Key Points• Humanized mice, IBMIhuNOG, were generated by intra-bone marrow injection of human CD1331 hematopoietic stem cells.• HTLV-1-infected IBMIhuNOG mice recapitulated distinct ATL-like symptoms as well as HTLV-1-specific adaptive immune responses.Human T-cell leukemia virus type 1 (HTLV-1) is causally associated with adult T-cell leukemia (ATL), an aggressive T-cell malignancy with a poor prognosis. To elucidate ATL pathogenesis in vivo, a variety of animal models have been established; however, the mechanisms driving this disorder remain poorly understood due to deficiencies in each of these animal models. Here, we report a novel HTLV-1-infected humanized mouse model generated by intra-bone marrow injection of human CD133 1 stem cells into NOD/Shi-scid/IL-2Rgc null (NOG) mice (IBMI-huNOG mice).Upon infection, the number of CD4 1 human T cells in the periphery increased rapidly, and atypical lymphocytes with lobulated nuclei resembling ATL-specific flower cells were observed 4 to 5 months after infection. Proliferation was seen in both CD25 2 and CD25 1 CD4 T cells with identical proviral integration sites; however, a limited number of CD25 1 -infected T-cell clones eventually dominated, indicating an association between clonal selection of infected T cells and expression of CD25. Additionally, HTLV-1-specific adaptive immune responses were induced in infected mice and might be involved in the control of HTLV-1-infected cells. Thus, the HTLV-1-infected IBMI-huNOG mouse model successfully recapitulated the development of ATL and may serve as an important tool for investigating in vivo mechanisms of ATL leukemogenesis and evaluating anti-ATL drug and vaccine candidates. (Blood. 2014;123(3):346-355)

In the peripheral blood leukocytes (PBLs) from the carriers of the human T-lymphotropic virus type-1 (HTLV-1) or the patients with adult T-cell leukemia (ATL), nuclear factor kappaB (NF-κB)-mediated antiapoptotic signals are constitutively activated primarily by the HTLV-1-encoded oncoprotein Tax. Tax interacts with the I κB kinase regulatory subunit NEMO (NF-κB essential modulator) to activate NF-κB, and this interaction is maintained in part by a molecular chaperone, heat-shock protein 90 (HSP90), and its co-chaperone cell division cycle 37 (CDC37). The antibiotic geldanamycin (GA) inhibits HSP90's ATP binding for its proper interaction with client proteins. Administration of a novel water-soluble and less toxic GA derivative, 17-dimethylaminoethylamino-17-demethoxygeldanamycin hydrochloride (17-DMAG), to Tax-expressing ATL-transformed cell lines, C8166 and MT4, induced significant degradation of Tax. 17-DMAG also facilitated growth arrest and cellular apoptosis to C8166 and MT4 and other ATL cell lines, although this treatment has no apparent effects on normal PBLs. 17-DMAG also downregulated Tax-mediated intracellular signals including the activation of NF-κB, activator protein 1 or HTLV-1 long terminal repeat in Tax-transfected HEK293 cells. Oral administration of 17-DMAG to ATL model mice xenografted with lymphomatous transgenic Lck-Tax (Lck proximal promoter-driven Tax transgene) cells or HTLV-1-producing tumor cells dramatically attenuated aggressive infiltration into multiple organs, inhibited de novo viral production and improved survival period. These observations identified 17-DMAG as a promising candidate for the prevention of ATL progression.

Background: The reliable diagnosis of human T-cell leukemia virus type 1 (HTLV-1) infection is important, particularly as it can be vertically transmitted by breast feeding mothers to their infants. However, current diagnosis in Japan requires a confirmatory western blot (WB) test after screening/primary testing for HTLV-1 antibodies, but this test often gives indeterminate results. Thus, this collaborative study evaluated the reliability of diagnostic assays for HTLV-1 infection, including a WB-based one, along with line immunoassay (LIA) as an alternative to WB for confirmatory testing. Results: Using peripheral blood samples from blood donors and pregnant women previously serologically screened and subjected to WB analysis, we analyzed the performances of 10 HTLV-1 antibody assay kits commercially available in Japan. No marked differences in the performances of eight of the screening kits were apparent. However, LIA determined most of the WB-indeterminate samples to be conclusively positive or negative (an 88.0% detection rate). When we also compared the sensitivity to HTLV-1 envelope gp21 with that of other antigens by LIA, the sensitivity to gp21 was the strongest. When we also compared the sensitivity to envelope gp46 by LIA with that of WB, LIA showed stronger sensitivity to gp46 than WB did. These findings indicate that LIA is an alternative confirmatory test to WB analysis without gp21. Therefore, we established a novel diagnostic test algorithm for HTLV-1 infection in Japan,

The cerebrovascular-specific molecular mechanism in Alzheimer’s disease (AD) was investigated by employing comprehensive and accurate quantitative proteomics. Highly purified brain capillaries were isolated from cerebral gray and white matter of four AD and three control donors, and examined by SWATH (sequential window acquisition of all theoretical fragment ion spectra) proteomics. Of the 29 ribosomal proteins that were quantified, 28 (RPLP0, RPL4, RPL6, RPL7A, RPL8, RPL10A, RPL11, RPL12, RPL14, RPL15, RPL18, RPL23, RPL27, RPL27A, RPL31, RPL35A, RPS2, RPS3, RPS3A, RPS4X, RPS7, RPS8, RPS14, RPS16, RPS20, RPS24, RPS25, and RPSA) were significantly upregulated in AD patients. This upregulation of ribosomal protein expression occurred only in brain capillaries and not in brain parenchyma. The protein expression of protein processing and N-glycosylation-related proteins in the endoplasmic reticulum (DDOST, STT3A, MOGS, GANAB, RPN1, RPN2, SEC61B, UGGT1, LMAN2, and SSR4) were also upregulated in AD brain capillaries and was correlated with the expression of ribosomal proteins. The findings reported herein indicate that the ribosome complex, the subsequent protein processing and N-glycosylation-related processes are significantly and specifically upregulated in the brain capillaries of AD patients.

Background In order to tackle the COVID‐19 pandemic, a COVID‐19 convalescent plasma (CCP) procurement program was initiated in Japan in April 2020. The program was a collaboration between a government‐managed national hospital, an infectious disease research institute, and a blood banking organization. Each party assumed different responsibilities: recruitment, SARS‐CoV‐2 antibody profiling, and plasmapheresis; conduction of screening tests; and SARS‐CoV‐2 blood testing, respectively. Methods We adopted a two‐point screening approach before the collected CCP was labeled as a CCP product for investigational use, for which we mainly tested anti‐SARS‐CoV‐2 antibody eligibility and blood product eligibility. Anti‐SARS‐CoV‐2 spike protein titer was measured using enzyme‐linked immunosorbent assay, and the IC 50 value was denoted as the neutralizing activity. Blood donor eligibility was extended beyond the normal blood donation guidelines to include a broader range of participants. After both eligibility criteria were confirmed, participants were asked to revisit the hospital for blood donation, which is a unique aspect of the Japanese CCP program, as most donations are taking place in normal blood donation venues in other countries. Some donors were re‐scheduled for repeat plasma donations. As public interest in anti‐SARS‐CoV‐2 antibodies increased, test results were given to the participants. Results As of September 17, 2020, our collection of CCP products was sufficient to treat more than 100 patients. As a result, projects for administration and distribution are also being conducted. Conclusions We successfully implemented a CCP procurement scheme with the goal to expand to other parts of the country to improve treatment options for COVID‐19.