Seaweed-derived fucoidans and rhamnan sulfates serve as potent anti-SARS-CoV-2 agents with potential for prophylaxis.

Seaweeds represent a rich source of sulfated polysaccharides with similarity to heparan sulfate, a facilitator of myriad virus host cell attachment. For this reason, attention has been drawn to their antiviral activity, including the potential for anti-SARS-CoV-2 activity. We have identified and structurally characterized several fucoidan extracts, including those from different species of brown macroalga, and a rhamnan sulfate from a green macroalga species. A high molecular weight fucoidan extracted from Saccharina japonica (FSjRPI-27), and a rhamnan sulfate extracted from Monostroma nitidum (RSMn), showed potent competitive inhibition of spike glycoprotein receptor binding to a heparin-coated SPR chip. This inhibition was also observed in cell-based assays using hACE2 HEK-293 T cells infected by pseudotyped SARS-CoV-2 virus with IC50 values <1 µg/mL. Effectiveness was demonstrated in vivo using hACE2-transgenic mice. Intranasal administration of FSjRPI-27 showed protection when dosed 6 h prior to and at infection, and then every 2 days post-infection, with 100 % survival and no toxicity at 104 plaque-forming units per mouse vs. buffer control. At 5-fold higher virus dose, FSjRPI-27 reduced mortality and yielded reduced viral titers in bronchioalveolar fluid and lung homogenates vs. buffer control. These findings suggest the potential application of seaweed-based sulfated polysaccharides as promising anti-SARS-CoV-2 prophylactics.

Split fluorescent protein-mediated multimerization of cell wall binding domain for highly sensitive and selective bacterial detection.

Cell wall peptidoglycan binding domains (CBDs) of cell lytic enzymes, including bacteriocins, autolysins and bacteriophage endolysins, enable highly selective bacterial binding, and thus, have potential as biorecognition molecules for nondestructive bacterial detection. Here, a novel design for a self-complementing split fluorescent protein (FP) complex is proposed, where a multimeric FP chain fused with specific CBDs ((FP-CBD)n) is assembled inside the cell, to improve sensitivity by enhancing the signal generated upon Staphylococcus aureus or Bacillus anthracis binding. Flow cytometry shows enhanced fluorescence on the cell surface with increasing FP stoichiometry and surface plasmon resonance reveals nanomolar binding affinity to isolated peptidoglycan. The breadth of function of these complexes is demonstrated through the use of CBD modularity and the ability to attach enzymatic detection modalities. Horseradish peroxidase-coupled (FP-CBD)n complexes generate a catalytic amplification, with the degree of amplification increasing as a function of FP length, reaching a limit of detection (LOD) of 103 cells/droplet (approximately 0.1 ng S. aureus or B. anthracis) within 15 min on a polystyrene surface. These fusion proteins can be multiplexed for simultaneous detection. Multimeric split FP-CBD fusions enable use as a biorecognition molecule with enhanced signal for use in bacterial biosensing platforms.

CAR-NK Cells Generated with mRNA-LNPs Kill Tumor Target Cells In Vitro and In Vivo.

Natural killer (NK) cells are cytotoxic lymphocytes that are critical for the innate immune system. Engineering NK cells with chimeric antigen receptors (CARs) allows CAR-NK cells to target tumor antigens more effectively. In this report, we present novel CAR mRNA-LNP (lipid nanoparticle) technology to effectively transfect NK cells expanded from primary PBMCs and to generate functional CAR-NK cells. CD19-CAR mRNA and BCMA-CAR mRNA were embedded into LNPs that resulted in 78% and 95% CAR expression in NK cells, respectively. BCMA-CAR-NK cells after transfection with CAR mRNA-LNPs killed multiple myeloma RPMI8226 and MM1S cells and secreted IFN-gamma and Granzyme B in a dose-dependent manner in vitro. In addition, CD19-CAR-NK cells generated with CAR mRNA-LNPs killed Daudi and Nalm-6 cells and secreted IFN-gamma and Granzyme B in a dose-dependent manner. Both BCMA-CAR-NK and CD19-CAR-NK cells showed significantly higher cytotoxicity, IFN-gamma, and Granzyme B secretion compared with normal NK cells. Moreover, CD19-CAR-NK cells significantly blocked Nalm-6 tumor growth in vivo. Thus, non-viral delivery of CAR mRNA-LNPs can be used to generate functional CAR-NK cells with high anti-tumor activity.

Trends in the Incidence of Cardiogenic Shock, and Utilization of Mechanical Circulatory Support in Myocarditis: Insights from the National Inpatient Sample 2016 to 2019.

A subset of patients with myocarditis present with cardiogenic shock. There is a lack of contemporary data assessing the use of mechanical circulatory support (MCS) in these patients. Myocarditis hospitalizations were analyzed using the National Inpatient Sample between 2016 and 2019. Characteristics of patients with and without cardiogenic shock were assessed. Trends in mortality, MCS, right-sided cardiac catheterization (RHC) and endomyocardial biopsy were evaluated. The impact of RHC on consequent MCS and mortality was studied. A total of 38,300 hospitalizations for myocarditis were included in the study, of which 3,490 hospitalizations (9.1%) had cardiogenic shock. Patients with cardiogenic shock were older (p <0.001) and had more chronic kidney disease and atrial fibrillation. Between 2016 and 2019, there was an increase in myocarditis admissions but no difference in rates of cardiogenic shock and mortality and the use of extracorporeal membrane oxygenation, percutaneous ventricular assist devices, intra-aortic balloon pumps, left ventricular assist devices, and cardiac transplant. The most common form of MCS used in myocarditis was extracorporeal membrane oxygenation. The rates of RHC (p = 0.02) and endomyocardial biopsy (p = 0.03) increased over time. Patients who underwent RHC were more likely to receive mechanical support, and in patients with shock, RHC was associated with lower mortality (adjusted odds ratio 0.34, p <0.01). Myocarditis admissions increased over time but with no increase in the rates of cardiogenic shock and MCS. In patients with cardiogenic shock, RHC resulted in lower mortality.

The global human day.

The daily activities of ≈8 billion people occupy exactly 24 h per day, placing a strict physical limit on what changes can be achieved in the world. These activities form the basis of human behavior, and because of the global integration of societies and economies, many of these activities interact across national borders. Yet, there is no comprehensive overview of how the finite resource of time is allocated at the global scale. Here, we estimate how all humans spend their time using a generalized, physical outcome-based categorization that facilitates the integration of data from hundreds of diverse datasets. Our compilation shows that most waking hours are spent on activities intended to achieve direct outcomes for human minds and bodies (9.4 h/d), while 3.4 h/d are spent modifying our inhabited environments and the world beyond. The remaining 2.1 h/d are devoted to organizing social processes and transportation. We distinguish activities that vary strongly with GDP per capita, including the time allocated to food provision and infrastructure, vs. those that do not vary consistently, such as meals and transportation time. Globally, the time spent directly extracting materials and energy from the Earth system is small, on the order of 5 min per average human day, while the time directly dealing with waste is on the order of 1 min per day, suggesting a large potential scope to modify the allocation of time to these activities. Our results provide a baseline quantification of the temporal composition of global human life that can be expanded and applied to multiple fields of research.

Phospholipid Encapsulation of an Anti-Fibrotic Endopeptide to Enhance Cellular Uptake and Myocardial Retention.

BACKGROUND: Cardioprotective effects of N-acetyl-ser-asp-lys-pro (Ac-SDKP) have been reported in preclinical models of myocardial remodeling. However, the rapid degradation of this endogenous peptide in vivo limits its clinical use. METHOD: To prolong its bioavailability, Ac-SDKP was encapsulated by phosphocholine lipid bilayers (liposomes) similar to mammalian cell membranes. The physical properties of the liposome structures were assessed by dynamic light scattering and scanning electron microscopy. The uptake of Ac-SDKP by RAW 264.7 macrophages and human and murine primary cardiac fibroblasts was confirmed by fluorescence microscopy and flow cytometry. Spectrum computerized tomography and competitive enzyme-linked immunoassays were performed to measure the ex vivo cardiac biodistribution of Ac-SDKP. The biological effects of this novel synthetic compound were examined in cultured macrophages and cardiac fibroblasts and in a murine model of acute myocardial infarction induced by permanent coronary artery ligation. RESULTS: A liposome formulation resulted in the greater uptake of Ac-SDKP than the naked peptide by cultured RAW 264.7 macrophages and cardiac fibroblasts. Liposome-delivered Ac-SDKP decreased fibroinflammatory genes in cultured cardiac fibroblasts co-treated with TGF-ß1 and macrophages stimulated with LPS. Serial tissue and serum immunoassays showed the high bioavailability of Ac-SDKP in mouse myocardium and in circulation. Liposome-delivered Ac-SDKP improved cardiac function and reduced myocardial fibroinflammatory responses in mice with acute myocardial infarction. CONCLUSION: Encapsulation of Ac-SDKP in a cell membrane-like phospholipid bilayer enhances its plasma and tissue bioavailability and offers cardioprotection against ischemic myocardial injury. Future clinical trials can use this novel approach to test small protective endogenous peptides in myocardial remodeling.

Highly Sensitive Detection of Bacteria by Binder-Coupled Multifunctional Polymeric Dyes.

Infectious diseases caused by pathogens are a health burden, but traditional pathogen identification methods are complex and time-consuming. In this work, we have developed well-defined, multifunctional copolymers with rhodamine B dye synthesized by atom transfer radical polymerization (ATRP) using fully oxygen-tolerant photoredox/copper dual catalysis. ATRP enabled the efficient synthesis of copolymers with multiple fluorescent dyes from a biotin-functionalized initiator. Biotinylated dye copolymers were conjugated to antibody (Ab) or cell-wall binding domain (CBD), resulting in a highly fluorescent polymeric dye-binder complex. We showed that the unique combination of multifunctional polymeric dyes and strain-specific Ab or CBD exhibited both enhanced fluorescence and target selectivity for bioimaging of Staphylococcus aureus by flow cytometry and confocal microscopy. The ATRP-derived polymeric dyes have the potential as biosensors for the detection of target DNA, protein, or bacteria, as well as bioimaging.

mRNA-Lipid Nanoparticle (LNP) Delivery of Humanized EpCAM-CD3 Bispecific Antibody Significantly Blocks Colorectal Cancer Tumor Growth.

The epithelial cell adhesion molecule (EpCAM) is often overexpressed in many types of tumors, including colorectal cancer. We sequenced and humanized an EpCAM mouse antibody and used it to develop bispecific EpCAM-CD3 antibodies. Three different designs were used to generate bispecific antibodies such as EpCAM-CD3 CrossMab knob-in-hole, EpCAM ScFv-CD3 ScFv (BITE), and EpCAM ScFv-CD3 ScFv-human Fc designs. These antibody designs showed strong and specific binding to the EpCAM-positive Lovo cell line and T cells, specifically killed EpCAM-positive Lovo cells and not EpCAM-negative Colo741 cells in the presence of T cells, and increased T cells' IFN-gamma secretion in a dose-dependent manner. In addition, transfection of HEK-293 cells with EpCAM ScFv-CD3 ScFv human Fc mRNA-LNPs resulted in antibody secretion that killed Lovo cells and did not kill EpCAM-negative Colo741 cells. The antibody increased IFN-gamma secretion against Lovo target cells and did not increase it against Colo741 target cells. EpCAM-CD3 hFc mRNA-LNP transfection of several cancer cell lines (A1847, C30, OVCAR-5) also demonstrated functional bispecific antibody secretion. In addition, intratumoral delivery of the EpCAM-CD3 human Fc mRNA-LNPs into OVCAR-5 tumor xenografts combined with intravenous injection of T cells significantly blocked xenograft tumor growth. Thus, EpCAM-CD3 hFc mRNA-LNP delivery to tumor cells shows strong potential for future clinical studies.

Suramin binds and inhibits infection of SARS-CoV-2 through both spike protein-heparan sulfate and ACE2 receptor interactions.

SARS-CoV-2 receptor binding domains (RBDs) interact with both the ACE2 receptor and heparan sulfate on the surface of host cells to enhance SARS-CoV-2 infection. We show that suramin, a polysulfated synthetic drug, binds to the ACE2 receptor and heparan sulfate binding sites on the RBDs of wild-type, Delta, and Omicron variants. Specifically, heparan sulfate and suramin had enhanced preferential binding for Omicron RBD, and suramin is most potent against the live SARS-CoV-2 Omicron variant (B.1.1.529) when compared to wild type and Delta (B.1.617.2) variants in vitro. These results suggest that inhibition of live virus infection occurs through dual SARS-CoV-2 targets of S-protein binding and previously reported RNA-dependent RNA polymerase inhibition and offers the possibility for this and other polysulfated molecules to be used as potential therapeutic and prophylactic options against COVID-19.

Interdisciplinary applications of human time use with generalized lexicons.

Time use studies quantify what people do, over particular time intervals. The results of these studies have illuminated diverse and important aspects of societies and economies, from populations around the world. Yet, these efforts have advanced in a fragmented manner, using non-standardized descriptions (lexicons) of time use that often require researchers to make arbitrary designations among non-exclusive categories, and are not easily translated between disciplines. Here we propose a new approach, assembling multiple dimensions of time use to construct what we call the human chronome, as a means to provide novel interdisciplinary perspectives on fundamental aspects of human behaviour and experience. The approach is enabled by parallel lexicons, each of which aims for low ambiguity by focusing on a single coherent categorical dimension, and which can then be combined to provide a multi-dimensional characterization. Each lexicon should follow a single, consistent theoretical orientation, ensure exhaustiveness and exclusivity, and minimize ambiguity arising from temporal and social aggregation. As a pragmatic first step towards this goal, we describe the development of the Motivating- Outcome- Oriented General Activity Lexicon (MOOGAL). The MOOGAL is theoretically oriented towards the outcomes of activities, is applicable to any human from hunter-gatherers to modern urbanites, and deliberately focuses on the physical outcomes which motivate the undertaking of activities to reduce ambiguity from social aggregation. We illustrate the utility of the MOOGAL by comparing it with existing economic, sociological and anthropological lexicons, showing that it exhaustively covers the previously-defined activities with low ambiguity, and apply it to time use and economic data from two countries. Our results support the feasibility of using generalized lexicons to incorporate diverse observational constraints on time use, thereby providing a rich interdisciplinary perspective on the human system that is particularly relevant to the current period of rapid social, technological and environmental change.

Novel CS1 CAR-T Cells and Bispecific CS1-BCMA CAR-T Cells Effectively Target Multiple Myeloma.

Multiple myeloma (MM) is a hematological cancer caused by abnormal proliferation of plasma cells in the bone marrow, and novel types of treatment are needed for this deadly disease. In this study, we aimed to develop novel CS1 CAR-T cells and bispecific CS1-BCMA CAR-T cells to specifically target multiple myeloma. We generated a new CS1 (CD319, SLAM-7) antibody, clone (7A8D5), which specifically recognized the CS1 antigen, and we applied it for the generation of CS1-CAR. CS1-CAR-T cells caused specific killing of CHO-CS1 target cells with secretion of IFN-gamma and targeted multiple myeloma cells. In addition, bispecific CS1-BCMA-41BB-CD3 CAR-T cells effectively killed CHO-CS1 and CHO-BCMA target cells, killed CS1/BCMA-positive multiple myeloma cells, and secreted IFN-gamma. Moreover, CS1-CAR-T cells and bispecific CS1-BCMA CAR-T cells effectively blocked MM1S multiple myeloma tumor growth in vivo. These data for the first time demonstrate that novel CS1 and bispecific CS1-BCMA-CAR-T cells are effective in targeting MM cells and provide a basis for future clinical trials.

Small Endogeneous Peptide Mitigates Myocardial Remodeling in a Mouse Model of Cardioselective Galectin-3 Overexpression.

BACKGROUND: Myocardial Gal3 (galectin-3) expression is associated with cardiac inflammation and fibrosis. Increased Gal3 portends susceptibility to heart failure and death. There are no data reporting the causative role of Gal3 to mediate cardiac fibro-inflammatory response and heart failure. METHODS: We developed a cardioselective Gal3 gain-of-function mouse (Gal3+/+) using α-myosin heavy chain promotor. We confirmed Gal3-transgene expression with real-time polymerase chain reaction and quantified cardiac/circulating Gal3 with Western blot and immunoassays. We used echocardiogram and cardiac magnetic resonance imaging to measure cardiac volumes, function, and myocardial velocities. Ex vivo, we studied myocardial inflammation/fibrosis and downstream TGF (transforming growth factor) ß1-mRNA expression. We examined the effects of acute myocardial ischemia in presence of excess Gal3 by inducing acute myocardial infarction in mice. Two subsets of mice including mice treated with N-acetyl-seryl-aspartyl-lysyl-proline (a Gal3-inhibitor) and mice with genetic Gal3 loss-of-function (Gal3-/-) were studied for comparative analysis of Gal3 function. RESULTS: Gal3+/+ mice had increased cardiac/circulating Gal3. Gal3+/+ mice showed excess pericardial fat pad, dilated ventricles and cardiac dysfunction, which was partly normalized by N-acetyl-seryl-aspartyl-lysyl-proline. Cardiac magnetic resonance imaging showed reduced myocardial contractile velocities in Gal3+/+. The majority of Gal3+/+ mice did not survive acute myocardial infarction, and the survivors had profound cardiac dysfunction. Myocardial histology of Gal3+/+ mice showed macrophage/mast-cell infiltration, fibrosis and higher TGFß1-mRNA expression, which were mitigated by both Gal3 gene deletion and N-acetyl-seryl-aspartyl-lysyl-proline administration. CONCLUSIONS: Our study shows that cardioselective Gal3 overexpression leads to multiple cardiac phenotypic defects including ventricular dilation and cardiac dysfunction. Pharmacological Gal3 inhibition conferred protective effects with reduction of inflammation and fibrosis. Our study highlights the importance of translational studies to counteract Gal3 function and prevent cardiac dysfunction.

Facile fabrication of antibacterial and antiviral perhydrolase-polydopamine composite coatings.

In situ generation of antibacterial and antiviral agents by harnessing the catalytic activity of enzymes on surfaces provides an effective eco-friendly approach for disinfection. The perhydrolase (AcT) from Mycobacterium smegmatis catalyzes the perhydrolysis of acetate esters to generate the potent disinfectant, peracetic acid (PAA). In the presence of AcT and its two substrates, propylene glycol diacetate and H2O2, sufficient and continuous PAA is generated over an extended time to kill a wide range of bacteria with the enzyme dissolved in aqueous buffer. For extended self-disinfection, however, active and stable AcT bound onto or incorporated into a surface coating is necessary. In the current study, an active, stable and reusable AcT-based coating was developed by incorporating AcT into a polydopamine (PDA) matrix in a single step, thereby forming a biocatalytic composite onto a variety of surfaces. The resulting AcT-PDA composite coatings on glass, metal and epoxy surfaces yielded up to 7-log reduction of Gram-positive and Gram-negative bacteria when in contact with the biocatalytic coating. This composite coating also possessed potent antiviral activity, and dramatically reduced the infectivity of a SARS-CoV-2 pseudovirus within minutes. The single-step approach enables rapid and facile fabrication of enzyme-based disinfectant composite coatings with high activity and stability, which enables reuse following surface washing. As a result, this enzyme-polymer composite technique may serve as a general strategy for preparing antibacterial and antiviral surfaces for applications in health care and common infrastructure safety, such as in schools, the workplace, transportation, etc.

Novel CD37, Humanized CD37 and Bi-Specific Humanized CD37-CD19 CAR-T Cells Specifically Target Lymphoma.

CD19 and CD37 proteins are highly expressed in B-cell lymphoma and have been successfully targeted with different monotherapies, including chimeric antigen receptor (CAR)-T cell therapy. The goal of this study was to target lymphoma with novel CD37, humanized CD37, and bi-specific humanized CD37-CD19 CAR-T cells. A novel mouse monoclonal anti-human CD37 antibody (clone 2B8D12F2D4) was generated with high binding affinity for CD37 antigen (KD = 1.6 nM). The CD37 antibody specifically recognized cell surface CD37 protein in lymphoma cells and not in multiple myeloma or other types of cancer. The mouse and humanized CD37-CAR-T cells specifically killed Raji and CHO-CD37 cells and secreted IFN-gamma. In addition, we generated bi-specific humanized hCD37-CD19 CAR-T cells that specifically killed Raji cells, CHO-CD37, and Hela-CD19 cells and did not kill control CHO or Hela cells. Moreover, the hCD37-CD19 CAR-T cells secreted IFN-gamma against CD37-positive and CD19-positive target CHO-CD37, Hela-CD19 cells, respectively, but not against CD19 and CD37-negative parental cell line. The bi-specific hCD37-CD19 significantly inhibited Raji xenograft tumor growth and prolonged mouse survival in NOD scid gamma mouse (NSG) mouse model. This study demonstrates that novel humanized CD37 and humanized CD37-CD19 CAR-T cells specifically targeted either CD37 positive or CD37 and CD19-positive cells and provides a basis for future clinical studies.

Immune Checkpoint Inhibitors: Cardiotoxicity in Pre-clinical Models and Clinical Studies.

Since the approval of the first immune checkpoint inhibitor (ICI) 9 years ago, ICI-therapy have revolutionized cancer treatment. Lately, antibodies blocking the interaction of programmed cell death protein (PD-1) and ligand (PD-L1) are gaining momentum as a cancer treatment, with multiple agents and cancer types being recently approved for treatment by the US Food and Drug Administration (FDA). Unfortunately, immunotherapy often leads to a wide range of immune related adverse events (IRAEs), including several severe cardiac effects and most notably myocarditis. While increased attention has been drawn to these side effects, including publication of multiple clinical observational data, the underlying mechanisms are unknown. In the event of IRAEs, the most widely utilized clinical solution is administration of high dose corticosteroids and in severe cases, discontinuation of these ICIs. This is detrimental as these therapies are often the last line of treatment options for many types of advanced cancer. In this review, we have systematically described the pathophysiology of the PD-1/PD-L1 axis (including a historical perspective) and cardiac effects in pre-clinical models, clinical trials, autoimmune mechanisms, and immunotherapy in combination with other cancer treatments. We have also reviewed the current challenges in the diagnosis of cardiac events and future directions in the field. In conclusion, this review will delve into this expanding field of cancer immunotherapy and the emerging adverse effects that should be quickly detected and prevented.

Macrophage-specific protein perforin-2 is associated with poor neurological recovery and reduced survival after sudden cardiac arrest.

BACKGROUND: Biomarkers involved in inflammation and stress response were implicated in patients who were successfully resuscitated from out of hospital cardiac arrest (sR-OHCA). Here we report that macrophage-expressed gene, perforin-2, an evolutionarily conserved protein with membrane attack domain, is associated with poor neurological outcomes and mortality after sR-OHCA. OBJECTIVES: To examine the association between circulating perforin-2 protein measured within 6-h of sR-OHCA, mortality and neurological outcomes. METHODS: We prospectively enrolled 144 sR-OHCA patients from 4 different tertiary care centers. We measured perforin-2 and other conventional clinical biomarkers and compared between survivors vs. non-survivors. The neurological outcomes were dichotomized as poor or good according to the cereberal performance score. RESULTS: At the end of the hospital stay, 45% of the patients had died and 46% had poor neurological outcomes. Serum perforin-2 levels were significantly higher in patients with poor neurological recovery, compared to the ones with good neurological recovery (ng/mL, 13.7 ±â€¯45.9 vs. 1.2 ±â€¯7.0, p = 0.01). There were no differences in other routinely measured biomarkers and left ventricular ejection fraction. On multivariate logistic regression, elevated perforin-2 (OR: 12.78, 95% CI: 1.0-17.8, p = 0.02), comatose on presentation (OR: 27.82, 95% CI: 0.2-19.5, p = 0.02) and non-shockable rhythm (OR: 17.04, 95% CI: 0.7-15.7, p = 0.01) were the significant predictors of poor neurological outcome. CONCLUSIONS: This study reports a novel macrophage-expressed circulating biomarker perforin-2 to be strongly associated with reduced survival and poor neurological outcomes in sR-OHCA. These data can guide clinicians to prognosticate survival and neurological outcomes in sR-OHCA, and also form the basis for future therapeutic approaches.

PLAP -CAR T cells mediate high specific cytotoxicity against colon cancer cells.

Placental alkaline phosphatase, PLAP encoded by ALPP gene in humans is mainly expressed in placenta and testis, and not expressed in any other normal tissues. PLAP is overexpressed in colorectal cancers which makes it an attractive target for CAR (chimeric antigen receptor)-T cell therapy. PLAP mRNA expression was detected in 21.5% (25 out of 116) of colorectal cancer cell lines and this expression was confirmed by FACS at the protein level. In addition, IHC staining on primary colorectal cancer tumors demonstrated PLAP expression in >20% of colorectal cancer tumors. We generated mouse and humanized PLAP ScFv-CAR-T cells and demonstrated high specificity against PLAP-positive colon cancer cells using RTCA (real-time cytotoxicity assay) and IFN-gamma secretion. In addition, humanized-CAR-T cells significantly decreased Lovo xenograft tumor growth in vivo. The combination of hPLAP-CAR-T cells with PD-1, PD-L1 or LAG-3 checkpoint inhibitors significantly increased the activity of hPLAP-CAR-T cells. This study demonstrates ability of novel PLAP-CAR-T cells to kill colorectal cancers and that the extent of killing can be increased by combination with checkpoint inhibitors.

Transferrin epitope-CD19-CAR-T cells effectively kill lymphoma cells in vitro and in vivo.

Chimeric antigen receptor (CAR) T cell immunotherapy has demonstrated clinical success in treatment of B-cell hematologic cancers. In this study, we compared human Transferrin epitope tagged CAR-T cells with non-tagged CAR-T cells for cytotoxicity, IFN-gamma secretion and tumor clearance in NSG mice. CD19-TF-CAR-T cells had similar cytotoxicity in vitro to CD19-CAR-T cells against cells expressing CD19 antigen: exogenously CD19+ Hela cells and endogenously CD19+ Raji cells. In addition, CD22-TF CAR-T cells were similarly cytotoxic against CD22+ CHO cells and CD22+  Raji cells. Both CD19-TF or CD22-TF-CAR-T cells secreted less IFN-gamma as compared to non-tagged CAR-T cells. In a Raji xenograft NSG mouse model, CD19-TF-CAR-T cells were as effective as CD19-CAR-T cells in reducing tumor growth and extending mouse survival. The results show that CD19-TF-CAR-T cells can be monitored using TF antibody in vitro and ex vivo, and that these cells effectively killed Raji cells in vitro and in vivo with reduced secretion of IFN-gamma. Thus, these TF-tagged CAR-T cells might have improved safety and provide a basis for future clinical studies.

A Real-time Potency Assay for Chimeric Antigen Receptor T Cells Targeting Solid and Hematological Cancer Cells.

Chimeric antigen receptor (CAR) T-cell therapy for cancer has achieved significant clinical benefit for resistant and refractory hematological malignancies such as childhood acute lymphocytic leukemia. Efforts are currently underway to extend this promising therapy to solid tumors in addition to other hematological cancers. Here, we describe the development and production of potent CAR T cells targeting antigens with unique or preferential expression on solid and liquid tumor cells. The in vitro potency of these CAR T cells is then evaluated in real-time using the highly sensitive impedance-based xCELLigence assay. Specifically, the impact of different costimulatory signaling domains, such as glucocorticoid-induced tumor necrosis factor receptor (TNFR)-related protein (GITR), on the in vitro potency of CAR T cells is examined. This report includes protocols for: generating CAR T cells for preclinical studies using lentiviral gene transduction, expanding CAR T cells, validating CAR expression, and running and analyzing xCELLigence potency assays.

DCLK1 Monoclonal Antibody-Based CAR-T Cells as a Novel Treatment Strategy against Human Colorectal Cancers.

CAR-T (chimeric antigen receptor T cells) immunotherapy is effective in many hematological cancers; however, efficacy in solid tumors is disappointing. Doublecortin-like kinase 1 (DCLK1) labels tumor stem cells (TSCs) in genetic mouse models of colorectal cancer (CRC). Here, we describe a novel CAR-T targeting DCLK1 (CBT-511; with our proprietary DCLK1 single-chain antibody variable fragment) as a treatment strategy to eradicate CRC TSCs. The cell surface expression of DCLK1 and cytotoxicity of CBT-511 were assessed in CRC cells (HT29, HCT116, and LoVo). LoVo-derived tumor xenografts in NOD Scid gamma (NSGTM)mice were treated with CBT-511 or mock CAR-T cells. Adherent CRC cells express surface DCLK1 (two-dimensional, 2D). A 4.5-fold increase in surface DCLK1 was observed when HT29 cells were grown as spheroids (three-dimensional, 3D). CBT-511 induced cytotoxicity (2D; p < 0.0001), and increased Interferon gamma (IFN-γ) release in CRC cells (2D) compared to mock CAR-T (p < 0.0001). Moreover, an even greater increase in IFN-γ release was observed when cells were grown in 3D. CBT-511 reduced tumor growth by approximately 50 percent compared to mock CAR-T. These data suggest that CRC cells with increased clonogenic capacity express increased surface DCLK1. A DCLK1-targeted CAR-T can induce cytotoxicity in vitro and inhibit xenograft growth in vivo.