Background Neuroblastoma is the commonest cancer in infants. Survival in high-risk groups is low (40-50%). Newer treatments are needed to improve survival and morbidity. Cytomegalovirus (CMV) is a ...common viral infection, which increases gamma delta T cells. We investigated the use of CMV-reactive gamma delta T cells as a potential new immunotherapy. Methods Peripheral blood mononuclear cells from 30 paediatric haemato-oncology patients with or without CMV infection were analysed by flow cytometry. gamma delta T cells were expanded, and then co-cultured with CMV targets or neuroblastoma cells. T-cell activation, cytokine secretion, killing activity, and mechanisms were determined by ELISA, MTT colorimetric assay, and blocking assays. Novel gamma delta T cell receptors (TCR) were identified by sequencing. Findings In paediatric haemato-oncology patients, acute CMV led to higher proportions of total gamma delta T cells (p=0.0002) with the dominant subtype V delta 1 (p=0.0035). CMV-reactive gamma delta T cells were of the effector memory phenotype and expanded to clinically significant numbers for adoptive transfer. When compared with gamma delta T cells from CMV-negative patients, CMV-reactive gamma delta T cells had statistically significantly higher interferon gamma release (p<0.001) in co-cultures with CMV-infected fibroblasts and showed cytolytic activity against CMV-infected fibroblasts and neuroblastoma cells which was mediated by gamma delta TCR and the NKG2D receptor. Sequencing showed that the dominant gamma delta T-cell chains in CMV-infected patients were V delta 1 V gamma 2. Within the TCRs, CDR3 sequences had minimal diversity, gamma chains had wide variations, and we identified a novel subpopulation in some patients. Interpretation We show that acute CMV infection in paediatric haemato-oncology patients leads to an increase in the V delta 1 V gamma 2 subtype of gamma delta T cells. They can be expanded for adoptive transfer and are likely to retain killing ability post expansion. They recognise and kill CMV-infected targets and neuroblastoma cells via the gamma delta TCR and the NKG2D receptor. We have identified a novel TCR in a subpopulation of CMV-positive patients. Funding Great Ormond Street Charity, National Institute for Health Research Biomedical Research Centre, Olivia Hodson Cancer Fund.
Herpes simplex virus 1 (HSV-1) remodels nuclear membranes during virus egress. Although the UL31 and UL34 proteins control nucleocapsid transit in infected cells, the molecular interactions required ...for their function are unclear. Here we report that the gamma 134.5 gene product of HSV-1 facilitates nucleocapsid release to the cytoplasm through bridging the UL31/UL34 complex, cellular p32, and protein kinase C. Unlike wild-type virus, an HSV mutant devoid of gamma 134.5 or its amino terminus is crippled for viral growth and release. This is attributable to a defect in virus nuclear egress. In infected cells, wild-type virus recruits protein kinase C to the nuclear membrane and triggers its activation, whereas the gamma 134.5 mutants fail to exert such an effect. Accordingly, the gamma 134.5 mutants are unable to induce phosphorylation and reorganization of lamin A/C. When expressed in host cells gamma 134.5 targets p32 and protein kinase C. Meanwhile, it communicates with the UL31/UL34 complex through UL31. Deletion of the amino terminus from gamma 134.5 disrupts its activity. These results suggest that disintegration of the nuclear lamina mediated by gamma 134.5 promotes HSV replication. IMPORTANCE HSV nuclear egress is a key step that determines the outcome of viral infection. While the nuclear egress complex mediates capsid transit across the nuclear membrane, the regulatory components are not clearly defined in virus-infected cells. We report that the gamma 134.5 gene product, a virulence factor of HSV-1, facilitates nuclear egress cooperatively with cellular p32, protein kinase C, and the nuclear egress complex. This work highlights a viral mechanism that may contribute to the pathogenesis of HSV infection.
While it is established that cytomegalovirus (CMV) disease affects NK-cell profiles, the functional consequences of asymptomatic CMV replication are unclear. Here, we characterize NK cells in ...clinically stable renal transplant recipients (RTRs; n = 48) >2 years after transplantation. RTRs and age-matched controls (n = 32) were stratified by their CMV serostatus and the presence of measurable CMV DNA. CMV antibody or CMV DNA influenced expression of NKG2C, LIR-1, NKp30, NKp46, and FcR gamma , a signaling adaptor molecule, on CD56 super(dim) NK cells. Phenotypic changes ascribed to CMV were clearer in RTRs than in control subjects and affected NK-cell function as assessed by TNF- alpha and CD107a expression. The most active NK cells were FcR gamma super(-)LIR-1 super(+)NKG2C super(-) and displayed high antibody-dependent cell cytotoxicity responses in the presence of immobilized CMV glycoprotein B reactive antibody. However, perforin levels in supernatants from RTRs with active CMV replication were low. Overall we demonstrate that CMV can be reactivated in symptom-free renal transplant recipients, affecting the phenotypic, and functional profiles of NK cells. Continuous exposure to CMV may maintain and expand NK cells that lack FcR gamma but express LIR-1. In asymptomatic posttransplant renal transplant recipients, persistent, and active CMV expands a population of FcR gamma super(-)LIR-1 super(+)NKG2C super(-) NK cells, which on cross-linking with CMV antibody displays increased antibody dependent cell cytotoxicity, i.e. increased expression of CD107a and TNF- alpha .
Members of the family
have enveloped, spherical virions with characteristic complex structures consisting of symmetrical and non-symmetrical components. The linear, double-stranded DNA genomes of ...125-241 kbp contain 70-170 genes, of which 43 have been inherited from an ancestral herpesvirus. In general, herpesviruses have coevolved with and are highly adapted to their hosts, which comprise many mammalian, avian and reptilian species. Following primary infection, they are able to establish lifelong latent infection, during which there is limited viral gene expression. Severe disease is usually observed only in the foetus, the very young, the immunocompromised or following infection of an alternative host. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family
, which is available at ictv.global/report/herpesviridae.
Patients undergoing allogeneic hematopoietic stem cell transplantation have a high risk of cytomegalovirus reactivation, which in the absence of T-cell immunity can result in the development of an ...acute inflammatory reaction and damage of internal organs. Transfusion of the virus-specific donor T-lymphocytes represents an alternative to a highly toxic and often ineffective antiviral therapy. Potentially promising cell therapy approach comprises transfusion of cytotoxic T-lymphocytes, specific to the viral antigens, immediately after their isolation from the donor's blood circulation without any in vitro expansion. Specific T-cells could be separated from potentially alloreactive lymphocytes using recombinant major histocompatibility complex (MHC) multimers, carrying synthetic viral peptides. Rapid transfusion of virus-specific T-cells to patients has several crucial advantages in comparison with methods based on the in vitro expansion of the cells. About 30% of hematopoietic stem cell donors and 46% of transplant recipients at the National Research Center for Hematology were carriers of the HLA-A*02 allele. Moreover, 94% of Russian donors have an immune response against the cytomegalovirus (CMV). Using recombinant HLA-A*02 multimers carrying an immunodominant cytomegalovirus peptide (NLV), we have shown that the majority of healthy donors have pronounced T-cell immunity against this antigen, whereas shortly after the transplantation the patients do not have specific T-lymphocytes. The donor cells have the immune phenotype of memory cells and can be activated and proliferate after stimulation with the specific antigen. Donor lymphocytes can be substantially enriched to significant purity by magnetic separation with recombinant MHC multimers and are not activated upon cocultivation with the antigen-presenting cells from HLA-incompatible donors without addition of the specific antigen. This study demonstrated that strong immune response to CMV of healthy donors and prevalence of HLA-A*02 allele in the Russian population make it possible to isolate a significant number of virus-specific cells using HLA-A*02-NLV multimers. After the transfusion, these cells should protect patients from CMV without development of allogeneic immune response.
The measurement of intracellular concentrations of adenosine triphosphate (iATP) in phytohemagglutinin-stimulated CD4 super(+) T cells constitutes a surrogate marker for post-transplant cell-mediated ...immunity (CMI). This assay has shown suboptimal accuracy for predicting infection after kidney transplantation (KT). We hypothesize that its predictive capacity depends on the specific contribution of the CMI to host-pathogen interactions. We assessed iATP levels in 100 KT recipients at baseline and months 1, 3, and 6 (363 measurements). No association was found between iATP at month 1 and the risk for overall or bacterial infection, although such association was evident for cytomegalovirus (CMV) disease (multivariate-adjusted hazard ratio per 50-unit increment: 0.83; P-value = 0.048). There were no significant differences in mean iATP between stable patients (319.4 ng/ml) and those developing overall (304.1 ng/ml) or bacterial infection (346.9 ng/ml) over the 45 days following monitoring. However, iATP was significantly lower in patients who developed CMV disease (223.5 ng/ml; P-values <0.002). The optimal cutoff (265 ng/ml) for predicting CMV disease in patients not receiving antiviral prophylaxis yielded sensitivity, specificity, positive, and negative predictive values of 85.7%, 68.3%, 15.2%, and 98.6%, respectively. In conclusion, a non-pathogen-specific monitoring of CMI by means of iATP informs the risk of CMV disease in KT recipients.
An epizootic with severe mortality has emerged in cultured gibel carp, Carassius auratus gibelio, in China since 2009, and caused huge economic loss. The signs and epidemiology background of the ...disease were investigated. Parasite examination, bacteria and virus isolation were carried out for pathogen isolation. The causative pathogen was obtained and identified as Cyprinid herpesvirus 2 (CyHV-2) by experimental infection, electron microscopy, cell culture, PCR assay and sequence alignment, designated as CyHV-2-JSSY. Experimental infection proved the high virulence of CyHV-2-JSSY to healthy gibel carp. Electron microscopy revealed that the viral nucleocapsid was hexagonal in shape measuring 110–120nm in diameter with a 170–200nm envelope. The virus caused significant CPE in Koi-Fin cells at the early passages, but not beyond the fifth passages. Sequence alignment of the partial viral helicase gene (JX566884) showed that it shared 99–100% identity to the published sequences of other CyHV-2 isolates. This study represented the first isolation and identification of CyHV-2 in cultured gibel carp in China and laid a foundation for the further studies of the disease.
Overview of Castleman disease Dispenzieri, Angela; Fajgenbaum, David C.
Blood,
04/2020, Letnik:
135, Številka:
16
Journal Article
Recenzirano
Odprti dostop
Castleman disease (CD) describes a group of at least 4 disorders that share a spectrum of characteristic histopathological features but have a wide range of etiologies, presentations, treatments, and ...outcomes. CD includes unicentric CD (UCD) and multicentric CD (MCD), the latter of which is divided into idiopathic MCD (iMCD), human herpes virus-8 (HHV8)-associated MCD (HHV8-MCD), and polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes (POEMS)-associated MCD (POEMS-MCD). iMCD can be further subclassified into iMCD–thrombocytopenia, ascites, reticulin fibrosis, renal dysfunction, organomegaly (iMCD-TAFRO) or iMCD–not otherwise specified (iMCD-NOS). Advances in diagnosis, classification, pathogenesis, and therapy are substantial since the original description of UCD by Benjamin Castleman in 1954. The advent of effective retroviral therapy and use of rituximab in HHV8-MCD have improved outcomes in HHV8-MCD. Anti–interleukin-6–directed therapies are highly effective in many iMCD patients, but additional therapies are required for refractory cases. Much of the recent progress has been coordinated by the Castleman Disease Collaborative Network (CDCN), and further progress will be made by continued engagement of physicians, scientists, and patients. Progress can also be facilitated by encouraging patients to self-enroll in the CDCN's ACCELERATE natural history registry (#NCT02817997; www.CDCN.org/ACCELERATE).
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More than 100 young captive and wild Asian elephants are known to have died from a rapid-onset, acute hemorrhagic disease caused primarily by multiple distinct strains of two closely related chimeric ...variants of a novel herpesvirus species designated elephant endotheliotropic herpesvirus (EEHV1A and EEHV1B). These and two other species of Probosciviruses (EEHV4 and EEHV5) are evidently ancient and likely nearly ubiquitous asymptomatic infections of adult Asian elephants worldwide that are occasionally shed in trunk wash secretions. Although only a handful of similar cases have been observed in African elephants, they also have proved to harbor their own multiple and distinct species of Probosciviruses—EEHV2, EEHV3, EEHV6, and EEHV7—found in lung and skin nodules or saliva. For reasons that are not yet understood, approximately 20% of Asian elephant calves appear to be susceptible to the disease when primary infections are not controlled by normal innate cellular and humoral immune responses. Sensitive specific polymerase chain reaction (PCR) DNA blood tests have been developed, routine monitoring has been established, the complete large DNA genomes of each of the four Asian EEHV species have now been sequenced, and PCR gene subtyping has provided unambiguous evidence that this is a sporadic rather than epidemic disease that it is not being spread among zoos or other elephant housing facilities. Nevertheless, researchers have not yet been able to propagate EEHV in cell culture, determine whether or not human antiherpesvirus drugs are effective inhibitors, or develop serology assays that can distinguish between antibodies against the multiple different EEHV species.
Herpesviruses are remarkable pathogens possessing elaborate mechanisms to seize various host cellular components for immune evasion, replication, and virion egress. As viruses are dependent upon ...their hosts, investigating this intricate interplay has revealed that the exosome pathway is utilised by alpha (Herpes Simplex Virus 1), beta (Human Cytomegalovirus, and Human Herpesvirus 6) and gamma (Epstein-Barr Virus, and Kaposi Sarcoma-associated Herpesvirus) herpesviruses. Virions and exosomes share similar properties and functions. For example, exosomes are small membranous nanovesicles (30–150nm) released from cells that contain proteins, DNA, and various coding and non-coding RNA species. Given exosomes can shuttle various molecular cargo from a donor to recipient cell, they serve as important vehicles facilitating cell-cell communication. Therefore, exploitation by herpesviruses impacts several aspects of infection including: i) acquisition of molecular machinery for secondary envelopment and viral assembly, ii) export of immune-related host proteins from infected cells, iii) enhancing infection in surrounding cells via transfer of viral proteins, mRNA and miRNA, and iv) regulation of viral protein expression to promote persistence. Studying the dichotomy that exists between host exosomes and herpesviruses has two benefits. Firstly, it will reveal the precise pathogenic mechanisms viruses have evolved, generating knowledge for antiviral development. Secondly, it will shed light upon fundamental exosome characteristics that remain unknown, including cargo selection, protein trafficking, and non-canonical biogenesis.
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