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Immune cells, particularly those expressing the ligand of the Fas-death receptor (FasL), e.g. cytotoxic T cells, induce apoptosis in 'undesirable' self- and non-self-cells, including lung fibroblasts, thus providing a means of immune surveillance. We aimed to validate this mechanism in resolution of lung fibrosis. In particular, we elucidated whether FasL(+) immune cells possess antifibrotic capabilities by induction of FasL-dependent myofibroblast apoptosis and whether antagonists of membrane (m) and soluble (s) FasL can inhibit these capabilities. Myofibroblast interaction with immune cells and its FasL-dependency, were investigated in vitro in coculture with T cells and in vivo, following transplantation into lungs of immune-deficient syngeneic Rag-/- as well as allogeneic SCID mice, and into lungs and air pouches of FasL-deficient (gld) mice, before and after reconstitution of the mice with wild-type (wt), FasL(+) immune cells. We found that myofibroblasts from lungs resolving fibrosis undergo FasL-dependent T cell-induced apoptosis in vitro and demonstrate susceptibility to in vivo immune surveillance in lungs of reconstituted, immune- and FasL-deficient, mice. However, immune-deficient Rag-/- and SCID mice, and gld-mice with FasL-deficiency, endure the accumulation of transplanted myofibroblasts in their lungs with subsequent development of fibrosis. Concomitantly, gld mice, in contrast to chimeric FasL-deficient mice with wt immune cells, accumulated transplanted myofibroblasts in the air pouch model. In humans we found that myofibroblasts from fibrotic lungs secrete sFasL and resist T cell-induced apoptosis, whereas normal lung myofibroblasts are susceptible to apoptosis but acquire resistance upon addition of anti-s/mFasL to the coculture. Immune surveillance, particularly functional FasL(+) immune cells, may represent an important extrinsic component in myofibroblast apoptosis and serve as a barrier to fibrosis. Factors interfering with Fas/FasL-immune cell-myofibroblast interaction such as sFasL secreted by fibrotic-lung myofibroblasts, may abrogate immune surveillance during fibrosis. Annulling these factors may pave a new direction to control human lung fibrosis.
Assuntos
Apoptose , Proteína Ligante Fas/metabolismo , Pulmão/patologia , Miofibroblastos/metabolismo , Linfócitos T Citotóxicos/imunologia , Transferência Adotiva , Animais , Anticorpos Bloqueadores/farmacologia , Apoptose/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Proteína Ligante Fas/genética , Fibrose , Genes RAG-1/genética , Humanos , Vigilância Imunológica/efeitos dos fármacos , Pulmão/imunologia , Camundongos , Camundongos Knockout , Camundongos SCID , Miofibroblastos/efeitos dos fármacos , Miofibroblastos/patologia , Linfócitos T Citotóxicos/transplanteRESUMO
Lung fibrosis is characterized by abnormal accumulation of fibroblasts in the interstitium of the alveolar space. Two populations of myofibroblasts, distinguished by Thy1 expression, are detected in human and murine lungs. Accumulation of Thy1-negative (Thy1(-)) myofibroblasts was shown in the lungs of humans with idiopathic pulmonary fibrosis (IPF) and of bleomycin-treated mice. We aimed to identify genetic changes in lung myofibroblasts following Thy1 crosslinking and assess the impact of specific lung myofibroblast Thy1-deficiency, in vivo, in bleomycin-injured mouse lungs. Thy1 increased in mouse lung lymphocytes following bleomycin injury but decreased in myofibroblasts when fibrosis was at the highest point (14 days), as assessed by immunohistochemistry. Using gene chip analysis, we detected that myofibroblast Thy1 crosslinking mediates downregulation of genes promoting cell proliferation, survival, and differentiation, and reduces production of extracellular matrix (ECM) components, while concurrently mediating the upregulation of genes known to foster inflammation and immunological functions. Chimeric Thy1-deficient mice with Thy1(+) lymphocytes and Thy1(-) myofibroblasts showed fibrosis similar to wild-type mice and an increased number of CD4/CD25 regulatory T cells, with a concomitant decrease in inflammation. Lung myofibroblasts downregulate Thy1 expression to increase their proliferation but to diminish the in vivo inflammatory milieu. Inflammation is not essential for evolution of fibrosis as was previously stated.
Assuntos
Bleomicina/farmacologia , Inflamação/prevenção & controle , Linfócitos/fisiologia , Miofibroblastos/fisiologia , Fibrose Pulmonar/etiologia , Antígenos Thy-1/fisiologia , Animais , Humanos , Pulmão/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Análise de Sequência com Séries de OligonucleotídeosRESUMO
Background and objectives: Children with autism spectrum disorder (ASD) present with distinctive clinical features. No objective laboratory assay has been developed to establish a diagnosis of ASD. Considering the known immunological associations with ASD, immunological biomarkers might enable ASD diagnosis and intervention at an early age when the immature brain has the highest degree of plasticity. This work aimed to identify diagnostic biomarkers discriminating between children with ASD and typically developing (TD) children. Methods: A multicenter, diagnostic case-control study trial was conducted in Israel and Canada between 2014 and 2021. In this trial, a single blood sample was collected from 102 children with ASD as defined in Diagnostic Statistical Manual of Mental Disorders [DSM)-IV (299.00) or DSM-V (299.00)], and from 97 typically developing control children aged 3-12 years. Samples were analyzed using a high-throughput, multiplexed ELISA array which quantifies 1,000 human immune/inflammatory-related proteins. Multiple logistic regression analysis was used to obtain a predictor from these results using 10-fold cross validation. Results: Twelve biomarkers were identified that provided an overall accuracy of 0.82 ± 0.09 (sensitivity: 0.87 ± 0.08; specificity: 0.77 ± 0.14) in diagnosing ASD with a threshold of 0.5. The resulting model had an area under the curve of 0.86 ± 0.06 (95% CI: 0.811-0.889). Of the 102 ASD children included in the study, 13% were negative for this signature. Most of the markers included in all models have been reported to be associated with ASD and/or autoimmune diseases. Conclusion: The identified biomarkers may serve as the basis of an objective assay for early and accurate diagnosis of ASD. In addition, the markers may shed light on ASD etiology and pathogenesis. It should be noted that this was only a pilot, case-control diagnostic study, with a high risk of bias. The findings should be validated in larger prospective cohorts of consecutive children suspected of ASD.
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Background: Breast cancer is one of the most common malignancies worldwide and remains incurable after metastasis, with a 3-year overall survival rate of <40%. Case presentation: A 40-year-old, Caucasian patient with a grade-3 estrogen receptor-, progesterone receptor-, Her2-positive breast tumor and two lung nodules was treated with intramuscular targeted immunotherapy with trastuzumab and oral tamoxifen hormone therapy, together with customized intra-tumoral oncolytic virotherapy (IT-OV) over a 17-month period. PET/CT imaging at 3 and 6 months showed increased primary tumor size and metabolic glucose uptake in the primary tumor, axillary lymph nodes and lung nodules, which were paralleled by a hyperimmune reaction in the bones, liver, and spleen. Thereafter, there was a steady decline in both tumor size and metabolic activity until no radiographic evidence of disease was observed. The treatment regimen was well tolerated and good quality of life was maintained throughout. Conclusion: Integration of IT-OV immunotherapy in standard treatment protocols presents an attractive modality for late-stage primary tumors with an abscopal effect on metastases.
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A prominent feature of fibrotic tissue in general and of lungs in particular is fibroblast proliferation and accumulation. In patients overcoming fibrosis, apoptosis limits this excessive cell growth. We have previously shown resistance to Fas-induced apoptosis of primary lung fibroblasts from mice with bleomycin-induced lung fibrosis, their escape from immune surveillance, and continued accumulation in spite of overexpression of the Fas death receptor. Cellular FLICE-like inhibitory protein (c-FLIP) is a regulator of cell death receptor-induced apoptosis in many cell types. We aimed to determine c-FLIP levels in myofibroblasts from fibrotic lungs and to directly assess c-FLIP's role in apoptosis and proliferation of primary lung myofibroblasts. c-FLIP levels were determined by apoptosis gene array, flow cytometry, Western blot, and immunofluorescence before and after down-regulation with a specific small interfering RNA. Apoptosis was assessed by caspase cleavage in Western blot and by Annexin V affinity labeling after FACS and tissue immunofluorescence. Proliferation was assessed by BrdU uptake, also using FACS and immunofluorescence. We show that myofibroblasts from lungs of humans with idiopathic pulmonary fibrosis and from bleomycin-treated versus normal saline-treated mice up-regulate c-FLIP levels. Using the animal model, we show that fibrotic lung myofibroblasts divert Fas signaling from apoptosis to proliferation and that this requires signaling by TNF receptor-associated factor (TRAF) and NF-κB. c-FLIP down-regulation reverses the effect of Fas activation, causing increased apoptosis, decreased proliferation, and diminished recruitment of TRAF to the DISC complex. This indicates that c-FLIP is essential for myofibroblast accumulation and may serve as a potential target to manipulate tissue fibrosis.
Assuntos
Apoptose/fisiologia , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/fisiologia , Proliferação de Células , Miofibroblastos/patologia , Fibrose Pulmonar/patologia , Receptor fas/fisiologia , Animais , Anexina A5/metabolismo , Sequência de Bases , Western Blotting , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Caspases/metabolismo , Primers do DNA , Citometria de Fluxo , Imunofluorescência , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de SinaisRESUMO
Intravenous neural precursor cell (NPCs) injection attenuates experimental autoimmune encephalomyelitis by reducing autoreactive T cell encephalitogenicity in lymph nodes in vivo. Here we examined NPC-lymphocyte interactions in vitro. NPCs inhibited the induction of T cell activation marker IL-2-Receptor alpha, ICOS, PD-1 and CTLA-4 and inhibited T cell proliferation. NPCs inhibited T cell activation and proliferation in response to Concavalin-A and to anti-CD3/anti-CD28, which are T cell receptor (TCR)-mediated stimuli, but not in response to phorbol myristate acetate/ionomycin, a TCR-independent stimulus. The suppressive effect was not mediated via downregulation of CD3epsilon or induction of apoptosis. We next examined NPCs effects on inflammatory-cytokine signaling. NPCs impaired IL-2-mediated phosphorylation of JAK3 in lymphocytes, and inhibited IL-6 mediated proliferation of B9 murine hybridoma cells. In conclusion, NPCs ameliorate TCR-mediated T cell activation and inhibit inflammatory cytokines' signaling in immune cells. These findings may underlie the broad anti-inflammatory effects of NPCs in vivo.
Assuntos
Inflamação/metabolismo , Neurônios/fisiologia , Transdução de Sinais/fisiologia , Células-Tronco/fisiologia , Animais , Proliferação de Células , Células Cultivadas , Técnicas de Cocultura , Feminino , Interleucina-2/imunologia , Interleucina-6/imunologia , Janus Quinase 3/metabolismo , Linfonodos/citologia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/citologia , Células-Tronco/citologia , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/fisiologiaRESUMO
OBJECTIVE: To compare the reported accuracy and sensitivity of the various modalities used to diagnose autism spectrum disorders (ASD) in efforts to help focus further biomarker research on the most promising methods for early diagnosis. METHODS: The Medline scientific literature database was searched to identify publications assessing potential clinical ASD biomarkers. Reports were categorized by the modality used to assess the putative markers, including protein, genetic, metabolic, or objective imaging methods. The reported sensitivity, specificity, area under the curve, and overall agreement were summarized and analyzed to determine weighted averages for each diagnostic modality. Heterogeneity was measured using the I2 test. RESULTS: Of the 71 papers included in this analysis, each belonging to one of five modalities, protein-based followed by metabolite-based markers provided the highest diagnostic accuracy, each with a pooled overall agreement of 83.3% and respective weighted area under the curve (AUC) of 89.5% and 88.3%. Sensitivity provided by protein markers was highest (85.5%), while metabolic (85.9%) and protein markers (84.7%) had the highest specificity. Other modalities showed degrees of sensitivity, specificity, and overall agreements in the range of 73%-80%. CONCLUSIONS: Each modality provided for diagnostic accuracy and specificity similar or slightly higher than those reported for the gold-standard Autism Diagnostic Observation Schedule (ADOS) instrument. Further studies are required to identify the most predictive markers within each modality and to evaluate biological pathways or clustering with possible etiological relevance. Analyses will also be necessary to determine the potential of these novel biomarkers in diagnosing pediatric patients, thereby enabling early intervention.
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With the recent success of oncolytic viruses in clinical trials, efforts toward improved monitoring of the viruses and their mechanism have intensified. Four main gene expression strategies have been employed to date including: analyzing overall gene expression in tumor cells, looking at gene expression of a few specific genes in the tumor cells, focusing on gene expression of specific transgenes introduced into the virus, and following gene expression of certain viral genes. Each strategy presents certain advantages and disadvantages over the others. Various methods to organize the dysregulated genes into clusters have provided a window into the mechanism of action for these viruses. Methodologically, the combined approach of looking at both overall gene expression, the tumor cells and gene expression of viral genes, enables researchers to assess correlation between the introduction of the virus and the changes in the tumor. This would seem to be the most productive approach for future studies, providing much information on mechanism and timing.
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Autism spectrum disorders (ASDs) are a group of complex neurodevelopmental conditions that present in early childhood and have a current estimated prevalence of about 1 in 68 US children, 1 in 42 boys. ASDs are heterogeneous, and arise from epigenetic, genetic and environmental origins, yet, the exact etiology of ASDs still remains unknown. Individuals with ASDs are characterized by having deficits in social interaction, impaired communication and a range of stereotyped and repetitive behaviors. Currently, a diagnosis of ASD is based solely on behavioral assessments and phenotype. Hundreds of diverse ASD susceptibility genes have been identified, yet none of the mutations found account for more than a small subset of autism cases. Therefore, a genetic diagnosis is not yet possible for the majority of the ASD population. The susceptibility genes that have been identified are involved in a wide and varied range of biological functions. Since the genetics of ASDs is so diverse, information on genome function as provided by transcriptomic data is essential to further our understanding. Gene expression studies have been extremely useful in comparing groups of individuals with ASD and control samples in order to measure which genes (or group of genes) are dysregulated in the ASD group. Transcriptomic studies are essential as a key link between measuring protein levels and analyzing genetic information. This review of recent autism gene expression studies highlights genes that are expressed in the brain, immune system, and processes such as cell metabolism and embryology. Various biological processes have been shown to be implicated with ASD individuals as well as differences in gene expression levels between different types of biological tissues. Some studies use gene expression to attempt to separate autism into different subtypes. An updated list of genes shown to be significantly dysregulated in individuals with autism from all recent ASD expression studies will help further research isolate any patterns useful for diagnosis or understanding the mechanisms involved. The functional relevance of transcriptomic studies as a method of classifying and diagnosing ASD cannot be underestimated despite the possible limitations of transcriptomic studies.
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High doses of bleomycin administered to patients with lymphomas and other tumors lead to significant lung toxicity in general, and to apoptosis of epithelial cells, in particular. Apoptosis of alveolar epithelium is an important step in the pathogenesis of bleomycin-induced pulmonary fibrosis. The Fas-FasL pathway is one of the main apoptotic pathways involved. Telomerase is a ribonucleoprotein RNA-dependent DNA polymerase complex consisting of an RNA template and a catalytic protein, telomerase reverse transcriptase (TERT). Telomerase also possess extra-telomeric roles, including modulation of transcription of anti-apoptotic genes, differentiation signals, and more. We hypothesized that telomerase overexpression affects Fas-induced epithelial cell apoptosis by an extra-telomeric role such as regulation of anti-apoptotic genes, specifically FLICE-like inhibitory protein (FLIP). Telomerase in mouse (MLE) and human (A549) lung epithelial cell lines was upregulated by transient transfection using cDNA hTERT expression vector. Telomerase activity was detected using a real-time PCR-based system. Bleomycin, and bleomycin-induced Fas-mediated apoptosis following treatment with anti-Fas activating mAb or control IgG, were assessed by Annexin V staining, FACS analysis, and confocal microscopy; caspase cleavage by Western blot; FLIP or Fas molecule detection by Western blot and flow cytometry. hTERT transfection of lung epithelial cells resulted in a 100% increase in their telomerase activity. Fas-induced lung epithelial cell apoptosis was significantly reduced in hTERT-transfected cells compared to controls in all experiments. Lung epithelial cells with increased telomerase activity had higher levels of FLIP expression but membrane Fas expression was unchanged. Upregulation of hTERT+ in human lung epithelial cells and subsequent downregulation of FLIP by shFLIP-RNA annulled hTERT-mediated resistance to apoptosis. Telomerase-mediated FLIP overexpression may be a novel mechanism to confer protection from apoptosis in bleomycin-exposed human lung epithelial cells.
Assuntos
Antibióticos Antineoplásicos/efeitos adversos , Bleomicina/efeitos adversos , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/genética , Células Epiteliais/efeitos dos fármacos , Telomerase/genética , Receptor fas/metabolismo , Animais , Apoptose/efeitos dos fármacos , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Linhagem Celular , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Humanos , Pulmão/citologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Camundongos , Telomerase/metabolismo , Transfecção , Regulação para CimaRESUMO
The regulated phosphorylation of ribosomal protein (rp) S6 has attracted much attention since its discovery in 1974, yet its physiological role has remained obscure. To directly address this issue, we have established viable and fertile knock-in mice, whose rpS6 contains alanine substitutions at all five phosphorylatable serine residues (rpS6(P-/-)). Here we show that contrary to the widely accepted model, this mutation does not affect the translational control of TOP mRNAs. rpS6(P-/-) mouse embryo fibroblasts (MEFs) display an increased rate of protein synthesis and accelerated cell division, and they are significantly smaller than rpS6(P+/+) MEFs. This small size reflects a growth defect, rather than a by-product of their faster cell division. Moreover, the size of rpS6(P-/-) MEFs, unlike wild-type MEFs, is not further decreased upon rapamycin treatment, implying that the rpS6 is a critical downstream effector of mTOR in regulation of cell size. The small cell phenotype is not confined to embryonal cells, as it also selectively characterizes pancreatic beta-cells in adult rpS6(P-/-) mice. These mice suffer from diminished levels of pancreatic insulin, hypoinsulinemia, and impaired glucose tolerance.