Yuichiro Hara, Haruki Kitamura, Kouki Matsuda, Sayaka Sukegawa, Kosuke Tanimoto, Chieko Fujisaki, Kenji Maeda, Hiroaki Takeuchi . Identification of a novel small molecule facilitating HIV elim2025 · 出版者・発行元： openRxiv Abstract The development of antiretroviral therapy (ART) has significantly improved the prognosis of people living with HIV (PLWH). However, reservoirs of latent viruses represent a major barrier to achieving a complete cure of HIV infection. To overcome the burden of viral latency, the “Shock-and-Kill” strategy employs latency-reversing agents (LRAs) to reactivate the virus and thus render it susceptible to elimination. Existing LRAs are not optimal and there is an unmet need for improvement. By screening a small molecule library, we identified the novel LRA candidate 2-HSB (2-hydrido-2,2’-spirobi(1,3,2-benzodioxaphosphole)) which not only reactivates latent HIV provirus but also induces specific cytopathic effects in both monocytic and T lymphocytic latent HIV reservoirs. Thus, this novel compound represents a dual “shock and kill” agent, unlike known LRAs which are limited to the “shock”. The probable involvement of HIV-1 tat protein may account for its selectivity. Although both shock and kill effects seemed to be regulated by spleen tyrosine kinase, they were independent of each other, indicating that neither activation-induced cell death nor cell death-induced reactivation was occurring. Crucially, 2-HSB induced viral transcription in ART-suppressed PLWH samples in vitro. Our findings present 2-HSB as a promising dual-action compound for the “Shock and Kill” strategy, demonstrating efficacy in both transformed cell lines and clinically-relevant primary samples. These results raise the possibility of distinguishing the mode of action of the two effects, potentially leading to the development of a single agent causing both HIV-1 reactivation and elimination and contributing to the improvement of treatment. DOI： 10.64898/2025.12.03.692014
Iwamoto N, Takamatsu Y, Asai Y, Tsuchiya K, Matsuda K, Oshiro Y, Inamura N, Terada M, Nemoto T, Kimura M, Saito S, Morioka S, Kenji M, Mitsuya H, Ohmagari N . High diagnostic accuracy of quant2024 · 記述言語： 英語 掲載種別： 研究論文（学術雑誌） 出版者・発行元： Heliyon Background: Antibody testing can easily evaluate the clinical status of patients, aid in the diagnosis of multisystem inflammatory syndrome, and monitor the immunity level in the population. However, the applicability of serological tests in detecting antibodies against the severe acute respiratory syndrome 2 (SARS-CoV-2) spike-binding protein remains limited. This study aimed to quantify both serum-derived neutralizing immunoglobulin-G (IgG) antibody activity and the amount of anti-SARS-CoV-2 Spike-IgG (S-IgG) in convalescent sera/plasmas and evaluate the direct correlation between the in vitro IgG-EC50 values and S-IgG values. Methods: We evaluated the neutralizing activity of purified IgG (IgG-EC50), quantified S-IgG in the serum/plasma of consecutive COVID-19 convalescent individuals using a cell-based virus-neutralizing assay, and determined the correlation between IgG-EC50 and S-IgG. In addition, we evaluated rational cut-off values using the receiver operating characteristic (ROC) curve and calculated the sensitivity and specificity of the quantitative S-IgG assay for moderate and high IgG-EC50. Results: A high correlation was observed between S-IgG and IgG-EC50 with a Spearman's ρ value of −0.748 (95 % confidence interval [CI]: −0.804–0.678). Using an IgG-EC50 of 50 μg/mL and 20 μg/mL as the cut-off values for moderate and high in vitro neutralizing activity, respectively, the Youden's index values of 287.5 binding antibody units (BAU)/mL and 454.1 BAU/mL determined from the ROC curve showed the highest diagnostic accuracy, with Kappa values of 0.884 (95 % CI: 0.823–0.946) and 0.920 (95 % CI: 0.681–0.979), respectively. Conclusions: Quantitative S-IgG tests are a useful and convenient tool for estimating in vitro virus-neutralizing activity, with a high correlation with IgG-EC50 when the rational cut-off value is carefully determined. DOI： 10.1016/j.heliyon.2024.e24513 Scopus PubMed
Yamamoto S, Matsuda K, Maeda K, Mizoue T, Horii K, Okudera K, Tan T, Oshiro Y, Inamura N, Nemoto T, S Takeuchi J, Konishi M, Sugiyama H, Aoyanagi N, Sugiura W, Ohmagari N . Protection of Omicr2023 · 記述言語： 英語 掲載種別： 研究論文（学術雑誌） 出版者・発行元： Open Forum Infectious Diseases Background: Data are limited on the protective role of the Omicron BA bivalent vaccine, previous infection, and their induced neutralizing antibodies against Omicron XBB.1.16 and EG.5.1 infection. Methods: We conducted a nested case-control analysis among tertiary hospital staff in Tokyo who had received ≥3 doses of COVID-19 vaccines and donated blood samples in June 2023 (1 month before the Omicron XBB.1.16 and EG.5.1 wave). We identified 206 symptomatic cases between June and September 2023 and selected their controls with 1:1 propensity score matching. We examined the association of vaccination, previous infection, and preinfection live virus neutralizing antibody titers against Omicron XBB.1.16 and EG.5.1 with the risk of COVID-19 infection. Results: Previous infection during the Omicron BA-or XBB-dominant phase was associated with a significantly lower infection risk during the XBB.1.16 and EG.5.1-dominant phase than infection-naive status, with 70% and 100% protection, respectively, whereas Omicron BA bivalent vaccination showed no association. Preinfection neutralizing titers against XBB.1.16 and EG.5.1 were 39% (95% CI, 8%-60%) and 28% (95% CI, 8%-44%) lower in cases than matched controls. Neutralizing activity against XBB.1.16 and EG.5.1 was somewhat detectable in the sera of individuals with previous infection but barely detectable in those who were infection naive and received the Omicron bivalent vaccine. Conclusions: In the era when the Omicron XBB vaccine was unavailable, the Omicron BA bivalent vaccine did not confer the neutralizing activity and protection against Omicron XBB.1.16 and EG.5.1 symptomatic infection. The previous infection afforded neutralizing titers and protection against symptomatic infection with these variants. DOI： 10.1093/ofid/ofae519 Scopus PubMed
