A Link Between a Common Mutation in CFTR and Impaired Innate and Adaptive Viral Defense

A new era of targeting cystic fibrosis with non-viral delivery of genomic medicines

Cystic fibrosis (CF) is a complex genetic respiratory disorder that necessitates innovative gene delivery strategies to address the mutations in the gene. This review delves into the promises and challenges of non-viral gene delivery for CF therapy and explores strategies to overcome these hurdles. Several emerging technologies and nucleic acid cargos for CF gene therapy are discussed. Novel formulation approaches including lipid and polymeric nanoparticles promise enhanced delivery through the CF mucus barrier, augmenting the potential of non-viral strategies. Additionally, safety considerations and regulatory perspectives play a crucial role in navigating the path toward clinical translation of gene therapy.

Clinical and genetic characterization of Epstein-Barr virus-associated T/NK-cell lymphoproliferative diseases

BACKGROUND

Epstein-Barr virus (EBV)-associated T-/natural killer (T/NK)-cell lymphoproliferative diseases clinically take on various forms, ranging from an indolent course to an aggressive condition.

OBJECTIVE

Clinically, failure to establish precise diagnosis and provide proper treatment makes it difficult to help patients. We sought to better understand the underlying pathogenesis and to identify genetic prognostic factors to achieve better treatment efficacy.

METHODS

In this study, 119 cases of EBV-associated lymphoproliferative diseases, including EBV-associated hemophagocytic lymphohistiocytosis (n = 46) and chronic active EBV disease of T/NK cell type (n = 73), were retrospectively examined.

RESULTS

Adults aged >20 years at onset accounted for 71.4% of our cohort. About 54.6% patients with unfavorable overall survival developed hemophagocytic lymphohistiocytosis and had higher plasma EBV load. Allogenic hematopoietic stem-cell transplantation was the sole independent favorable factor. We systematically screened germline and somatic aberrations by whole-exome and targeted sequencing. Among 372 antiviral immunity genes, germline variants of 8 genes were significantly enriched. From a panel of 24 driver genes, somatic mutations were frequently identified in dominant EBV-infected T/NK cells. Patients carrying any germline/somatic aberrations in epigenetic modifiers and RIG-I-like receptor (RLR) pathway had worse overall survival than those without 2 type aberrations. Importantly, patients with IFIH1 and/or DDX3X aberrations in the RLR pathway had higher plasma and NK-cell EBV load. Knockdown of DDX3X in NKYS cells downregulated RLR signaling activities and elevated the expression of EBV-encoded oncogenes such as LMP1 and EBNA1.

CONCLUSION

Genetic defects were prevalent in adult EBV-associated hemophagocytic lymphohistiocytosis patients and patients with chronic active EBV disease of T/NK cell type; these defects were associated with unfavorable prognosis. These findings can help clinicians work out more precise staging of the condition and provide new insights into these EBV-associated diseases.

Coxsackievirus B infections are common in Cystic Fibrosis and experimental evidence supports protection by vaccination

Viral respiratory tract infections exacerbate airway disease and facilitate life-threatening bacterial colonization in cystic fibrosis (CF). Annual influenza vaccination is recommended and vaccines against other common respiratory viruses may further reduce pulmonary morbidity risk. Enteroviruses have been found in nasopharyngeal samples from CF patients experiencing pulmonary exacerbations. Using serology tests, we found that infections by a group of enteroviruses, Coxsackievirus Bs (CVBs), are prevalent in CF. We next showed that a CVB vaccine, currently undergoing clinical development, prevents infection and CVB-instigated lung damage in a murine model of CF. Finally, we demonstrate that individuals with CF have normal vaccine responses to a similar, commonly used enterovirus vaccine (inactivated poliovirus vaccine). Our study demonstrates that CVB infections are common in CF and provides experimental evidence indicating that CVB vaccines could be efficacious in the CF population. The role of CVB infections in contributing to pulmonary exacerbations in CF should be further studied.

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CVB infections are common in CF

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A CVB vaccine prevents infection and tissue damage in a model of CF

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Most people with CF have robust antibody responses to a similar enterovirus vaccine

Antibody Deficiency, Chronic Lung Disease, and Comorbid Conditions: A Case-Based Approach

New emerging pulmonary phenotypes associated with antibody deficiency, such as neutrophilic asthma, frequent exacerbations of chronic obstructive pulmonary disease, and unexplained interstitial lung disease, particularly in younger adults, are discussed in this review through a case-based approach. Also discussed in similar fashion are antibody deficiency syndromes that lead to end-stage lung disease and the indications for lung transplantation in primary immunodeficiency disease. These challenging cases require timely and individualized strategies for genetic and immunologic diagnosis, decisions about therapeutic approaches, and long-term monitoring.

Structural Insight into CVB3-VLP Non-Adjuvanted Vaccine

Coxsackievirus B (CVB) enteroviruses are common pathogens that can cause acute and chronic myocarditis, dilated cardiomyopathy, aseptic meningitis, and they are hypothesized to be a causal factor in type 1 diabetes. The licensed enterovirus vaccines and those currently in clinical development are traditional inactivated or live attenuated vaccines. Even though these vaccines work well in the prevention of enterovirus diseases, new vaccine technologies, like virus-like particles (VLPs), can offer important advantages in the manufacturing and epitope engineering. We have previously produced VLPs for CVB3 and CVB1 in insect cells. Here, we describe the production of CVB3-VLPs with enhanced production yield and purity using an improved purification method consisting of tangential flow filtration and ion exchange chromatography, which is compatible with industrial scale production. We also resolved the CVB3-VLP structure by Cryo-Electron Microscopy imaging and single particle reconstruction. The VLP diameter is 30.9 nm on average, and it is similar to Coxsackievirus A VLPs and the expanded enterovirus cell-entry intermediate (the 135s particle), which is ~2 nm larger than the mature virion. High neutralizing and total IgG antibody levels, the latter being a predominantly Th2 type (IgG1) phenotype, were detected in C57BL/6J mice immunized with non-adjuvanted CVB3-VLP vaccine. The structural and immunogenic data presented here indicate the potential of this improved methodology to produce highly immunogenic enterovirus VLP-vaccines in the future.

Phosphorylation of the Chaperone-Like HspB5 Rescues Trafficking and Function of F508del-CFTR

Cystic Fibrosis is a lethal monogenic autosomal recessive disease linked to mutations in Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein. The most frequent mutation is the deletion of phenylalanine at position 508 of the protein. This F508del-CFTR mutation leads to misfolded protein that is detected by the quality control machinery within the endoplasmic reticulum and targeted for destruction by the proteasome. Modulating quality control proteins as molecular chaperones is a promising strategy for attenuating the degradation and stabilizing the mutant CFTR at the plasma membrane. Among the molecular chaperones, the small heat shock protein HspB1 and HspB4 were shown to promote degradation of F508del-CFTR. Here, we investigated the impact of HspB5 expression and phosphorylation on transport to the plasma membrane, function and stability of F508del-CFTR. We show that a phosphomimetic form of HspB5 increases the transport to the plasma membrane, function and stability of F508del-CFTR. These activities are further enhanced in presence of therapeutic drugs currently used for the treatment of cystic fibrosis (VX-770/Ivacaftor, VX-770+VX-809/Orkambi). Overall, this study highlights the beneficial effects of a phosphorylated form of HspB5 on F508del-CFTR rescue and its therapeutic potential in cystic fibrosis.

Druggable Sphingolipid Pathways: Experimental Models and Clinical Opportunities

Intensive research in the field of sphingolipids has revealed diverse roles in cell biological responses and human health and disease. This immense molecular family is primarily represented by the bioactive molecules ceramide, sphingosine, and sphingosine 1-phosphate (S1P). The flux of sphingolipid metabolism at both the subcellular and extracellular levels provides multiple opportunities for pharmacological intervention. The caveat is that perturbation of any single node of this highly regulated flux may have effects that propagate throughout the metabolic network in a dramatic and sometimes unexpected manner. Beginning with S1P, the receptors for which have thus far been the most clinically tractable pharmacological targets, this review will describe recent advances in therapeutic modulators targeting sphingolipids, their chaperones, transporters, and metabolic enzymes.

Formalin treatment increases the stability and immunogenicity of coxsackievirus B1 VLP vaccine

Type B Coxsackieviruses (CVBs) are a common cause of acute and chronic myocarditis, dilated cardiomyopathy and aseptic meningitis. However, no CVB-vaccines are available for human use. We have previously produced virus-like particles (VLPs) for CVB3 with a baculovirus-insect cell production system. Here we have explored the potential of a VLP-based vaccine targeting CVB1 and describe the production of CVB1-VLPs with a scalable VLP purification method. The developed purification method consisting of tangential flow filtration and ion exchange chromatography is compatible with industrial scale production. CVB1-VLP vaccine was treated with UV-C or formalin to study whether stability and immunogenicity was affected. Untreated, UV treated and formalin treated VLPs remained morphologically intact for 12  months  at 4 °C. Formalin treatment increased, whereas UV treatment decreased the thermostability of the VLP-vaccine. High neutralising and total IgG antibody levels, the latter predominantly of a Th2 type (IgG1) phenotype, were detected in female BALB/c mice immunised with non-adjuvanted, untreated CVB1-VLP vaccine. The immunogenicity of the differently treated CVB1-VLPs (non-adjuvanted) were compared in C57BL/6 J mice and animals vaccinated with formalin treated CVB1-VLPs mounted the strongest neutralising and, CVB1-specific IgG and IgG1 antibody responses. This study demonstrates that formalin treatment increases the stability and immunogenicity of CVB1-VLP vaccine and may offer a universal tool for the stabilisation of VLPs in the production of more efficient vaccines.

Genetic and Environmental Interaction in Type 1 Diabetes: a Relationship Between Genetic Risk Alleles and Molecular Traits of Enterovirus Infection?

PURPOSE OF REVIEW

We provide an overview of the current knowledge regarding the natural history of human type 1 diabetes (T1D) and the documented associations between virus infections (in particular the enteroviruses) and disease development. We review studies that examine whether T1D-specific risk alleles in genes involved in the function of the immune system can alter susceptibility to virus infections or affect the magnitude of the host antiviral response. We also highlight where the major gaps in our knowledge exist and consider possible implications that new insights gained from the discussed gene-environment interaction studies may bring.

RECENT FINDINGS

A commonality between several of the studied T1D risk variants studied is their role in modulating the host immune response to viral infection. Generally, little support exists indicating that the risk variants increase susceptibility to infection and moreover, they usually appear to predispose the immune system towards a hyper-reactive state, decrease the risk of infection, and/or favor the establishment of viral persistence. In conclusion, although the current number of studies is limited, this type of research can provide important insights into the mechanisms that are central to disease pathogenesis and further describe how genetic and environmental factors jointly influence the risk of T1D development. The latter may provide genetic markers that could be used for patient stratification and for the selection of method(s) for disease prevention.

Adapting Proteostasis and Autophagy for Controlling the Pathogenesis of Cystic Fibrosis Lung Disease

Cystic fibrosis (CF), a fatal genetic disorder predominant in the Caucasian population, is caused by mutations in the cystic fibrosis transmembrane conductance regulator (Cftr) gene. The most common mutation is the deletion of phenylalanine from the position-508 (F508del-CFTR), resulting in a misfolded-CFTR protein, which is unable to fold, traffic and retain its plasma membrane (PM) localization. The resulting CFTR dysfunction, dysregulates variety of key cellular mechanisms such as chloride ion transport, airway surface liquid (ASL) homeostasis, mucociliary-clearance, inflammatory-oxidative signaling, and proteostasis that includes ubiquitin-proteasome system (UPS) and autophagy. A collective dysregulation of these key homoeostatic mechanisms contributes to the development of chronic obstructive cystic fibrosis lung disease, instead of the classical belief focused exclusively on ion-transport defect. Hence, therapeutic intervention(s) aimed at rescuing chronic CF lung disease needs to correct underlying defect that mediates homeostatic dysfunctions and not just chloride ion transport. Since targeting all the myriad defects individually could be quite challenging, it will be prudent to identify a process which controls almost all disease-promoting processes in the CF airways including underlying CFTR dysfunction. There is emerging experimental and clinical evidence that supports the notion that impaired cellular proteostasis and autophagy plays a central role in regulating pathogenesis of chronic CF lung disease. Thus, correcting the underlying proteostasis and autophagy defect in controlling CF pulmonary disease, primarily via correcting the protein processing defect of F508del-CFTR protein has emerged as a novel intervention strategy. Hence, we discuss here both the rationale and significant therapeutic utility of emerging proteostasis and autophagy modulating drugs/compounds in controlling chronic CF lung disease, where targeted delivery is a critical factor-influencing efficacy.