Phenotypic CD8 T cell profiling in chronic hepatitis B to predict HBV-specific CD8 T cell susceptibility to functional restoration in vitro.

OBJECTIVE: Exhausted hepatitis B virus (HBV)-specific CD8 T cells in chronic HBV infection are broadly heterogeneous. Characterisation of their functional impairment may allow to distinguish patients with different capacity to control infection and reconstitute antiviral function. DESIGN: HBV dextramer+CD8 T cells were analysed ex vivo for coexpression of checkpoint/differentiation markers, transcription factors and cytokines in 35 patients with HLA-A2+chronic hepatitis B (CHB) and in 29 control HBsAg negative CHB patients who seroconverted after NUC treatment or spontaneously. Cytokine production was also evaluated in HBV peptide-stimulated T cell cultures, in the presence or absence of antioxidant, polyphenolic, PD-1/PD-L1 inhibitor and TLR-8 agonist compounds and the effect on HBV-specific responses was further validated on additional 24 HLA-A2 negative CHB patients. RESULTS: Severely exhausted HBV-specific CD8 T cell subsets with high expression of inhibitory receptors, such as PD-1, TOX and CD39, were detected only in a subgroup of chronic viraemic patients. Conversely, a large predominance of functionally more efficient HBV-specific CD8 T cell subsets with lower expression of coinhibitory molecules and better response to in vitro immune modulation, typically detected after resolution of infection, was also observed in a proportion of chronic viraemic HBV patients. Importantly, the same subset of patients who responded more efficiently to in vitro immune modulation identified by HBV-specific CD8 T cell analysis were also identified by staining total CD8 T cells with PD-1, TOX, CD127 and Bcl-2. CONCLUSIONS: The possibility to distinguish patient cohorts with different capacity to respond to immune modulatory compounds in vitro by a simple analysis of the phenotypic CD8 T cell exhaustion profile deserves evaluation of its clinical applicability.

Deregulated intracellular pathways define novel molecular targets for HBV-specific CD8 T cell reconstitution in chronic hepatitis B.

BACKGROUND & AIMS: In chronic HBV infection, elevated reactive oxygen species levels derived from dysfunctional mitochondria can cause increased protein oxidation and DNA damage in exhausted virus-specific CD8 T cells. The aim of this study was to understand how these defects are mechanistically interconnected to further elucidate T cell exhaustion pathogenesis and, doing so, to devise novel T cell-based therapies. METHODS: DNA damage and repair mechanisms, including parylation, CD38 expression, and telomere length were studied in HBV-specific CD8 T cells from chronic HBV patients. Correction of intracellular signalling alterations and improvement of antiviral T cell functions by the NAD precursor nicotinamide mononucleotide and by CD38 inhibition was assessed. RESULTS: Elevated DNA damage was associated with defective DNA repair processes, including NAD-dependent parylation, in HBV-specific CD8 cells of chronic HBV patients. NAD depletion was indicated by the overexpression of CD38, the major NAD consumer, and by the significant improvement of DNA repair mechanisms, and mitochondrial and proteostasis functions by NAD supplementation, which could also improve the HBV-specific antiviral CD8 T cell function. CONCLUSIONS: Our study delineates a model of CD8 T cell exhaustion whereby multiple interconnected intracellular defects, including telomere shortening, are causally related to NAD depletion suggesting similarities between T cell exhaustion and cell senescence. Correction of these deregulated intracellular functions by NAD supplementation can also restore antiviral CD8 T cell activity and thus represents a promising potential therapeutic strategy for chronic HBV infection. IMPACT AND IMPLICATIONS: Correction of HBV-specific CD8 T cell dysfunction is believed to represent a rational strategy to cure chronic HBV infection, which however requires a deep understanding of HBV immune pathogenesis to identify the most important targets for functional T cell reconstitution strategies. This study identifies a central role played by NAD depletion in the intracellular vicious circle that maintains CD8 T cell exhaustion, showing that its replenishment can correct impaired intracellular mechanisms and reconstitute efficient antiviral CD8 T cell function, with implications for the design of novel immune anti-HBV therapies. As these intracellular defects are likely shared with other chronic virus infections where CD8 exhaustion can affect virus clearance, these results can likely also be of pathogenetic relevance for other infection models.

Noncoding RNAs in Pulmonary Arterial Hypertension: Current Knowledge and Translational Perspectives.

Several microRNAs and long noncoding RNAs contribute to pulmonary arterial hypertension (PAH) pathogenesis by impairing nitric oxide production, enhancing proliferation and migration and decreasing apoptosis of smooth muscle cells, and promoting endothelial-to-mesenchymal transition in pulmonary arteries. These noncoding RNAs (ncRNAs) could serve as both biomarkers and therapeutic targets for PAH. Nonetheless, the knowledge about their role in PAH is still incomplete. Furthermore, ncRNAs may vary across species and often act differently in different tissues and organs, and technical issues currently limit the implementation of ncRNA-based technologies. Additional studies are warranted to finally bring ncRNA into the clinical arena.

Ventricular arrhythmias and ARNI: is it time to reappraise their management in the light of new evidence?

The remarkable scientific progress in the treatment of patients with heart failure (HF) and reduced ejection fraction (HFrEF) has more than halved the risk of sudden cardiac death (SCD) in this setting. However, SCD remains one of the major causes of death in this patient population. Beyond the acknowledged role of beta blockers and inhibitors of the renin-angiotensin-aldosterone system (RAAS), a new class of drugs, the angiotensin receptor neprilysin inhibitors (ARNI), proved to reduce the overall cardiovascular mortality and, more specifically, the risk of SCD in HFrEF patients. The mechanism by which ARNI may reduce the mortality connected with harmful ventricular arrhythmias is not utterly clear. A variety of direct and indirect mechanisms have been suggested, but a favorable left ventricular reverse remodeling seems to play a key role in this setting. Furthermore, the well-known protective effect of implantable cardioverter-defibrillator (ICD) has been debated in HFrEF patients with non-ischemic cardiomyopathy (NICM) arguing against the role of primary prevention ICD in this setting, particularly when ARNI therapy is considered. The purpose of this review was to provide insights into the SCD mechanisms involved in HFrEF patients together with the current role of electrical therapies and new drug agents in this setting. Graphical abstract.

Functional reconstitution of HBV-specific CD8 T cells by in vitro polyphenol treatment in chronic hepatitis B.

BACKGROUND & AIMS: In chronic HBV infection, mitochondrial functions and proteostasis are dysregulated in exhausted HBV-specific CD8 T cells. To better characterise the potential involvement of deregulated protein degradation mechanisms in T cell exhaustion, we analysed lysosome-mediated autophagy in HBV-specific CD8 T cells. Bioactive compounds able to simultaneously target both mitochondrial functions and proteostasis were tested to identify optimal combination strategies to reconstitute efficient antiviral CD8 T cell responses in patients with chronic HBV infection. METHODS: Lysosome-mediated degradation pathways were analysed by flow cytometry in virus-specific CD8 T cells from patients with chronic HBV infection. Mitochondrial function, intracellular proteostasis, and cytokine production were evaluated in HBV-peptide-stimulated T cell cultures, in the presence or absence of the polyphenols resveratrol (RSV) and oleuropein (OLE) and their metabolites, either alone or in combination with other bioactive compounds. RESULTS: HBV-specific CD8 T cells from patients with CHB showed impaired autophagic flux. RSV and OLE elicited a significant improvement in mitochondrial, proteostasis and antiviral functions in CD8 T cells. Cytokine production was also enhanced by synthetic metabolites, which correspond to those generated by RSV and OLE metabolism in vivo, suggesting that these polyphenols may also display an effect after transformation in vivo. Moreover, polyphenolic compounds improved the T cell revitalising effect of mitochondria-targeted antioxidants and of programmed cell death protein 1/programmed cell death ligand 1 blockade. CONCLUSIONS: Simultaneously targeting multiple altered intracellular pathways with the combination of mitochondria-targeted antioxidants and natural polyphenols may represent a promising immune reconstitution strategy for the treatment of chronic HBV infection. LAY SUMMARY: In chronic hepatitis B, antiviral T lymphocytes are deeply impaired, with many altered intracellular functions. In vitro exposure to polyphenols, such as resveratrol and oleuropein, can correct some of the deregulated intracellular pathways and improve antiviral T cell function. This effect can be further strengthened by the association of polyphenols with antioxidant compounds in a significant proportion of patients. Thus, the combination of antioxidants and natural polyphenols represents a promising strategy for chronic hepatitis B therapy.

Similar, Yet Different: Long-Range Metal-Metal Coupling and Electron-Transfer Processes in Metal-Free 5,10,15,20-Tetra(ruthenocenyl)porphyrin.

The electronic structure, redox properties, and long-range metal-metal coupling in metal-free 5,10,15,20-tetra(ruthenocenyl)porphyrin (H2TRcP) were probed by spectroscopic (NMR, UV-vis, magnetic circular dichroism (MCD), and atmospheric pressure chemical ionization (APCI)), electrochemical (cyclic voltammetry, CV, and differential pulse voltammetry, DPV), spectroelectrochemical, and chemical oxidation methods, as well as theoretical (density functional theory, DFT, and time-dependent DFT, TDDFT) approaches. It was demonstrated that the spectroscopic properties of H2TRcP are significantly different from those in H2TFcP (metal-free 5,10,15,20-tetra(ferrocenyl)porphyrin). Ruthenocenyl fragments in H2TRcP have higher oxidation potentials than the ferrocene groups in the H2TFcP complex. Similar to H2TFcP, we were able to access and spectroscopically characterize the one- and two-electron oxidized mixed-valence states in the H2TRcP system. DFT predicts that the porphyrin π-system stabilizes the [H2TRcP]+ mixed-valence cation and prevents its dimerization, which is characteristic for ruthenocenyl systems. However, formation of the mixed-valence [H2TRcP]2+ is significantly less reproducible than the formation of [H2TRcP]+. DFT and TDDFT calculations suggest the ruthenocenyl fragment dominance in the highest occupied molecular orbital (HOMO) energy region and the presence of the low-energy MLCT (Rc → porphyrin (π*)) transitions in the visible region with energies higher than the predominantly porphyrin-centered Q-bands.

Combined GS-4774 and Tenofovir Therapy Can Improve HBV-Specific T-Cell Responses in Patients With Chronic Hepatitis.

BACKGROUND & AIMS: One strategy to treat chronic hepatitis B virus (HBV) infection could be to increase the functions of virus-specific T cells. We performed a multicenter phase 2 study to evaluate the safety and efficacy of GS-4774, a yeast-based therapeutic vaccine engineered to express HBV antigens, given with tenofovir disoproxil fumarate (TDF) to untreated patients with chronic HBV infection. METHODS: We performed an open-label study at 34 sites in Canada, Italy, New Zealand, Romania, South Korea, and United States from July 2014 to August 2016. Adults who were positive for HB surface antigen (HBsAg) > 6 months and levels of HBV DNA ≥2000 IU/mL who had not received antiviral treatment for HBV within 3 months of screening were randomly assigned (1:2:2:2) to groups given oral TDF 300 mg daily alone (n = 27; controls) or with 2, 10, or 40 yeast units GS-4774 (n = 168), administered subcutaneously every 4 weeks until week 20 for a total of 6 doses. Blood samples were collected and analyzed and patients received regular physical examinations. Efficacy was measured by decrease in HBsAg from baseline to week 24. Specific responses to HBV (production of interferon gamma [IFNG], tumor necrosis factor [TNF], interleukin 2 [IL2], and degranulation) were measured in T cells derived from 12 HBeAg-negative patients with genotype D infections, after overnight or 10 days of stimulation of peripheral blood mononuclear cells with peptides from the entire HBV proteome. T-regulatory cells were analyzed for frequency and phenotype. Data from studies of immune cells were compared with data on reductions in HBsAg, HBV DNA, and alanine aminotransferase in blood samples from patients. RESULTS: GS-4774 was safe and well tolerated but did not produce significant decreases in levels of HBsAg. Production of IFNG, TNF, and IL2 increased significantly at weeks 24 and 48, compared with baseline, in HBV-specific CD8+ T cells from patients given GS-4774 but not from controls. GS-4774 had greater effects on CD8+ than CD4+ T cells, which were not affected at all or very weakly by TDF with or without GS-4774. GS-4774 did not affect responses of T cells to other viruses tested. HBV core peptides induced the greatest production of IFNG by T cells following overnight stimulation, whereas HBV envelope antigens did not induce a response. Following 10 days of stimulation, production of IFNG and TNF increased with time of exposure to GS-4774; the greatest levels of responses were to HBV envelope antigens followed by core and polymerase peptides. We observed a correlation in patients given GS-4774 between increased T-cell functions and reductions in numbers of T-regulatory cells. CONCLUSIONS: In a phase 2 study of patients with chronic HBV infection given TDF with or without GS-4774, we found that vaccination can increase production of IFNG, TNF, and IL2 by CD8+ T cells exposed to antigenic peptides, with little effect on CD4+ T cells. Although GS-4774 did not reduce levels of HBsAg in patients, its strong immune stimulatory effect on CD8+ T cells might be used in combination with other antiviral agents to boost the antivirus immune response. Clinicaltrials.gov no: NCT02174276.

TLR7 Agonist Increases Responses of Hepatitis B Virus-Specific T Cells and Natural Killer Cells in Patients With Chronic Hepatitis B Treated With Nucleos(T)Ide Analogues.

BACKGROUND & AIMS: The oral Toll-like receptor (TLR) 7 agonist GS-9620 has antiviral effects in woodchuck and chimpanzee models of chronic hepatitis B virus (HBV) infection. We investigated, in a clinical trial, the capacity of this agent to reconstitute protective immunity in patients with chronic HBV infection. METHODS: We performed a prospective study of 28 patients with suppression of HBV infection by nucleos(t)ide analogue therapy and who tested negative for hepatitis B e antigen at 4 medical centers in Italy. Patients were randomly assigned (1:3:3:3) to groups given placebo or different doses of GS-9620 (1, 2, and 4 mg, weekly for 12 weeks). We added data from 8 patients receiving nucleos(t)ide analogue therapy to the placebo group (controls); 13 treatment-naïve patients with chronic HBV infection and 15 subjects who spontaneously recovered from an acute HBV infection served as additional controls. Peripheral blood mononuclear cells were collected at baseline, during administration of GS-9620 or placebo, and 12 weeks afterward. Phenotype and function of natural killer (NK) and HBV-specific T cells were analyzed by flow cytometry. T cells were expanded by incubation with peptides from the entire HBV proteome and studied after overnight or 10 days culture. NK-cell inhibition of T-cell responses was measured by assessing cytokine production by T cells stimulated with peptides in the presence or absence of NK cells. RESULTS: T cells collected at baseline before addition of GS-9620, when patients were receiving only nucleos(t)ide therapy, had greater responses to HBV than T cells from treatment-naïve patients, based on cytokine production in response to HBV peptides. However, during or after administration of GS-9620, T cells produced higher levels of cytokines compared to baseline. NK-cell activation and function increased after patients were given GS-9620, but the ability of NK cells to suppress T-cell responses was lower during GS-9620 therapy than before. Changes in T-cell or NK-cell function did not correlate with levels of hepatitis B surface antigen. Serum levels of hepatitis B surface antigen did not decrease significantly compared to baseline in patients given any dose of GS-9620. CONCLUSIONS: Twelve weeks administration of GS-9620 had no significant effect on serum hepatitis B surface antigen levels, but did appear to increase T-cell and NK-cell responses and reduce the ability of NK to suppress T cells. GS-9620 might therefore be included in therapies to increase the immune response to HBV.

Evaluation of the usage-induced degradation of Genius and Reciproc nickel-titanium reciprocating instruments.

The aim of this study was to characterize the main features and the usage-induced degradation of the Genius file after four severely curved root canal instrumentations and to compare their properties to the Reciproc files. Brand new and ex vivo used files were analysed by scanning electron microscopy (SEM) with energy-dispersive X-ray spectrometry (EDS), differential scanning calorimetry (DSC), X-ray diffraction (XRD), optical metallography, and nano-indentation to disclose their morphological, chemical, mechanical, thermal, and phase composition features. Nano-indentation data were statistically analysed using the Student's t test for normal distribution or the Kolmogorov-Smirnov test for not-normal distributions. SEM analysis showed the presence of micro-cracks near the tip on both files after ex vivo usage test. EDS analysis confirmed that both files are manufactured from an almost equiatomic NiTi alloy. DSC analysis revealed that the transition temperature of the Genius is below 20 °C, while that of the Reciproc is above 20 °C. XRD analysis of Genius files identified cubic B2 austenite with minor peaks of residual monoclinic B19 martensite, while the contemporaneous presence of martensite, austenite and hexagonal R-phase was observed in the Reciproc files. Significant differences in nanohardness and modulus of elasticity (P < .05) were observed in both Genius and Reciproc files before and after use. The collected results showed that both instruments can be safely used as single-use files.

HBV Immune-Therapy: From Molecular Mechanisms to Clinical Applications.

Chronic hepatitis B virus (HBV) infection represents a worldwide public health concern with approximately 250 million people chronically infected and at risk of developing liver cirrhosis and hepatocellular carcinoma. Nucleos(t)ide analogues (NUC) are the most widely used therapies for HBV infection, but they often require long-lasting administration to avoid the risk of HBV reactivation at withdrawal. Therefore, there is an urgent need to develop novel treatments to shorten the duration of NUC therapy by accelerating virus control, and to complement the effect of available anti-viral therapies. In chronic HBV infection, virus-specific T cells are functionally defective, and this exhaustion state is a key determinant of virus persistence. Reconstitution of an efficient anti-viral T cell response may thus represent a rational strategy to treat chronic HBV patients. In this perspective, the enhancement of adaptive immune responses by a checkpoint inhibitor blockade, specific T cell vaccines, lymphocyte metabolism targeting, and autologous T cell engineering, including chimeric antigen receptor (CAR) and TCR-redirected T cells, constitutes a promising immune modulatory approach for a therapeutic restoration of protective immunity. The advances of the emerging immune-based therapies in the setting of the HBV research field will be outlined.

The Good and the Bad of Natural Killer Cells in Virus Control: Perspective for Anti-HBV Therapy.

Immune modulatory therapies are widely believed to represent potential therapeutic strategies for chronic hepatitis B infection (CHB). Among the cellular targets for immune interventions, Natural Killer (NK) cells represent possible candidates because they have a key role in anti-viral control by producing cytokines and by exerting cytotoxic functions against virus-infected cells. However, in patients with chronic hepatitis B, NK cells have been described to be more pathogenic than protective with preserved cytolytic activity but with a poor capacity to produce anti-viral cytokines. In addition, NK cells can exert a regulatory activity and possibly suppress adaptive immune responses in the setting of persistent viral infections. Consequently, a potential drawback of NK-cell targeted modulatory interventions is that they can potentiate the suppressive NK cell effect on virus-specific T cells, which further causes impairment of exhausted anti-viral T cell functions. Thus, clinically useful NK-cell modulatory strategies should be not only suited to improve positive anti-viral NK cell functions but also to abrogate T cell suppression by NK cell-mediated T cell killing. This review outlines the main NK cell features with a particular focus on CHB infection. It describes different mechanisms involved in NK-T cell interplay as well as how NK cells can have positive anti-viral effector functions and negative suppressive effects on T cells activity. This review discusses how modulation of their balance can have potential therapeutic implications.

Effector CD8+ T cell-derived interleukin-10 enhances acute liver immunopathology.

BACKGROUND & AIMS: Besides secreting pro-inflammatory cytokines, chemokines and effector molecules, effector CD8+ T cells that arise upon acute infection with certain viruses have been shown to produce the regulatory cytokine interleukin (IL)-10 and, therefore, contain immunopathology. Whether the same occurs during acute hepatitis B virus (HBV) infection and role that IL-10 might play in liver disease is currently unknown. METHODS: Mouse models of acute HBV pathogenesis, as well as chimpanzees and patients acutely infected with HBV, were used to analyse the role of CD8+ T cell-derived IL-10 in liver immunopathology. RESULTS: Mouse HBV-specific effector CD8+ T cells produce significant amounts of IL-10 upon in vivo antigen encounter. This is corroborated by longitudinal data in a chimpanzee acutely infected with HBV, where serum IL-10 was readily detectable and correlated with intrahepatic CD8+ T cell infiltration and liver disease severity. Unexpectedly, mouse and human CD8+ T cell-derived IL-10 was found to act in an autocrine/paracrine fashion to enhance IL-2 responsiveness, thus preventing antigen-induced HBV-specific effector CD8+ T cell apoptosis. Accordingly, the use of mouse models of HBV pathogenesis revealed that the IL-10 produced by effector CD8+ T cells promoted their own intrahepatic survival and, thus supported, rather than suppressed liver immunopathology. CONCLUSION: Effector CD8+ T cell-derived IL-10 enhances acute liver immunopathology. Altogether, these results extend our understanding of the cell- and tissue-specific role that IL-10 exerts in immune regulation. Lay summary: Interleukin-10 is mostly regarded as an immunosuppressive cytokine. We show here that HBV-specific CD8+ T cells produce IL-10 upon antigen recognition and that this cytokine enhances CD8+ T cell survival. As such, IL-10 paradoxically promotes rather than suppresses liver disease.

IL21R expressing CD14+CD16+ monocytes expand in multiple myeloma patients leading to increased osteoclasts.

Bone marrow monocytes are primarily committed to osteoclast formation. It is, however, unknown whether potential primary alterations are specifically present in bone marrow monocytes from patients with multiple myeloma, smoldering myeloma or monoclonal gammopathy of undetermined significance. We analyzed the immunophenotypic and transcriptional profiles of bone marrow CD14+ monocytes in a cohort of patients with different types of monoclonal gammopathies to identify alterations involved in myeloma-enhanced osteoclastogenesis. The number of bone marrow CD14+CD16+ cells was higher in patients with active myeloma than in those with smoldering myeloma or monoclonal gammopathy of undetermined significance. Interestingly, sorted bone marrow CD14+CD16+ cells from myeloma patients were more pro-osteoclastogenic than CD14+CD16-cells in cultures ex vivo Moreover, transcriptional analysis demonstrated that bone marrow CD14+ cells from patients with multiple myeloma (but neither monoclonal gammopathy of undetermined significance nor smoldering myeloma) significantly upregulated genes involved in osteoclast formation, including IL21RIL21R mRNA over-expression by bone marrow CD14+ cells was independent of the presence of interleukin-21. Consistently, interleukin-21 production by T cells as well as levels of interleukin-21 in the bone marrow were not significantly different among monoclonal gammopathies. Thereafter, we showed that IL21R over-expression in CD14+ cells increased osteoclast formation. Consistently, interleukin-21 receptor signaling inhibition by Janex 1 suppressed osteoclast differentiation from bone marrow CD14+ cells of myeloma patients. Our results indicate that bone marrow monocytes from multiple myeloma patients show distinct features compared to those from patients with indolent monoclonal gammopathies, supporting the role of IL21R over-expression by bone marrow CD14+ cells in enhanced osteoclast formation.

Natural killer cell phenotype modulation and natural killer/T-cell interplay in nucleos(t)ide analogue-treated hepatitis e antigen-negative patients with chronic hepatitis B.

UNLABELLED: Natural killer (NK) and hepatitis B virus (HBV)-specific T cells are functionally impaired in chronic hepatitis B (CHB). Understanding to what extent nucleos(t)ide analogue (NUC) therapy can improve T- and NK-cell responses is important in the perspective of immunomonitoring strategies for a safe and earlier NUC withdrawal and of novel combination therapies based on modulation of antiviral immunity. To gain further insights into T/NK-cell interplay, we studied NK-cell phenotype and function in hepatitis B e antigen-negative chronic HBV patients either untreated (25) or NUC treated (36 hepatitis B surface antigen [HBsAg](+) and 10 HBsAg(-)/hepatitis B surface antibody [anti-HBs](+)). Interferon-gamma, interleukin-2, and tumor necrosis factor alpha (TNF-α) production by HBV-specific T cells was also analyzed in NUC-treated patients. NK cells from chronic naïve patients showed an "inflammatory" phenotype defined by increased expression of TNF-related apoptosis-inducing ligand (TRAIL), CD38, and Ki67 that significantly declined upon viremia suppression and alanine aminotransferase normalization induced by NUC therapy. Reversion to a quiescent NK-cell phenotype was associated with restoration of the HBV-specific T-cell function. T- and NK-cell responses showed an inverse correlation, with an opposite behavior in individual NUC-treated patients. NK-cell depletion as well as TRAIL and NKG2D pathway blockade induced a significant improvement of the HBV-specific T-cell function. CONCLUSIONS: NK cells can express regulatory activity on T cells in NUC-treated patients with prevalent inhibition of CD4 T cells, likely needed to limit persistent T-cell activation. NK-cell phenotype is modulated by NUC therapy and its reversion to quiescence mirrors efficient HBV-specific T-cell responses. Thus, changes of NK-cell phenotype may predict acquisition of antiviral control before anti-HBs seroconversion and represent the groundwork for future studies aimed at assessing whether NK phenotyping can be translated into the clinical practice to guide NUC suspension.

Electronic properties of mono-substituted tetraferrocenyl porphyrins in solution and on a gold surface: assessment of the influencing factors for photoelectrochemical applications.

Two unsymmetric meso-tetraferrocenyl-containing porphyrins of general formula Fc3 (FcCOR)Por (Fc=ferrocenyl, R=CH3 or (CH2)5 Br, Por=porphyrin) were prepared and characterized by a variety of spectroscopic methods, whereas their redox properties were investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) approaches. The mixed-valence [Fc3 (FcCOR)Por](n+) (n=1,3) were investigated using spectroelectrochemical as well as chemical oxidation methods and corroborated with density functional theory (DFT) calculations. Inter-valence charge-transfer (IVCT) transitions in [Fc3 (FcCOR)Por](+) were analyzed, and the resulting data matched closely previously reported complexes and were assigned as Robin-Day class II mixed-valence compounds. Self-assembled monolayers (SAMs) of a thioacetyl derivative (Fc3 (FcCO(CH2)5 SCOCH3 )Por) were also prepared and characterized. Photoelectrochemical properties of SAMs in different electrolyte systems were investigated by electrochemical techniques and photocurrent generation experiments, showing that the choice of electrolyte is critical for efficiency of redox-active SAMs.

5,10,15-Triferrocenylcorrole Complexes.

Complexes of 5,10,15-triferrocenylcorrole were synthesized from the crude free-base corrole product obtained by the reaction of ferrocenyl aldehyde and pyrrole. Direct formation of the complex in this manner leads to an increase of the reaction yield by protecting the corrole ring toward oxidative decomposition. The procedure was successful and gave the expected product in the case of the copper and triphenylphosphinecobalt complexes, but an unexpected result was obtained in the case of the nickel derivative, where metal insertion led to a ring opening of the macrocycle at the 5 position, giving as a final product a linear tetrapyrrole nickel complex bearing two ferrocenyl groups. The purified 5,10,15-triferrocenylcorrole complexes have been fully characterized by a combination of spectroscopic methods, electrochemistry, spectroelectrochemistry, and density functional theory calculations. Copper derivatives of 10-monoferrocenyl- and 5,15-diferrocenylcorrole were prepared to investigate how the number and position of the ferrocenyl groups influenced the spectroscopic and electrochemical properties of the resulting complexes. A complete assignment of resonances in the (1)H and (13)C NMR spectra was performed for the cobalt and nickel complexes, and detailed electrochemical characterization was carried out to provide additional insight into the degree of communication between the meso-ferrocenyl groups on the conjugated macrocycle and the central metal ion of the ferrocenylcorrole derivatives.

New example of hemiporphycene formation from the corrole ring expansion.

The reaction of 5,10,15-tris(4-tert-butylphenyl)corrole with 2,3-bis(bromomethyl)-5,6-dicyanopyrazine provides a new example of corrole ring expansion to a hemiporphycene derivative. The ring expansion is regioselective, with insertion of the pyrazine derivative at the 5-position of the corrole ring, affording the corresponding 5-hemiporphycene. Different macrocyclic products accompany formation of the 5-hemiporphycene, depending on the reaction experimental conditions. Br-substitued 5-hemiporphycenes and the 2-Br substituted corrole were obtained in 1,2,4-trichlorobenzene, while in refluxing toluene traces of an inner core substituted corrole were observed together with a significant amount of the unreacted corrole. These results provide an important indication of the reaction pathway. The coordination behavior of the 5-hemiporphycene, together with detailed electrochemical characterization of the free-base and some metal complexes, provides evidence for the reactivity of the peripheral pyrazino group.

PeptiVAX: A new adaptable peptides-delivery platform for development of CTL-based, SARS-CoV-2 vaccines.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) posed a threat to public health and the global economy, necessitating the development of various vaccination strategies. Mutations in the SPIKE protein gene, a crucial component of mRNA and adenovirus-based vaccines, raised concerns about vaccine efficacy, prompting the need for rapid vaccine updates. To address this, we leveraged PeptiCRAd, an oncolytic vaccine based on tumor antigen decorated oncolytic adenoviruses, creating a vaccine platform called PeptiVAX. First, we identified multiple CD8 T-cell epitopes from highly conserved regions across coronaviruses, expanding the range of T-cell responses to non-SPIKE proteins. We designed short segments containing the predicted epitopes presented by common HLA-Is in the global population. Testing the immunogenicity, we characterized T-cell responses to candidate peptides in peripheral blood mononuclear cells (PBMCs) from pre-pandemic healthy donors and ICU patients. As a proof of concept in mice, we selected a peptide with epitopes predicted to bind to murine MHC-I haplotypes. Our technology successfully elicited peptide-specific T-cell responses, unaffected by the use of unarmed adenoviral vectors or adeno-based vaccines encoding SPIKE. In conclusion, PeptiVAX represents a fast and adaptable SARS-CoV-2 vaccine delivery system that broadens T-cell responses beyond the SPIKE protein, offering potential benefits for vaccine effectiveness.

High CD49a+ NK cell infiltrate is associated with poor clinical outcomes in Hepatocellular Carcinoma.

NK cells infiltrating Hepatocellular Carcinoma (HCC) may express residency markers such as Integrin Subunit Alpha 1 (CD49a) that have been associated with nurturing functions in the decidua, and characterized by the production of angiogenic factors as well as loss of cytotoxicity. CIBERSORT, a computational analysis method for quantifying cell fractions from bulk tissue gene expression profiles, was used to estimate the infiltrating immune cell composition of the tumor microenvironment from gene expression profiles of a large cohort of 225 HCCs in the public GEO database. Decidual-like CD49a+ NK cells, in addition to another 22 immune cell populations, were characterized and thoroughly investigated so that HCC cell heterogeneity in a large cohort of 225 HCCs from the public GEO database could be studied. An inverse correlation of the expression of CD49a+ NK-cells and CD8+ T-cells suggested a negative association with clinical outcomes. This result was confirmed in a further validation cohort of 100 HCC patients from The Cancer Genome Atlas, Liver Hepatocellular Carcinoma (TCGA-LIHC). Cox regression analysis did not identify CD49a+ cells as a variable independently associated with survival. However, a more abundant infiltrate of this subset was present in patients at a more advanced pathological and clinical HCC stage. In conclusion, we found that NK cells, with a decidual-like gene expression profile, are enriched in HCC, and their abundance increases not only in tumor size but also at advanced stages of the disease suggesting that these cells play a role in tumor growth. For this reason, these NK cells may represent a possible new target for immunotherapeutic approaches in HCC.

FluoroSpot assay to analyze SARS-CoV-2-specific T cell responses.

Monitoring antigen-specific T cell frequency and function is essential to assess the host immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, we present a FluoroSpot assay for concurrently detecting ex vivo antiviral cytokine production by SARS-CoV-2-specific T cells following peptide stimulation. We then detail intracellular cytokine staining by flow cytometry to further validate the FluoroSpot assay results and define the specific T cell subpopulations. For complete details on the use and execution of this protocol, please refer to Tiezzi et al. (2023).1.