RESUMEN
Humanized mouse models have been developed to study cell-mediated immune responses to human pathogens in vivo. How immunocompetent human T cells are selected in a murine thymus in such humanized mice remains poorly explored. To gain insights into this mechanism, we investigated the differentiation of human immune compartments in mouse MHC class II-deficient immune-compromised mice (humanized Ab0 mice). We observed a strong reduction in human CD4+ T-cell development but despite this reduction Ab0 mice had no disadvantage during Epstein-Barr virus (EBV) infection. Viral loads were equally well controlled in humanized Ab0 mice compared to humanized NSG mice, and improved T-cell recognition of autologous EBV-transformed B cells was observed, especially with respect to cytotoxicity. MHC class II blocking experiments with CD4+ T cells from humanized Ab0 mice demonstrated MHC class II restriction of lymphoblastoid cell line recognition. These findings suggest that a small number of CD4+ T cells in humanized mice can be solely selected on human MHC class II molecules, presumably expressed by reconstituted human immune cells, leading to improved effector functions.
Asunto(s)
Infecciones por Virus de Epstein-Barr , Humanos , Animales , Ratones , Herpesvirus Humano 4 , Linfocitos T , Linfocitos T CD4-Positivos , Diferenciación Celular , Antígenos de Histocompatibilidad Clase II/genética , Antígenos de Histocompatibilidad Clase II/metabolismoRESUMEN
Immune responses to Epstein-Barr virus (EBV) infection synergize with the main genetic risk factor HLA-DRB1*15:01 (HLA-DR15) to increase the likelihood to develop the autoimmune disease multiple sclerosis (MS) at least sevenfold. In order to gain insights into this synergy, we investigated HLA-DR15 positive human immune compartments after reconstitution in immune-compromised mice (humanized mice) with and without EBV infection. We detected elevated activation of both CD4+ and CD8+ T cells in HLA-DR15 donor-reconstituted humanized mice at steady state, even when compared to immune compartments carrying HLA-DRB1*04:01 (HLA-DR4), which is associated with other autoimmune diseases. Increased CD8+ T cell expansion and activation was also observed in HLA-DR15 donor-reconstituted humanized mice after EBV infection. Despite this higher immune activation, EBV viral loads were less well controlled in the context of HLA-DR15. Indeed, HLA-DR15-restricted CD4+ T cell clones recognized EBV-transformed B cell lines less efficiently and demonstrated cross-reactivity toward allogeneic target cells and one MS autoantigen. These findings suggest that EBV as one of the main environmental risk factors and HLA-DR15 as the main genetic risk factor for MS synergize by priming hyperreactive T-cell compartments, which then control the viral infection less efficiently and contain cross-reactive CD4+ T cell clones.
Asunto(s)
Infecciones por Virus de Epstein-Barr/inmunología , Subtipos Serológicos HLA-DR/inmunología , Esclerosis Múltiple/inmunología , Inmunidad Adaptativa , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Reacciones Cruzadas , Modelos Animales de Enfermedad , Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por Virus de Epstein-Barr/virología , Predisposición Genética a la Enfermedad , Antígeno HLA-A2/genética , Antígeno HLA-A2/inmunología , Subtipos Serológicos HLA-DR/genética , Herpesvirus Humano 4/inmunología , Humanos , Isoantígenos , Activación de Linfocitos , Ratones , Ratones Endogámicos NOD , Ratones SCID , Ratones Transgénicos , Esclerosis Múltiple/etiología , Esclerosis Múltiple/genética , Vaina de Mielina/inmunología , Factores de RiesgoRESUMEN
IVIG preparations consisting of pooled IgG are increasingly used for the treatment of autoimmune diseases. IVIG is known to regulate the viability of immune cells, including neutrophils. We report that plasma-derived IgA efficiently triggers death of neutrophils primed by cytokines or TLR agonists. IgA-mediated programmed neutrophil death was PI3K-, p38 MAPK-, and JNK-dependent and evoked anti-inflammatory cytokines in macrophage cocultures. Neutrophils from patients with acute Crohn's disease, rheumatoid arthritis, or sepsis were susceptible to both IgA- and IVIG-mediated death. In contrast to IVIG, IgA did not promote cell death of quiescent neutrophils. Our findings suggest that plasma-derived IgA might provide a therapeutic option for the treatment of neutrophil-associated inflammatory disorders.
Asunto(s)
Artritis Reumatoide/tratamiento farmacológico , Enfermedad de Crohn/tratamiento farmacológico , Inmunoglobulina A/farmacología , Neutrófilos/efectos de los fármacos , Sepsis/tratamiento farmacológico , Animales , Apoptosis/efectos de los fármacos , Apoptosis/inmunología , Artritis Reumatoide/sangre , Artritis Reumatoide/inmunología , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/inmunología , Células Cultivadas , Técnicas de Cocultivo , Enfermedad de Crohn/sangre , Enfermedad de Crohn/inmunología , Humanos , Inmunoglobulina A/uso terapéutico , Inmunoglobulinas Intravenosas/farmacología , Inmunoglobulinas Intravenosas/uso terapéutico , Macrófagos , Ratones , Neutrófilos/inmunología , Cultivo Primario de Células , Sepsis/sangre , Sepsis/inmunologíaRESUMEN
After infection of B cells, Epstein-Barr virus (EBV) engages host pathways that mediate cell proliferation and transformation, contributing to the propensity of the virus to drive immune dysregulation and lymphomagenesis. We found that the EBV protein EBNA2 initiates nicotinamide adenine dinucleotide (NAD) de novo biosynthesis by driving expression of the metabolic enzyme indoleamine 2,3-dioxygenase 1 (IDO1) in infected B cells. Virus-enforced NAD production sustained mitochondrial complex I activity, to match adenosine triphosphate (ATP) production with bioenergetic requirements of proliferation and transformation. In transplant patients, IDO1 expression in EBV-infected B cells, and a serum signature of increased IDO1 activity, preceded development of lymphoma. In humanized mice infected with EBV, IDO1 inhibition reduced both viremia and lymphomagenesis. Virus-orchestrated NAD biosynthesis is therefore a druggable metabolic vulnerability of EBV-driven B cell transformation, opening therapeutic possibilities for EBV-related diseases.
Asunto(s)
Adenosina Trifosfato , Linfocitos B , Transformación Celular Viral , Infecciones por Virus de Epstein-Barr , Antígenos Nucleares del Virus de Epstein-Barr , Herpesvirus Humano 4 , Indolamina-Pirrol 2,3,-Dioxigenasa , NAD , Animales , Humanos , Ratones , Adenosina Trifosfato/metabolismo , Linfocitos B/inmunología , Linfocitos B/metabolismo , Proliferación Celular , Complejo I de Transporte de Electrón/metabolismo , Infecciones por Virus de Epstein-Barr/virología , Antígenos Nucleares del Virus de Epstein-Barr/metabolismo , Herpesvirus Humano 4/fisiología , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenasa/genética , Linfoma/virología , NAD/metabolismo , Proteínas Virales , ViremiaRESUMEN
X-linked lymphoproliferative disease (XLP) is either caused by loss of the SLAM-associated protein (SAP; XLP-1) or the X-linked inhibitor of apoptosis (XIAP; XLP-2). In both instances, infection with the oncogenic human Epstein Barr virus (EBV) leads to pathology, but EBV-associated lymphomas only emerge in XLP-1 patients. Therefore, we investigated the role of XIAP during B cell transformation by EBV. Using humanized mice, IAP inhibition in EBV-infected mice led to a loss of B cells and a tendency to lower viral titers and lymphomagenesis. Loss of memory B cells was also observed in four newly described patients with XIAP deficiency. EBV was able to transform their B cells into lymphoblastoid cell lines (LCLs) with similar growth characteristics to patient mothers' LCLs in vitro and in vivo. Gene expression analysis revealed modest elevated lytic EBV gene transcription as well as the expression of the tumor suppressor cell adhesion molecule 1 (CADM1). CADM1 expression on EBV-infected B cells might therefore inhibit EBV-associated lymphomagenesis in patients and result in the absence of EBV-associated malignancies in XLP-2 patients.
Asunto(s)
Infecciones por Virus de Epstein-Barr , Trastornos Linfoproliferativos , Animales , Humanos , Ratones , Molécula 1 de Adhesión Celular/genética , Molécula 1 de Adhesión Celular/metabolismo , Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por Virus de Epstein-Barr/genética , Herpesvirus Humano 4/metabolismo , Trastornos Linfoproliferativos/genética , Trastornos Linfoproliferativos/patología , Proteína Asociada a la Molécula de Señalización de la Activación Linfocitaria/metabolismo , Proteína Inhibidora de la Apoptosis Ligada a X/genética , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismo , Linfocitos BRESUMEN
HIV and EBV are human pathogens that cause a considerable burden to worldwide health. In combination, these viruses are linked to AIDS-associated lymphomas. We found that EBV, which transforms B cells, renders them susceptible to HIV-1 infection in a CXCR4 and CD4-dependent manner in vitro and that CXCR4-tropic HIV-1 integrates into the genome of these B cells with the same molecular profile as in autologous CD4+ T cells. In addition, we established a humanized mouse model to investigate the in vivo interactions of EBV and HIV-1 upon coinfection. The respective mice that reconstitute human immune system components upon transplantation with CD34+ human hematopoietic progenitor cells could recapitulate aspects of EBV and HIV immunobiology observed in dual-infected patients. Upon coinfection of humanized mice, EBV/HIV dual-infected B cells could be detected, but were susceptible to CD8+ T-cell-mediated immune control.
Asunto(s)
Infecciones por VIH/inmunología , Infecciones por VIH/virología , Herpesvirus Humano 4/patogenicidad , Animales , Linfocitos B/metabolismo , Linfocitos B/patología , Linfocitos B/virología , Antígenos CD4/inmunología , Antígenos CD4/metabolismo , Coinfección , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades/metabolismo , Susceptibilidad a Enfermedades/virología , Infecciones por Virus de Epstein-Barr/inmunología , Infecciones por VIH/genética , Seropositividad para VIH , VIH-1/metabolismo , VIH-1/patogenicidad , Células Madre Hematopoyéticas/patología , Herpesvirus Humano 4/inmunología , Herpesvirus Humano 4/metabolismo , Humanos , Masculino , Ratones , Ratones Endogámicos NOD , Receptores CXCR4/metabolismo , Receptores CXCR4/fisiología , Linfocitos T/inmunologíaRESUMEN
Epstein-Barr virus (EBV) and Kaposi sarcoma-associated herpesvirus (KSHV) comprise the oncogenic human γ-herpesvirus family and are responsible for 2-3% of all tumours in man. With their prominent growth-transforming abilities and high prevalence in the human population, these pathogens have probably shaped the human immune system throughout evolution for near perfect immune control of the respective chronic infections in the vast majority of healthy pathogen carriers. The exclusive tropism of EBV and KSHV for humans has, however, made it difficult in the past to study their infection, tumourigenesis and immune control in vivo. Mice with reconstituted human immune system components (humanized mice) support replication of both viruses with both persisting latent and productive lytic infection. Moreover, B-cell lymphomas can be induced by EBV alone and KSHV co-infection with gene expression hallmarks of human malignancies that are associated with both viruses. Furthermore, cell-mediated immune control by primarily cytotoxic lymphocytes is induced upon infection and can be probed for its functional characteristics as well as putative requirements for its priming. Insights that have been gained from this model and remaining questions will be discussed in this review. This article is part of the theme issue 'Silent cancer agents: multi-disciplinary modelling of human DNA oncoviruses'.
Asunto(s)
Infecciones por Virus de Epstein-Barr/virología , Herpesvirus Humano 4/fisiología , Herpesvirus Humano 8/fisiología , Sarcoma de Kaposi/virología , Animales , Modelos Animales de Enfermedad , Infecciones por Virus de Epstein-Barr/inmunología , Humanos , Ratones , Ratones Transgénicos , Sarcoma de Kaposi/inmunologíaRESUMEN
The Epstein-Barr virus (EBV) is one of the predominant tumor viruses in humans, but so far no therapeutic or prophylactic vaccination against this transforming pathogen is available. We demonstrated that heterologous prime-boost vaccination with the nuclear antigen 1 of EBV (EBNA1), either targeted to the DEC205 receptor on DCs or expressed from a recombinant modified vaccinia virus Ankara (MVA) vector, improved priming of antigen-specific CD4+ T cell help. This help supported the expansion and maintenance of EBNA1-specific CD8+ T cells that are most efficiently primed by recombinant adenoviruses that encode EBNA1. These combined CD4+ and CD8+ T cell responses protected against EBNA1-expressing T and B cell lymphomas, including lymphoproliferations that emerged spontaneously after EBNA1 expression. In particular, the heterologous EBNA1-expressing adenovirus, boosted by EBNA1-encoding MVA vaccination, demonstrated protection as a prophylactic and therapeutic treatment for the respective lymphoma challenges. Our study shows that such heterologous prime-boost vaccinations against EBV-associated malignancies as well as symptomatic primary EBV infection should be further explored for clinical development.