技术资料

Background & AimsThe immune tolerance induced by hepatitis B virus (HBV) is a major challenge for achieving effective viral clearance,and the mechanisms involved are not well-understood. One potential factor involved in modulating immune responses is mesencephalic astrocyte-derived neurotrophic factor (MANF),which has been reported to be increased in patients with chronic hepatitis B. In this study,our objective is to examine the role of MANF in regulating immune responses to HBV.MethodsWe utilized a commonly used HBV-harboring mouse model,where mice were hydrodynamically injected with the pAAV/HBV1.2 plasmid. We assessed the HBV load by measuring the levels of various markers including hepatitis B surface antigen,hepatitis B envelope antigen,hepatitis B core antigen,HBV DNA,and HBV RNA.ResultsOur study revealed that following HBV infection,both myeloid cells and hepatocytes exhibited increased expression of MANF. Moreover,we observed that mice with myeloid-specific MANF knockout (ManfMye-/-) displayed reduced HBV load and improved HBV-specific T cell responses. The decreased HBV-induced tolerance in ManfMye-/- mice was associated with reduced accumulation of myeloid-derived suppressor cells (MDSCs) in the liver. Restoring MDSC levels in ManfMye-/- mice through MDSC adoptive transfer reinstated HBV-induced tolerance. Mechanistically,we found that MANF promoted MDSC expansion by activating the IL-6/STAT3 pathway. Importantly,our study demonstrated the effectiveness of a combination therapy involving an hepatitis B surface antigen vaccine and nanoparticle-encapsulated MANF siRNA in effectively clearing HBV in HBV-carrier mice.ConclusionThe current study reveals that MANF plays a previously unrecognized regulatory role in liver tolerance by expanding MDSCs in the liver through IL-6/STAT3 signaling,leading to MDSC-mediated CD8+ T cell exhaustion. Graphical abstract View Publication

Mitochondria react to infection with sub-lethal signals in the apoptosis pathway. Mitochondrial signals can be inflammatory but mechanisms are only partially understood. We show that activation of the caspase-activated DNase (CAD) mediates mitochondrial pro-inflammatory functions and substantially contributes to host defense against viral infection. In cells lacking CAD,the pro-inflammatory activity of sub-lethal signals was reduced. Experimental activation of CAD caused transient DNA-damage and a pronounced DNA damage response,involving major kinase signaling pathways,NF-κB and cGAS/STING,driving the production of interferon,cytokines/chemokines and attracting neutrophils. The transcriptional response to CAD-activation was reminiscent of the reaction to microbial infection. CAD-deficient cells had a diminished response to viral infection. Influenza virus infected CAD-deficient mice displayed reduced inflammation in lung tissue,higher viral titers and increased weight loss. Thus,CAD links the mitochondrial apoptosis system and cell death caspases to host defense. CAD-driven DNA damage is a physiological element of the inflammatory response to infection. View Publication

Human regulatory T cells (Treg) suppress other immune cells. Their dysfunction contributes to the pathophysiology of autoimmune diseases,including type 1 diabetes (T1D). Infusion of Tregs is being clinically evaluated as a novel way to prevent or treat T1D. Genetic modification of Tregs,most notably through the introduction of a chimeric antigen receptor (CAR) targeting Tregs to pancreatic islets,may improve their efficacy. We evaluated CAR targeting of human Tregs to monocytes,a human β cell line and human islet β cells in vitro. Targeting of HLA-A2-CAR (A2-CAR) bulk Tregs to HLA-A2+ cells resulted in dichotomous cytotoxic killing of human monocytes and islet β cells. In exploring subsets and mechanisms that may explain this pattern,we found that CD39 expression segregated CAR Treg cytotoxicity. CAR Tregs from individuals with more CD39low/- Tregs and from individuals with genetic polymorphism associated with lower CD39 expression (rs10748643) had more cytotoxicity. Isolated CD39− CAR Tregs had elevated granzyme B expression and cytotoxicity compared to the CD39+ CAR Treg subset. Genetic overexpression of CD39 in CD39low CAR Tregs reduced their cytotoxicity. Importantly,β cells upregulated protein surface expression of PD-L1 and PD-L2 in response to A2-CAR Tregs. Blockade of PD-L1/PD-L2 increased β cell death in A2-CAR Treg co-cultures suggesting that the PD-1/PD-L1 pathway is important in protecting islet β cells in the setting of CAR immunotherapy. In summary,introduction of CAR can enhance biological differences in subsets of Tregs. CD39+ Tregs represent a safer choice for CAR Treg therapies targeting tissues for tolerance induction. View Publication

TIGIT is an alternative checkpoint receptor (CR) whose inhibition promotes Graft-versus-Leukemia effects of NK cells. Given the significant immune-permissiveness of NK cells circulating in acute myeloid leukemia (AML) patients,we asked whether adoptive transfer of activated NK cells would benefit from additional TIGIT-blockade. Hence,we characterized cytokine-induced memory-like (CIML)-NK cells and NK cell lines for the expression of inhibitory CRs. In addition,we analyzed the transcription of CR ligands in AML patients (CCLE and Beat AML 2.0 cohort) in silico and evaluated the efficacy of CR blockade using in vitro cytotoxicity assays,CD69,CD107a and IFN-γ expression. Alternative but not classical CRs were abundantly expressed on healthy donor NK cells and even further upregulated on CIML-NK cells. In line with our finding that CD155,one important TIGIT-ligand,is reliably expressed on AMLs,we show improved killing of CD155+-AML blasts by NK-92 but interestingly not CIML-NK cells in the presence of TIGIT-blockade. Additionally,our in silico data (n = 671) show that poor prognosis AML patients rather displayed a CD86low CD112/CD155high phenotype,whereas patients with a better outcome rather exhibited a CD86high CD112/CD155low phenotype. Collectively,our data evidence that the complex CR ligand expression profile on AML blasts may be one explanation for the intrinsic NK cell exhaustion observed in AML patients which might be overcome with adoptive NK-92 transfer in combination with TIGIT-blockade.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00262-024-03766-7. View Publication

AbstractObjectiveUnique metabolic requirements accompany the development and functional fates of immune cells. How cellular metabolism is important in natural killer (NK) cells and their memory‐like differentiation in bacterial infections remains elusive.MethodsHere,we utilise our established NK cell memory assay to investigate the metabolic requirement for memory‐like NK cell formation and function in response to the Gram‐negative intracellular bacteria Burkholderia pseudomallei (BP),the causative agent of melioidosis.ResultsWe demonstrate that CD160+ memory‐like NK cells upon BP stimulation upregulate glucose and amino acid transporters in a cohort of recovered melioidosis patients which is maintained at least 3‐month post‐hospital admission. Using an in vitro assay,human BP‐specific CD160+ memory‐like NK cells show metabolic priming including increased expression of glucose and amino acid transporters with elevated glucose uptake,increased mTOR activation and mitochondrial membrane potential upon BP re‐stimulation. Antigen‐specific and cytokine‐induced IFN‐γ production of this memory‐like NK cell subset are highly dependent on oxidative phosphorylation (OXPHOS) with some dependency on glycolysis,whereas the formation of CD160+ memory‐like NK cells in vitro is dependent on fatty acid oxidation and OXPHOS and further increased by metformin.ConclusionThis study reveals the link between metabolism and cellular function of memory‐like NK cells,which can be exploited for vaccine design and for monitoring protection against Gram‐negative bacterial infection. This study reveals the link between metabolism and cellular function of memory‐like NK cells in melioidosis. We demonstrate that CD160+ memory‐like NK cells upon Burkholderia pseudomallei (BP) stimulation upregulate glucose and amino acid transporters in a cohort of recovered melioidosis patients. Using an in vitro assay,human BP‐specific CD160+ memory‐like NK cells show metabolic priming including increased expression of glucose and amino acid transporters with elevated glucose uptake,increased mTOR activation and mitochondrial membrane potential upon BP re‐stimulation. View Publication

AbstractBackgroundCancer‐targeted T‐cell receptor T (TCR‐T) cells hold promise in treating cancers such as hematological malignancies and breast cancers. However,approaches to obtain cancer‐reactive TCR‐T cells have been unsuccessful.MethodsHere,we developed a novel strategy to screen for cancer‐targeted TCR‐T cells using a special humanized mouse model with person‐specific immune fingerprints. Rare steady‐state circulating hematopoietic stem and progenitor cells were expanded via three‐dimensional culture of steady‐state peripheral blood mononuclear cells,and then the expanded cells were applied to establish humanized mice. The human immune system was evaluated according to the kinetics of dendritic cells,monocytes,T‐cell subsets,and cytokines. To fully stimulate the immune response and to obtain B‐cell precursor NAML‐6‐ and triple‐negative breast cancer MDA‐MB‐231‐targeted TCR‐T cells,we used the inactivated cells above to treat humanized mice twice a day every 7 days. Then,human T cells were processed for TCR β‐chain (TRB) sequencing analysis. After the repertoires had been constructed,features such as the fraction,diversity,and immune signature were investigated.ResultsThe results demonstrated an increase in diversity and clonality of T cells after treatment. The preferential usage and features of TRBV,TRBJ,and the V–J combination were also changed. The stress also induced highly clonal expansion. Tumor burden and survival analysis demonstrated that stress induction could significantly inhibit the growth of subsequently transfused live tumor cells and prolong the survival of the humanized mice.ConclusionsWe constructed a personalized humanized mouse model to screen cancer‐targeted TCR‐T pools. Our platform provides an effective source of cancer‐targeted TCR‐T cells and allows for the design of patient‐specific engineered T cells. It therefore has the potential to greatly benefit cancer treatment. Cancer‐targeted T‐cell receptor T (TCR‐T) cells hold promise in treating malignancies but with limited source. We applied steady‐state peripheral blood mononuclear cells via three‐dimensional culture to construct humanized mouse model for cancer‐targeted TCR‐T repertoire screening. View Publication

IntroductionBispecific antibodies (BsAbs) can simultaneously target two epitopes of different antigenic targets,bringing possibilities for diversity in antibody drug design and are promising tools for the treatment of cancers and other diseases. T-cell engaging bsAb is an important application of the bispecific antibody,which could promote T cell-mediated tumor cell killing by targeting tumor-associated antigen (TAA) and CD3 at the same time.MethodsThis study comprised antibodies purification,Elisa assay for antigen binding,cytotoxicity assays,T cell activation by flow cytometry in vitro and xenogenic tumor model in vivo.ResultsWe present a novel bsAb platform named PHE-Ig technique to promote cognate heavy chain (HC)-light chain (LC) pairing by replacing the CH1/CL regions of different monoclonal antibodies (mAbs) with the natural A and B chains of PHE1 fragment of Integrin β2 based on the knob-in-hole (KIH) technology. We had also verified that PHE-Ig technology can be effectively used as a platform to synthesize different desired bsAbs for T-cell immunotherapy. Especially,BCMA×CD3 PHE-Ig bsAbs exhibited robust anti-multiple myeloma (MM) activity in vitro and in vivo.DiscussionMoreover,PHE1 domain was further shortened with D14G and R41S mutations,named PHE-S,and the PHE-S-based BCMA×CD3 bsAbs also showed anti BCMA+ tumor effect in vitro and in vivo,bringing more possibilities for the development and optimization of different bsAbs. To sum up,PHE1-based IgG-like antibody platform for bsAb construction provides a novel strategy for enhanced T-cell immunotherapy. View Publication

BackgroundAllergen-specific immunotherapy (AIT) is able to restore immune tolerance to allergens in allergic patients. However,some patients do not or only poorly respond to current treatment protocols. Therefore,there is a need for deeper mechanistic insights and further improvement of treatment strategies. The relevance of the aryl hydrocarbon receptor (AhR),a ligand-dependent transcription factor,has been investigated in several inflammatory diseases,including allergic asthma. However,its potential role in AIT still needs to be addressed.MethodsA murine model of AIT in ovalbumin-induced allergic airway inflammation was performed in AhR-deficient (AhR-/-) and wild-type mice. Furthermore,AIT was combined with the application of the high-affinity AhR agonist 10-chloro-7H-benzimidazo[2,1-a]benzo[de]iso-quinolin-7-one (10-Cl-BBQ) as an adjuvant to investigate the effects of AhR activation on therapeutic outcome.ResultsAlthough AhR-/- mice suffer stronger allergic responses than wild-type mice,experimental AIT is comparably effective in both. Nevertheless,combining AIT with the administration of 10-Cl-BBQ improved therapeutic effects by an AhR-dependent mechanism,resulting in decreased cell counts in the bronchoalveolar fluid,decreased pulmonary Th2 and Th17 cell levels,and lower sIgE levels.ConclusionThis study demonstrates that the success of AIT is not dependent on the AhR. However,targeting the AhR during AIT can help to dampen inflammation and improve tolerogenic vaccination. Therefore,AhR ligands might represent promising candidates as immunomodulators to enhance the efficacy of AIT. View Publication

Given the marginal penetration of most drugs across the blood-brain barrier,the efficacy of various agents remains limited for glioblastoma (GBM). Here we employ low-intensity pulsed ultrasound (LIPU) and intravenously administered microbubbles (MB) to open the blood-brain barrier and increase the concentration of liposomal doxorubicin and PD-1 blocking antibodies (aPD-1). We report results on a cohort of 4 GBM patients and preclinical models treated with this approach. LIPU/MB increases the concentration of doxorubicin by 2-fold and 3.9-fold in the human and murine brains two days after sonication,respectively. Similarly,LIPU/MB-mediated blood-brain barrier disruption leads to a 6-fold and a 2-fold increase in aPD-1 concentrations in murine brains and peritumoral brain regions from GBM patients treated with pembrolizumab,respectively. Doxorubicin and aPD-1 delivered with LIPU/MB upregulate major histocompatibility complex (MHC) class I and II in tumor cells. Increased brain concentrations of doxorubicin achieved by LIPU/MB elicit IFN-γ and MHC class I expression in microglia and macrophages. Doxorubicin and aPD-1 delivered with LIPU/MB results in the long-term survival of most glioma-bearing mice,which rely on myeloid cells and lymphocytes for their efficacy. Overall,this translational study supports the utility of LIPU/MB to potentiate the antitumoral activities of doxorubicin and aPD-1 for GBM. Ultrasound-mediated blood-brain barrier opening has been exploited to improve drug delivery in the brain. Here the authors show that low-intensity pulsed ultrasound in combination with intravenous injection of microbubbles enhances the delivery of doxorubicin and anti-PD1 in gliomas,improving anti-tumor immune responses. View Publication

AbstractEncouraged by the observations of significant B7-H3 protein overexpression in many human solid tumors compared to healthy tissues,we directed our focus towards targeting B7-H3 using chimeric antigen receptor (CAR) T cells. We utilized a nanobody as the B7-H3–targeting domain in our CAR construct to circumvent the stability issues associated with single-chain variable fragment–based domains. In efforts to expand patient access to CAR T-cell therapy,we engineered our nanobody-based CAR into human Epstein-Barr virus–specific T cells (EBVST),offering a readily available off-the-shelf treatment. B7H3.CAR-armored EBVSTs demonstrated potent in vitro and in vivo activities against multiple B7-H3–positive human tumor cell lines and patient-derived xenograft models. Murine T cells expressing a murine equivalent of our B7H3.CAR exhibited no life-threatening toxicities in immunocompetent mice bearing syngeneic tumors. Further in vitro evaluation revealed that while human T,B,and natural killer cells were unaffected by B7H3.CAR EBVSTs,monocytes were targeted because of upregulation of B7-H3. Such targeting of myeloid cells,which are key mediators of cytokine release syndrome (CRS),contributed to a low incidence of CRS in humanized mice after B7H3.CAR EBVST treatment. Notably,we showed that B7H3.CAR EBVSTs can target B7-H3–expressing myeloid-derived suppressor cells (MDSC),thereby mitigating MDSC-driven immune suppression. In summary,our data demonstrate that our nanobody-based B7H3.CAR EBVSTs are effective as an off-the-shelf therapy for B7-H3–positive solid tumors. These cells also offer an avenue to modulate the immunosuppressive tumor microenvironment,highlighting their promising clinical potential in targeting solid tumors.Significance:Clinical application of EBVSTs armored with B7-H3–targeting CARs offer an attractive solution to translate off-the-shelf CAR T cells as therapy for solid tumors. View Publication

IntroductionThe effector function of T cells is regulated via immune checkpoints,activating or inhibiting the immune response. The BTLA-HVEM complex,the inhibitory immune checkpoint,may act as one of the tumor immune escape mechanisms. Therefore,interfering with the binding of these proteins can prove beneficial in cancer treatment. Our study focused on peptides interacting with HVEM at the same place as BTLA,thus disrupting the BTLA-HVEM interaction. These peptides’ structure and amino acid sequences are based on the gD protein,the ligand of HVEM. Here,we investigated their immunomodulatory potential in melanoma patients.MethodsFlow cytometry analyses of activation,proliferation,and apoptosis of T cells from patients were performed. Additionally,we evaluated changes within the T cell memory compartment.ResultsThe most promising compound – Pep(2),increased the percentages of activated T cells and promoted their proliferation. Additionally,this peptide affected the proliferation rate and apoptosis of melanoma cell line in co-culture with T cells.DiscussionWe conclude that the examined peptide may act as a booster for the immune system. Moreover,the adjuvant and activating properties of the gD-derived peptide could be used in a combinatory therapy with currently used ICI-based treatment. Our studies also demonstrate that even slight differences in the amino acid sequence of peptides and any changes in the position of the disulfide bond can strongly affect the immunomodulatory properties of compounds. View Publication

Thrombopoietin (Tpo),which binds to its specific receptor,the Mpl protein,is the major cytokine regulator of megakaryopoiesis and circulating platelet number. Tpo binding to Mpl triggers activation of Janus kinase 2 (Jak2) and phosphorylation of the receptor,as well as activation of several intracellular signalling cascades that mediate cellular responses. Three tyrosine (Y) residues in the C-terminal region of the Mpl intracellular domain have been implicated as sites of phosphorylation required for regulation of major Tpo-stimulated signalling pathways: Mpl-Y565,Mpl-Y599 and Mpl-Y604. Here,we have introduced mutations in the mouse germline and report a consistent physiological requirement for Mpl-Y599,mutation of which resulted in thrombocytopenia,deficient megakaryopoiesis,low hematopoietic stem cell (HSC) number and function,and attenuated responses to myelosuppression. We further show that in models of myeloproliferative neoplasms (MPN),where Mpl is required for pathogenesis,thrombocytosis was dependent on intact Mpl-Y599. In contrast,Mpl-Y565 was required for negative regulation of Tpo responses; mutation of this residue resulted in excess megakaryopoiesis at steady-state and in response to myelosuppression,and exacerbated thrombocytosis associated with MPN. View Publication