Engineered CD147-CAR macrophages for enhanced phagocytosis of cancers.

Chimeric antigen receptor (CAR) T cell therapy has shown promising results in hematologic malignancies, but its effectiveness in solid cancers remains challenging. Macrophages are immune cells residing within the tumor microenvironment. They can phagocytose tumor cells. Recently, CAR macrophages (CAR-M) have been a promising candidate for treating solid cancers. One of the common cancer antigens overexpressed in various types of cancer is CD147. CAR-T and NK cells targeting CD147 antigen have shown significant efficacy against hepatocellular carcinoma. Nevertheless, CAR-M targeting the CD147 molecule has not been investigated. In this study, we generated CAR targeting the CD147 molecule using the THP-1 monocytic cell line (CD147 CAR-M). The CD147 CAR-M exhibited typical macrophage characteristics, including phagocytosis of zymosan bioparticles and polarization ability toward M1 and M2 phenotypes. Furthermore, the CD147 CAR-M demonstrated enhanced anti-tumor activity against K562 and MDA-MB-231 cells without exhibiting off-target cytotoxicity against normal cells. Our research provides valuable insights into the potential of CD147 CAR-M as a promising platform for cancer immunotherapy, with applications in both hematologic malignancies and solid cancers.

Role of cyclins and cyclin-dependent kinases in pluripotent stem cells and their potential as a therapeutic target.

Over the last 15 years connections between cell cycle control, maintenance of pluripotency, and control of cell fate decisions have been firmly established. With the emergence of powerful tools, such as highly-specific small molecule inhibitors for cyclin-dependent protein kinase (CDK) activity and single-cell imaging technologies, the mechanistic links between cyclins, CDKs and regulation in PSCs in mechanistic detail has been made possible. In this review, we discuss new developments that mechanistically link the CDK regulatory network to control of cell fate decisions, including maintenance of the pluripotent state. Overall, these findings have potential to impact the translational applications of stem cells in regenerative medicine, drug discovery and cancer treatment.

Efficient generation of endothelial cells from induced pluripotent stem cells derived from a patient with peripheral arterial disease.

Peripheral arterial disease (PAD) is caused by atherosclerotic plaque accumulation, which results in ischemia in lower extremity ischemia. Cell-based therapy using endothelial progenitor cells (EPCs) or endothelial cells (ECs) has been challenging due to an insufficient number and replicative senescence of primary cells isolated from patients. To overcome this limitation, we generated induced pluripotent stem cells (iPSCs) from a patient with PAD for the first time. The patient-specific iPSCs have unlimited proliferation and can be used to generate a clinically relevant number of functional ECs. Here we developed a strategy to efficiently generate high EC yields within 5 days of differentiation. The generated iPSC-derived ECs from a PAD patient were phenotypically and functionally similar to the primary blood outgrowth endothelial cells (BOECs) and iPSC-ECs derived from healthy donors as evidenced by expression of EC-specific markers, capillary-like tube-forming potential, and the ability to uptake acetylated low-density lipoprotein (Ac-LDL). Our approach may provide an alternative renewable source of large-scale ECs for regenerative therapy. This study represents the first step toward the development of an autologous cell-based strategy for the treatment of PAD in the future.

Validation of Promoters and Codon Optimization on CRISPR/Cas9-Engineered Jurkat Cells Stably Expressing αRep4E3 for Interfering with HIV-1 Replication.

Persistent and efficient therapeutic protein expression in the specific target cell is a significant concern in gene therapy. The controllable integration site, suitable promoter, and proper codon usage influence the effectiveness of the therapeutic outcome. Previously, we developed a non-immunoglobulin scaffold, alpha repeat protein (αRep4E3), as an HIV-1 RNA packaging interference system in SupT1 cells using the lentiviral gene transfer. Although the success of anti-HIV-1 activity was evidenced, the integration site is uncontrollable and may not be practical for clinical translation. In this study, we use the CRISPR/Cas9 gene editing technology to precisely knock-in αRep4E3 genes into the adeno-associated virus integration site 1 (AAVS1) safe harbor locus of the target cells. We compare the αRep4E3 expression under the regulation of three different promoters, including cytomegalovirus (CMV), human elongation factor-1 alpha (EF1α), and ubiquitin C (UbC) promoters with and without codon optimization in HEK293T cells. The results demonstrated that the EF1α promoter with codon-optimized αRep4E3mCherry showed higher protein expression than other promoters with non-optimized codons. We then performed a proof-of-concept study by knocking in the αRep4E3mCherry gene at the AAVS1 locus of the Jurkat cells. The results showed that the αRep4E3mCherry-expressing Jurkat cells exhibited anti-HIV-1 activities against HIV-1NL4-3 strain as evidenced by decreased capsid (p24) protein levels and viral genome copies as compared to the untransfected Jurkat control cells. Altogether, our study demonstrates that the αRep4E3 could interfere with the viral RNA packaging and suggests that the αRep4E3 scaffold protein could be a promising anti-viral molecule that offers a functional cure for people living with HIV-1.

Engineered Zinc Finger Protein Targeting 2LTR Inhibits HIV Integration in Hematopoietic Stem and Progenitor Cell-Derived Macrophages: In Vitro Study.

Human hematopoietic stem/progenitor cell (HSPC)-based gene therapy is a promising direction for curing HIV-1-infected individuals. The zinc finger protein (2LTRZFP) designed to target the 2-LTR-circle junction of HIV-1 cDNA was previously reported as an intracellular antiviral molecular scaffold that prevents HIV integration. Here, we elucidate the efficacy and safety of using 2LTRZFP in human CD34+ HSPCs. We transduced 2LTRZFP which has the mCherry tag (2LTRZFPmCherry) into human CD34+ HSPCs using a lentiviral vector. The 2LTRZFPmCherry-transduced HSPCs were subsequently differentiated into macrophages. The expression levels of pro-apoptotic proteins of the 2LTRZFPmCherry-transduced HSPCs showed no significant difference from those of the non-transduced control. Furthermore, the 2LTRZFPmCherry-transduced HSPCs were successfully differentiated into mature macrophages, which had normal phagocytic function. The cytokine secretion assay demonstrated that 2LTRZFPmCherry-transduced CD34+ derived macrophages promoted the polarization towards classically activated (M1) subtypes. More importantly, the 2LTRZFPmCherry transduced cells significantly exhibited resistance to HIV-1 integration in vitro. Our findings demonstrate that the 2LTRZFPmCherry-transduced macrophages were found to be functionally and phenotypically normal, with no adverse effects of the anti-HIV-1 scaffold. Our data suggest that the anti-HIV-1 integrase scaffold is a promising antiviral molecule that could be applied to human CD34+ HSPC-based gene therapy for AIDS patients.

Cell type of origin influences iPSC generation and differentiation to cells of the hematoendothelial lineage.

The use of induced pluripotent stem cells (iPSCs) as a source of cells for cell-based therapy in regenerative medicine is hampered by the limited efficiency and safety of the reprogramming procedure and the low efficiency of iPSC differentiation to specialized cell types. Evidence suggests that iPSCs retain an epigenetic memory of their parental cells with a possible influence on their differentiation capacity in vitro. We reprogramme three cell types, namely human umbilical cord vein endothelial cells (HUVECs), endothelial progenitor cells (EPCs) and human dermal fibroblasts (HDFs), to iPSCs and compare their hematoendothelial differentiation capacity. HUVECs and EPCs were at least two-fold more efficient in iPSC reprogramming than HDFs. Both HUVEC- and EPC-derived iPSCs exhibited high potentiality toward endothelial cell differentiation compared with HDF-derived iPSCs. However, only HUVEC-derived iPSCs showed efficient differentiation to hematopoietic stem/progenitor cells. Examination of DNA methylation at promoters of hematopoietic and endothelial genes revealed evidence for the existence of epigenetic memory at the endothelial genes but not the hematopoietic genes in iPSCs derived from HUVECs and EPCs indicating that epigenetic memory involves an endothelial differentiation bias. Our findings suggest that endothelial cells and EPCs are better sources for iPSC derivation regarding their reprogramming efficiency and that the somatic cell type used for iPSC generation toward specific cell lineage differentiation is of importance.

Generation of induced pluripotent stem cells as a potential source of hematopoietic stem cells for transplant in PNH patients.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hemolytic anemia caused by lack of CD55 and CD59 on blood cell membrane leading to increased sensitivity of blood cells to complement. Hematopoietic stem cell transplantation (HSCT) is the only curative therapy for PNH, however, lack of HLA-matched donors and post-transplant complications are major concerns. Induced pluripotent stem cells (iPSCs) derived from patients are an attractive source for generating autologous HSCs to avoid adverse effects resulting from allogeneic HSCT. The disease involves only HSCs and their progeny; therefore, other tissues are not affected by the mutation and may be used to produce disease-free autologous HSCs. This study aimed to derive PNH patient-specific iPSCs from human dermal fibroblasts (HDFs), characterize and differentiate to hematopoietic cells using a feeder-free protocol. Analysis of CD55 and CD59 expression was performed before and after reprogramming, and hematopoietic differentiation. Patients' dermal fibroblasts expressed CD55 and CD59 at normal levels and the normal expression remained after reprogramming. The iPSCs derived from PNH patients had typical pluripotent properties and differentiation capacities with normal karyotype. After hematopoietic differentiation, the differentiated cells expressed early hematopoietic markers (CD34 and CD43) with normal CD59 expression. The iPSCs derived from HDFs of PNH patients have normal levels of CD55 and CD59 expression and hold promise as a potential source of HSCs for autologous transplantation to cure PNH patients.

Enhanced human mesenchymal stem cell survival under oxidative stress by overexpression of secreted frizzled-related protein 2 gene.

Human mesenchymal stem cells (hMSCs) have been used to improve engraftment and to treat graft versus host disease following allogeneic hematopoietic stem cell transplantation. However, oxidative stress presented in the microenvironment can damage the transplanted hMSCs and therefore reduce their survival in target organs. We investigated how to enhance the survival of hMSCs under oxidative stress by overexpressing secreted frizzled-related protein 2 (sFRP2) gene in bone marrow-derived hMSCs and umbilical cord-derived hMSCs. The survival and characteristics of those sFRP2-overexpressing hMSCs (sFRP2-BM-hMSCs and sFRP2-UC-hMSCs) were studied compared with non-transduced hMSCs. We found that the percentages of viable cells in culture of sFRP2-BM-hMSCs and sFRP2-UC-hMSCs in the absence or presence of 0.75 mM H2O2 were significantly higher than those of their non-transduced counterparts. The overexpression of sFRP2 gene did not affect the characteristics of hMSCs regarding their morphology, surface marker expression, and differentiation potential. Our study suggests that overexpression of sFRP2 gene in hMSCs might improve the therapeutic effectiveness of hMSC transplantation.

Bortezomib enhances the osteogenic differentiation capacity of human mesenchymal stromal cells derived from bone marrow and placental tissues.

Bortezomib (BZB) is a chemotherapeutic agent approved for treating multiple myeloma (MM) patients. In addition, there are several reports showing that bortezomib can induce murine mesenchymal stem cells (MSCs) to undergo osteogenic differentiation and increase bone formation in vivo. MSCs are the multipotent stem cells that have capacity to differentiate into several mesodermal derivatives including osteoblasts. Nowadays, MSCs mostly bone marrow derived have been considered as a valuable source of cell for tissue replacement therapy. In this study, the effect of bortezomib on the osteogenic differentiation of human MSCs derived from both bone marrow (BM-MSCs) and postnatal sources such as placenta (PL-MSCs) were investigated. The degree of osteogenic differentiation of BM-MSCs and PL-MSCs after bortezomib treatment was assessed by alkaline phosphatase (ALP) activity, matrix mineralization by Alizarin Red S staining and the expression profiles of osteogenic differentiation marker genes, Osterix, RUNX2 and BSP. The results showed that 1 nM and 2 nM BZB can induce osteogenic differentiation of BM-MSCs and PL-MSCs as demonstrated by increased ALP activity, increased matrix mineralization and up-regulation of osteogenic differentiation marker genes, Osterix, RUNX2 and BSP as compared to controls. The enhancement of osteogenic differentiation of MSCs by bortezomib may lead to the potential therapeutic applications in human diseases especially patients with osteopenia.

A live single-cell reporter system reveals drug-induced plasticity of a cancer stem cell-like population in cholangiocarcinoma.

Cancer stem cells (CSC) play an important role in carcinogenesis and are acknowledged to be responsible for chemoresistance in cholangiocarcinoma (CCA). Studying CCA CSC has been challenging, due to lack of consensus CSC markers, and to their plastic nature. Since dual expression of the core pluripotent factors SOX2/OCT4 has been shown to correlate with poor outcome in CCA patients, we selected the SOX2/OCT4 activating short half-life GFP-based live reporter (SORE6-dsCopGFP) to study CSC dynamics at the single-cell level. Transduction of five human CCA cell lines resulted in the expression of 1.8-13.1% GFP-positive (SORE6POS) cells. By live imaging, we found that SORE6POS CCA cells possess self-renewal capacity and that they can be induced to differentiate. Significantly, the SORE6POS cells were highly tumorigenic, both in vitro and in vivo, thus implicating the characteristics of primary CSCs. When we then analyzed for selected CSC-related markers, we found that the majority of both CD133+/CD44+, and CD133+/LGR5+ CCA cells were SORE6POS cells. Exposing transduced cells to standard CCA chemotherapy revealed higher growth rate inhibition at 50% (GR50s) for SORE6POS cells compared to GFP-negative (SORE6NEG) ones indicating that these CSC-like cells were more resistant to the treatment. Moreover, the chemotherapy induced SORE6POS from SORE6NEG cells, while retaining the existing SORE6POS population. Finally, treatment of transduced cells with CDK4/6 inhibitors in vitro for 3 days resulted in a lowered CSC number in the culture. Thus, applying a live reporter system allowed us to elucidate the stem cell diversity and drug-induced plasticity of CCA CSCs. These findings have clear implications for future management of such patients.

CRISPR-Cas9-mediated disruption of B2M and CIITA genes eliminates HLA class I and II expression in human induced pluripotent stem cells (MUSIi001-A-2).

Cell-based therapy offers great promise for treating degenerative diseases. Although autologous cell-based therapy is ideal, it may be impractical due to the high manufacturing cost and long production time. Allogeneic cell-based therapy offers a more cost-effective alternative; however, the risk of graft rejection is a major concern. Here, we generated HLA class-I and -II null iPSC line by knocking out CIITA gene in the B2M-knockout MUSIi001-A-1 cell line using CRISPR/Cas9 system. The MUSIi001-A-2 line provides a valuable model for studying immunological responses against allogeneic T cells and serves as a prototype for developing specific cell types for future cell-based therapy.

Analysis of Influenza A virus infection in human induced pluripotent stem cells (hiPSCs) and their derivatives.

Influenza A virus (IAV) infection in pregnant women is a major public health concern. However, the effect of IAV infection on human embryogenesis is still unclear. Here we show that human induced pluripotent stem cells (hiPSCs) and hiPSC-derived ectodermal, mesodermal and endodermal cells are susceptible to IAV infection. These cell types stained positive for α2,6-linked sialic acid, the receptor for IAV infection expressed on the cell surface. While hiPSCs produced high viral titers for up to 7 days with increasing infected cell number suggesting that the viral progenies produced from hiPSCs without exogenous protease were infectious and could spread to other cells, the three germ-layer cells showed a decline in viral titers suggesting the lack of viral spreading. Amongst the three germ layers, endodermal cells were less susceptible than ectodermal and mesodermal cells. These results indicate the permissiveness of cells of early embryogenesis, and suggest a risk of detrimental effects of IAV infection in early human embryonic development.

An induced pluripotent stem cell line (MUSIi019-A) generated from a patient with distal renal tubular acidosis carrying a compound heterozygous mutation in solute carrier family 4 member 1 (SLC4A1) gene.

Distal renal tubular acidosis (dRTA), a disease characterized by the failure of the distal nephron to secrete acid into the urine, can be caused by mutations in SLC4A1 gene encoding erythroid and kidney anion exchanger 1 (AE1). Here, an induced pluripotent stem cell (iPSC) line was generated from a patient with dRTA and hemolytic anemia carrying compound heterozygous SLC4A1 mutations containing c.1199_1225del (p.Ala400_Ala408del), resulting in Southeast Asian ovalocytosis (SAO), and c.1331C>A (p.Thr444Asn). Peripheral blood mononuclear cells (PBMCs) were reprogrammed using Sendai viral reprogramming. The established iPSC line, MUSIi019-A, exhibited pluripotent property and retained the same mutations observed in the patients.

A three-dimensional immune-oncology model for studying in vitro primary human NK cell cytotoxic activity.

Immunotherapy has emerged as a promising therapeutic approach for treating several forms of cancer. Adoptive cell transfer of immune cells, such as natural killer (NK) cells, provides a powerful therapeutic potential against tumor cells. In the past decades, two-dimensional (2D) tumor models have been used to investigate the effectiveness of immune cell killing. However, the 2D tumor models exhibit less structural complexity and cannot recapitulate the physiological condition of the tumor microenvironment. Thus, the effectiveness of immune cells against tumor cells using these models cannot fully be translated to clinical studies. In order to gain a deeper insight into immune cell-tumor interaction, more physiologically relevant in vivo-like three-dimensional (3D) tumor models have been developed. These 3D tumor models can mimic the dynamic cellular activities, making them a much closer representation of the in vivo tumor profiles. Here, we describe a simple and effective protocol to study the cytotoxic activity of primary human NK cells toward the 3D tumor spheroids. Our protocol includes isolation and expansion of human NK cells, labeling and formation of tumor spheroids, co-culture of NK cells and tumor spheroids, and evaluation of cytotoxic activity using a confocal microscope. This protocol is also applicable to other types of tumors and immune cells.

CRISPR/Cas9 Ribonucleoprotein Complex-Mediated Efficient B2M Knockout in Human Induced Pluripotent Stem Cells (iPSCs).

Advances in induced pluripotent stem cell (iPSC) technology provide a renewable source of cells for tissue regeneration and therefore hold great promise for cell replacement therapy. However, immune rejection of allograft due to human leukocyte antigen (HLA) mismatching remains a major challenge. Considerable efforts have been devoted to overcoming the immunogenicity of allograft transplantation. One of the approaches is an elimination of HLA molecules on the surface of allogeneic cells using genome editing technology to generate universal stem cells. Here, we present a simple and effective genome editing approach to knockout the ß-2-immunoglobulin (B2M) gene, which encodes B2M protein that forms a heterodimer with HLA class I proteins, in induced pluripotent stem cells (iPSCs) leading to HLA class I (HLA-I) depletion. We also describe detailed procedures for validation of the B2M-knockout iPSCs using flow cytometry, and genotypic analysis for potential off-target regions. Our protocol is also applicable for knocking out other genes in iPSCs and other cell types.

A precise gene delivery approach for human induced pluripotent stem cells using Cas9 RNP complex and recombinant AAV6 donor vectors.

Genome editing in human induced pluripotent stem cells (hiPSCs) offers a potential tool for studying gene functions in disease models and correcting genetic mutations for cell-based therapy. Precise transgene insertion in hiPSCs represents a significant challenge. In the past decade, viral transduction has been widely used due to its high transduction efficiency; however, it can result in random transgene integration and variable transgene copy numbers. Non-viral-based strategies are generally safer but limited by their low transfection efficiency in hiPSCs. Recently, genome engineering using adeno-associated virus (AAV) vectors has emerged as a promising gene delivery approach due to AAVs' low immunogenicity, toxicity, and ability to infect a broad range of cells. The following protocol describes the workflow for genome editing in hiPSCs using the CRISPR/Cas9 ribonucleoprotein (RNP) complex combined with the recombinant AAV serotype 6 (AAV6) donor vectors to introduce a gene of interest (GOI) fused with mCherry fluorescent reporter gene into the AAVS1 safe harbor site. This approach leads to efficient transgene insertion and is applicable to precise genome editing of hiPSCs or other types of stem cells for research purposes.

Efficient Generation of iPSC-Derived Hematoendothelial Progenitors and Specification Toward T cell Lineage.

One of the major obstacles for adoptive cell transfer (ACT) of T cells is the loss of effector function and proliferative ability of isolated antigen-specific T cells after prolonged ex vivo expansion. To overcome this issue, induced pluripotent stem cells (iPSCs), which have unlimited proliferation and differentiation potential, can be used to generate a large number of antigen-specific T cells. Here, we describe an efficient differentiation protocol for the generation of cytotoxic CD8+ T cells from human T cell-derived iPSCs (T-iPSCs). The protocol consists of three main steps including differentiation of T-iPSCs toward hematoendothelial progenitors (HEPs), co-culture of HEPs with OP9-DL1 cells, and stimulation of T cell receptor (TCR) signaling to obtain CD8 single-positive (SP) T cells. This culture system is simple and efficient; therefore, will offer a powerful tool for studying T cell development and applications in adoptive immunotherapy.

Genetic correction of haemoglobin E in an immortalised haemoglobin E/beta-thalassaemia cell line using the CRISPR/Cas9 system.

ß-thalassaemia is one of the most common genetic blood diseases worldwide with over 300 mutations in the HBB gene affecting red blood cell functions. Recently, advances in genome editing technology have provided a powerful tool for precise genetic correction. Generation of patient-derived induced pluripotent stem cells (iPSCs) followed by genetic correction of HBB mutations and differentiation into haematopoietic stem/progenitor cells (HSPCs) offers a potential therapy to cure the disease. However, the biggest challenge is to generate functional HSPCs that are capable of self-renewal and transplantable. In addition, functional analyses of iPSC-derived erythroid cells are hampered by poor erythroid expansion and incomplete erythroid differentiation. Previously, we generated an immortalised erythroid cell line (SiBBE) with unique properties, including unlimited expansion and the ability to differentiate into mature erythrocytes. In this study, we report a highly efficient genetic correction of HbE mutation in the SiBBE cells using the CRISPR/Cas9 system. The HbE-corrected clones restored ß-globin production with reduced levels of HbE upon erythroid differentiation. Our approach provides a sustainable supply of corrected erythroid cells and represents a valuable model for validating the therapeutic efficacy of gene editing systems.

Generation of an induced pluripotent stem cell line (MUSIi015-A) from a diabetic patient carrying mutations in ZYG11A (p.L475P) and GATA6 (p.E51K).

Two heterozygous mutations (p.L475P in ZYG11A and p.E51K in GATA6) were identified in a family with autosomal dominant diabetes. ZYG11A-p.L475P was proposed as a causative mutation because of the complete segregation with hyperglycemia and the proven pathogenic effect on beta-cell expansion. The modifying effect of GATA6-p.E51K was proposed owing to the earlier onset of the carriers. Herein, we establish a line of induced pluripotent stem cells (iPSCs) from peripheral blood mononuclear cells (PBMCs) of a proband who carries both mutations using Sendai viral vectors. The generated iPSC line was characterized for pluripotency, chromosomal normality, and authentication.

Generation of an induced pluripotent stem cell line (MUSIi014-A) from an affected member of a family with autosomal dominant diabetes carrying p.L475P mutation in ZYG11A gene associated with a cell cycle arrest in beta-cell.

A heterozygous mutation (c.T1424C: p.L475P) in ZYG11A completely segregating with hyperglycemia in a Thai family with familial diabetes of the adulthood has been reported as a cause of cell cycle arrest in 1.1B4 cell line. This mutation is a suggestive cause of failure in adaptive beta-cell expansion which, thereby, contributes to the development of diabetes in the family. Here, an induced pluripotent stem cell (iPSC) line from peripheral blood mononuclear cells (PBMCs) of an affected family member carrying the mutation was generated using Sendai viral reprogramming. The established iPSC line is characterized and confirmed for pluripotency and chromosomal integrity.