Clinical perspectives of Treponema pallidum subsp. Endemicum infection in adults, particularly men who have sex with men in the Kansai area, Japan: A case series

Bejel, caused by Treponema pallidum subsp. Endemicum (TEN), is a locally transmitted disease among children and juveniles in hot and dry regions. The number of adult cases of TEN infection outside of endemic areas has recently increased. We clinically examined five cases of TEN infection among adult cases previously reported in Japan. TEN infection mainly developed among young to middle-aged men who have sex with men (MSM). The clinical features of cases of TEN infection were similar to those of primary- and secondary-stage T. pallidum subsp. pallidum (TPA) infection. Genital lesions were common as the primary lesion. The clinical features and laboratory parameters of cases of TEN infection were similar to those of TPA infection. Most of the isolated strains had the A2058G mutation in 23S rDNA, which is responsible for resistance to macrolides. We also performed the systemic literature review of the TEN cases outside the endemic countries. The recent reported cases diagnosed with molecular methods shared the clinical features, occurred in young-to middle-aged sexually active persons in urban areas of developed countries and often accompanied with genital lesions, which were distinct from the classic description of bejel. This case series and the literature review provides important clinical insights and will contribute to the clinical detection of this rarely identified disease in developed countries. The surveillance of treponematoses, including TEN infection, using molecular diagnostic techniques is also warranted in developed countries, for the purpose of grasping the epidemic situation and control the local transmission

Identification of the P-TEFb complex-interacting domain of Brd4 as an inhibitor of HIV-1 replication by functional cDNA library screening in MT-4 cells

AbstractWe conducted a phenotypic cDNA screening using a T cell line-based assay to identify human genes that render cells resistant to human immunodeficiency virus type 1 (HIV-1). We isolated potential HIV-1 resistance genes, including the carboxy terminal domain (CTD) of bromodomain-containing protein 4 (Brd4). Expression of GFP-Brd4-CTD was tolerated in MT-4 and Jurkat cells in which HIV-1 replication was markedly inhibited. We provide direct experimental data demonstrating that Brd4-CTD serves as a specific inhibitor of HIV-1 replication in T cells. Our method is a powerful tool for the identification of host factors that regulate HIV-1 replication in T cells

Substitution of the myristoylation signal of human immunodeficiency virus type 1 Pr55Gag with the phospholipase C-δ1 pleckstrin homology domain results in infectious pseudovirion production

The matrix domain (MA) of human immunodeficiency virus type 1 Pr55Gag is covalently modified with a myristoyl group that mediates efficient viral production. However, the role of myristoylation, particularly in the viral entry process, remains uninvestigated. This study replaced the myristoylation signal of MA with a well-studied phosphatidylinositol 4,5-biphosphate-binding plasma membrane (PM) targeting motif, the phospholipase C-δ1 pleckstrin homology (PH) domain. PH–Gag–Pol PM targeting and viral production efficiencies were improved compared with Gag–Pol, consistent with the estimated increases in Gag–PM affinity. Both virions were recovered in similar sucrose density-gradient fractions and had similar mature virion morphologies. Importantly, PH–Gag–Pol and Gag–Pol pseudovirions had almost identical infectivity, suggesting a dispensable role for myristoylation in the virus life cycle. PH–Gag–Pol might be useful in separating the myristoylation-dependent processes from the myristoylation-independent processes. This the first report demonstrating infectious pseudovirion production without myristoylated Pr55Gag

Extracellular nanovesicles for packaging of CRISPR-Cas9 protein and sgRNA to induce therapeutic exon skipping

Prolonged expression of the CRISPR-Cas9 nuclease and gRNA from viral vectors may cause off-target mutagenesis and immunogenicity. Thus, a transient delivery system is needed for therapeutic genome editing applications. Here, we develop an extracellular nanovesicle-based ribonucleoprotein delivery system named NanoMEDIC by utilizing two distinct homing mechanisms. Chemical induced dimerization recruits Cas9 protein into extracellular nanovesicles, and then a viral RNA packaging signal and two self-cleaving riboswitches tether and release sgRNA into nanovesicles. We demonstrate efficient genome editing in various hard-to-transfect cell types, including human induced pluripotent stem (iPS) cells, neurons, and myoblasts. NanoMEDIC also achieves over 90% exon skipping efficiencies in skeletal muscle cells derived from Duchenne muscular dystrophy (DMD) patient iPS cells. Finally, single intramuscular injection of NanoMEDIC induces permanent genomic exon skipping in a luciferase reporter mouse and in mdx mice, indicating its utility for in vivo genome editing therapy of DMD and beyond

Novel Mouse Xenograft Models Reveal a Critical Role of CD4+ T Cells in the Proliferation of EBV-Infected T and NK Cells

Epstein-Barr virus (EBV), a ubiquitous B-lymphotropic herpesvirus, ectopically infects T or NK cells to cause severe diseases of unknown pathogenesis, including chronic active EBV infection (CAEBV) and EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH). We developed xenograft models of CAEBV and EBV-HLH by transplanting patients' PBMC to immunodeficient mice of the NOD/Shi-scid/IL-2Rγnull strain. In these models, EBV-infected T, NK, or B cells proliferated systemically and reproduced histological characteristics of the two diseases. Analysis of the TCR repertoire expression revealed that identical predominant EBV-infected T-cell clones proliferated in patients and corresponding mice transplanted with their PBMC. Expression of the EBV nuclear antigen 1 (EBNA1), the latent membrane protein 1 (LMP1), and LMP2, but not EBNA2, in the engrafted cells is consistent with the latency II program of EBV gene expression known in CAEBV. High levels of human cytokines, including IL-8, IFN-γ, and RANTES, were detected in the peripheral blood of the model mice, mirroring hypercytokinemia characteristic to both CAEBV and EBV-HLH. Transplantation of individual immunophenotypic subsets isolated from patients' PBMC as well as that of various combinations of these subsets revealed a critical role of CD4+ T cells in the engraftment of EBV-infected T and NK cells. In accordance with this finding, in vivo depletion of CD4+ T cells by the administration of the OKT4 antibody following transplantation of PBMC prevented the engraftment of EBV-infected T and NK cells. This is the first report of animal models of CAEBV and EBV-HLH that are expected to be useful tools in the development of novel therapeutic strategies for the treatment of the diseases

High transmissibility of norovirus among infants and school children during the 2016/17 season in Osaka, Japan

The number of person-to-person transmitted norovirus cases (n = 4,712) in school children in Osaka, Japan, during 2016/17 was the largest since 2012/13. Norovirus outbreaks were reported by 101 schools including 53 nursery schools (1,927 cases), 18 kindergartens (1,086 cases) and 30 elementary schools (1,699 cases). The dominant genotype among outbreaks was GII.P16-GII. 2 (57.4%; 58/101), followed by GII.P2-GII.2 (8.9%; 9/101) and GII.P7-GII.6 (5.9%; 6/101). GII.4 was not detected despite dominance in previous years

A child with acute encephalopathy associated with quadruple viral infection

infection does not always result in AE. The risk factors for developing infantile AE upon such infection remain to be determined. Here we report an infant with AE coinfected with human herpesvirus 6 (HHV-6) and three picornaviruses: coxsackievirus A6 (CVA6), enterovirus D68 (EV-D68), and human parechovirus (HPeV). EV-D68 was vertically transmitted to the infant from his mother. CVA6 and HPeV were likely transmitted to the infant at the nursery school. HHV-6 might have been re-activated in the patient. It remains undetermined which pathogen played the central role in the AE pathogenesis. However, active, simultaneous infection by four viruses likely evoke a cytokine storm, leading to the pathogenesis of AE. Conclusion: Infant cases with active quadruple infection by potentially AE-causing viruses have seldom been reported, partly because systematic nucleic acid-based laboratory tests on picornaviruses are not common. We propose that simultaneous viral infection may serve as a risk factor for the development of AE

Impact of COVID-19 Countermeasures on Pediatric Infections

(1) Background: General infection control measures have been implemented at the societal level against COVID-19 since the middle of 2020, namely, hand hygiene, universal masking, and social distancing. The suppressive effect of the social implementation of general infection control measures on pediatric infections has not been systematically assessed. (2) Methods: We addressed this issue based on publicly available data on 11 pediatric infections reported weekly by sentinel sites in Osaka and Iwate prefectures in Japan since 2010. We obtained the 5-year average for 2015–2019 and compared it to the weekly report for 2020–2021. (3) Results: The rate of 6 of the 11 pediatric infections decreased significantly during 2020–2021, regardless of the magnitude of the prevalence of COVID-19 in both areas. However, only RSV infection, one of the six infections, was endemic in 2021. Exanthem subitum was not as affected by COVID-19 countermeasures as other diseases. (4) Conclusions: The social implementation of infectious disease control measures was effective in controling certain infectious diseases in younger age groups, where compliance with the countermeasures should not be as high as that of adults