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1.
Nat Immunol ; 23(9): 1324-1329, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36038709

RESUMEN

T cells can contribute to clearance of respiratory viruses that cause acute-resolving infections such as SARS-CoV-2, helping to provide long-lived protection against disease. Recent studies have suggested an additional role for T cells in resisting overt infection: pre-existing cross-reactive responses were preferentially enriched in healthcare workers who had abortive infections1, and in household contacts protected from infection2. We hypothesize that such early viral control would require pre-existing cross-reactive memory T cells already resident at the site of infection; such airway-resident responses have been shown to be critical for mediating protection after intranasal vaccination in a murine model of SARS-CoV3. Bronchoalveolar lavage samples from the lower respiratory tract of healthy donors obtained before the COVID-19 pandemic revealed airway-resident, SARS-CoV-2-cross-reactive T cells, which correlated with the strength of human seasonal coronavirus immunity. We therefore demonstrate the potential to harness functional airway-resident SARS-CoV-2-reactive T cells in next-generation mucosal vaccines.


Asunto(s)
COVID-19 , SARS-CoV-2 , Animales , Anticuerpos Antivirales , Reacciones Cruzadas , Humanos , Ratones , Pandemias , Sistema Respiratorio
2.
Nat Immunol ; 21(6): 684-694, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32231301

RESUMEN

Aging is associated with remodeling of the immune system to enable the maintenance of life-long immunity. In the CD8+ T cell compartment, aging results in the expansion of highly differentiated cells that exhibit characteristics of cellular senescence. Here we found that CD27-CD28-CD8+ T cells lost the signaling activity of the T cell antigen receptor (TCR) and expressed a protein complex containing the agonistic natural killer (NK) receptor NKG2D and the NK adaptor molecule DAP12, which promoted cytotoxicity against cells that expressed NKG2D ligands. Immunoprecipitation and imaging cytometry indicated that the NKG2D-DAP12 complex was associated with sestrin 2. The genetic inhibition of sestrin 2 resulted in decreased expression of NKG2D and DAP12 and restored TCR signaling in senescent-like CD27-CD28-CD8+ T cells. Therefore, during aging, sestrins induce the reprogramming of non-proliferative senescent-like CD27-CD28-CD8+ T cells to acquire a broad-spectrum, innate-like killing activity.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Senescencia Celular/inmunología , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Proteínas Nucleares/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Citotoxicidad Inmunológica , Perfilación de la Expresión Génica , Humanos , Proteínas de la Membrana/metabolismo , Subfamilia K de Receptores Similares a Lectina de Células NK/metabolismo , Proteínas Nucleares/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores de Células Asesinas Naturales/metabolismo , Transducción de Señal , Fiebre Amarilla/genética , Fiebre Amarilla/inmunología , Fiebre Amarilla/metabolismo , Fiebre Amarilla/virología , Virus de la Fiebre Amarilla/inmunología
3.
Nature ; 614(7947): 334-342, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36697826

RESUMEN

The liver is bathed in bacterial products, including lipopolysaccharide transported from the intestinal portal vasculature, but maintains a state of tolerance that is exploited by persistent pathogens and tumours1-4. The cellular basis mediating this tolerance, yet allowing a switch to immunity or immunopathology, needs to be better understood for successful immunotherapy of liver diseases. Here we show that a variable proportion of CD8+ T cells compartmentalized in the human liver co-stain for CD14 and other prototypic myeloid membrane proteins and are enriched in close proximity to CD14high myeloid cells in hepatic zone 2. CD14+CD8+ T cells preferentially accumulate within the donor pool in liver allografts, among hepatic virus-specific and tumour-infiltrating responses, and in cirrhotic ascites. CD14+CD8+ T cells exhibit increased turnover, activation and constitutive immunomodulatory features with high homeostatic IL-10 and IL-2 production ex vivo, and enhanced antiviral/anti-tumour effector function after TCR engagement. This CD14+CD8+ T cell profile can be recapitulated by the acquisition of membrane proteins-including the lipopolysaccharide receptor complex-from mononuclear phagocytes, resulting in augmented tumour killing by TCR-redirected T cells in vitro. CD14+CD8+ T cells express integrins and chemokine receptors that favour interactions with the local stroma, which can promote their induction through CXCL12. Lipopolysaccharide can also increase the frequency of CD14+CD8+ T cells in vitro and in vivo, and skew their function towards the production of chemotactic and regenerative cytokines. Thus, bacterial products in the gut-liver axis and tissue stromal factors can tune liver immunity by driving myeloid instruction of CD8+ T cells with immunomodulatory ability.


Asunto(s)
Linfocitos T CD8-positivos , Tolerancia Inmunológica , Receptores de Lipopolisacáridos , Lipopolisacáridos , Hígado , Células Mieloides , Humanos , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Receptores de Lipopolisacáridos/metabolismo , Lipopolisacáridos/inmunología , Lipopolisacáridos/farmacología , Células Mieloides/inmunología , Células Mieloides/metabolismo , Neoplasias/inmunología , Neoplasias/patología , Receptores de Antígenos de Linfocitos T/inmunología , Receptores de Antígenos de Linfocitos T/metabolismo , Tolerancia Inmunológica/efectos de los fármacos , Tolerancia Inmunológica/inmunología , Hígado/efectos de los fármacos , Hígado/inmunología , Hígado/patología , Hígado/virología , Interleucina-2/biosíntesis , Interleucina-2/inmunología , Quimiotaxis de Leucocito , Bacterias/inmunología , Intestinos/inmunología , Intestinos/microbiología
4.
Nature ; 601(7891): 110-117, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34758478

RESUMEN

Individuals with potential exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) do not necessarily develop PCR or antibody positivity, suggesting that some individuals may clear subclinical infection before seroconversion. T cells can contribute to the rapid clearance of SARS-CoV-2 and other coronavirus infections1-3. Here we hypothesize that pre-existing memory T cell responses, with cross-protective potential against SARS-CoV-2 (refs. 4-11), would expand in vivo to support rapid viral control, aborting infection. We measured SARS-CoV-2-reactive T cells, including those against the early transcribed replication-transcription complex (RTC)12,13, in intensively monitored healthcare workers (HCWs) who tested repeatedly negative according to PCR, antibody binding and neutralization assays (seronegative HCWs (SN-HCWs)). SN-HCWs had stronger, more multispecific memory T cells compared with a cohort of unexposed individuals from before the pandemic (prepandemic cohort), and these cells were more frequently directed against the RTC than the structural-protein-dominated responses observed after detectable infection (matched concurrent cohort). SN-HCWs with the strongest RTC-specific T cells had an increase in IFI27, a robust early innate signature of SARS-CoV-2 (ref. 14), suggesting abortive infection. RNA polymerase within RTC was the largest region of high sequence conservation across human seasonal coronaviruses (HCoV) and SARS-CoV-2 clades. RNA polymerase was preferentially targeted (among the regions tested) by T cells from prepandemic cohorts and SN-HCWs. RTC-epitope-specific T cells that cross-recognized HCoV variants were identified in SN-HCWs. Enriched pre-existing RNA-polymerase-specific T cells expanded in vivo to preferentially accumulate in the memory response after putative abortive compared to overt SARS-CoV-2 infection. Our data highlight RTC-specific T cells as targets for vaccines against endemic and emerging Coronaviridae.


Asunto(s)
Infecciones Asintomáticas , COVID-19/inmunología , COVID-19/virología , ARN Polimerasas Dirigidas por ADN/inmunología , Células T de Memoria/inmunología , SARS-CoV-2/inmunología , Seroconversión , Proliferación Celular , Estudios de Cohortes , ARN Polimerasas Dirigidas por ADN/metabolismo , Evolución Molecular , Femenino , Personal de Salud , Humanos , Masculino , Proteínas de la Membrana/inmunología , Células T de Memoria/citología , Complejos Multienzimáticos/inmunología , SARS-CoV-2/enzimología , SARS-CoV-2/crecimiento & desarrollo , Transcripción Genética/inmunología
6.
Semin Immunol ; 70: 101828, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37651850

RESUMEN

Efficient immune protection against viruses such as SARS-CoV-2 requires the coordinated activity of innate immunity, B and T cells. Accumulating data point to a critical role for T cells not only in the clearance of established infection, but also for aborting viral replication independently of humoral immunity. Here we review the evidence supporting the contribution of antiviral T cells and consider which of their qualitative features favour efficient control of infection. We highlight how studies of SARS-CoV-2 and other coronaviridae in animals and humans have provided important lessons on the optimal timing (When), functionality and specificity (Which), and location (Where) of antiviral T cells. We discuss the clinical implications, particularly for the development of next-generation vaccines, and emphasise areas requiring further study.


Asunto(s)
COVID-19 , SARS-CoV-2 , Animales , Humanos , Linfocitos T , Inmunidad Humoral , Antivirales , Vacunación , Anticuerpos Antivirales
7.
PLoS Pathog ; 19(5): e1011323, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37134108

RESUMEN

The severity of disease following infection with SARS-CoV-2 is determined by viral replication kinetics and host immunity, with early T cell responses and/or suppression of viraemia driving a favourable outcome. Recent studies uncovered a role for cholesterol metabolism in the SARS-CoV-2 life cycle and in T cell function. Here we show that blockade of the enzyme Acyl-CoA:cholesterol acyltransferase (ACAT) with Avasimibe inhibits SARS-CoV-2 pseudoparticle infection and disrupts the association of ACE2 and GM1 lipid rafts on the cell membrane, perturbing viral attachment. Imaging SARS-CoV-2 RNAs at the single cell level using a viral replicon model identifies the capacity of Avasimibe to limit the establishment of replication complexes required for RNA replication. Genetic studies to transiently silence or overexpress ACAT isoforms confirmed a role for ACAT in SARS-CoV-2 infection. Furthermore, Avasimibe boosts the expansion of functional SARS-CoV-2-specific T cells from the blood of patients sampled during the acute phase of infection. Thus, re-purposing of ACAT inhibitors provides a compelling therapeutic strategy for the treatment of COVID-19 to achieve both antiviral and immunomodulatory effects. Trial registration: NCT04318314.


Asunto(s)
Antivirales , COVID-19 , Humanos , Aciltransferasas/antagonistas & inhibidores , Antivirales/farmacología , SARS-CoV-2 , Linfocitos T
8.
Hepatology ; 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38687604

RESUMEN

BACKGROUND AND AIMS: HBV and HIV coinfection is a common occurrence globally, with significant morbidity and mortality. Both viruses lead to immune dysregulation including changes in natural killer (NK) cells, a key component of antiviral defense and a promising target for HBV cure strategies. Here we used high-throughput single-cell analysis to explore the immune cell landscape in people with HBV mono-infection and HIV/HBV coinfection, on antiviral therapy, with emphasis on identifying the distinctive characteristics of NK cell subsets that can be therapeutically harnessed. APPROACH AND RESULTS: Our data show striking differences in the transcriptional programs of NK cells. HIV/HBV coinfection was characterized by an over-representation of adaptive, KLRC2 -expressing NK cells, including a higher abundance of a chemokine-enriched ( CCL3/CCL4 ) adaptive cluster. The NK cell remodeling in HIV/HBV coinfection was reflected in enriched activation pathways, including CD3ζ phosphorylation and ZAP-70 translocation that can mediate stronger antibody-dependent cellular cytotoxicity responses and a bias toward chemokine/cytokine signaling. By contrast, HBV mono-infection imposed a stronger cytotoxic profile on NK cells and a more prominent signature of "exhaustion" with higher circulating levels of HBsAg. Phenotypic alterations in the NK cell pool in coinfection were consistent with increased "adaptiveness" and better capacity for antibody-dependent cellular cytotoxicity compared to HBV mono-infection. Overall, an adaptive NK cell signature correlated inversely with circulating levels of HBsAg and HBV-RNA in our cohort. CONCLUSIONS: This study provides new insights into the differential signature and functional profile of NK cells in HBV and HIV/HBV coinfection, highlighting pathways that can be manipulated to tailor NK cell-focused approaches to advance HBV cure strategies in different patient groups.

9.
Immunol Rev ; 299(1): 108-117, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33559128

RESUMEN

Humoral immunity is a critical component of the coordinated response required to resolve viral infections and mediate protection following pathogen clearance or vaccination. A better understanding of factors shaping the memory B cell response will allow tailored development of efficient preventative vaccines against emerging acute viral infections, therapeutic vaccines, and immunotherapies for chronic viral infections. Here, we use recent data obtained by profiling antigen-specific B cell responses in hepatitis B as a framework to explore lessons that can be learnt from different viral infections about the diverse influences on humoral immunity. Hepatitis B provides a paradigm where successful B cell responses in resolved or vaccinated individuals can be contrasted to the failed response in chronic infection, while also exemplifying the degree to which B cell responses within infected individuals can differ to two antigens from the same virus. Drawing on studies in other human and murine infections, including emerging data from COVID-19, we consider the influence of antigen quantity and structure on the quality of the B cell response, the role of differential CD4 help, the importance of germinal center vs extrafollicular responses and the emerging concept that responses residing in non-lymphoid organs can participate in B cell memory.


Asunto(s)
Anticuerpos Antivirales/metabolismo , Linfocitos B/inmunología , Vacunas contra la COVID-19/inmunología , COVID-19/inmunología , Virus de la Hepatitis B/fisiología , Hepatitis B/inmunología , SARS-CoV-2/fisiología , Linfocitos T Colaboradores-Inductores/inmunología , Formación de Anticuerpos , Antígenos Virales/inmunología , Humanos , Inmunidad Humoral , Epítopos Inmunodominantes/inmunología , Memoria Inmunológica
10.
Clin Infect Dis ; 78(4): 983-990, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-37633256

RESUMEN

Chronic hepatitis B, a major cause of liver disease and cancer, affects >250 million people worldwide. Currently there is no cure, only suppressive therapies. Efforts to develop finite curative hepatitis B virus (HBV) therapies are underway, consisting of combinations of multiple novel agents with or without nucleos(t)ide reverse-transcriptase inhibitors. The HBV Forum convened a webinar in July 2021, along with subsequent working group discussions to address how and when to stop finite therapy for demonstration of sustained off-treatment efficacy and safety responses. Participants included leading experts in academia, clinical practice, pharmaceutical companies, patient representatives, and regulatory agencies. This Viewpoints article outlines areas of consensus within our multistakeholder group for stopping finite therapies in chronic hepatitis B investigational studies, including trial design, patient selection, outcomes, biomarkers, predefined stopping criteria, predefined retreatment criteria, duration of investigational therapies, and follow-up after stopping therapy. Future research of unmet needs are discussed.


Asunto(s)
Hepatitis B Crónica , Hepatitis B , Humanos , Hepatitis B Crónica/tratamiento farmacológico , Antivirales/uso terapéutico , Virus de la Hepatitis B/genética , Resultado del Tratamiento , Biomarcadores , Antígenos de Superficie de la Hepatitis B , ADN Viral , Hepatitis B/tratamiento farmacológico
11.
Int J Mol Sci ; 24(5)2023 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-36901802

RESUMEN

Despite the highly infectious nature of the SARS-CoV-2 virus, it is clear that some individuals with potential exposure, or even experimental challenge with the virus, resist developing a detectable infection. While a proportion of seronegative individuals will have completely avoided exposure to the virus, a growing body of evidence suggests a subset of individuals are exposed, but mediate rapid viral clearance before the infection is detected by PCR or seroconversion. This type of "abortive" infection likely represents a dead-end in transmission and precludes the possibility for development of disease. It is, therefore, a desirable outcome on exposure and a setting in which highly effective immunity can be studied. Here, we describe how early sampling of a new pandemic virus using sensitive immunoassays and a novel transcriptomic signature can identify abortive infections. Despite the challenges in identifying abortive infections, we highlight diverse lines of evidence supporting their occurrence. In particular, expansion of virus-specific T cells in seronegative individuals suggests abortive infections occur not only after exposure to SARS-CoV-2, but for other coronaviridae, and diverse viral infections of global health importance (e.g., HIV, HCV, HBV). We discuss unanswered questions related to abortive infection, such as: 'Are we just missing antibodies? Are T cells an epiphenomenon? What is the influence of the dose of viral inoculum?' Finally, we argue for a refinement of the current paradigm that T cells are only involved in clearing established infection; instead, we emphasise the importance of considering their role in terminating early viral replication by studying abortive infections.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Linfocitos T , Anticuerpos Antivirales
12.
Gut ; 71(7): 1399-1411, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-34548339

RESUMEN

OBJECTIVE: Tissue-resident memory T cells (TRM) are vital immune sentinels that provide protective immunity. While hepatic CD8+ TRM have been well described, little is known about the location, phenotype and function of CD4+ TRM. DESIGN: We used multiparametric flow cytometry, histological assessment and novel human tissue coculture systems to interrogate the ex vivo phenotype, function and generation of the intrahepatic CD4+ T-cell compartment. We also used leukocytes isolated from human leukocyte antigen (HLA)-disparate liver allografts to assess long-term retention. RESULTS: Hepatic CD4+ T cells were delineated into three distinct populations based on CD69 expression: CD69-, CD69INT and CD69HI. CD69HICD4+ cells were identified as tissue-resident CD4+ T cells on the basis of their exclusion from the circulation, phenotypical profile (CXCR6+CD49a+S1PR1-PD-1+) and long-term persistence within the pool of donor-derived leukcoocytes in HLA-disparate liver allografts. CD69HICD4+ T cells produced robust type 1 polyfunctional cytokine responses on stimulation. Conversely, CD69INTCD4+ T cells represented a more heterogenous population containing cells with a more activated phenotype, a distinct chemokine receptor profile (CX3CR1+CXCR3+CXCR1+) and a bias towards interleukin-4 production. While CD69INTCD4+ T cells could be found in the circulation and lymph nodes, these cells also formed part of the long-term resident pool, persisting in HLA-mismatched allografts. Notably, frequencies of CD69INTCD4+ T cells correlated with necroinflammatory scores in chronic hepatitis B infection. Finally, we demonstrated that interaction with hepatic epithelia was sufficient to generate CD69INTCD4+ T cells, while additional signals from the liver microenvironment were required to generate liver-resident CD69HICD4+ T cells. CONCLUSIONS: High and intermediate CD69 expressions mark human hepatic CD4+ TRM and a novel functionally distinct recirculating population, respectively, both shaped by the liver microenvironment to achieve diverse immunosurveillance.


Asunto(s)
Linfocitos T CD4-Positivos , Hígado , Linfocitos T CD8-positivos , Citocinas/inmunología , Humanos , Memoria Inmunológica , Hígado/inmunología , Monitorización Inmunológica
13.
Immunology ; 166(1): 68-77, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35156709

RESUMEN

SARS-CoV-2 infection results in different outcomes ranging from asymptomatic infection to mild or severe disease and death. Reasons for this diversity of outcome include differences in challenge dose, age, gender, comorbidity and host genomic variation. Human leukocyte antigen (HLA) polymorphisms may influence immune response and disease outcome. We investigated the association of HLAII alleles with case definition symptomatic COVID-19, virus-specific antibody and T-cell immunity. A total of 1364 UK healthcare workers (HCWs) were recruited during the first UK SARS-CoV-2 wave and analysed longitudinally, encompassing regular PCR screening for infection, symptom reporting, imputation of HLAII genotype and analysis for antibody and T-cell responses to nucleoprotein (N) and spike (S). Of 272 (20%) HCW who seroconverted, the presence of HLA-DRB1*13:02 was associated with a 6·7-fold increased risk of case definition symptomatic COVID-19. In terms of immune responsiveness, HLA-DRB1*15:02 was associated with lower nucleocapsid T-cell responses. There was no association between DRB1 alleles and anti-spike antibody titres after two COVID vaccine doses. However, HLA DRB1*15:01 was associated with increased spike T-cell responses following both first and second dose vaccination. Trial registration: NCT04318314 and ISRCTN15677965.


Asunto(s)
COVID-19 , Anticuerpos Antivirales , COVID-19/genética , Vacunas contra la COVID-19 , Cadenas HLA-DRB1/genética , Antígenos de Histocompatibilidad Clase I/genética , Humanos , SARS-CoV-2
14.
J Hepatol ; 77(2): 525-538, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35259469

RESUMEN

There have been unprecedented advances in the identification of new treatment targets for chronic hepatitis B that are being developed with the goal of achieving functional cure in patients who would otherwise require lifelong nucleoside analogue treatment. Many of the new investigational therapies either directly target the immune system or are anticipated to impact immunity indirectly through modulation of the viral lifecycle and antigen production. While new viral biomarkers (HBV RNA, HBcAg, small, middle, large HBs isoforms) are proceeding through validation steps in clinical studies, immunological biomarkers are non-existent outside of clinical assays for antibodies to HBs, HBc and HBe. To develop clinically applicable immunological biomarkers to measure mechanisms of action, inform logical combination strategies, and guide clinical management for use and discontinuation of immune-targeting drugs, immune assays must be incorporated into phase I/II clinical trials. This paper will discuss the importance of sample collection, the assays available for immunological analyses, their advantages/disadvantages and suggestions for their implementation in clinical trials. Careful consideration must be given to ensure appropriate immunological studies are included as a primary component of the trial with deeper immunological analysis provided by ancillary studies. Standardising immunological assays and data obtained from clinical trials will identify biomarkers that can be deployed in the clinic, independently of specialised immunology laboratories.


Asunto(s)
Hepatitis B Crónica , Hepatitis B , Biomarcadores , ADN Viral/genética , Anticuerpos contra la Hepatitis B , Antígenos del Núcleo de la Hepatitis B , Antígenos de Superficie de la Hepatitis B , Virus de la Hepatitis B/genética , Humanos
15.
Hepatology ; 74(1): 55-71, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33368377

RESUMEN

BACKGROUND AND AIMS: GS-9688 (selgantolimod) is a toll-like receptor 8 agonist in clinical development for the treatment of chronic hepatitis B (CHB). Antiviral activity of GS-9688 has previously been evaluated in vitro in HBV-infected hepatocytes and in vivo in the woodchuck model of CHB. Here we evaluated the potential of GS-9688 to boost responses contributing to viral control and to modulate regulatory mediators. APPROACH AND RESULTS: We characterized the effect of GS-9688 on immune cell subsets in vitro in peripheral blood mononuclear cells of healthy controls and patients with CHB. GS-9688 activated dendritic cells and mononuclear phagocytes to produce IL-12 and other immunomodulatory mediators, inducing a comparable cytokine profile in healthy controls and patients with CHB. GS-9688 increased the frequency of activated natural killer (NK) cells, mucosal-associated invariant T cells, CD4+ follicular helper T cells, and, in about 50% of patients, HBV-specific CD8+ T cells expressing interferon-γ. Moreover, in vitro stimulation with GS-9688 induced NK-cell expression of interferon-γ and TNF-α, and promoted hepatocyte lysis. We also assessed whether GS-9688 inhibited immunosuppressive cell subsets that might enhance antiviral efficacy. Stimulation with GS-9688 reduced the frequency of CD4+ regulatory T cells and monocytic myeloid-derived suppressor cells (MDSCs). Residual MDSCs expressed higher levels of negative immune regulators, galectin-9 and programmed death-ligand 1. Conversely, GS-9688 induced an expansion of immunoregulatory TNF-related apoptosis-inducing ligand+ NK cells and degranulation of arginase-I+ polymorphonuclear MDSCs. CONCLUSIONS: GS-9688 induces cytokines in human peripheral blood mononuclear cells that are able to activate antiviral effector function by multiple immune mediators (HBV-specific CD8+ T cells, CD4+ follicular helper T cells, NK cells, and mucosal-associated invariant T cells). Although reducing the frequency of some immunoregulatory subsets, it enhances the immunosuppressive potential of others, highlighting potential biomarkers and immunotherapeutic targets to optimize the antiviral efficacy of GS-9688.


Asunto(s)
Antivirales/farmacología , Hepatitis B Crónica/tratamiento farmacológico , Hexanoles/farmacología , Pirimidinas/farmacología , Receptor Toll-Like 8/antagonistas & inhibidores , Adulto , Anciano , Animales , Antivirales/uso terapéutico , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , Estudios de Cohortes , Modelos Animales de Enfermedad , Femenino , Voluntarios Sanos , Células Hep G2 , Hepatitis B Crónica/inmunología , Hepatitis B Crónica/virología , Hexanoles/uso terapéutico , Interacciones Huésped-Patógeno/efectos de los fármacos , Interacciones Huésped-Patógeno/inmunología , Humanos , Células Asesinas Naturales/efectos de los fármacos , Células Asesinas Naturales/inmunología , Leucocitos Mononucleares , Masculino , Marmota , Persona de Mediana Edad , Cultivo Primario de Células , Pirimidinas/uso terapéutico , Linfocitos T Reguladores/efectos de los fármacos , Linfocitos T Reguladores/inmunología , Receptor Toll-Like 8/metabolismo , Adulto Joven
16.
J Hepatol ; 74(5): 1064-1074, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33278456

RESUMEN

BACKGROUND & AIMS: Factors associated with a successful outcome upon nucleos(t)ide analogue (NA) treatment withdrawal in HBeAg-negative chronic hepatitis B (CHB) patients have yet to be clarified. The objective of this study was to analyse the HBV-specific T cell response, in parallel with peripheral and intrahepatic viral parameters, in patients undergoing NA discontinuation. METHODS: Twenty-seven patients without cirrhosis with HBeAg-negative CHB with complete viral suppression (>3 years) were studied prospectively. Intrahepatic HBV-DNA (iHBV-DNA), intrahepatic HBV-RNA (iHBV-RNA), and covalently closed circular DNA (cccDNA) were quantified at baseline. Additionally, serum markers (HBV-DNA, HBsAg, HBV core-related antigen [HBcrAg] and HBV-RNA) and HBV-specific T cell responses were analysed at baseline and longitudinally throughout follow-up. RESULTS: After a median follow-up of 34 months, 22/27 patients (82%) remained off-therapy, of whom 8 patients (30% of the total cohort) lost HBsAg. Baseline HBsAg significantly correlated with iHBV-DNA and iHBV-RNA, and these parameters were lower in patients who lost HBsAg. All patients had similar levels of detectable cccDNA regardless of their clinical outcome. Patients achieving functional cure had baseline HBsAg levels ≤1,000 IU/ml. Similarly, an increased frequency of functional HBV-specific CD8+ T cells at baseline was associated with sustained viral control off treatment. These HBV-specific T cell responses persisted, but did not increase, after treatment withdrawal. A similar, but not statistically significant trend, was observed for HBV-specific CD4+ T cell responses. CONCLUSIONS: Decreased cccDNA transcription and low HBsAg levels are associated with HBsAg loss upon NA discontinuation in patients with HBeAg-negative CHB. The presence of functional HBV-specific T cells at baseline are associated with a successful outcome after treatment withdrawal. LAY SUMMARY: Nucleos(t)ide analogue therapy can be discontinued in a high proportion of chronic hepatitis B patients without cirrhosis. The strength of HBV-specific immune T cell responses may contribute to successful viral control after antiviral treatment interruption. Our comprehensive study provides in-depth data on virological and immunological factors than can help guide individualised therapy in patients with chronic hepatitis B.


Asunto(s)
ADN Viral/aislamiento & purificación , Antígenos de la Hepatitis B , Virus de la Hepatitis B , Hepatitis B Crónica , Inmunidad Celular , Hígado , Nucleósidos/uso terapéutico , Privación de Tratamiento/estadística & datos numéricos , Antivirales/uso terapéutico , Biomarcadores/sangre , ADN Circular/aislamiento & purificación , Femenino , Antígenos de la Hepatitis B/análisis , Antígenos de la Hepatitis B/aislamiento & purificación , Antígenos de Superficie de la Hepatitis B/análisis , Virus de la Hepatitis B/genética , Virus de la Hepatitis B/aislamiento & purificación , Hepatitis B Crónica/sangre , Hepatitis B Crónica/diagnóstico , Humanos , Inmunidad Celular/efectos de los fármacos , Inmunidad Celular/inmunología , Hígado/patología , Hígado/virología , Masculino , Persona de Mediana Edad , Planificación de Atención al Paciente
19.
Hepatology ; 72(5): 1528-1540, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32770836

RESUMEN

BACKGROUND AND AIMS: Therapies for chronic hepatitis B virus (HBV) infection are urgently needed because of viral integration, persistence of viral antigen expression, inadequate HBV-specific immune responses, and treatment regimens that require lifelong adherence to suppress the virus. Immune mobilizing monoclonal T Cell receptors against virus (ImmTAV) molecules represent a therapeutic strategy combining an affinity-enhanced T Cell receptor with an anti-CD3 T Cell-activating moiety. This bispecific fusion protein redirects T cells to specifically lyse infected cells expressing the target virus-derived peptides presented by human leukocyte antigen (HLA). APPROACH AND RESULTS: ImmTAV molecules specific for HLA-A*02:01-restricted epitopes from HBV envelope, polymerase, and core antigens were engineered. The ability of ImmTAV-Env to activate and redirect polyclonal T cells toward cells containing integrated HBV and cells infected with HBV was assessed using cytokine secretion assays and imaging-based killing assays. Elimination of infected cells was further quantified using a modified fluorescent hybridization of viral RNA assay. Here, we demonstrate that picomolar concentrations of ImmTAV-Env can redirect T cells from healthy and HBV-infected donors toward hepatocellular carcinoma (HCC) cells containing integrated HBV DNA resulting in cytokine release, which could be suppressed by the addition of a corticosteroid in vitro. Importantly, ImmTAV-Env redirection of T cells induced cytolysis of antigen-positive HCC cells and cells infected with HBV in vitro, causing a reduction of hepatitis B e antigen and specific loss of cells expressing viral RNA. CONCLUSIONS: The ImmTAV platform has the potential to enable the elimination of infected cells by redirecting endogenous non-HBV-specific T cells, bypassing exhausted HBV-specific T cells. This represents a promising therapeutic option in the treatment of chronic hepatitis B, with our lead candidate now entering trials.


Asunto(s)
Virus de la Hepatitis B/inmunología , Hepatitis B Crónica/tratamiento farmacológico , Receptores de Antígenos de Linfocitos T/uso terapéutico , Proteínas Recombinantes de Fusión/farmacología , Linfocitos T/efectos de los fármacos , Anticuerpos Monoclonales/genética , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/uso terapéutico , Complejo CD3/antagonistas & inhibidores , Línea Celular Tumoral , Epítopos/inmunología , Antígeno HLA-A2/inmunología , Antígenos de Superficie de la Hepatitis B/inmunología , Virus de la Hepatitis B/aislamiento & purificación , Hepatitis B Crónica/inmunología , Hepatitis B Crónica/virología , Hepatocitos , Humanos , Inmunoconjugados/genética , Inmunoconjugados/inmunología , Inmunoconjugados/farmacología , Inmunoconjugados/uso terapéutico , Activación de Linfocitos/efectos de los fármacos , Cultivo Primario de Células , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/inmunología , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/uso terapéutico , Linfocitos T/inmunología
20.
J Virol ; 93(4)2019 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-30518652

RESUMEN

Distinct populations of hepatocytes infected with hepatitis B virus (HBV) or only harboring HBV DNA integrations coexist within an HBV chronically infected liver. These hepatocytes express HBV antigens at different levels and with different intracellular localizations, but it is not known whether this heterogeneity of viral antigen expression could result in an uneven hepatic presentation of distinct HBV epitopes/HLA class I complexes triggering different levels of activation of HBV-specific CD8+ T cells. Using antibodies specific to two distinct HLA-A*02:01/HBV epitope complexes of HBV nucleocapsid and envelope proteins, we mapped their topological distributions in liver biopsy specimens of two anti-hepatitis B e antigen-positive (HBe+) chronic HBV (CHB) patients. We demonstrated that the core and envelope CD8+ T cell epitopes were not uniformly distributed in the liver parenchyma but preferentially located in distinct and sometimes mutually exclusive hepatic zones. The efficiency of HBV epitope presentation was then tested in vitro utilizing HLA-A*02:01/HBV epitope-specific antibodies and the corresponding CD8+ T cells in primary human hepatocyte and hepatoma cell lines either infected with HBV or harboring HBV DNA integration. We confirmed the existence of a marked variability in the efficiency of HLA class I/HBV epitope presentation among the different targets that was influenced by the presence of gamma interferon (IFN-γ) and availability of newly translated viral antigens. In conclusion, HBV antigen presentation can be heterogeneous within an HBV-infected liver. As a consequence, CD8+ T cells of different HBV specificities might have different antiviral efficacies.IMPORTANCE The inability of patients with chronic HBV infection to clear HBV is associated with defective HBV-specific CD8+ T cells. Hence, the majority of immunotherapy developments focus on HBV-specific T cell function restoration. However, knowledge of whether distinct HBV-specific T cells can equally target all the HBV-infected hepatocytes of a chronically infected liver is lacking. In this work, analysis of CHB patient liver parenchyma and in vitro HBV infection models shows a nonuniform distribution of HBV CD8+ T cell epitopes that is influenced by the presence of IFN-γ and availability of newly translated viral antigens. These results suggest that CD8+ T cells recognizing different HBV epitopes can be necessary for efficient immune therapeutic control of chronic HBV infection.


Asunto(s)
Linfocitos T CD8-positivos/fisiología , Virus de la Hepatitis B/inmunología , Hepatitis B/inmunología , Linfocitos T CD8-positivos/inmunología , Epítopos/inmunología , Epítopos de Linfocito T/inmunología , Células Hep G2 , Hepatitis B/metabolismo , Antígenos del Núcleo de la Hepatitis B/metabolismo , Virus de la Hepatitis B/genética , Virus de la Hepatitis B/patogenicidad , Humanos , Interferón gamma/metabolismo , Hígado/inmunología , Análisis Espacio-Temporal
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