Co-Delivery of the Human NY-ESO-1 Tumor-Associated Antigen and Alpha-GalactosylCeramide by Filamentous Bacteriophages Strongly Enhances the Expansion of Tumor-Specific CD8+ T Cells

Tumor-associated antigens (TAAs) represent attractive targets in the development of anti-cancer vaccines. The filamentous bacteriophage is a safe and versatile delivery nanosystem, and recombinant bacteriophages expressing TAA-derived peptides at a high density on the viral coat proteins improve TAA immunogenicity, triggering effective in vivo anti-tumor responses. To enhance the efficacy of the bacteriophage as an anti-tumor vaccine, we designed and generated phage particles expressing a CD8+ peptide derived from the human cancer germline antigen NY-ESO-1 decorated with the immunologically active lipid alpha-GalactosylCeramide (α-GalCer), a potent activator of invariant natural killer T (iNKT) cells. The immune response to phage expressing the human TAA NY-ESO-1 and delivering α-GalCer, namely fdNY-ESO-1/α-GalCer, was analyzed either in vitro or in vivo, using an HLA-A2 transgenic mouse model (HHK). By using NY-ESO-1-specific TCR-engineered T cells and iNKT hybridoma cells, we observed the efficacy of the fdNY-ESO-1/α-GalCer co-delivery strategy at inducing activation of both the cell subsets. Moreover, in vivo administration of fdNY-ESO-1 decorated with α-GalCer lipid in the absence of adjuvants strongly enhances the expansion of NY-ESO-1-specific CD8+ T cells in HHK mice. In conclusion, the filamentous bacteriophage delivering TAA-derived peptides and the α-GalCer lipid may represent a novel and promising anti-tumor vaccination strategy.

PLGA microparticle formulations for tunable delivery of a nano-engineered filamentous bacteriophage-based vaccine: in vitro and in silico-supported approach

Bacteriophages have attracted great attention in the bioengineering field in diverse research areas from tissue engineering to therapeutic and clinical applications. Recombinant filamentous bacteriophage, carrying multiple copies of foreign peptides on protein capsid has been successfully used in the vaccine delivery setting, even if their plasma instability and degradation have limited their use on the pharmaceutical market. Encapsulation techniques in polymeric materials can be applied to preserve bacteriophage activity, extend its half-life, and finely regulate their release in the target environment. The main goal of this study was to provide tunable formulations of the bacteriophage encapsulated in polymeric microparticles (MPs). We used poly (lactic-co-glycolic-acid) as a biocompatible and biodegradable polymer with ammonium bicarbonate as a porogen to encapsulate bacteriophage expressing OVA (257-264) antigenic peptide. We demonstrate that nano-engineered fdOVA bacteriophages encapsulated in MPs preserve their structure and are immunologically active, inducing a strong immune response towards the delivered peptide. Moreover, MP encapsulation prolongs bacteriophage stability over time also at room temperature. Additionally, in this study, we show the ability of in silico-supported approach to predict and tune the release of bacteriophages. These results lay the framework for a versatile bacteriophage-based vaccine delivery system that could successfully generate robust immune responses in a sustained manner, to be used as a platform against cancer and new emerging diseases.

Graphical abstract

Synopsis: administration of recombinant bacteriophage-loaded PLGA microparticles for antigen delivery. PLGA microparticles release the bacteriophages, inducing activation of dendritic cells and enhancing antigen presentation and specific T cell response. Bacteriophage-encapsulated microneedles potentially can be administered into human body and generate robust immune responses.

Exploiting viral sensing mediated by Toll-like receptors to design innovative vaccines

Toll-like receptors (TLRs) are transmembrane proteins belonging to the family of pattern-recognition receptors. They function as sensors of invading pathogens through recognition of pathogen-associated molecular patterns. After their engagement by microbial ligands, TLRs trigger downstream signaling pathways that culminate into transcriptional upregulation of genes involved in immune defense. Here we provide an updated overview on members of the TLR family and we focus on their role in antiviral response. Understanding of innate sensing and signaling of viruses triggered by these receptors would provide useful knowledge to prompt the development of vaccines able to elicit effective and long-lasting immune responses. We describe the mechanisms developed by viral pathogens to escape from immune surveillance mediated by TLRs and finally discuss how TLR/virus interplay might be exploited to guide the design of innovative vaccine platforms.

Viral Emerging Diseases: Challenges in Developing Vaccination Strategies

In the last decades, a number of infectious viruses have emerged from wildlife or re-emerged, generating serious threats to the global health and to the economy worldwide. Ebola and Marburg hemorrhagic fevers, Lassa fever, Dengue fever, Yellow fever, West Nile fever, Zika, and Chikungunya vector-borne diseases, Swine flu, Severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and the recent Coronavirus disease 2019 (COVID-19) are examples of zoonoses that have spread throughout the globe with such a significant impact on public health that the scientific community has been called for a rapid intervention in preventing and treating emerging infections. Vaccination is probably the most effective tool in helping the immune system to activate protective responses against pathogens, reducing morbidity and mortality, as proven by historical records. Under health emergency conditions, new and alternative approaches in vaccine design and development are imperative for a rapid and massive vaccination coverage, to manage a disease outbreak and curtail the epidemic spread. This review gives an update on the current vaccination strategies for some of the emerging/re-emerging viruses, and discusses challenges and hurdles to overcome for developing efficacious vaccines against future pathogens.

Persistent epigenetic memory impedes rescue of the telomeric phenotype in human ICF iPSCs following DNMT3B correction

DNA methyltransferase 3B (DNMT3B) is the major DNMT that methylates mammalian genomes during early development. Mutations in human DNMT3B disrupt genome-wide DNA methylation patterns and result in ICF syndrome type 1 (ICF1). To study whether normal DNA methylation patterns may be restored in ICF1 cells, we corrected DNMT3B mutations in induced pluripotent stem cells from ICF1 patients. Focusing on repetitive regions, we show that in contrast to pericentromeric repeats, which reacquire normal methylation, the majority of subtelomeres acquire only partial DNA methylation and, accordingly, the ICF1 telomeric phenotype persists. Subtelomeres resistant to de novo methylation were characterized by abnormally high H3K4 trimethylation (H3K4me3), and short-term reduction of H3K4me3 by pharmacological intervention partially restored subtelomeric DNA methylation. These findings demonstrate that the abnormal epigenetic landscape established in ICF1 cells restricts the recruitment of DNMT3B, and suggest that rescue of epigenetic diseases with genome-wide disruptions will demand further manipulation beyond mutation correction.

Adolescents and epilepsy: hormonal aspects

Epilepsy is one of the most frequent disease in children, particularly in adolescents. Some types of epilepsy begin typically in the peripubertal period and many studies found changes in frequency or features of seizures in adolescents. This is probably related to sex hormone effects on neuronal excitability. Estrogens seem to decrease neuronal electric threshold with proconvulsant effects. On the contrary progesterone seems to have anticonvulsivant action, as well as testosterone. Changes in hormone serum levels that occur during pubertal period are probably related to modifications in seizure features and are involved in some types of epilepsy that begin typically in adolescence.

Influence of sex hormones on brain excitability and epilepsy

Epilepsy is one of the most common neurologic problems worldwide. In spite of the many studies carried out, our understanding of generalized epileptogenesis remains far from complete. In recent years many data have clarified the effects of sexual hormones on brain excitability. Female and male sexual hormones may be considered pharmacoactive compounds that alter the seizure threshold, changing the frequency and semeiology of the seizures. In particular, estrogens may increase neuronal excitability while progesterone enhances inhibitions and increases the seizure threshold; on the other hand, androgens can decrease ictal activity in the human brain. This review provides an overview of the current knowledge in this field and highlights some of the prevailing hypotheses about the effects of sexual hormones on neuronal excitability analysing data from both animal and clinical studies.

Update of the medical treatment of West syndrome

West syndrome is a generalized epilepsy syndrome composed of infantile spasms and onset is usually within the first year of life. Although West syndrome is well known clinical epileptic syndrome, there is no agreement about the first- and second-line treatments. In the last years a great progress in the development of new antiepileptic drugs allow us to have a large choice of treatment options to control the seizures. This review outlines the usefulness of the different antiepileptic drugs for the treatment of West syndrome.

Topiramate in frontal lobe epilepsy

BACKGROUND

Frontal lobe epilepsy (FLE) is a type of epilepsy that is difficult to treat and there are few studies about the use of topiramate (TPM).

AIM OF THE STUDY

To evaluate the efficacy and tolerability of TPM monotherapy in FLE.

METHODS

The study group consisted of 55 (33 male; 22 female) patients. TPM was administered as a first drug (n = 16) or converted after previous treatment (n = 39). All patients were followed every 3 months for at least 1 year. The patients were subdivided into two groups: 'newly diagnosed' patients and 'difficult-to-treat' patients.

RESULTS

Overall, all patients completed the 1-year study. At the end of follow-up, 10 patients showed disappearance of seizures and 33 patients showed improvement in seizure frequency. In particular, among the newly diagnosed patients 6/16 patients showed complete cessation of seizures and 5/16 patients showed very good response; in the other group, 4/39 patients showed complete cessation and 4/39 patients showed a very good response. No patients of both groups had worsening of seizures. No treatment-limiting adverse events associated with TPM were reported.

CONCLUSIONS

TPM is effective in newly diagnosed patients with FLE; TPM can be considered for the treatment of FLE.

Levetiracetam monotherapy for children and adolescents with benign rolandic seizures

To assess the efficacy, tolerability and safety of Levetiracetam (LEV) therapy, we identified 21 (15 male; 6 female) patients with a history of benign epilepsy with centrotemporal spikes (BECTS), with and without secondarily generalization in children and adolescents aged between 5.0 and 12.1 years. LEV was administered as a first drug (number of patients=9) or converted after previous treatment with other AEDs (number of patients=12). The patients were subdivided into two groups: "newly diagnosed" patients and "converted" patients. Patients were followed up for 12 months and all patients were able to continue on LEV treatment. At the end of follow-up (12 months), all patients were seizure free or showed a reduction of seizures >50%. LEV dosage ranged from 1000 to 2500mg/daily. Overall, 100% of patients completed the 12 months study, without any important side effect. Somnolence and irritability occurred in two (9.5%) patients. Our results support findings that LEV monotherapy is effective and well tolerated in children with BECTS. Prospective, large, long-term double-blind studies are needed to confirm these findings.

Multiple and giant mandibular osteomas in a Gardner's syndrome. Case report

Though rare, Gardner's syndrome is a systemic disease with frequent jawbones involvement. Dento-maxillo-facial lesions both in early and in advanced stages should be known by dentists and other specialists. In fact, these lesions should be sought in patients with intestinal polyposis, while they could be the first sign of Gardner's syndrome not yet diagnosed.