Generation of T-cell receptors targeting a genetically stable and immunodominant cytotoxic T-lymphocyte epitope within hepatitis C virus non-structural protein 3

Hepatitis C virus (HCV) is a major cause of severe liver disease, and one major contributing factor is thought to involve a dysfunction of virus-specific T-cells. T-cell receptor (TCR) gene therapy with HCV-specific TCRs would increase the number of effector T-cells to promote virus clearance. We therefore took advantage of HLA-A2 transgenic mice to generate multiple TCR candidates against HCV using DNA vaccination followed by generation of stable T-cell–BW (T-BW) tumour hybrid cells. Using this approach, large numbers of non-structural protein 3 (NS3)-specific functional T-BW hybrids can be generated efficiently. These predominantly target the genetically stable HCV genotype 1 NS31073–1081 CTL epitope, frequently associated with clearance of HCV in humans. These T-BW hybrid clones recognized the NS31073 peptide with a high avidity. The hybridoma effectively recognized virus variants and targeted cells with low HLA-A2 expression, which has not been reported previously. Importantly, high-avidity murine TCRs effectively redirected human non-HCV-specific T-lymphocytes to recognize human hepatoma cells with HCV RNA replication driven by a subgenomic HCV replicon. Taken together, TCR candidates with a range of functional avidities, which can be used to study immune recognition of HCV-positive targets, have been generated. This has implications for TCR-related immunotherapy against HCV

rBCG Induces Strong Antigen-Specific T Cell Responses in Rhesus Macaques in a Prime-Boost Setting with an Adenovirus 35 Tuberculosis Vaccine Vector

BACKGROUND: BCG vaccination, combined with adenoviral-delivered boosts, represents a reasonable strategy to augment, broaden and prolong immune protection against tuberculosis (TB). We tested BCG (SSI1331) (in 6 animals, delivered intradermally) and a recombinant (rBCG) AFRO-1 expressing perfringolysin (in 6 animals) followed by two boosts (delivered intramuscullary) with non-replicating adenovirus 35 (rAd35) expressing a fusion protein composed of Ag85A, Ag85B and TB10.4, for the capacity to induce antigen-specific cellular immune responses in rhesus macaques (Macaca mulatta). Control animals received diluent (3 animals). METHODS AND FINDINGS: Cellular immune responses were analyzed longitudinally (12 blood draws for each animal) using intracellular cytokine staining (TNF-alpha, IL-2 and IFN-gamma), T cell proliferation was measured in CD4(+), CD8alpha/beta(+), and CD8alpha/alpha(+) T cell subsets and IFN-gamma production was tested in 7 day PBMC cultures (whole blood cell assay, WBA) using Ag85A, Ag85B, TB10.4 recombinant proteins, PPD or BCG as stimuli. Animals primed with AFRO-1 showed i) increased Ag85B-specific IFN-gamma production in the WBA assay (median >400 pg/ml for 6 animals) one week after the first boost with adenoviral-delivered TB-antigens as compared to animals primed with BCG (<200 pg/ml), ii) stronger T cell proliferation in the CD8alpha/alpha(+) T cell subset (proliferative index 17%) as compared to BCG-primed animals (proliferative index 5% in CD8alpha/alpha(+) T cells). Polyfunctional T cells, defined by IFN-gamma, TNF-alpha and IL-2 production were detected in 2/6 animals primed with AFRO-1 directed against Ag85A/b and TB10.4; 4/6 animals primed with BCG showed a Ag85A/b responses, yet only a single animal exhibited Ag85A/b and TB10.4 reactivity. CONCLUSION: AFRO-1 induces qualitatively and quantitatively different cellular immune responses as compared with BCG in rhesus macaques. Increased IFN-gamma-responses and antigen-specific T cell proliferation in the CD8alpha/alpha+ T cell subset represents a valuable marker for vaccine-take in BCG-based TB vaccine trials

Towards a European Health Research and Innovation Cloud (HRIC)

The European Union (EU) initiative on the Digital Transformation of Health and Care (Digicare) aims to provide the conditions necessary for building a secure, flexible, and decentralized digital health infrastructure. Creating a European Health Research and Innovation Cloud (HRIC) within this environment should enable data sharing and analysis for health research across the EU, in compliance with data protection legislation while preserving the full trust of the participants. Such a HRIC should learn from and build on existing data infrastructures, integrate best practices, and focus on the concrete needs of the community in terms of technologies, governance, management, regulation, and ethics requirements. Here, we describe the vision and expected benefits of digital data sharing in health research activities and present a roadmap that fosters the opportunities while answering the challenges of implementing a HRIC. For this, we put forward five specific recommendations and action points to ensure that a European HRIC: i) is built on established standards and guidelines, providing cloud technologies through an open and decentralized infrastructure; ii) is developed and certified to the highest standards of interoperability and data security that can be trusted by all stakeholders; iii) is supported by a robust ethical and legal framework that is compliant with the EU General Data Protection Regulation (GDPR); iv) establishes a proper environment for the training of new generations of data and medical scientists; and v) stimulates research and innovation in transnational collaborations through public and private initiatives and partnerships funded by the EU through Horizon 2020 and Horizon Europe

Pattern Recognition in Pulmonary Tuberculosis Defined by High Content Peptide Microarray Chip Analysis Representing 61 Proteins from M. tuberculosis

Background: Serum antibody-based target identification has been used to identify tumor-associated antigens (TAAs) for development of anti-cancer vaccines. A similar approach can be helpful to identify biologically relevant and clinically meaningful targets in M.tuberculosis (MTB) infection for diagnosis or TB vaccine development in clinically well defined populations. Method: We constructed a high-content peptide microarray with 61 M.tuberculosis proteins as linear 15 aa peptide stretches with 12 aa overlaps resulting in 7446 individual peptide epitopes. Antibody profiling was carried with serum from 34 individuals with active pulmonary TB and 35 healthy individuals in order to obtain an unbiased view of the MTB epitope pattern recognition pattern. Quality data extraction was performed, data sets were analyzed for significant differences and patterns predictive of TB+/2. Findings: Three distinct patterns of IgG reactivity were identified: 89/7446 peptides were differentially recognized (in 34/34 TB+ patients and in 35/35 healthy individuals) and are highly predictive of the division into TB+ and TB2, other targets were exclusively recognized in all patients with TB (e.g. sigmaF) but not in any of the healthy individuals, and a third peptide set was recognized exclusively in healthy individuals (35/35) but no in TB+ patients. The segregation between TB+ and TB2 does no

Atención al paciente oncológico en tiempos de COVID-19

Introduction: with the emergence of the new coronavirus and the wide worldwide distribution, its effects in people with some comorbidities are a global concern. Cancer is a disease with a high incidence and prevalence in society, included among the main causes of mortality.Objective: to describe the management of cancer patients during COVID-19Method: a literature review of articles published up to June 2020 was carried out, using the Pubmed / Medline, SCOPUS and SciELO databases. 28 references were selected for the preparation of the present.Development: cancer has variable clinical and prognostic behaviors that generally lead to states of immunosuppression caused by the therapeutics used for its treatment; Therefore, they are more vulnerable to infectious diseases. The proper care of this group of people is the responsibility of the health systems. Some measures are based on social distancing, either in reducing the number of companions of the patient in the consultation or chemotherapy sessions, the prohibition of visits to hospitalized patients and the use of technologies with the use of teleconsultations for routine follow-up, as well as the change from intravenous to oral treatmentsConclusions: the study of the behavior of COVID-19 in cancer patients is under development. The measures that the institutions take to achieve quality care for people with cancer are varied and are based mainly on social distancing.Introducción: con el surgimiento del nuevo coronavirus y la amplia distribución mundial, es una preocupación global sus efectos en personas con algunas comorbilidades. El cáncer es una enfermedad con alta incidencia y prevalencia en la sociedad, incluida entre las principales causas de mortalidad.Objetivo: describir el manejo del paciente oncológico durante la COVID-19Método: se realizó una revisión de la literatura de artículos publicados hasta junio del 2020, utilizando las bases de datos de Pubmed/Medline, SCOPUS y SciELO. Se seleccionaron 28 referencias para la elaboración de la presente.Desarrollo: el cáncer posee comportamientos clínicos y pronóstico variables que generalmente conllevan a estados de inmunosupresión causada por la terapéutica empleada para su tratamiento; por lo cual presentan mayor vulnerabilidad ante enfermedades infecciosas. Es responsabilidad de los sistemas de salud la correcta atención a este grupo de personas. Algunas medidas se basan en el distanciamiento social, ya sea en la reducción de la cantidad de acompañantes del paciente en la consulta o las sesiones de quimioterapia, la prohibición de las visitas a los pacientes hospitalizados y el empleo de las tecnologías con el uso de las teleconsultas para el seguimiento rutinario, así como el cambio de tratamientos por vía intravenosa a vía oralConclusiones: el estudio del comportamiento de la COVID-19 en pacientes oncológicos está en desarrollo. Las medidas que tomen las instituciones para lograr una atención de calidad a las personas que poseen cáncer son variadas y se basan sobre todo en el distanciamiento social

Opportunistic infections in immunosuppressed patients with juvenile idiopathic arthritis: Analysis by the Pharmachild Safety Adjudication Committee

Background: To derive a list of opportunistic infections (OI) through the analysis of the juvenile idiopathic arthritis (JIA) patients in the Pharmachild registry by an independent Safety Adjudication Committee (SAC). Methods: The SAC (3 pediatric rheumatologists and 2 pediatric infectious disease specialists) elaborated and approved by consensus a provisional list of OI for use in JIA. Through a 5 step-procedure, all the severe and serious infections, classified as per MedDRA dictionary and retrieved in the Pharmachild registry, were evaluated by the SAC by answering six questions and adjudicated with the agreement of 3/5 specialists. A final evidence-based list of OI resulted by matching the adjudicated infections with the provisional list of OI. Results: A total of 772 infectious events in 572 eligible patients, of which 335 serious/severe/very severe non-OI and 437 OI (any intensity/severity), according to the provisional list, were retrieved. Six hundred eighty-two of 772 (88.3%) were adjudicated as infections, of them 603/682 (88.4%) as common and 119/682 (17.4%) as OI by the SAC. Matching these 119 opportunistic events with the provisional list, 106 were confirmed by the SAC as OI, and among them infections by herpes viruses were the most frequent (68%), followed by tuberculosis (27.4%). The remaining events were divided in the groups of non-OI and possible/patient and/or pathogen-related OI. Conclusions: We found a significant number of OI in JIA patients on immunosuppressive therapy. The proposed list of OI, created by consensus and validated in the Pharmachild cohort, could facilitate comparison among future pharmacovigilance studies. Trial registration: Clinicaltrials.gov NCT 01399281; ENCePP seal: awarded on 25 November 2011

CD8alpha/alpha+ T-cells and Immune Memory

A better understanding of T-cell memory formation is crucial for rationale vaccine design and the identification of correlates of immune protection. The CD8alphaalpha homodimer expressed on CD8+ T-cells is not anymore considered to represent a TCR co-receptor, it may rather represent a mechanism to modulate T-cell avidity and identify a subset of memory T-cells. The aim of the work presented in this thesis was to characterize the CD8alphaalpha+ T-cell compartment in the context of vaccination, where Tcell memory plays a pivotal role. We analyzed in Paper I the phenotype of CD8alphaalpha+ Tcells in healthy donors and in rhesus macaque monkeys (Macaca mulatta) which represent a very valuable animal model for preclinical vaccine trials. CD8alphaalpha+ T-cells were present in healthy donors and in a higher frequency in rhesus monkeys. In both species, the CD8alphaalpha+ T-cell compartment was enriched in differentiated (effector and memory) T-cells, as compared to the CD4+ and CD8alphabeta+ T-cell compartments, and displayed a polyfunctional capacity. We developed assays allowing to study the T-cell compartment in rhesus monkeys, and showed that CD8alphaalpha+ T-cells can be studied in rhesus monkeys. In Paper II, we assessed longitudinally the presence of CD8alphaalpha+ Tcells in patients with melanoma who underwent peptide-based vaccination and showed a partial or complete tumor regression. CD8alphaalpha+ T-cells represented a stable population with an effector or terminally differentiated phenotype, and Melan-A/MART-1-specific CD8alphaalpha+ T-cells were detected in one patient up to five years after vaccination. The oligoclonal TCR repertoire of CD8alphaalpha+ T-cells and the similar TCR repertoire of Melan-A/MART-1 of CD8alphaalpha+ and CD8alphabeta+ T-cells, supported our hypothesis that CD8alphaalpha+ T-cells arise from CD8alphabeta+ T-cells which downregulated CD8beta chain expression upon Ag stimulation. We identified, in Paper III, an increase of Mtb-specific CD8alphaalpha+ T-cells in rhesus monkeys after TB vaccination. The characterization of CD8alphaalpha+ T-cells phenotype in rhesus monkeys after TB vaccination and after Mtb infection was further analyzed in Paper IV. CD8alphaalpha+ T-cells underwent similar phenotypical changes as observed in the CD4+ and CD8alphabet + T-cell compartments, in vaccinated but not in non-vaccinated animals: loss of IL-7Ralpha after the first Ad boost, and transient decrease of precursor T-cells (defined by CD45RA/CCR7 expression) after Mtb challenge. These results suggest that CD8alphaalpha+ T-cells contribute to the formation of immunological memory and participate in the formation of the cellular immune response. We hypothesize that the expression of CD8alphaalpha enables to modulate the avidity of CD8+ T-cells with high affinity TCRs. Yet, the mechanisms of CD8alphaalpha+ T-cells formation need to be further elucidated. Altogether, our data underscores the role of CD8alphaalpha+ T-cells in the establishment of immune memory in humans and rhesus monkeys. The detection and characterization of Ag-specific CD8alphaalpha+ T-cells may represent a relevant marker in the context of vaccine trials and to custom-tailor immune therapeutic strategies with the aim to establish long-lived and Ag-specific immune responses

iNKT and MAIT cell alterations in diabetes

International audienceType 1 diabetes (T1D) and type 2 diabetes (T2D) are multifactorial diseases with different etiologies in which chronic inflammation takes place. Defects in invariant natural killer T (iNKT) cell populations have been reported in both T1D and T2D patients, mouse models and our recent study revealed mucosal-associated invariant T (MAIT) cell defects in T2D and obese patients. Regarding iNKT cells many studies in non-obese diabetic mice demonstrated their protective role against T1D whereas their potential role in human T1D is still under debate. Studies in mouse models and patients suggest that iNKT cells present in adipose tissue (AT) could exert a regulatory role against obesity and associated metabolic disorders, such as T2D. Scarce data are yet available on MAIT cells; however, we recently described MAIT cell abnormalities in the blood and ATs from obese and T2D patients. These data show that a link between MAIT cells and metabolic disorders pave the way for further investigations on MAIT cells in T1D and T2D in humans and mouse models. Furthermore, we hypothesize that the gut microbiota alterations associated with T1D and T2D could modulate iNKT and MAIT cell frequency and functions. The potential role of iNKT and MAIT cells in the regulation of metabolic pathways and their cross-talk with microbiota represent exciting new lines of research