Biology subjects

Funaki, M.

Publications and source records attributed to Funaki, M..

7 recordsLinked to original sources

bioRxiv2026

Promyelocytic leukemia (PML) suppresses hepatitis B virus cccDNA transcription through SUMOylation- and SMC5/6-dependent mechanisms

Chronic hepatitis B virus (HBV) infection persists under current antiviral therapy because covalently closed circular DNA (cccDNA) remains in the infected hepatocytes as a durable transcriptional template. Although type I interferon (IFN-I) can reduce HBV cccDNA gene expression, the host effectors and mechanisms that restrict cccDNA remain incompletely defined. Using a minicircle-based HBV cccDNA expressing a Gaussia luciferase reporter gene (mcHBV-GLuc), we investigated how promyelocytic leukemia protein (PML) suppresses HBV cccDNA activity. Multiple PML isoforms reduced cccDNA-driven reporter activity and HBsAg production, and HBx-deficient ({Delta}X) mcHBV cccDNA was more susceptible than wild-type cccDNA to PML-mediated inhibition. Interestingly, efficient antiviral activity required the major PML SUMOylation sites. Disruption of SMC5/6 function attenuated PML-mediated repression of HBx-deficient cccDNA, associated with reduced PML SUMOylation and PML nuclear-body organization. These findings identify PML as a SUMO-dependent inhibitor of HBV cccDNA activity and reveal a context-dependent functional relationship between PML and SMC5/6 that is modulated by HBx.

immunology↗

bioRxiv2026

HEPLISAV-B Breaks Immune Tolerance and Induces HBV Control via CD4 T Cell-Dependent Mechanisms in a Chronic Hepatitis B Mouse Model

BackgroundChronic hepatitis B virus (HBV) infection (CHB) affects nearly 300 million individuals globally and remains incurable with current antiviral therapies, which suppress viral replication but rarely achieve functional cure defined by sustained loss of hepatitis B surface antigen (HBsAg). CHB is characterized by profound virus-induced immune tolerance that limits the efficacy of conventional therapeutic vaccination strategies. ObjectiveTo evaluate the therapeutic efficacy and immunological mechanisms of HEPLISAV-B, a CpG-1018-adjuvanted HBsAg vaccine, in breaking immune tolerance and inducing functional cure-like responses in a murine model of CHB. DesignUsing the adeno-associated virus-HBV (AAV-HBV) mouse model, mice with high levels of persistent HBV viremia were vaccinated with two doses of HEPLISAV-B. Virological outcomes in the blood and liver, immune responses and mechanisms were assessed. ResultsHEPLISAV-B induced rapid and durable HBsAg clearance, markedly reduced circulating and intrahepatic HBV DNA and RNA, and suppressed viral replication without hepatocellular injury. Vaccination elicited robust, sustained anti-HBs IgG1 and IgA responses, enhanced HBsAg-specific T and B cell immunity, reduced CD4 regulatory T cells, and decreased PD-1 expression on CD4 T cells. Therapeutic efficacy was strictly dependent on CD4 T cells and the CD40/CD40L signaling pathway, but independent of CD8 T cells, indicating a CD4-driven, non-cytolytic antiviral mechanism critical for HEPLISAV-B induced HBV control. ConclusionHEPLISAV-B effectively breaks HBV-induced immune tolerance and restores coordinated antiviral immunity through a CD4 T cell-/CD40L-dependent pathway. The findings support its potential as a therapeutic vaccine in CHB patients. Key messagesO_ST_ABSWhat is already known on this topicC_ST_ABSChronic HBV infection is marked by profound virus-induced immune tolerance, current antiviral therapies and vaccines fail to reliably induce HBsAg loss or restore effective antiviral immunity, highlighting the need for immune-based therapeutic strategies. What this study addsThis study demonstrates that the clinically approved vaccine HEPLISAV-B can break HBV immune tolerance in a chronic HBV mouse model, inducing durable HBsAg clearance and anti-HBs immunity, non-cytolytic depletion of intrahepatic HBV DNA, through a mechanism strictly dependent on CD4 T cells and CD40/CD40L signaling. How this study might affect research, practice or policyThese findings defined a CD4 T cell-CD40L/CD40 axis that is critical in CHB functional cure, and support testing HEPLISAV-B as a therapeutic vaccine in CHB patients. O_FIG O_LINKSMALLFIG WIDTH=165 HEIGHT=200 SRC="FIGDIR/small/711721v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@1f78e63org.highwire.dtl.DTLVardef@1a54631org.highwire.dtl.DTLVardef@1a33ee2org.highwire.dtl.DTLVardef@75a2bd_HPS_FORMAT_FIGEXP M_FIG Graphical Abstract C_FIG

immunology↗

bioRxiv2024

CD24-Fc resolves inflammation and rescues CD8 T cells with polyfunctionality during HIV-1 infection under cART

The persistence of HIV-1 reservoirs during combination anti-retroviral therapy (cART) leads to chronic immune activation and systemic inflammation in people with HIV (PWH), associating with a suboptimal immune reconstitution as well as an increased risk of non-AIDS events. This highlights the needs to develop novel therapy for HIV-1 related diseases in PWH. In this study, we assessed the therapeutic effect of CD24-Fc, a fusion protein with anti-inflammatory properties that interacts with danger-associated molecular patterns (DAMPs) and siglec-10, in chronic HIV-1 infection model using humanized mice undergoing suppressive cART. Our findings show that CD24-Fc treatment significantly reduced inflammation and immune hyperactivation in vivo when combined with cART. CD24-Fc mediated resolution of inflammation was associated with improved recovery of CD4 T cells, reduced immune activation, restored central memory T cells and reversal of immune cell exhaustion phenotype. Notably, CD24-Fc treatment rescued CXCR5+ CD8 central memory T cell (TCM) which correlated with increased polyfunctionality in HIV-specific T cells in humanized mice and in cultured peripheral blood mononuclear cells (PBMCs) from PWH. This restoration of CXCR5+ memory CD8 T cells was associated with HIV replication inhibition, delayed viral rebound and reduced HIV-1 pathogenesis upon cART cessation. This study suggests that CD24-Fc treatment could represent a promising new therapeutic strategy for managing chronic systemic inflammation and associated diseases in PWH. Author summaryCombination antiretroviral therapy (cART) cannot block viral gene expression from activated HIV proviral DNA in reservoir cells, contributing to chronic immune activation and inflammation associated diseases in people with HIV (PWH). The therapeutic treatment of anti-inflammatory fusion protein CD24-Fc in humanized mice during suppressive cART (i) resolves inflammation and chronic HIV-1 immune pathogenesis during suppressive cART, (ii) rescues CXCR5-expressing CD8 memory T cells and enhances antiviral response in humanized mice and PWH PBMCs, (iii) delays virus rebound and reduces viral pathogenesis after cART cessation. Thus, CD24-Fc could provide a novel therapeutic strategy for treating chronic systemic inflammation and associated diseases in PWH.

immunology↗

bioRxiv2023

Persistent hepatitis B virus and HIV coinfections in dually humanized mice engrafted with human liver and immune system

Chronic hepatitis B (CHB), caused by hepatitis B virus (HBV), remains a major medical problem. HBV has a high propensity for progressing to chronicity and can result in severe liver disease, including fibrosis, cirrhosis and hepatocellular carcinoma. CHB patients frequently present with viral coinfection, including HIV and hepatitis delta virus. About 10% of chronic HIV carriers are also persistently infected with HBV which can result in more exacerbated liver disease. Mechanistic studies of HBV-induced immune responses and pathogenesis, which could be significantly influenced by HIV infection, have been hampered by the scarcity of immunocompetent animal models. Here, we demonstrate that humanized mice dually engrafted with components of a human immune system and a human liver supported HBV infection, which was partially controlled by human immune cells, as evidenced by lower levels of serum viremia and HBV replication intermediates in the liver. HBV infection resulted in priming and expansion of human HLA-restricted CD8+ T cells, which acquired an activated phenotype. Notably, our dually humanized mice support persistent coinfections with HBV and HIV which opens opportunities for analyzing immune dysregulation during HBV and HIV coinfection and preclinical testing of novel immunotherapeutics.

microbiology↗

bioRxiv2022

Molecular engineering of emicizumab to improve hemophilia A treatment

Emicizumab, a factor (F)VIIIa-function mimetic bispecific antibody (BsAb) to FIXa and FX, has become an indispensable treatment for people with hemophilia A (PwHA). Although emicizumab is very potent, long-term outcomes from the clinical studies suggest that a small proportion of PwHA still experiences bleeds. Additionally, non-clinical studies indicate that the maximum cofactor activity of emicizumab is lower than international standard activity (100 IU/dL of FVIII). An increased cofactor activity BsAb would benefit such patients. Here, we report NXT007, a BsAb binding FIXa and FX developed through further engineering of emicizumab. Emicizumab has a common light chain, but through advances in antibody engineering, we were able to create a more potent BsAb with two new non-common light chains. After extensive optimization of the heavy and light chains, the resulting BsAb, NXT007, exerted in vitro thrombin generation (TG) activity in hemophilia A plasma equivalent to 100 IU/dL of FVIII when triggered by tissue factor. NXT007 demonstrated potent hemostatic activity in an acquired hemophilia A model in non-human primates at a much lower dosage than emicizumab, consistent with an around 30-fold dose shift in the in vitro TG activity between NXT007 and emicizumab. Moreover, together with Fc engineering that enhanced FcRn binding and reduced in vivo clearance, we demonstrate that NXT007 could be effective at a much lower dosage with a longer dosing interval compared to emicizumab. These non-clinical results suggest that NXT007 could maintain a non-hemophilic range of coagulation potential in PwHA and provides a rationale for its clinical testing.

bioengineering↗

bioRxiv2021

Non-neutralizing antibodies targeting the immunogenic regions of HIV-1 envelope reduce mucosal infection and virus burden in humanized mice

Antibodies are principal immune components elicited by vaccines to induce protection from microbial pathogens. In the Thai RV144 HIV-1 vaccine trial, vaccine efficacy was 31% and the sole primary correlate of reduced risk was shown to be vigorous antibody response targeting the V1V2 region of HIV-1 envelope. Antibodies against V3 also were inversely correlated with infection risk in subsets of vaccinees. Antibodies recognizing these regions, however, do not exhibit potent neutralizing activity. Therefore, we examined the antiviral potential of poorly neutralizing monoclonal antibodies (mAbs) against immunodominant V1V2 and V3 sites by passive administration of human mAbs to humanized mice engrafted with CD34+ hematopoietic stem cells, followed by mucosal challenge with an HIV-1 infectious molecular clone (IMC) expressing the envelope of a tier 2 resistant HIV-1 strain. Treatment with anti-V1V2 mAb 2158 or anti-V3 mAb 2219 did not prevent infection, but both reduced the virus burden, and V3 mAb 2219 displayed a superior potency compared to V1V2 mAb 2158. While these mAbs had no or weak neutralizing activity and elicited undetectable levels of antibody-dependent cellular cytotoxicity (ADCC), V3 mAb 2219 displayed a greater capacity to bind virus- and cell-associated HIV-1 envelope and to mediate antibody-dependent cellular phagocytosis (ADCP) and C1q complement binding as compared to V1V2 mAb 2158. Mutations in the Fc region of 2219 abolished these effector activities and abrogated virus control in humanized mice. These results demonstrate the importance of Fc functions other than ADCC for antibodies without potent neutralizing activity.

immunology↗

bioRxiv2019

Non-production vegetation has a positive effect on ecological processes in agroecosystems

An ever-expanding human population, ongoing global climatic changes, and the spread of intensive farming practices is putting increasing pressure on agroecosystems and the inherent biodiversity they contain. Non-production vegetation elements, such as woody patches, riparian margins, and inter-crop and restoration plantings, are vital for conserving biodiversity in agroecosystems and are therefore considered key to sustaining the biotic and abiotic processes underpinning sustainable and resilient agroecosystems. Despite this critical role, there is a surprising lack of synthesis of which types of non-production vegetation elements drive and/or support ecological processes and the mechanisms by which this occurs. Using a systematic, quantitative literature review of 342 articles, we asked: what are the effects of non-production vegetation elements on agroecosystem processes and how are these processes measured within global agroecosystems? Our literature search focussed on the effects of non-production vegetation related to faunal, weed, disease, and abiotic processes. The majority (61%) of studies showed positive effects on ecological processes: non-production vegetation increased the presence, level or rate of the studied process. However, rather than directly measuring ecosystem processes, 83% of studies inferred processes using proxies for ecosystem function, such as biodiversity and soil physicochemical properties. Studies that directly measured non-production vegetation effects focussed on a limited number of vegetation effects including comparisons of vegetation types, farm-scale configuration, and proximity to vegetation. Moreover, studies directly measuring ecosystem processes were similarly limited, dominated by invertebrate biocontrol, predator and natural enemy spillover, animal movement, and ecosystem cycling. We identify research gaps and present a pathway for future research in understanding the ecosystem components and processes that build resilient, sustainable agroecosystems.

ecology↗