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

OBJECTIVE: The aim of this study is to investigate the effects of oral cadmium (Cd) ingestion on the pulmonary immune response. METHODS: Determination of Cd content in lungs and histopathological evaluation of the tissue was performed in rats following 30-day oral Cd administration (5 and 50 mg/L). Antioxidant enzyme defense (superoxide dismutase and catalase), cell infiltration, and production of tumor necrosis factor (TNF) and interferon (IFN)-γ, as well as the activity of myeloperoxidase (MPO), nitric oxide (NO), and various cytokines [interleukin (IL)-1β, IL-6, IL-10, and IL-17] were investigated. RESULTS: Cd caused tissue damage and cell infiltration in the lungs, and this damage was more pronounced at higher doses. Cd deposition resulted in lung inflammation characterized by a dose-dependent IL-1β increase in lung homogenates, increased TNF levels at both doses, and IL-6 stimulation at low doses with inhibition observed at higher doses. Cd exerted differential effects on lung leukocytes isolated by enzyme digestion, and these effects were characterized by a lack of change in the production of reactive oxygen and nitrogen species, an inhibition of IL-1β and TNF, and stimulation of MPO and IFN-γ. The higher capacity of Cd-exposed lung cells to respond to the opportunistic pathogen Staphylococcus epidermidis was demonstrated in vitro. CONCLUSION The potential of ingested Cd to exert both proinflammatory and immunosuppressive effects on pulmonary tissue inflammation and immune reactivity highlights the complex immunomodulatory actions of this metal.
Administration, Oral ; Animals ; Cadmium ; administration & dosage ; toxicity ; Leukocytes ; metabolism ; Lung ; drug effects ; immunology ; pathology ; Male ; Rats ; Staphylococcus epidermidis ; Toxicity Tests, Subchronic

BackgroundVentilator-induced lung injury (VILI) is commonly associated with barrier dysfunction and inflammation reaction. Glutamine could ameliorate VILI, but its role has not been fully elucidated. This study examined the relationship between inflammatory cytokines (interleukin [IL]-6, tumor necrosis factor [TNF]-α, and IL-10) and adherens junctions (E-cadherin, p120-catenin), which were ameliorated by glutamine in VILI, both in vitro and in vivo.

MethodsFor the in vivo study, 30 healthy C57BL/6 mice weighing 25-30 g were randomly divided into five groups with random number table (n = 6 in each group): control (Group C); low tidal volume (Group L); low tidal volume + glutamine (Group L + G); high tidal volume (Group H); and high tidal volume + glutamine (Group H + G). Mice in all groups, except Group C, underwent mechanical ventilation for 4 h. For the in vitro study, mouse lung epithelial 12 (MLE-12) cells pretreated with glutamine underwent cyclic stretching at 20% for 4 h. Cell lysate and lung tissue were obtained to detect the junction proteins, inflammatory cytokines, and lung pathological changes by the Western blotting, cytokine assay, hematoxylin and eosin staining, and immunofluorescence.

ResultsIn vivo, compared with Group C, total cell counts (t = -28.182, P < 0.01), the percentage of neutrophils (t = -28.095, P < 0.01), IL-6 (t = -28.296, P < 0.01), and TNF-α (t = -19.812, P < 0.01) in bronchoalveolar lavage (BAL) fluid, lung injury scores (t = -6.708, P < 0.01), and the wet-to-dry ratio (t = -15.595, P < 0.01) were increased in Group H; IL-10 in BAL fluid (t = 9.093, P < 0.01) and the expression of E-cadherin (t = 10.044, P < 0.01) and p120-catenin (t = 13.218, P < 0.01) were decreased in Group H. Compared with Group H, total cell counts (t = 14.844, P < 0.01), the percentage of neutrophils (t = 18.077, P < 0.01), IL-6 (t = 18.007, P < 0.01), and TNF-α (t = 10.171, P < 0.01) in BAL fluid were decreased in Group H + G; IL-10 in BAL fluid (t = -7.531, P < 0.01) and the expression of E-cadherin (t = -14.814, P < 0.01) and p120-catenin (t = -9.114, P < 0.01) were increased in Group H + G. In vitro, compared with the nonstretching group, the levels of IL-6 (t = -21.111, P < 0.01) and TNF-α (t = -15.270, P < 0.01) were increased in the 20% cyclic stretching group; the levels of IL-10 (t = 5.450, P < 0.01) and the expression of E-cadherin (t = 17.736, P < 0.01) and p120-catenin (t = 16.136, P < 0.01) were decreased in the 20% cyclic stretching group. Compared with the stretching group, the levels of IL-6 (t = 11.818, P < 0.01) and TNF-α (t = 8.631, P < 0.01) decreased in the glutamine group; the levels of IL-10 (t = -3.203, P < 0.05) and the expression of E-cadherin (t = -13.567, P < 0.01) and p120-catenin (t = -10.013, P < 0.01) were increased in the glutamine group.

ConclusionsHigh tidal volume mechanical ventilation and 20% cyclic stretching could cause VILI. Glutamine regulates VILI by improving cytokines and increasing the adherens junctions, protein E-cadherin and p120-catenin, to enhance the epithelial barrier function.

Animals ; Cadherins ; metabolism ; Catenins ; metabolism ; Glutamine ; metabolism ; Inflammation ; metabolism ; Interleukin-6 ; metabolism ; Lung ; metabolism ; pathology ; Mice ; Mice, Inbred C57BL ; Ventilator-Induced Lung Injury ; immunology ; metabolism

BACKGROUNDAspergillosis infection is common in the patients with insufficient immunity. The role of mammalian target of rapamycin (mTOR), T-box expressed in T-cells (T-bet), and eomesodermin (EOMES) in mediating T lymphocytes differentiation in response to Aspergillus fumigatus infection in immunocompromised rats was investigated in this study.

METHODSInvasive pulmonary aspergillosis (IPA) of immunosuppressive twenty male rats were established and sacrificed at 24 h (n = 5), 48 h (n = 5), 72 h (n = 5), and 96 h (n = 5) after A. fumigatus infection. In addition, control (n = 5), cyclophosphamide (CTX) (n = 5), and aspergillosis (n = 5) group were also established the tissues and pathology of lung tissue was examined by hematoxylin and eosin staining. CD8+ T-cells was sorted by flow cytometry. Serum mTOR, S6K, T-bet, and EOMES were quantified by enzyme-linked immunosorbent assay.

RESULTSHistology of lung tissue indicated severe lung tissue injury including infiltration of inflammatory cells, alveolar wall damage or degradation, blood congestion, and hemorrhage in the CTX, IPA, and CTX + IPA rats. Hyphae were seen in the IPA, and CTX + IPA groups. The proportion of CD8+ T-cells was significantly increased in the animals of CTX + IPA. Memory CD8+ T-cells was significantly increased in early stage (24 h and 48 h, P < 0.001), but decreased in the late phase of fungal infection (72 h and 96 h) in the animals of CTX + IPA. In addition, at early stage of fungal infection (24 h and 48 h), serum mTOR (P < 0.001), S6K (P < 0.001), and T-bet (P < 0.05) was significantly higher, while EOMES was significantly lower (P < 0.001), in CTX + IPA group than that in control, CTX alone or IPA alone group. Conversely, serum mTOR, S6K, T-bet, and EOMES showed opposite changed in the late stage (72 h and 96 h). Pearson's correlation analysis indicated that mTOR and S6K were significantly correlated with T-bet (r = 0.901 and 0.91, respectively, P < 0.001), but negatively and significantly correlated with EOMES (r = -0.758 and -0.751, respectively, P < 0.001).

CONCLUSIONSmTOR may regulate transcription factors of EOMES and T-bet, and by which mechanism, it may modulate lymphocytes differentiation in animals with immune suppression and fungal infection.

Animals ; CD8-Positive T-Lymphocytes ; cytology ; metabolism ; Cell Differentiation ; genetics ; physiology ; Invasive Pulmonary Aspergillosis ; metabolism ; pathology ; Lung ; metabolism ; pathology ; Lymphocytes ; cytology ; immunology ; Male ; Rats ; Rats, Wistar ; T-Box Domain Proteins ; genetics ; metabolism ; TOR Serine-Threonine Kinases ; genetics ; metabolism ; Tissue Culture Techniques

In the present study, we analyzed the role of Ginkgo biloba extract in lipopolysaccharide(LPS)-induced acute lung injury (ALI). ALI was induced in mice by intratracheal instillation of LPS. G. biloba extract (12 and 24 mg·kg(-1)) and dexamethasone (2 mg·kg(-1)), as a positive control, were given by i.p. injection. The cells in the bronchoalveolar lavage fluid (BALF) were counted. The degree of animal lung edema was evaluated by measuring the wet/dry weight ratio. The superoxidase dismutase (SOD) and myeloperoxidase (MPO) activities were assayed by SOD and MPO kits, respectively. The levels of inflammatory mediators, tumor necrosis factor-a, interleukin-1b, and interleukin-6, were assayed by enzyme-linked immunosorbent assay. Pathological changes of lung tissues were observed by H&E staining. The levels of NF-κB p65 and COX-2 expression were detected by Western blotting. Compared to the LPS group, the treatment with the G. biloba extract at 12 and 24 mg·kg(-1) markedly attenuated the inflammatory cell numbers in the BALF, decreased NF-κB p65 and COX-2 expression, and improved SOD activity, and inhibited MPO activity. The histological changes of the lungs were also significantly improved. The results indicated that G. biloba extract has a protective effect on LPS-induced acute lung injury in mice. The protective mechanism of G. biloba extract may be partly attributed to the inhibition of NF-κB p65 and COX-2 activation.
Acute Lung Injury ; chemically induced ; drug therapy ; metabolism ; Animals ; Bronchoalveolar Lavage Fluid ; cytology ; Cell Count ; Cyclooxygenase 2 ; genetics ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Gene Expression ; drug effects ; Ginkgo biloba ; chemistry ; Interleukin-1beta ; analysis ; Interleukin-6 ; analysis ; Lipopolysaccharides ; Lung ; immunology ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; Peroxidase ; metabolism ; Phytotherapy ; Plant Extracts ; pharmacology ; Pulmonary Edema ; Superoxide Dismutase ; metabolism ; Transcription Factor RelA ; genetics ; metabolism ; Tumor Necrosis Factor-alpha ; analysis

OBJECTIVETo study the correlation between airway inflammation and osteopontin (OPN) level in the lung tissue, and to study the effect of dexamethasone (DXM) on OPN expression.

METHODSFifty mice were randomly divided into 5 groups: normal control, ovalbumin (OVA)-challenged asthma groups (OVA inhalation for 1 week or 2 weeks) and DXM-treated asthma groups (DXM treatment for 1 week or 2 weeks). The mice were sensitized and challenged with OVA to prepare mouse model of acute asthma. Alterations of airway inflammation were observed by haematoxylin-eosin staining. Serum level of OVA-sIgE was evaluated using ELISA. OPN expression in the lung tissue was located and measured by immunohistochemistry and Western blot respectively. OPN mRNA level in the lung tissue was detected by real-time PCR.

RESULTSThe asthma groups showed more pathological changes in the airway than the normal control and the DXM-treated groups. Compared with the OVA-challenged 1 week group, the pathological alterations increased in the OVA-challenged 2 weeks group. The level of OVA-sIgE in serum increased in the asthma groups compared with the control and the DXM groups (P<0.01). Serum OVA-sIgE sevel increased more significantly in the OVA-challenged 2 weeks group compared with the OVA-challenged 1 week group (P<0.01). OPN protein and mRNA levels were significantly raised in the asthma groups compared with the normal control and the DXM groups (P<0.01), and both levels increased more significantly in the OVA-challenged 2 weeks group compared with the OVA-challenged 1 week group (P<0.01).

CONCLUSIONSThe increased OPN expression in the lung tissue is associated with more severe airway inflammation in asthmatic mice, suggesting that OPN may play an important role in the pathogenesis of asthma. DXM can alleviate airway inflammation possibly by inhibiting OPN production.

Animals ; Asthma ; drug therapy ; metabolism ; pathology ; Dexamethasone ; therapeutic use ; Enzyme-Linked Immunosorbent Assay ; Female ; Immunoglobulin E ; blood ; Lung ; metabolism ; pathology ; Mice ; Mice, Inbred BALB C ; Osteopontin ; analysis ; genetics ; physiology ; Ovalbumin ; immunology

OBJECTIVETo evaluate immunologic mechanisms underlying Aspergillus fumigatus pulmonary infections in immunocompetent Dark Agouti (DA) and Albino Oxford (AO) rats recognized as being susceptible to some inflammatory diseases in different manners.

METHODSLung fungal burden (quantitative colony forming units, CFU, assay), leukocyte infiltration (histology, cell composition) and their function (phagocytosis, oxidative activity, CD11b adhesion molecule expression) and cytokine interferon-γ (IFN-γ) and interleukin-17 and -4 (IL-17 and IL-4) lung content were evaluated following infection (intratracheally, 1x10(7) conidia).

RESULTSSlower reduction of fungal burden was observed in AO rats in comparison with that in DA rats, which was coincided with less intense histologically evident lung cell infiltration and leukocyte recovery as well as lower level of most of the their activities including intracellular myeloperoxidase activity, the capacity of nitroblue tetrazolium salt reduction and CD11b adhesion molecule expression (except for phagocytosis of conidia) in these rats. Differential patterns of changes in proinflammatory cytokine levels (unchanged levels of IFN-γ and transient increase of IL-17 in AO rats vs continuous increase of both cytokines in DA rats) and unchanged levels of IL-4 were observed.

CONCLUSIONGenetically-based differences in the pattern of antifungal lung leukocyte activities and cytokine milieu, associated with differential efficiency of fungal elimination might be useful in the future use of rat models in studies of pulmonary aspergillosis.

Animals ; Aspergillus fumigatus ; immunology ; Cytokines ; metabolism ; Lung ; immunology ; metabolism ; microbiology ; pathology ; Male ; Pulmonary Aspergillosis ; immunology ; Rats

OBJECTIVETo investigate the effect and mechanism of B16F10-ESAT-6-gpi/IL-21 tumor cell vaccine on pulmonary metastasis in mouse model of melanoma.

METHODSTwelve 8-week old female C57BL/6 mice were used in this study. The mice were injected with wild-type B16F10 cells through tail vein after immunization with B16F10-ESAT-6-gpi/IL-21 tumor cell vaccine, and the pulmonary metastasis was observed. The CD4(+) and CD8(+) T cells were isolated by magnetic activated cell sorting, and then used for the detection of CFSE/7-AAD cytotoxicity by flow cytometry. Serum from the mice immunized with tumor-cell vaccine was used to detect IFN-γ expression by ELISA. The expression of TGF-β2, ZEB1, E-cadherin, and N-cadherin of tumor tissues was detected by RT-PCR and immunofluorescence, respectively.

RESULTSThe mice vaccinated with B16F10-ESAT-6-gpi/IL-21 had significantly fewer nodules in the lung and lower lung weight [(285.8 ± 19.01) mg vs. (406.3 ± 27.12) mg], with lower levels of TGF-β2, ZEB1 and N-cadherin proteins but higher level of E-cadherin protein within the tumor tissue, as compared with the control mice. Meanwhile, the immunized mice had significantly increased CD8(+) T cell killing activity [(42.62 ± 3.465)% vs. (22.29 ± 1.804)%] and IFN-γ expression level [(55.200 ± 7.173) pg/ml vs. (6.435 ± 1.339) pg/ml] over the control mice.

CONCLUSIONSThe B16F10-ESAT-6-gpi/IL-21 vaccine can inhibit the metastasis of melanoma in the lung in vaccinated melanoma-bearing mice. This inhibitory effect is associated with CD8(+) T cell immune response and a higher level of IFN-γ, which may influence on the mesenchymal-epithelial transition of tumor cells.

Animals ; CD8-Positive T-Lymphocytes ; immunology ; Cadherins ; metabolism ; Cancer Vaccines ; immunology ; Cell Line, Tumor ; Epithelial-Mesenchymal Transition ; Female ; Homeodomain Proteins ; metabolism ; Humans ; Interferon-gamma ; metabolism ; Interleukins ; immunology ; Lung ; pathology ; Lung Neoplasms ; metabolism ; secondary ; Melanoma ; metabolism ; pathology ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Organ Size ; Transcription Factors ; metabolism ; Transforming Growth Factor beta2 ; metabolism ; Zinc Finger E-box-Binding Homeobox 1

OBJECTIVETo study the effects of suplatast tosilate (IPD) on the airway inflammation and expression of interleukin-5 in asthmatic rats.

METHODSFifty adult male Sprague-Dawley rats (4-week- old) were randomly assigned to five groups: placebo control, untreated asthma, budesonide(BUD)-treated asthma , early or late IPD intervention group (n=10 rats each). Asthmatic mode was prepared by ovalbumin sensitizion and challenge. Inflammatory cells and the percentage of EOS were detected in bronchoalveolar lavage fluid (BALF). The lung tissues were removed to detect the lung histomorphology. Gene expression of IL-5 was measured by reverse transcription-polymerase chain reaction (RT-PCR). Levels of interleukin 5 (IL-5) in BALF were measured using ELISA.

RESULTSThe inflammatory cells and the percentage of EOS in BALF, IL-5 levels in BALF and IL-5 mRNA expression in the lung tissues were obviously higher in the untreated asthma group than the control group (P<0.05), while the parameters in the IPD or BUD-treated asthma groups were significantly lower than the untreated asthma group (P<0.05).

CONCLUSIONSIPD treatment can alleviate airway inflammation in asthmatic rats, possibly through inhibiting IL-5 mRNA transcripts.

Animals ; Arylsulfonates ; therapeutic use ; Asthma ; drug therapy ; immunology ; pathology ; Eosinophils ; drug effects ; Interleukin-5 ; analysis ; antagonists & inhibitors ; genetics ; Lung ; metabolism ; pathology ; Male ; Rats ; Rats, Sprague-Dawley ; Sulfonium Compounds ; therapeutic use

OBJECTIVETo evaluate the immunohistochemical detection of epidermal growth factor receptor(EGFR) mutations using two EGFR mutation-specific monoclonal antibodies: delE746-A750 and L858R.

METHODSA total of 175 paraffin-embedded lung adenocarcinoma tissue samples previously genotyped by directive DNA sequencing were subject to immunostaining using delE746-A750 and L858R antibodies.

RESULTSThere was no significant difference of mutation detection between DNA sequence analysis and delE746-A750 and/or L858R immunostaining (33.7% vs 30.9%, P > 0.05). The overall sensitivity, specificity, positive predictive value and negative predictive value of immunostaining using these two EGFR mutation-specific antibodies were 83.1%, 95.7%, 90.7% and 90.9%, respectively.

CONCLUSIONWith high sensitivity and good specificity, immunohistochemistry using EGFR mutation-specific monoclonal antibodies is an adequate, easy and cost-effective prescreening method to detect EGFR mutations using paraffin-embedded tissue specimens of lung adenocarcinomas.

Adenocarcinoma ; genetics ; metabolism ; pathology ; Adult ; Aged ; Aged, 80 and over ; Antibodies, Monoclonal ; DNA Mutational Analysis ; Female ; Gene Deletion ; Humans ; Immunohistochemistry ; Lung Neoplasms ; genetics ; metabolism ; pathology ; Male ; Middle Aged ; Paraffin Embedding ; Point Mutation ; Receptor, Epidermal Growth Factor ; genetics ; immunology ; metabolism ; Sensitivity and Specificity