Chronic active Epstein-Barr virus disease originates from infected hematopoietic stem cells.

ABSTRACT: Chronic active Epstein-Barr virus (EBV) disease (CAEBV) is a lethal syndrome because of persistent EBV infection. When diagnosed as CAEBV, EBV infection was observed in multiple hematopoietic lineages, but the etiology of CAEBV is still elusive. Bone marrow and peripheral cells derived from 5 patients with CAEBV, 1 patient with EBV-associated hemophagocytic lymphohistiocytosis, and 2 healthy controls were analyzed. Multiple assays were applied to identify and characterize EBV-infected cells, including quantitative polymerase chain reaction, PrimeFlow, and single-cell RNA-sequencing (scRNA-seq). Based on scRNA-seq data, alterations in gene expression of particular cell types were analyzed between patients with CAEBV and controls, and between infected and uninfected cells. One patient with CAEBV was treated with allogeneic hematopoietic stem cell transplantation (HSCT), and the samples derived from this patient were analyzed again 6 months after HSCT. EBV infected the full spectrum of the hematopoietic system including both lymphoid and myeloid lineages, as well as the hematopoietic stem cells (HSCs) of the patients with CAEBV. EBV-infected HSCs exhibited a higher differentiation rate toward downstream lineages, and the EBV infection had an impact on both the innate and adaptive immunity, resulting in inflammatory symptoms. EBV-infected cells were thoroughly removed from the hematopoietic system after HSCT. Taken together, multiple lines of evidence presented in this study suggest that CAEBV disease originates from the infected HSCs, which might potentially lead to innovative therapy strategies for CAEBV.

Molecular epidemiological characteristics of osteoarthritis-associated Brucella melitensis in China: evidence from whole-genome sequencing-based analysis.

BACKGROUND: Brucellosis, developing complications including arthritis, spondylitis, sacroiliitis, and osteomyelitis, is one of the most common zoonotic diseases in the current world which causes economic losses to the livestock industry and is a great public health concern. Brucella melitensis are the main pathogen of brucellosis epidemics in China, most of which are located in northern China. However, there is limited knowledge about the epidemiology of osteoarthritis-associated brucellosis. This study was aimed to reveal the prevalence of osteoarthritis-associated brucellosis in Inner Mongolia and also to investigate the molecular characteristics of B. melitensis isolates. METHODS AND RESULTS: In 2018, the osteoarthritis symptoms of brucellosis in the Brucellosis department of a hospital in Inner Mongolia were investigated. Twenty osteoarthritis-associated B. melitensis strains, isolated from the inpatients in Inner Mongolia during 2013-2017, were subjected to whole genome sequencing. The multilocus sequence type (MLST) and core genome SNP (cgSNP) analysis were conducted to detect molecular epidemiological characteristics. The incidence of brucellosis osteoarthritis symptoms in males (85/120, 70.8%) was significantly higher than that in females (35/120, 29.2%), and the age of patients was concentrated between 41 and 60 years old. In silico analyses indicated ST8 was the prevalent sequence type and the transmission of osteoarthritis-associated B. melitensis among different geographical areas. All strains carry virulence genes, including cgs, lpsA, manCoAg, pgm, pmm, virB4, wbdA and wboA. CONCLUSION: Our study showed the close epidemiologically connection of osteoarthritis-associated B. melitensis strains in northern China. And ST8 was the prevalent sequence type which need our attention.

[Expression of the Ces5a gene in the rat testis].

OBJECTIVE: To study the expression of the Ces5a gene in the development of the rat testis. METHODS: Using RT-PCR, Western blot, immunohistochemistry and HE staining, we determined the mRNA transcription level, protein expression and localization of the Ces5a gene in the testes of three litters of rats at different postnatal (PN) days. RESULTS: The expression of Ces5a mRNA was found in the testis tissue of the rats at 2－65 PN days, low at 2－12 days, decreased to the lowest level at 14－16 days (P < 0.05), but significantly increased at 20－35 days (P < 0.05), and elevated to the highest level at 40－65 days (P < 0.05). The expression of the Ces5a protein was also observed in the testis tissue of the rats at 2－65 PN, low at 2－12 days, with no significant change at 14－16 days (P > 0.05), but markedly increased at 20－35 days (P < 0.05), and again with no significant change at 40－65 days (P > 0.05). The Ces5a protein was expressed in the spermatogonia, spermatocytes and round sperm cells. CONCLUSIONS: The Ces5a gene may be involved in the proliferation and meiosis of rat spermatogonia and play a special role in round spermatogenesis and sperm deformation.

ECSIT facilitates memory CD8+ T cell development by mediating fumarate synthesis during viral infection and tumorigenesis.

Memory CD8+ T cells play a crucial role in infection and cancer and mount rapid responses to repeat antigen exposure. Although memory cell transcriptional programmes have been previously identified, the regulatory mechanisms that control the formation of CD8+ T cells have not been resolved. Here we report ECSIT as an essential mediator of memory CD8+ T cell differentiation. Ablation of ECSIT in T cells resulted in loss of fumarate synthesis and abrogated TCF-1 expression via demethylation of the TCF-1 promoter by the histone demethylase KDM5, thereby impairing memory CD8+ T cell development in a cell-intrinsic manner. In addition, ECSIT expression correlated positively with stem-like memory progenitor exhausted CD8+ T cells and the survival of patients with cancer. Our study demonstrates that ECSIT-mediated fumarate synthesis stimulates TCF-1 activity and memory CD8+ T cell development during viral infection and tumorigenesis and highlights the utility of therapeutic fumarate analogues and PD-L1 inhibition for tumour immunotherapy.

Data analysis guidelines for single-cell RNA-seq in biomedical studies and clinical applications.

The application of single-cell RNA sequencing (scRNA-seq) in biomedical research has advanced our understanding of the pathogenesis of disease and provided valuable insights into new diagnostic and therapeutic strategies. With the expansion of capacity for high-throughput scRNA-seq, including clinical samples, the analysis of these huge volumes of data has become a daunting prospect for researchers entering this field. Here, we review the workflow for typical scRNA-seq data analysis, covering raw data processing and quality control, basic data analysis applicable for almost all scRNA-seq data sets, and advanced data analysis that should be tailored to specific scientific questions. While summarizing the current methods for each analysis step, we also provide an online repository of software and wrapped-up scripts to support the implementation. Recommendations and caveats are pointed out for some specific analysis tasks and approaches. We hope this resource will be helpful to researchers engaging with scRNA-seq, in particular for emerging clinical applications.