Cross-reactive CD8+ T cell responses to tumor-associated antigens (TAAs) and homologous microbiota-derived antigens (MoAs)

BACKGROUND

We have recently shown extensive sequence and conformational homology between tumor-associated antigens (TAAs) and antigens derived from microorganisms (MoAs). The present study aimed to assess the breadth of T-cell recognition specific to MoAs and the corresponding TAAs in healthy subjects (HS) and patients with cancer (CP).

METHOD

A library of > 100 peptide-MHC (pMHC) combinations was used to generate DNA-barcode labelled multimers. Homologous peptides were selected from the Cancer Antigenic Peptide Database, as well as Bacteroidetes/Firmicutes-derived peptides. They were incubated with CD8 + T cells from the peripheral blood of HLA-A*02:01 healthy individuals (n = 10) and cancer patients (n = 16). T cell recognition was identified using tetramer-staining analysis. Cytotoxicity assay was performed using as target cells TAP-deficient T2 cells loaded with MoA or the paired TuA.

RESULTS

A total of 66 unique pMHC recognized by CD8+ T cells across all groups were identified. Of these, 21 epitopes from microbiota were identified as novel immunological targets. Reactivity against selected TAAs was observed for both HS and CP. pMHC tetramer staining confirmed CD8+ T cell populations cross-reacting with CTA SSX2 and paired microbiota epitopes. Moreover, PBMCs activated with the MoA where shown to release IFNγ as well as to exert cytotoxic activity against cells presenting the paired TuA.

CONCLUSIONS

Several predicted microbiota-derived MoAs are recognized by T cells in HS and CP. Reactivity against TAAs was observed also in HS, primed by the homologous bacterial antigens. CD8+ T cells cross-reacting with MAGE-A1 and paired microbiota epitopes were identified in three subjects. Therefore, the microbiota can elicit an extensive repertoire of natural memory T cells to TAAs, possibly able to control tumor growth ("natural anti-cancer vaccination"). In addition, non-self MoAs can be included in preventive/therapeutic off-the-shelf cancer vaccines with more potent anti-tumor efficacy than those based on TAAs.

Chronic Viral Infections and Cancer, Openings for Therapies and Vaccines

Infections are responsible for approximately one out of six cases of cancer worldwide [...].

Integrated plasma metabolomics and lipidomics profiling highlights distinctive signature of hepatocellular carcinoma in HCV patients

BACKGROUND

Early diagnosis of hepatocellular carcinoma (HCC) is essential towards the improvement of prognosis and patient survival. Circulating markers such as α-fetoprotein (AFP) and micro-RNAs represent useful tools but still have limitations. Identifying new markers can be fundamental to improve both diagnosis and prognosis. In this approach, we harness the potential of metabolomics and lipidomics to uncover potential signatures of HCC.

METHODS

A combined untargeted metabolomics and lipidomics plasma profiling of 102 HCV-positive patients was performed by HILIC and RP-UHPLC coupled to Mass Spectrometry. Biochemical parameters of liver function (AST, ALT, GGT) and liver cancer biomarkers (AFP, CA19.9 e CEA) were evaluated by standard assays.

RESULTS

HCC was characterized by an elevation of short and long-chain acylcarnitines, asymmetric dimethylarginine, methylguanine, isoleucylproline and a global reduction of lysophosphatidylcholines. A supervised PLS-DA model showed that the predictive accuracy for HCC class of metabolomics and lipidomics was superior to AFP for the test set (100.00% and 94.40% vs 55.00%). Additionally, the model was applied to HCC patients with AFP values < 20 ng/mL, and, by using only the top 20 variables selected by VIP scores achieved an Area Under Curve (AUC) performance of 0.94.

CONCLUSION

These exploratory findings highlight how metabo-lipidomics enables the distinction of HCC from chronic HCV conditions. The identified biomarkers have high diagnostic potential and could represent a viable tool to support and assist in HCC diagnosis, including AFP-negative patients.

Reactivation of telomerase reverse transcriptase expression in cancer: the role of TERT promoter mutations

Telomerase activity and telomere elongation are essential conditions for the unlimited proliferation of neoplastic cells. Point mutations in the core promoter region of the telomerase reverse transcriptase (TERT) gene have been found to occur at high frequencies in several tumour types and considered a primary cause of telomerase reactivation in cancer cells. These mutations promote TERT gene expression by multiple mechanisms, including the generation of novel binding sites for nuclear transcription factors, displacement of negative regulators from DNA G-quadruplexes, recruitment of epigenetic activators and disruption of long-range interactions between TERT locus and telomeres. Furthermore, TERT promoter mutations cooperate with TPP1 promoter nucleotide changes to lengthen telomeres and with mutated BRAF and FGFR3 oncoproteins to enhance oncogenic signalling in cancer cells. TERT promoter mutations have been recognized as an early marker of tumour development or a major indicator of poor outcome and reduced patients survival in several cancer types. In this review, we summarize recent findings on the role of TERT promoter mutations, telomerase expression and telomeres elongation in cancer development, their clinical significance and therapeutic opportunities.

Microorganisms-derived antigens for preventive anti-cancer vaccines

Cancer prevention is one of the aim with the highest priority in order to reduce the burden of cancer diagnosis and treatment on individuals as well as on healthcare systems. To this aim, vaccines represent the most efficient primary cancer prevention strategy. Indeed, anti-cancer immunological memory elicited by preventive vaccines might promptly expand and prevent tumor from progressing. Antigens derived from microorganisms (MoAs), represent the obvious target for developing highly effective preventive vaccines for virus-induced cancers. In this respect, the drastic reduction in cancer incidence following HBV and HPV preventive vaccines are the paradigmatic example of such evidence. More recently, experimental evidences suggest that MoAs may represent a "natural" anti-cancer preventive vaccination or can be exploited for developing vaccines to prevent cancers presenting highly homologous tumor-associated antigens (TAAs) (e.g. molecular mimicry). The present review describes the different preventive anti-cancer vaccines based on antigens derived from pathogens at the different stages of development.

Proceedings of the Online Conference "Vaccines and Vaccination during and Post COVID Pandemics" (7-9 December 2022)

The COVID-19 pandemic put focus on various aspects of vaccine research and development. These include mass vaccination strategies, vaccination compliance and hesitancy, acceptance of novel vaccine approaches, preclinical and animal models used to assess vaccine safety and efficacy, and many other related issues. These issues were addressed by the international online conference "Vaccines and Vaccination During and Post COVID Pandemics" (VAC&VAC 2022) held on the platform of Riga Stradins University, Riga, Latvia. Conference was supported by the International Society for Vaccines, the National Cancer Institute "Fondazione Pascale" (Naples, Italy), and the scientific journal VACCINES (mdpi). VAC&VAC 2022 attracted nearly 150 participants from 14 countries. This report summarizes conference presentations and their discussion. Sessions covered the topics of (1) COVID-19 vaccine development, evaluation, and attitude towards these vaccines, (2) HPV and cancer vaccines, (3) progress and challenges of HIV vaccine development, (4) new and re-emerging infectious threats, and (5) novel vaccine vehicles, adjuvants, and carriers. Each session was introduced by a plenary lecture from renowned experts from leading research institutions worldwide. The conference also included sessions on research funding and grant writing and an early career researcher contest in which the winners received monetary awards and a chance to publish their results free of charge in the special issue of VACCINES covering the meeting.

Molecular mimicry and cancer vaccine development

BACKGROUND

The development of cancer immunotherapeutic strategies relies on the identification and validation of optimal target tumor antigens, which should be tumor-specific as well as able to elicit a swift and potent anti-tumor immune response. The vast majority of such strategies are based on tumor associated antigens (TAAs) which are shared wild type cellular self-epitopes highly expressed on tumor cells. Indeed, TAAs can be used to develop off-the-shelf cancer vaccines appropriate to all patients affected by the same malignancy. However, given that they may be also presented by HLAs on the surface of non-malignant cells, they may be possibly affected by immunological tolerance or elicit autoimmune responses.

MAIN BODY

In order to overcome such limitations, analogue peptides with improved antigenicity and immunogenicity able to elicit a cross-reactive T cell response are needed. To this aim, non-self-antigens derived from microorganisms (MoAs) may be of great benefit.

Immune profiling of SARS-CoV-2 epitopes in asymptomatic and symptomatic pediatric and adult patients

BACKGROUND

The infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has unpredictable manifestations of coronavirus disease (COVID-19) and variable clinical course with some patients being asymptomatic whereas others experiencing severe respiratory distress, or even death. We aimed to evaluate the immunoglobulin G (IgG) response towards linear peptides on a peptide array containing sequences from SARS-CoV-2, Middle East respiratory syndrome-related coronavirus (MERS) and common-cold coronaviruses 229E, OC43, NL63 and HKU1 antigens, in order to identify immunological indicators of disease outcome in SARS-CoV-2 infected patients.

METHODS

We included in the study 79 subjects, comprising 19 pediatric and 30 adult SARS-CoV-2 infected patients with increasing disease severity, from mild to critical illness, and 30 uninfected subjects who were vaccinated with one dose of SARS-CoV-2 spike mRNA BNT162b2 vaccine. Serum samples were analyzed by a peptide microarray containing 5828 overlapping 15-mer synthetic peptides corresponding to the full SARS-CoV-2 proteome and selected linear epitopes of spike (S), envelope (E) and membrane (M) glycoproteins as well as nucleoprotein (N) of MERS, SARS and coronaviruses 229E, OC43, NL63 and HKU1 (isolates 1, 2 and 5).

RESULTS

All patients exhibited high IgG reactivity against the central region and C-terminus peptides of both SARS-CoV-2 N and S proteins. Setting the threshold value for serum reactivity above 25,000 units, 100% and 81% of patients with severe disease, 36% and 29% of subjects with mild symptoms, and 8% and 17% of children younger than 8-years reacted against N and S proteins, respectively. Overall, the total number of peptides in the SARS-CoV-2 proteome targeted by serum samples was much higher in children compared to adults. Notably, we revealed a differential antibody response to SARS-CoV-2 peptides of M protein between adults, mainly reacting against the C-terminus epitopes, and children, who were highly responsive to the N-terminus of M protein. In addition, IgG signals against NS7B, NS8 and ORF10 peptides were found elevated mainly among adults with mild (63%) symptoms. Antibodies towards S and N proteins of other coronaviruses (MERS, 229E, OC43, NL63 and HKU1) were detected in all groups without a significant correlation with SARS-CoV-2 antibody levels.

CONCLUSIONS

Overall, our results showed that antibodies elicited by specific linear epitopes of SARS-CoV-2 proteome are age dependent and related to COVID-19 clinical severity. Cross-reaction of antibodies to epitopes of other human coronaviruses was evident in all patients with distinct profiles between children and adult patients. Several SARS-CoV-2 peptides identified in this study are of particular interest for the development of vaccines and diagnostic tests to predict the clinical outcome of SARS-CoV-2 infection.

The Molecular Interplay between Human Oncoviruses and Telomerase in Cancer Development

Human oncoviruses are able to subvert telomerase function in cancer cells through multiple strategies. The activity of the catalytic subunit of telomerase (TERT) is universally enhanced in virus-related cancers. Viral oncoproteins, such as high-risk human papillomavirus (HPV) E6, Epstein-Barr virus (EBV) LMP1, Kaposi's sarcoma-associated herpesvirus (HHV-8) LANA, hepatitis B virus (HBV) HBVx, hepatitis C virus (HCV) core protein and human T-cell leukemia virus-1 (HTLV-1) Tax protein, interact with regulatory elements in the infected cells and contribute to the transcriptional activation of TERT gene. Specifically, viral oncoproteins have been shown to bind TERT promoter, to induce post-transcriptional alterations of TERT mRNA and to cause epigenetic modifications, which have important effects on the regulation of telomeric and extra-telomeric functions of the telomerase. Other viruses, such as herpesviruses, operate by integrating their genomes within the telomeres or by inducing alternative lengthening of telomeres (ALT) in non-ALT cells. In this review, we recapitulate on recent findings on virus-telomerase/telomeres interplay and the importance of TERT-related oncogenic pathways activated by cancer-causing viruses.

Antigenic molecular mimicry in viral-mediated protection from cancer: the HIV case

Background

People living with HIV/AIDS (PLWHA) show a reduced incidence for three cancer types, namely breast, prostate and colon cancers. In the present study, we assessed whether a molecular mimicry between HIV epitopes and tumor associated antigens and, consequently, a T cell cross-reactivity could provide an explanation for such an epidemiological evidence.

Methods

Homology between published TAAs and non-self HIV-derived epitopes have been assessed by BLAST homology. Structural analyses have been performed by bioinformatics tools. Immunological validation of CD8⁺ T cell cross-reactivity has been evaluated ex vivo by tetramer staining.

Findings

Sequence homologies between multiple TAAs and HIV epitopes have been found. High structural similarities between the paired TAAs and HIV epitopes as well as comparable patterns of contact with HLA and TCR α and β chains have been observed. Furthermore, cross-reacting CD8⁺ T cells have been identified.

Interpretation

This is the first study showing a molecular mimicry between HIV antigens an TAAs identified in breast, prostate and colon cancers. Therefore, it is highly reasonable that memory CD8⁺ T cells elicited during the HIV infection may play a key role in controlling development and progression of such cancers in the PLWHA lifetime. This represents the first demonstration ever that a viral infection may induce a natural “preventive” anti-cancer memory T cells, with highly relevant implications beyond the HIV infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03681-4.

Molecular mimicry between tumor associated antigens and microbiota-derived epitopes

Background

The gut microbiota profile is unique for each individual and are composed by different bacteria species according to individual birth-to-infant transitions. In the last years, the local and systemic effects of microbiota on cancer onset, progression and response to treatments, such as immunotherapies, has been extensively described. Here we offer a new perspective, proposing a role for the microbiota based on the molecular mimicry of tumor associated antigens by microbiome-associated antigens.

Methods

In the present study we looked for homology between published TAAs and non-self microbiota-derived epitopes. Blast search for sequence homology was combined with extensive bioinformatics analyses.

Results

Several evidences for homology between TAAs and microbiota-derived antigens have been found. Strikingly, three cases of 100% homology between the paired sequences has been identified. The predicted average affinity to HLA molecules of microbiota-derived antigens is very high (< 100 nM). The structural conformation of the microbiota-derived epitopes is, in general, highly similar to the corresponding TAA. In some cases, it is identical and contact areas with both HLA and TCR chains are indistinguishable. Moreover, the spatial conformation of TCR-facing residues can be identical in paired TAA and microbiota-derived epitopes, with exactly the same values of planar as well as dihedral angles.

Conclusions

The data reported in the present study show for the first time the high homology in the linear sequence as well as in structure and conformation between TAAs and peptides derived from microbiota species of the Firmicutes and the Bacteroidetes phyla, which together account for 90% of gut microbiota. Cross-reacting CD8⁺ T cell responses are very likely induced. Therefore, the anti-microbiota T cell memory may turn out to be an anti-cancer T cell memory, able to control the growth of a cancer developed during the lifetime if the expressed TAA is similar to the microbiota epitope. This may ultimately represent a relevant selective advantage for cancer patients and may lead to a novel preventive anti-cancer vaccine strategy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03512-6.

An overview of "Chronic viral infection and cancer, openings for vaccines" virtual symposium of the TechVac Network - December 16-17, 2021

This is a report on the research activities currently ongoing in virology, oncology and virus-associated cancers and possibilities of their treatment and prevention by vaccines and immunotherapies as outlined at the symposium “Chronic viral infection and cancer, openings for vaccines” virtually held on December 16–17, 2021. Experts from the various disciplines involved in the study of the complex relationships between solid tumors and viruses met to discuss recent developments in the field and to report their personal contributions to the specified topics. Secondary end point was to sustain the TECHVAC Network established in 2016 as a multidisciplinary work group specifically devoted to development of vaccines and immunotherapies against chronic viral infections and associated cancers, with the aim to identify areas of common interest, promote research cooperation, establish collaborative cross-border programs and projects, and to coordinate clinical and research activities.

Mutations in the telomerase reverse transcriptase promoter and PIK3CA gene are common events in penile squamous cell carcinoma of Italian and Ugandan patients

Penile carcinoma develops either through human papillomavirus (HPV) related or unrelated carcinogenic pathways. Genetic alterations and nucleotide changes in coding regions (ie, TP53, CDKN2A, PIK3CA and NOTCH1) are main cancer driver events either in HPV positive or in HPV negative tumours. We investigated the presence of hotspot nucleotide mutations in TERT promoter (TERTp) and PIK3CA exon 9 and their relationship with HPV status in 69 penile cancer cases from Italian and Ugandan patients. Genetic variations and viral sequences have been characterised by end‐point polymerase chain reaction (PCR) and Sanger sequencing. The mutant allele frequencies (MAFs) of TERTp −124A/−146A and PIK3CA E545K have been determined by droplet digital PCR (ddPCR) assays. The results showed that TERTp mutations are highly prevalent in penile carcinoma (53.6%) and significantly more frequent in HPV negative (67.6%) than HPV positive (32.4%) cases (P = .0482). PIK3CA mutations were similarly distributed in virus‐related and unrelated cases (25.9% and 26.7%, respectively) and coexisted with TERTp changes in 15.8% of penile carcinoma samples. Notably, MAFs of co‐occurring mutations were frequently discordant indicating that PIK3CA E545K nucleotide changes are subsequent genetic events occurring in subclones of TERTp mutated cells. The frequencies of TERTp and PIK3CA mutations were higher among Italian compared to Ugandan cases and inversely correlated with the HPV status. In conclusion, TERTp mutations are very common in penile carcinoma and their coexistence with PIK3CA in a substantial number of cases may represent a novel oncogenic synergy relevant for patient stratification and use of therapeutic strategies against new actionable targets.

Long-term memory T cells as preventive anticancer immunity elicited by TuA-derived heteroclitic peptides

The host's immune system may be primed against antigens during the lifetime (e.g. microorganisms antigens-MoAs), and swiftly recalled upon growth of a tumor expressing antigens similar in sequence and structure. C57BL/6 mice were immunized in a preventive setting with tumor antigens (TuAs) or corresponding heteroclitic peptides specific for TC-1 and B16 cell lines. Immediately or 2-months after the end of the vaccination protocol, animals were implanted with cell lines. The specific anti-vaccine immune response as well as tumor growth were regularly evaluated for 2 months post-implantation. The preventive vaccination with TuA or their heteroclitic peptides (hPep) was able to delay (B16) or completely suppress (TC-1) tumor growth when cancer cells were implanted immediately after the end of the vaccination. More importantly, TC-1 tumor growth was significantly delayed, and suppressed in 6/8 animals, also when cells were implanted 2-months after the end of the vaccination. The vaccine-specific T cell response provided a strong immune correlate to the pattern of tumor growth. A preventive immunization with heteroclitic peptides resembling a TuA is able to strongly delay or even suppress tumor growth in a mouse model. More importantly, the same effect is observed also when tumor cells are implanted 2 months after the end of vaccination, which corresponds to 8 - 10 years in human life. The observed potent tumor control indicates that a memory T cell immunity elicited during the lifetime by a antigens similar to a TuA, i.e. viral antigens, may ultimately represent a great advantage for cancer patients and may lead to a novel preventive anti-cancer vaccine strategy.

MHC-Optimized Peptide Scaffold for Improved Antigen Presentation and Anti-Tumor Response

Tumor Associated Antigens (TAAs) may suffer from an immunological tolerance due to expression on normal cells. In order to potentiate their immunogenicity, heteroclitic peptides (htcPep) were designed according to prediction algorithms. In particular, specific modifications were introduced in peptide residues facing to TCR. Moreover, a MHC-optimized scaffold was designed for improved antigen presentation to TCR by H-2Db allele. The efficacy of such htcPep was assessed in C57BL/6 mice injected with syngeneic melanoma B16F10 or lung TC1 tumor cell lines, in combination with metronomic chemotherapy and immune checkpoint inhibitors. The immunogenicity of htcPep was significantly stronger than the corresponding wt peptide and the modification involving both MHC and TCR binding residues scored the strongest. In particular, the H-2Db-specific scaffold significantly potentiated the peptides' immunogenicity and control of tumor growth was comparable to wt peptide in a therapeutic setting. Overall, we demonstrated that modified TAAs show higher immunogenicity compared to wt peptide. In particular, the MHC-optimized scaffold can present different antigen sequences to TCR, retaining the conformational characteristics of the corresponding wt. Cross-reacting CD8+ T cells are elicited and efficiently kill tumor cells presenting the wild-type antigen. This novel approach can be of high clinical relevance in cancer vaccine development.

HLA Does Not Impact on Short-Medium-Term Antibody Response to Preventive Anti-SARS-Cov-2 Vaccine

The response to anti-SARS-Cov-2 preventive vaccine shows high interpersonal variability at short and medium term. One of the explanations might be the individual HLA allelic variants. Indeed, B cell response is stimulated and sustained by CD4⁺ T helper cells activated by antigens presented by HLA-class II alleles on antigen-presenting cells (APCs). The impact of the number of antigens binding to HLA class-II alleles on the antibody response to the COVID vaccine has been assessed in a cohort of 56 healthcare workers who received the full schedule of the Pfizer-BioNTech BNT162b2 vaccine. Such vaccine is based on the entire spike protein of the SARS-CoV-2. Ab titers have been evaluated 2 weeks after the first dose as well as 2 weeks and 4 months after the boosting dose. HLA-DRB1 and DBQ1 for each of the vaccinees have been assessed, and strong binders have been predicted. The analysis showed no significant correlation between the short-medium-term Ab titers and the number of strong binders (SB) for each individual. These results indicate that levels of Ab response to the spike glycoprotein is not dependent on HLA class II allele, suggesting an equivalent efficacy at global level of the currently used vaccines. Furthermore, the pattern of persistence in Ab titer does not correlate with specific alleles or with the number of SBs.

Identification and validation of viral antigens sharing sequence and structural homology with tumor-associated antigens (TAAs)

Background

The host’s immune system develops in equilibrium with both cellular self-antigens and non-self-antigens derived from microorganisms which enter the body during lifetime. In addition, during the years, a tumor may arise presenting to the immune system an additional pool of non-self-antigens, namely tumor antigens (tumor-associated antigens, TAAs; tumor-specific antigens, TSAs).

Methods

In the present study, we looked for homology between published TAAs and non-self-viral-derived epitopes. Bioinformatics analyses and ex vivo immunological validations have been performed.

Results

Surprisingly, several of such homologies have been found. Moreover, structural similarities between paired TAAs and viral peptides as well as comparable patterns of contact with HLA and T cell receptor (TCR) α and β chains have been observed. Therefore, the two classes of non-self-antigens (viral antigens and tumor antigens) may converge, eliciting cross-reacting CD8⁺ T cell responses which possibly drive the fate of cancer development and progression.

Conclusions

An established antiviral T cell memory may turn out to be an anticancer T cell memory, able to control the growth of a cancer developed during the lifetime if the expressed TAA is similar to the viral epitope. This may ultimately represent a relevant selective advantage for patients with cancer and may lead to a novel preventive anticancer vaccine strategy.

Genetic instability and anti-HPV immune response as drivers of infertility associated with HPV infection

Human papillomavirus (HPV) is a sexually transmitted infection common among men and women of reproductive age worldwide. HPV viruses are associated with epithelial lesions and cancers. HPV infections have been shown to be significantly associated with many adverse effects in reproductive function. Infection with HPVs, specifically of high-oncogenic risk types (HR HPVs), affects different stages of human reproduction, resulting in a series of adverse outcomes: 1) reduction of male fertility (male infertility), characterized by qualitative and quantitative semen alterations; 2) impairment of couple fertility with increase of blastocyst apoptosis and reduction of endometrial implantation of trophoblastic cells; 3) defects of embryos and fetal development, with increase of spontaneous abortion and spontaneous preterm birth. The actual molecular mechanism(s) by which HPV infection is involved remain unclear. HPV-associated infertility as Janus, has two faces: one reflecting anti-HPV immunity, and the other, direct pathogenic effects of HPVs, specifically, of HR HPVs on the infected/HPV-replicating cells. Adverse effects observed for HR HPVs differ depending on the genotype of infecting virus, reflecting differential response of the host immune system as well as functional differences between HPVs and their individual proteins/antigens, including their ability to induce genetic instability/DNA damage. Review summarizes HPV involvement in all reproductive stages, evaluate the adverse role(s) played by HPVs, and identifies mechanisms of viral pathogenicity, common as well as specific for each stage of the reproduction process.

PDCD1 and IFNL4 genetic variants and risk of developing hepatitis C virus-related diseases

BACKGROUND

Genetic variants of IFNL4 and PDCD1 genes have been shown to influence the spontaneous clearance of hepatitis C virus (HCV) infection. We investigated the IFNL4 rs12979860 and the PDCD1 polymorphisms in 734 HCV-positive patients, including 461 cases with liver disease of varying severity and 273 patients with lymphoproliferative disorders to determine the association of these genes with patient's outcome.

METHODS

Expression levels of PDCD1 mRNA encoded by haplotypes were investigated by quantitative PCR in hepatocellular carcinoma (HCC) tissue and peripheral blood mononuclear cells. Flow cytometry was used to detect PD-1 and its ligand PD-L1.

RESULTS

The frequency of IFNL4 rs12979860 C/T or T/T genotypes was significantly higher in patients with HCV-related diseases than blood donors (P < .0001). Patients expressing the IFNλ4 variant with one amino acid change that reduces IFNλ4 secretion was found increased in frequency in HCV-related diseases compared to HCC PDCD1 mRNA levels in HCC tissue were significantly higher in cases carrying the PD-1.3 A or the PD-1.7 G allele (P = .0025 and P = .0167). Linkage disequilibrium (LD) between PD-1.3 and IFNL4 was found in patients with mixed cryoglobulinaemia (MC) only (LD = 0 in HCC; LD = 72 in MC). PBMCs of MC patients expressed low levels of PD-L1 in CD19+IgM+B cells and of PD-1 in CD4+T cells suggesting the involvement of regulatory B cell-T cell interaction to the pathogenesis of MC.

CONCLUSION

Collectively, our data indicate an important contribution of IFNλ4 expression to the development of HCV-related HCC and an epistatic contribution of IFNL4 and PDCD1 in MC.

LAY SUMMARY

Studies of IFNL4 and PDCD1 genes are helpful to better understand the role of host genetic factors and immune antigens influencing the outcome of HCV-related diseases. Our data support an association between the expression of IFNλ4, which prevents the expression of IFNλ3, with all the different HCV-related diseases studied, and besides, evidence that a higher IFNλ4 expression is associated with hepatocellular at a younger age. The expression pattern of low PD-L1 on B cells and high PD-1 on CD4+T-cells in patients with HCV-positive cryoglobulinaemia suggests a critical role of the PD-1/PD-L1 signaling in modulating B cell-T cell interaction in this lymphoproliferative disease.

The clinical and translational research activities at the INT - IRCCS "Fondazione Pascale" cancer center (Naples, Italy) during the COVID-19 pandemic

COVID-19 pandemic following the outbreak in China and Western Europe, where it finally lost the momentum, is now devastating North and South America. It has not been identified the reason and the molecular mechanisms of the two different patterns of the pulmonary host responses to the virus from a minimal disease in young subjects to a severe distress syndrome (ARDS) in older subjects, particularly those with previous chronic diseases (including diabetes) and cancer. The Management of the Istituto Nazionale Tumori - IRCCS "Fondazione Pascale" in Naples (INT-Pascale), along with all Health professionals decided not to interrupt the treatment of those hospitalized and to continue, even if after a careful triage in order not to allow SARS-CoV-2 positive subjects to access, to take care of cancer patients with serious conditions. Although very few (n = 3) patients developed a symptomatic COVID-19 and required the transfer to a COVID-19 area of the Institute, no patients died during the hospitalization and completed their oncology treatment. Besides monitoring of the patients, all employees of the Institute (physicians, nurses, researchers, lawyers, accountants, gatekeepers, guardians, janitors) have been tested for a possible exposure. Personnel identified as positive, has been promptly subjected to home quarantine and subdued to health surveillance. One severe case of respiratory distress has been reported in a positive employees and one death of a family member. Further steps to home monitoring of COVID-19 clinical course have been taken with the development of remote Wi-Fi connected digital devices for the detection of early signs of respiratory distress, including heart rate and oxygen saturation.In conclusion cancer care has been performed and continued safely also during COVID-19 pandemic and further remote home strategies are in progress to ensure the appropriate monitoring of cancer patients.

The Role of RNA Splicing Factors in Cancer: Regulation of Viral and Human Gene Expression in Human Papillomavirus-Related Cervical Cancer

The spliceosomal complex components, together with the heterogeneous nuclear ribonucleoproteins (hnRNPs) and serine/arginine-rich (SR) proteins, regulate the process of constitutive and alternative splicing, the latter leading to the production of mRNA isoforms coding multiple proteins from a single pre-mRNA molecule. The expression of splicing factors is frequently deregulated in different cancer types causing the generation of oncogenic proteins involved in cancer hallmarks. Cervical cancer is caused by persistent infection with oncogenic human papillomaviruses (HPVs) and constitutive expression of viral oncogenes. The aberrant activity of hnRNPs and SR proteins in cervical neoplasia has been shown to trigger the production of oncoproteins through the processing of pre-mRNA transcripts either derived from human genes or HPV genomes. Indeed, hnRNP and SR splicing factors have been shown to regulate the production of viral oncoprotein isoforms necessary for the completion of viral life cycle and for cell transformation. Target-therapy strategies against hnRNPs and SR proteins, causing simultaneous reduction of oncogenic factors and inhibition of HPV replication, are under development. In this review, we describe the current knowledge of the functional link between RNA splicing factors and deregulated cellular as well as viral RNA maturation in cervical cancer and the opportunity of new therapeutic strategies.

Knowledge-based repositioning of the anti-HCV direct antiviral agent Sofosbuvir as SARS-CoV-2 treatment

The new human coronavirus named SARS-CoV-2 is a positive-sense RNA virus for which no specific drugs are currently available. A knowledge-based analysis strongly suggests a possible repositioning of the anti-HCV direct antiviral agent (DAA) Sofosbuvir as treatment for SARS-CoV-2. Indeed, the RNA-dependent RNA-polymerases (RdRp) of the two viruses show high sequence and structural homology, supporting the likelihood of binding the Sofosbuvir molecule with similar efficiency. Such a repositioning would allow the containment of the SARS-CoV-2 pandemic and limit the progression of disease to potentially deadly COVID19.

SARS-CoV-2 RNA polymerase as target for antiviral therapy

A new human coronavirus named SARS-CoV-2 was identified in several cases of acute respiratory syndrome in Wuhan, China in December 2019. On March 11 2020, WHO declared the SARS-CoV-2 infection to be a pandemic, based on the involvement of 169 nations. Specific drugs for SARS-CoV-2 are obviously not available. Currently, drugs originally developed for other viruses or parasites are currently in clinical trials based on empiric data. In the quest of an effective antiviral drug, the most specific target for an RNA virus is the RNA-dependent RNA-polymerase (RdRp) which shows significant differences between positive-sense and negative-sense RNA viruses. An accurate evaluation of RdRps from different viruses may guide the development of new drugs or the repositioning of already approved antiviral drugs as treatment of SARS-CoV-2. This can accelerate the containment of the SARS-CoV-2 pandemic and, hopefully, of future pandemics due to other emerging zoonotic RNA viruses.

Nanoparticles to Improve the Efficacy of Peptide-Based Cancer Vaccines

Nanoparticles represent a potent antigen presentation and delivery system to elicit an optimal immune response by effector cells targeting tumor-associated antigens expressed by cancer cells. Many types of nanoparticles have been developed, such as polymeric complexes, liposomes, micelles and protein-based structures such as virus like particles. All of them show promising results for immunotherapy approaches. In particular, the immunogenicity of peptide-based cancer vaccines can be significantly potentiated by nanoparticles. Indeed, nanoparticles are able to enhance the targeting of antigen-presenting cells (APCs) and trigger cytokine production for optimal T cell response. The present review summarizes the categories of nanoparticles and peptide cancer vaccines which are currently under pre-clinical evaluation.