技术资料

A subset of antibodies found in cattle comprises ultralong CDR-H3 regions of up to 70 amino acids. Interestingly,this type of immunoglobulin usually pairs with the single germline VL gene,V30 that is typically very conserved in sequence. In this work,we have engineered ultralong CDR-H3 common light chain bispecific antibodies targeting Epidermal Growth Factor Receptor (EGFR) on tumor cells as well as Natural Cytotoxicity Receptor NKp30 on Natural Killer (NK) cells. Antigen-specific common light chain antibodies were isolated by yeast surface display by means of pairing CDR-H3 diversities following immunization with a single V30 light chain. After selection,EGFR-targeting paratopes as well as NKp30-specific binders were combined into common light chain bispecific antibodies by exploiting the strand-exchange engineered domain (SEED) technology for heavy chain heterodimerization. Biochemical characterization of resulting bispecifics revealed highly specific binding to the respective antigens as well as simultaneous binding to both targets. Most importantly,engineered cattle-derived bispecific common light chain molecules elicited potent NK cell redirection and consequently tumor cell lysis of EGFR-overexpressing cells as well as robust release of proinflammatory cytokine interferon-$\gamma$. Taken together,this data is giving clear evidence that bovine bispecific ultralong CDR-H3 common light chain antibodies are versatile for biotechnological applications. View Publication

Solid tumor cells have an altered metabolism that can protect them from cytotoxic lymphocytes. The anti-diabetic drug metformin modifies tumor cell metabolism and several clinical trials are testing its effectiveness for the treatment of solid cancers. The use of metformin in hematologic cancers has received much less attention,although allogeneic cytotoxic lymphocytes are very effective against these tumors. We show here that metformin induces expression of Natural Killer G2-D (NKG2D) ligands (NKG2DL) and intercellular adhesion molecule-1 (ICAM-1),a ligand of the lymphocyte function-associated antigen 1 (LFA-1). This leads to enhance sensitivity to cytotoxic lymphocytes. Overexpression of anti-apoptotic Bcl-2 family members decrease both metformin effects. The sensitization to activated cytotoxic lymphocytes is mainly mediated by the increase on ICAM-1 levels,which favors cytotoxic lymphocytes binding to tumor cells. Finally,metformin decreases the growth of human hematological tumor cells in xenograft models,mainly in presence of monoclonal antibodies that recognize tumor antigens. Our results suggest that metformin could improve cytotoxic lymphocyte-mediated therapy. View Publication

HLA-DQ donor-specific antibodies (DSA) are the most prevalent type of DSA after renal transplantation and have been associated with eplet mismatches between donor and recipient HLA. Eplets are theoretically defined configurations of surface exposed amino acids on HLA molecules that require verification to confirm that they can be recognized by alloantibodies and are therefore clinically relevant. In this study,we isolated HLA-DQ specific memory B cells from immunized individuals by using biotinylated HLA-DQ monomers to generate 15 recombinant human HLA-DQ specific monoclonal antibodies (mAb) with six distinct specificities. Single antigen bead reactivity patterns were analyzed with HLA-EMMA to identify amino acids that were uniquely shared by the reactive HLA alleles to define functional epitopes which were mapped to known eplets. The HLA-DQB1*03:01-specific mAb LB_DQB0301_A and the HLA-DQB1*03-specific mAb LB_DQB0303_C supported the antibody-verification of eplets 45EV and 55PP respectively,while mAbs LB_DQB0402_A and LB_DQB0602_B verified eplet 55R on HLA-DQB1*04/05/06. For three mAbs,multiple uniquely shared amino acid configurations were identified,warranting further studies to define the inducing functional epitope and corresponding eplet. Our unique set of HLA-DQ specific mAbs will be further expanded and will facilitate the in-depth analysis of HLA-DQ epitopes,which is relevant for further studies of HLA-DQ alloantibody pathogenicity in transplantation. View Publication

Chimeric antigen receptor (CAR) T cells targeting CD19 mediate potent antitumor effects in B-cell malignancies including acute lymphoblastic leukemia (ALL),but antigen loss remains the major cause of treatment failure. To mitigate antigen escape and potentially improve the durability of remission,we developed a dual-targeting approach using an optimized,bispecific CAR construct that targets both CD19 and BAFF-R. CD19/BAFF-R dual CAR T cells exhibited antigen-specific cytokine release,degranulation,and cytotoxicity against both CD19-/- and BAFF-R-/- variant human ALL cells in vitro. Immunodeficient mice engrafted with mixed CD19-/- and BAFF-R-/- variant ALL cells and treated with a single dose of CD19/BAFF-R dual CAR T cells experienced complete eradication of both CD19-/- and BAFF-R-/- ALL variants,whereas mice treated with monospecific CD19 or BAFF-R CAR T cells succumbed to outgrowths of CD19-/BAFF-R+ or CD19+/BAFF-R- tumors,respectively. Further,CD19/BAFF-R dual CAR T cells showed prolonged in vivo persistence,raising the possibility that these cells may have the potential to promote durable remissions. Together,our data support clinical translation of BAFF-R/CD19 dual CAR T cells to treat ALL. View Publication

BACKGROUND Adoptive T-cell transfer has become an attractive therapeutic approach for hematological malignancies but shows poor activity against large and heterogeneous solid tumors. Interleukin-12 (IL-12) exhibits potent antitumor efficacy against solid tumors,but its clinical application has been stalled because of toxicity. Here,we aimed to develop a safe approach to IL-12 T-cell therapy for eliminating large solid tumors. METHODS We generated a cell membrane-anchored IL-12 (aIL12),a tumor-targeted IL-12 (ttIL12),and a cell membrane-anchored and ttIL-12 (attIL12) and a cell membrane-anchored and tumor-targeted ttIL-12 (attIL12) armed T cells,chimeric antigen receptor-T cells,and T cell receptor-T (TCR-T) cells with each. We compared the safety and efficacy of these armed T cells in treating osteosarcoma patient-derived xenograft tumors and mouse melanoma tumors after intravenous infusions of the armed T cells. RESULTS attIL12-T cell infusion showed remarkable antitumor efficacy in human and mouse large solid tumor models. Mechanistically,attIL12-T cells targeted tumor cells expressing cell-surface vimentin,enriching effector T cell and interferon $\gamma$ production in tumors,which in turn stimulates dendritic cell maturation for activating secondary T-cell responses and tumor antigen spreading. Both attIL12- and aIL12-T-cell transfer eliminated peripheral cytokine release and the associated toxic effects. CONCLUSIONS This novel approach sheds light on the safe application of IL-12-based T-cell therapy for large and heterogeneous solid tumors. View Publication

Early erythroid progenitors are transit-amplifying cells with high proliferative capacity committed to undergoing red cell differentiation. CD71/CD24low progenitors are less mature and have greater proliferative capacity than CD71/CD24high. We present protocols for isolation of CD71/CD24low progenitors from mouse fetal liver using both fluorescence-activated cell sorting (FACS) and immunomagnetic enrichment. CD71/CD24low progenitors isolated with both approaches show similar transcriptomes at single-cell resolution and exhibit characteristic proliferative responses to glucocorticoids. For complete details on the use and execution of this protocol,please refer to Li et al. (2019). View Publication

MicroRNAs (miRNAs/miRs) are small,endogenous noncoding RNAs that are important post-transcriptional regulators with clear roles in the development of the immune system and immune responses. Using miRNA microarray profiling,we characterized the expression profile of naive and in vivo generated murine effector antiviral CD8+ T cells. We observed that out of 362 measurable mature miRNAs,120 were differentially expressed by at least 2-fold in influenza-specific effector CD8+ CTLs compared with naive CD8+ T cells. One miRNA found to be highly downregulated on both strands in effector CTLs was miR-139. Because previous studies have indicated a role for miR-139-mediated regulation of CTL effector responses,we hypothesized that deletion of miR-139 would enhance antiviral CTL responses during influenza virus infection. We generated miR-139-/- mice or overexpressed miR-139 in T cells to assess the functional contribution of miR-139 expression in CD8+ T cell responses. Our study demonstrates that the development of naive T cells and generation or differentiation of effector or memory CD8+ T cell responses to influenza virus infection are not impacted by miR-139 deficiency or overexpression; yet,miR-139-/- CD8+ T cells are outcompeted by wild-type CD8+ T cells in a competition setting and demonstrate reduced responses to Listeria monocytogenes Using an in vitro model of T cell exhaustion,we confirmed that miR-139 expression similarly does not impact the development of T cell exhaustion. We conclude that despite significant downregulation of miR-139 following in vivo and in vitro activation,miR-139 expression is dispensable for influenza-specific CTL responses. View Publication

PURPOSE Glioblastoma (GBM) patients suffer from a dismal prognosis,with standard of care therapy inevitably leading to therapy-resistant recurrent tumors. The presence of cancer stem cells (CSCs) drives the extensive heterogeneity seen in GBM,prompting the need for novel therapies specifically targeting this subset of tumor-driving cells. Here,we identify CD70 as a potential therapeutic target for recurrent GBM CSCs. EXPERIMENTAL DESIGN In the current study,we identified the relevance and functional influence of CD70 on primary and recurrent GBM cells,and further define its function using established stem cell assays. We use CD70 knockdown studies,subsequent RNAseq pathway analysis,and in vivo xenotransplantation to validate CD70's role in GBM. Next,we developed and tested an anti-CD70 chimeric antigen receptor (CAR)-T therapy,which we validated in vitro and in vivo using our established preclinical model of human GBM. Lastly,we explored the importance of CD70 in the tumor immune microenvironment (TIME) by assessing the presence of its receptor,CD27,in immune infiltrates derived from freshly resected GBM tumor samples. RESULTS CD70 expression is elevated in recurrent GBM and CD70 knockdown reduces tumorigenicity in vitro and in vivo. CD70 CAR-T therapy significantly improves prognosis in vivo. We also found CD27 to be present on the cell surface of multiple relevant GBM TIME cell populations,notably putative M1 macrophages and CD4 T cells. CONCLUSION CD70 plays a key role in recurrent GBM cell aggressiveness and maintenance. Immunotherapeutic targeting of CD70 significantly improves survival in animal models and the CD70/CD27 axis may be a viable polytherapeutic avenue to co-target both GBM and its TIME. View Publication

BACKGROUND Leucine rich repeat kinase 2 (LRRK2) and SNCA are genetically linked to late-onset Parkinson's disease (PD). Aggregated $\alpha$-synuclein pathologically defines PD. Recent studies identified elevated LRRK2 expression in pro-inflammatory CD16+ monocytes in idiopathic PD,as well as increased phosphorylation of the LRRK2 kinase substrate Rab10 in monocytes in some LRRK2 mutation carriers. Brain-engrafting pro-inflammatory monocytes have been implicated in dopaminergic neurodegeneration in PD models. Here we examine how $\alpha$-synuclein and LRRK2 interact in monocytes and subsequent neuroinflammatory responses. METHODS Human and mouse monocytes were differentiated to distinct transcriptional states resembling macrophages,dendritic cells,or microglia,and exposed to well-characterized human or mouse $\alpha$-synuclein fibrils. LRRK2 expression and LRRK2-dependent Rab10 phosphorylation were measured with monoclonal antibodies,and myeloid cell responses to $\alpha$-synuclein fibrils in R1441C-Lrrk2 knock-in mice or G2019S-Lrrk2 BAC mice were evaluated by flow cytometry. Chemotaxis assays were performed with monocyte-derived macrophages stimulated with $\alpha$-synuclein fibrils and microglia in Boyden chambers. RESULTS $\alpha$-synuclein fibrils robustly stimulate LRRK2 and Rab10 phosphorylation in human and mouse macrophages and dendritic-like cells. In these cells,$\alpha$-synuclein fibrils stimulate LRRK2 through JAK-STAT activation and intrinsic LRRK2 kinase activity in a feed-forward pathway that upregulates phosphorylated Rab10. In contrast,LRRK2 expression and Rab10 phosphorylation are both suppressed in microglia-like cells that are otherwise highly responsive to $\alpha$-synuclein fibrils. Corroborating these results,LRRK2 expression in the brain parenchyma occurs in pro-inflammatory monocytes infiltrating from the periphery,distinct from brain-resident microglia. Mice expressing pathogenic LRRK2 mutations G2019S or R1441C have increased numbers of infiltrating pro-inflammatory monocytes in acute response to $\alpha$-synuclein fibrils. In primary cultured macrophages,LRRK2 kinase inhibition dampens $\alpha$-synuclein fibril and microglia-stimulated chemotaxis. CONCLUSIONS Pathologic $\alpha$-synuclein activates LRRK2 expression and kinase activity in monocytes and induces their recruitment to the brain. These results predict that LRRK2 kinase inhibition may attenuate damaging pro-inflammatory monocyte responses in the brain. View Publication

Fibroblast growth factor receptor 1 (FGFR1) is overexpressed in multiple types of solid tumors,including head and neck squamous cell carcinoma (HNSCC). Being associated with poor prognosis,FGFR1 is a potential therapeutic target for aggressive tumors. T cell-based cancer immunotherapy has played a central role in novel cancer treatments. However,the potential of antitumor immunotherapy targeting FGFR1 has not been investigated. Here,we showed that FGFR-tyrosine kinase inhibitors (TKIs) augmented antitumor effects of immune checkpoint inhibitors in an HNSCC mouse model and upregulated tumoral MHC class I and MHC class II expression in vivo and in vitro. This upregulation was associated with the mitogen-activated protein kinase signaling pathway,which is a crucial pathway for cancer development through FGFR signaling. Moreover,we identified an FGFR1-derived peptide epitope (FGFR1305-319) that could elicit antigen-reactive and multiple HLA-restricted CD4+ T cell responses. These T cells showed direct cytotoxicity against tumor cells that expressed FGFR1. Notably,FGFR-TKIs augmented antitumor effects of FGFR1-reactive T cells against human HNSCC cells. These results indicate that the combination of FGFR-TKIs with immunotherapy,such as an FGFR1-targeting peptide vaccine or immune checkpoint inhibitor,could be a novel and robust immunologic approach for treating patients with FGFR1-expressing cancer cells. View Publication

BACKGROUND Monocytes are thought to be involved in venous thrombosis but the role of individual monocyte subpopulations on thrombus formation,clot inflammation,and degradation is an important unresolved issue. We investigate the role of inflammatory Ly6Chi monocytes in deep vein thrombosis and their potential therapeutic impact. METHODS Frequencies and compositions of blood monocytes were analyzed by flow cytometry in CCR2-/- (C-C chemokine receptor type 2) and wild-type mice of different ages and after treatment with the NR4A1 (nuclear receptor group 4 family A member 1,Nur77) agonist CnsB (cytosporone B). TF (tissue factor) sufficient and deficient Ly6Chi monocytes were adoptively transferred into aged CCR2-/- mice. Thrombus formation and size were followed by ultrasound over a 3-week period after surgical reduction of blood flow (stenosis) in the inferior vena cava. RESULTS Reduced numbers of peripheral monocytes in aged (>30 w) CCR2-/- mice are accompanied by reduced thrombus formation after inferior vena cava ligation. Reducing the number of inflammatory Ly6Chi monocytes in wild-type mice by CsnB treatment before ligation,similarly suspends clotting,while later treatment (d1 or d4) reduces thrombus growth and accelerates resolution. We describe how changes in inflammatory monocyte numbers affect the gradual differentiation of monocytes in thrombi and show that only tissue factor-competent Ly6Chi monocytes restore thrombosis in aged CCR2-/- mice. CONCLUSIONS We conclude that the number of inflammatory Ly6Chi monocytes controls deep vein thrombosis formation,growth,and resolution and can be therapeutically manipulated with a NR4A1 agonist at all disease stages. View Publication

CD8+ memory T (TM) cells play a critical role in immune defense against infection. Two common $\gamma$-chain family cytokines,IL-2 and IL-7,although triggering the same mTORC1-S6K pathway,distinctly induce effector T (TE) cells and TM cells,respectively,but the underlying mechanism(s) remains elusive. In this study,we generated IL-7R-/and AMPK$\alpha$1-knockout (KO)/OTI mice. By using genetic and pharmaceutical tools,we demonstrate that IL-7 deficiency represses expression of FOXO1,TCF1,p-AMPK$\alpha$1 (T172),and p-ULK1 (S555) and abolishes T cell memory differentiation in IL-7R KO T cells after Listeria monocytogenesis rLmOVA infection. IL-2- and IL-7-stimulated strong and weak S6K (IL-2/S6Kstrong and IL-7/S6Kweak) signals control short-lived IL-7R-CD62L-KLRG1+ TE and long-term IL-7R+CD62L+KLRG1- TM cell formations,respectively. To assess underlying molecular pathway(s),we performed flow cytometry,Western blotting,confocal microscopy,and Seahorse assay analyses by using the IL-7/S6Kweak-stimulated TM (IL-7/TM) and the control IL-2/S6Kstrong-stimulated TE (IL-2/TE) cells. We determine that the IL-7/S6Kweak signal activates transcriptional FOXO1,TCF1,and Id3 and metabolic p-AMPK$\alpha$1,p-ULK1,and ATG7 molecules in IL-7/TM cells. IL-7/TM cells upregulate IL-7R and CD62L,promote mitochondria biogenesis and fatty acid oxidation metabolism,and show long-term cell survival and functional recall responses. Interestingly,AMPK$\alpha$1 deficiency abolishes the AMPK$\alpha$1 but maintains the FOXO1 pathway and induces a metabolic switch from fatty acid oxidation to glycolysis in AMPK$\alpha$1 KO IL-7/TM cells,leading to loss of cell survival and recall responses. Taken together,our data demonstrate that IL-7-stimulated weak strength of mTORC1-S6K signaling controls T cell memory via activation of transcriptional FOXO1-TCF1-Id3 and metabolic AMPK$\alpha$1-ULK1-ATG7 pathways. This (to our knowledge) novel finding provides a new mechanism for a distinct IL-2/IL-7 stimulation model in T cell memory and greatly impacts vaccine development. View Publication