erythematosus, Systemic ; complications ; drug therapy ; immunology ; Lupus Nephritis ; etiology ; pathology ; Male ; Pneumonia ; etiology ; pathology ; Prednisolone ; administration & dosage ; therapeutic use ; Rituximab ; Severity of Illness Index ; Treatment Outcome