Project description:The most prevalent "rare" disease worldwide, cystic fibrosis (CF), is an autosomal recessive multisystem disease, caused by mutations in the CFTR gene. The knowledge of CFTR mutations present in certain population is important for designing a simple, fast and cost-effective genetic testing approach, also for better management of CF patients, including the administration of novel targeted therapies. Here, we present genetic results of 158 unrelated CF patients from the National CF Registry of the Republic of North Macedonia. Initially, patients were screened for the 11 most common CF mutations. Additional CF mutations and large deletions/duplications in the CFTR gene were analyzed using commercial kits. If the genotype was undetermined, all CFTR exons were analyzed using Sanger DNA sequencing or next generation sequencing (NGS) (since 2014). The most common CF mutation, c.l521_ 1523del (legacy name F508del), was found with an overall incidence of 75.9%. Additionally, 26 other pathogenic variants and three large deletions were identified in the CFTR gene as a genetic cause of CF. Two of these, c.1070 C>T (p.Ala357Val) and c.2779_2788dup CTTGCTATGG (p.Gly930AlafsTer48), were novel. According to the distribution and prevalence of the pathogenic variants detected in our patients, a fast and cost-effective method, based on a single base extension was designed as a first-line CF genetic test with a 90.0% detection rate within our population. Furthermore, the knowledge of CFTR mutation classes in our CF patients represents the first step toward personalized therapy for CF in our country.
Project description:Multidrug-resistant bacteria are the cause of an increasing number of deadly pulmonary infections. Because there is currently a paucity of novel antibiotics, phage therapy--the use of specific viruses that infect bacteria--is now more frequently being considered as a potential treatment for bacterial infections. Using a mouse lung-infection model caused by a multidrug resistant Pseudomonas aeruginosa mucoid strain isolated from a cystic fibrosis patient, we evaluated bacteriophage treatments. New bacteriophages were isolated from environmental samples and characterized. Bacteria and bacteriophages were applied intranasally to the immunocompetent mice. Survival was monitored and bronchoalveolar fluids were analysed. Quantification of bacteria, bacteriophages, pro-inflammatory and cytotoxicity markers, as well as histology and immunohistochemistry analyses were performed. A curative treatment (one single dose) administrated 2 h after the onset of the infection allowed over 95% survival. A four-day preventive treatment (one single dose) resulted in a 100% survival. All of the parameters measured correlated with the efficacy of both curative and preventive bacteriophage treatments. We also showed that in vitro optimization of a bacteriophage towards a clinical strain improved both its efficacy on in vivo treatments and its host range on a panel of 20 P. aeruginosa cystic fibrosis strains. This work provides an incentive to develop clinical studies on pulmonary bacteriophage therapy to combat multidrug-resistant lung infections.
Project description:The deletion of phenylalanine 508 in the first nucleotide binding domain of the cystic fibrosis transmembrane conductance regulator is directly associated with >90% of cystic fibrosis cases. This mutant protein fails to traffic out of the endoplasmic reticulum and is subsequently degraded by the proteasome. The effects of this mutation may be partially reversed by the application of exogenous osmolytes, expression at low temperature, and the introduction of second site suppressor mutations. However, the specific steps of folding and assembly of full-length cystic fibrosis transmembrane conductance regulator (CFTR) directly altered by the disease-causing mutation are unclear. To elucidate the effects of the ?F508 mutation, on various steps in CFTR folding, a series of misfolding and suppressor mutations in the nucleotide binding and transmembrane domains were evaluated for effects on the folding and maturation of the protein. The results indicate that the isolated NBD1 responds to both the ?F508 mutation and intradomain suppressors of this mutation. In addition, identification of a novel second site suppressor of the defect within the second transmembrane domain suggests that ?F508 also effects interdomain interactions critical for later steps in the biosynthesis of CFTR.
Project description:Gene therapy for cystic fibrosis (CF) is making encouraging progress into clinical trials. However, further improvements in transduction efficiency are desired. To develop a novel gene transfer vector that is improved and truly effective for CF gene therapy, a simian immunodeficiency virus (SIV) was pseudotyped with envelope proteins from Sendai virus (SeV), which is known to efficiently transduce unconditioned airway epithelial cells from the apical side. This novel vector was evaluated in mice in vivo and in vitro directed toward CF gene therapy. Here, we show that (i) we can produce relevant titers of an SIV vector pseudotyped with SeV envelope proteins for in vivo use, (ii) this vector can transduce the respiratory epithelium of the murine nose in vivo at levels that may be relevant for clinical benefit in CF, (iii) this can be achieved in a single formulation, and without the need for preconditioning, (iv) expression can last for 15 months, (v) readministration is feasible, (vi) the vector can transduce human air-liquid interface (ALI) cultures, and (vii) functional CF transmembrane conductance regulator (CFTR) chloride channels can be generated in vitro. Our data suggest that this lentiviral vector may provide a step change in airway transduction efficiency relevant to a clinical programme of gene therapy for CF.
Project description:The human airway epithelium is regenerated by basal cells. Thus, basal cell therapy has the potential to cure cystic fibrosis (CF) lung disease. We previously reported that the human basal cells repopulated the mouse airway epithelium after transplantation, and we estimated that 60 million cells would be needed to treat a human patient. To further develop cell therapy, we compared the proliferation potential of non-CF and CF tissue-derived bronchial basal cells. Three methods were used: regenerative cell frequency, burst size, and cell division frequency. Second, we used a serial passage strategy to determine if CF basal cells could be amplified to the estimated therapeutic dose. These studies evaluated that tissue-derived bronchial basal cells and the basal cells that were recovered by brushing bronchial airways or the nasal respiratory epithelium. Finally, we used the limiting dilution method to isolate non-CF and CF basal cell clones. The proliferation assays and the air-liquid-interface differentiation method were used to determine if cell amplification altered the proliferation and/or differentiation potential of clonal isolates. We demonstrate that: (a) non-CF and CF basal cell proliferation is similar, (b) CF basal cells can be amplified to a therapeutic cell dose, and (c) amplified non-CF and CF basal cell clones differentiate normally. Despite these encouraging findings, we also find that the cell amplification process depletes the regenerative basal cell pool. Analysis of basal cell clones indicates that serial passage selects for long-lived basal cells and raise the possibility that prospective isolation of these stem-like cells will improve the efficacy of cell replacement therapy. Stem Cells Translational Medicine 2019;8:225&235.
Project description:INTRODUCTION:Cystic fibrosis (CF) outcomes and survival have improved over the last century primarily due to advancements in antibiotics, nutritional, and pulmonary therapies. Reviewed here are the significant unmet needs that exist for individuals with CF. Areas covered: With the recent development of medications that address the underlying defect in the CF protein, there is hope that there will be continued improvement in CF outcomes. However, there remains a need to prevent or stop progression of CF-related complications, as the CF protein is important to several body systems. As end stage lung disease is the primary cause of mortality in CF, a need exists for advancements in pulmonary therapies to reduce time burden, identification of best practices for the treatment of pulmonary exacerbations, further development of anti-infective and anti-inflammatory therapies, and appropriately timed referral for lung transplantation at end-stage lung disease. Extra-pulmonary complications are increasingly recognized and better understanding of such problems as CF related liver disease is needed. Expert commentary: While CFTR modulators are available for the majority of CF patients, there remains a need for effective therapies to address infection, inflammation, irreversible lung disease, and extrapulmonary complications of CF.
Project description:This multi-center study will compare multi-target DNA and quantitative FIT stool-based testing to colonoscopy in individuals with Cystic Fibrosis (CF) undergoing colon cancer screening with colonoscopy. The primary endpoint is detection of any adenomas, including advanced adenomas and colorectal cancer (CRC).
Project description:Cystic fibrosis (CF) is caused by loss-of-function mutations in the CFTR (CF transmembrane regulator) gene. Pharmacologic therapies directed at CFTR have been developed but are not effective for mutations that result in little or no mRNA or protein expression. Cell therapy is a potential mutation-agnostic approach to treatment. One strategy is to harvest human bronchial epithelial cells (HBECs) for gene addition or genetic correction, followed by expansion and engraftment. This approach will require cells to grow extensively while retaining their ability to reconstitute CFTR activity. We hypothesized that conditionally reprogrammed cell (CRC) technology, namely growth in the presence of irradiated feeder cells and a Rho kinase inhibitor, would enable expansion while maintaining cell capacity to express functional CFTR. Our goal was to compare expression of the basal cell marker NGFR (nerve growth factor receptor) and three-dimensional bronchosphere colony-forming efficiency (CFE) in early- and later-passage HBECs grown using nonproprietary bronchial epithelial growth medium or the CRC method. Cell number and CFTR activity were determined in a competitive repopulation assay employing chimeric air-liquid interface cultures. HBECs expanded using the CRC method expressed the highest NGFR levels, had the greatest 3D colony-forming efficiency at later passage, generated greater cell numbers in chimeric cultures, and most effectively reconstituted CFTR activity. In our study, the HBEC air-liquid interface model, an informative testing platform proven vital for the development of other CF therapies, illustrated that cells grown by CRC technology or equivalent methods may be useful for cell therapy of CF.
Project description:(1) Background: Cystic fibrosis (CF) is a disease with well-documented clinical differences between female and male patients. However, this gender gap is very poorly studied at the molecular level. (2) Methods: Expression differences in whole blood transcriptomics between female and male CF patients are analyzed in order to determine the pathways related to sex-biased genes and assess their potential influence on sex-specific effects in CF patients. (3) Results: We identify sex-biased genes in female and male CF patients and provide explanations for some sex-specific differences at the molecular level. (4) Conclusion: Genes in key pathways associated with CF are differentially expressed between sexes, and thus may account for the gender gap in morbidity and mortality in CF.