Current Knowledge about CD3+CD20+ T Cells in Patients with Multiple Sclerosis.

Multiple sclerosis (MS) is a disease of the central nervous system (CNS) characterized by inflammation and autoimmune responses. This review explores the participation of T cells, particularly certain CD3+CD20+ T cells, in the clinical manifestations of MS and highlights their presence in diagnosed patients. These T cells show aberrant expression of CD20, normally considered a B-cell marker. In this review, relevant journal articles available in PubMed and CINAHL were identified by employing diverse search terms, such as MS, CD3+CD20+ T cells, the incidence and significance of CD3+CD20+ T cells in MS patients, and the impact of rituximab treatment. The search was limited to articles published in the ten-year period from 2014 to 2024. The results of this review suggest that most scholars agree on the presence of CD3+CD20+ T cells in cerebrospinal fluid. Emerging concepts relate to the fundamental role of CD20-expressing T cells in determining the target and efficacy of MS therapeutics and the presence of T cells in the cerebrospinal fluid of MS patients. The results clearly show that CD20+ T cells indicate disease chronicity and high disease activity.

The expression of PD-L1 on tumor-derived exosomes enhances infiltration and anti-tumor activity of αCD3 × αPD-L1 bispecific antibody-armed T cells.

Anti-cluster of differentiation (CD) 3 × α programmed death-ligand 1 (PD-L1) bispecific T-cell engager (BsTE)-bound T-cells (BsTE:T) are a promising new cancer treatment agent. However, the mechanisms of action of bispecific antibody-armed activated T-cells are poorly understood. Therefore, this study aimed to investigate the anti-tumor mechanism and efficacy of BsTE:T. The BsTE:T migration was assessed in vivo and in vitro using syngeneic and xenogeneic tumor models, flow cytometry, immunofluorescence staining, transwell migration assays, microfluidic chips, Exo View R100, western blotting, and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 technology. In murine B16 melanoma, MC38 colon cancer, and human multiple myeloma cells, BsTE:T exhibited superior tumor elimination relative to that of T-cells or BsTE alone. Moreover, BsTE:T migration into tumors was significantly enhanced owing to the presence of PD-L1 in tumor cells and secretion of PD-L1-containing exosomes. Furthermore, increased infiltration of CD44highCD62Llow effector memory CD8+ T-cells into tumors was closely associated with the anti-tumor effect of BsTE:T. Therefore, BsTE:T is an innovative potential anti-tumor therapy, and exosomal PD-L1 plays a crucial role both in vitro and in vivo in the anti-tumor activity of BsTE:T.

CD3-engaging bispecific antibodies trigger a paracrine regulated wave of T-cell recruitment for effective tumor killing.

The mechanism of action of bispecific antibodies (bsAbs) directing T-cell immunity to solid tumors is incompletely understood. Here, we screened a series of CD3xHER2 bsAbs using extracellular matrix (ECM) embedded breast cancer tumoroid arrays exposed to healthy donor-derived T-cells. An initial phase of random T-cell movement throughout the ECM (day 1-2), was followed by a bsAb-dependent phase of active T-cell recruitment to tumoroids (day 2-4), and tumoroid killing (day 4-6). Low affinity HER2 or CD3 arms were compensated for by increasing bsAb concentrations. Instead, a bsAb binding a membrane proximal HER2 epitope supported tumor killing whereas a bsAb binding a membrane distal epitope did not, despite similar affinities and intra-tumoroid localization of the bsAbs, and efficacy in 2D co-cultures. Initial T-cell-tumor contact through effective bsAbs triggered a wave of subsequent T-cell recruitment. This critical surge of T-cell recruitment was explained by paracrine signaling and preceded a full-scale T-cell tumor attack.

A novel bispecific T-cell engager using the ligand-target csGRP78 against acute myeloid leukemia.

Current medical therapies for treating acute myeloid leukemia (AML) remain unmet, and AML patients may benefit from targeted immunotherapy approaches that focus on specific tumor antigens. GRP78, which is upregulated in various malignant tumors such as AML, is partially expressed as cell surface GRP78 (csGRP78) on the cell membrane, making it an ideal target for redirecting T cells, including T-cell engagers. However, considering the conventional approach of using two scFv segments to construct a bispecific T-cell engager (BiTE), we have undertaken the development of a novel BiTE that utilizes a cyclic peptide ligand to specifically target csGRP78, which we refer to as GRP78-CD3/BiTE. We studied the effects of GRP78-CD3/BiTE on treatments for AML in vitro and in vivo and assessed the pharmacokinetics of this engager. Our findings demonstrated that GRP78-CD3/BiTE could not only effectively mediate the cytotoxicity of T cells against csGRP78-expressing AML cells but also specifically eliminate primary AML tumor cells in vitro. Furthermore, GRP78-CD3/BiTE exhibited a longer half-life despite having a lower molecular weight than CD19-CD3/BiTE. In a xenograft mouse model of AML, treatment with GRP78-CD3/BiTE prolonged the survival time of the mice. Our findings demonstrate that GRP78-CD3/BiTE is effective and selective for eliminating csGRP78-expressing AML cells and suggest that this approach to targeted immunotherapy could lead to effective new treatments for AML.

Safety and clinical activity of JNJ-78306358, a human leukocyte antigen-G (HLA-G) x CD3 bispecific antibody, for the treatment of advanced stage solid tumors.

BACKGROUND: JNJ-78306358 is a bispecific antibody that redirects T cells to kill human leukocyte antigen-G (HLA-G)-expressing tumor cells. This dose escalation study evaluated the safety, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity of JNJ-78306358 in patients with advanced solid tumors. METHODS: Adult patients with metastatic/unresectable solid tumors with high prevalence of HLA-G expression were enrolled. Dose escalation was initiated with once-weekly subcutaneous administration with step-up dosing to mitigate cytokine release syndrome (CRS). RESULTS: Overall, 39 heavily pretreated patients (colorectal cancer: n = 23, ovarian cancer: n = 10, and renal cell carcinoma: n = 6) were dosed in 7 cohorts. Most patients (94.9%) experienced ≥ 1 treatment-emergent adverse events (TEAEs); 87.2% had ≥ 1 related TEAEs. About half of the patients (48.7%) experienced CRS, which were grade 1/2. Nine patients (23.1%) received tocilizumab for CRS. No grade 3 CRS was observed. Dose-limiting toxicities (DLTs) of increased transaminases, pneumonitis and recurrent CRS requiring a dose reduction were reported in 4 patients, coinciding with CRS. No treatment-related deaths reported. No objective responses were noted, but 2 patients had stable disease > 40 weeks. JNJ-78306358 stimulated peripheral T cell activation and cytokine release. Anti-drug antibodies were observed in 45% of evaluable patients with impact on exposure. Approximately half of archival tumor samples (48%) had expression of HLA-G by immunohistochemistry. CONCLUSION: JNJ-78306358 showed pharmacodynamic effects with induction of cytokines and T cell activation. JNJ-78306358 was associated with CRS-related toxicities including increased transaminases and pneumonitis which limited its dose escalation to potentially efficacious levels. Trial registration number ClinicalTrials.gov (No. NCT04991740).

Key links in the physiological regulation of the immune system and disease induction: T cell receptor -CD3 complex.

T cell receptor (TCR) is a kind of surface marker that are specific to T cells. The TCR regulates T cell function and participates in the body's immunological response to prevent immune dysregulation and inflammatory reactions by identifying and binding exogenous antigens. Due to its brief intracellular segment, TCR requires intracellular molecules to assist with signaling. Among these, the CD3 molecule is one of the most important. The CD3 molecule involves in TCR structural stability as well as T cell activation signaling. A TCR-CD3 complex is created when TCR and CD3 form a non-covalent bond. Antigen recognition and T cell signaling are both facilitated by the TCR-CD3 complex. When a CD3 subunit is absent, a TCR-CD3 complex cannot form, and none of the subunits is transported to the cell surface. Thus, T cells cannot develop. Consequently, research on the physiological functions and potential pathogenicity of CD3 subunits can clarify the pathogenesis of immune system diseases and can offer fresh approaches to the treatment of it. In this review, the structure and function of the TCR-CD3 complex in the immune system was summarized, the pathogenicity of each CD3 subunit and therapeutic approaches to related diseases was explored and research directions for the development of new targeted drugs was provided.

Current landscape of CD3 bispecific antibodies in hematologic malignancies.

Over the past 30 years the incorporation of monoclonal antibody (mAb) treatments into the management of hematologic malignancies has led to significant improvements in patient outcomes. The key limitation of mAb treatments is the necessity for target antigen presentation on major histocompatibility complex (MHC) and costimulatory molecules to elicit a cytotoxic immune response. With the advent of bispecific antibodies (BsAbs), these limitations can be overcome through direct stimulation of cytotoxic T cells, thus limiting tumor cell evasion. BsAbs are rapidly being incorporated into treatment regimens for hematologic malignancies, and there are now seven FDA-approved treatments in this class, six of which have been approved in the past year. In this review we describe the function, complications, and clinical trial data available for CD3 BsAbs in the treatment of lymphoma, myeloma, and leukemia.

Lung-resident CD3-NK1.1+CD69+CD103+ Cells Play an Important Role in Bacillus Calmette-Guérin Vaccine-Induced Protective Immunity against Mycobacterium tuberculosis Infection.

Tissue-resident immune cells play important roles in local tissue homeostasis and infection control. There is no information on the functional role of lung-resident CD3-NK1.1+CD69+CD103+ cells in intranasal Bacillus Calmette-Guérin (BCG)-vaccinated and/or Mycobacterium tuberculosis (Mtb)-infected mice. Therefore, we phenotypically and functionally characterized these cells in mice vaccinated intranasally with BCG. We found that intranasal BCG vaccination increased CD3-NK1.1+ cells with a tissue-resident phenotype (CD69+CD103+) in the lungs during the first 7 d after BCG vaccination. Three months post-BCG vaccination, Mtb infection induced the expansion of CD3-NK1.1+CD69+CD103+ (lung-resident) cells in the lung. Adoptive transfer of lung-resident CD3-NK1.1+CD69+CD103+ cells from the lungs of BCG-vaccinated mice to Mtb-infected naive mice resulted in a lower bacterial burden and reduced inflammation in the lungs. Our findings demonstrated that intranasal BCG vaccination induces the expansion of CD3-NK1.1+CD69+CD103+ (lung-resident) cells to provide protection against Mtb infection.

Looking ahead to CD3, T-cell engager bispecific antibodies for hematological malignancies.

INTRODUCTION: Since the approval of the bispecific antibody blinatumomab in 2017 for the treatment of acute lymphoblastic leukemia in relapse, the development of numerous bispecific antibody constructs has dramatically expanded in hematologic malignancies. Many have recently received Food Drug Administration and European Medicines Agency approvals in various stages of treatment for lymphomas, leukemias, and multiple myeloma. AREAS COVERED: The purpose of this review is to provide an overview of bispecific antibody treatment including the mechanisms leading to effector T cells targeting tumor-associated antigens, the treatment indications, efficacies, toxicities, and challenges of the different constructs. A literature search was performed through access to PubMed and clinicaltrials.gov. EXPERT OPINION: While there has been substantial success in the treatment of NHL, MM, and ALL, there are still hematologic malignancies such as AML where there has been limited progress. It is important to continue to investigate new designs, tumor antigen targets, and further refine where current approved bispecific antibodies fit in terms of sequencing of therapy. Hopefully, with the knowledge gained in recent years and the explosion of these therapies, patients with blood cancers will continue to benefit from these treatments for years to come.

Engineering a tumor-selective prodrug T-cell engager bispecific antibody for safer immunotherapy.

T-cell engaging (TCE) bispecific antibodies are potent drugs that trigger the immune system to eliminate cancer cells, but administration can be accompanied by toxic side effects that limit dosing. TCEs function by binding to cell surface receptors on T cells, frequently CD3, with one arm of the bispecific antibody while the other arm binds to cell surface antigens on cancer cells. On-target, off-tumor toxicity can arise when the target antigen is also present on healthy cells. The toxicity of TCEs may be ameliorated through the use of pro-drug forms of the TCE, which are not fully functional until recruited to the tumor microenvironment. This can be accomplished by masking the anti-CD3 arm of the TCE with an autoinhibitory motif that is released by tumor-enriched proteases. Here, we solve the crystal structure of the antigen-binding fragment of a novel anti-CD3 antibody, E10, in complex with its epitope from CD3 and use this information to engineer a masked form of the antibody that can activate by the tumor-enriched protease matrix metalloproteinase 2 (MMP-2). We demonstrate with binding experiments and in vitro T-cell activation and killing assays that our designed prodrug TCE is capable of tumor-selective T-cell activity that is dependent upon MMP-2. Furthermore, we demonstrate that a similar masking strategy can be used to create a pro-drug form of the frequently used anti-CD3 antibody SP34. This study showcases an approach to developing immune-modulating therapeutics that prioritizes safety and has the potential to advance cancer immunotherapy treatment strategies.

Human plasma cells engineered to secrete bispecifics drive effective in vivo leukemia killing.

Bispecific antibodies are an important tool for the management and treatment of acute leukemias. As a next step toward clinical translation of engineered plasma cells, we describe approaches for secretion of bispecific antibodies by human plasma cells. We show that human plasma cells expressing either fragment crystallizable domain-deficient anti-CD19 × anti-CD3 (blinatumomab) or anti-CD33 × anti-CD3 bispecific antibodies mediate T cell activation and direct T cell killing of B acute lymphoblastic leukemia or acute myeloid leukemia cell lines in vitro. We demonstrate that knockout of the self-expressed antigen, CD19, boosts anti-CD19-bispecific secretion by plasma cells and prevents self-targeting. Plasma cells secreting anti-CD19-bispecific antibodies elicited in vivo control of acute lymphoblastic leukemia patient-derived xenografts in immunodeficient mice co-engrafted with autologous T cells. In these studies, we found that leukemic control elicited by engineered plasma cells was similar to CD19-targeted chimeric antigen receptor-expressing T cells. Finally, the steady-state concentration of anti-CD19 bispecifics in serum 1 month after cell delivery and tumor eradication was comparable with that observed in patients treated with a steady-state infusion of blinatumomab. These findings support further development of ePCs for use as a durable delivery system for the treatment of acute leukemias, and potentially other cancers.

Selective lysis of acute myeloid leukemia cells by CD34/CD3 bispecific antibody through the activation of γδ T-cells.

Despite the considerable progress in acute myeloid leukemia (AML) treatment, relapse after allogeneic hematopoietic stem cell transplantation (HSCT) is still frequent and associated with a poor prognosis. Relapse has been shown to be correlated with an incomplete eradication of CD34+ leukemic stem cells prior to HSCT. Previously, we have shown that a novel CD34-directed, bispecific T-cell engager (BTE) can efficiently redirect the T-cell effector function toward cancer cells, thus eliminating leukemic cells in vitro and in vivo. However, its impact on γδ T-cells is still unclear. In this study, we tested the efficacy of the CD34-specific BTE using in vitro expanded γδ T-cells as effectors. We showed that the BTEs bind to γδ T-cells and CD34+ leukemic cell lines and induce target cell killing in a dose-dependent manner. Additionally, γδ T-cell mediated killing was found to be superior to αß T-cell mediated cytotoxicity. Furthermore, we observed that only in the presence of BTE the γδ T-cells induced primary AML blast killing in vitro. Importantly, our results show that γδ T-cells did not target the healthy CD34intermediate endothelial blood-brain barrier cell line (hCMEC/D3) nor lysed CD34+ HSCs from healthy bone marrow samples.

Extracellular vesicle surface display of αPD-L1 and αCD3 antibodies via engineered late domain-based scaffold to activate T-cell anti-tumor immunity.

Extracellular vesicles (EVs) are emerging as promising carriers for the delivery of therapeutic biologics. Genetic engineering represents a robust strategy for loading proteins of interest into EVs. Identification of EV-enriched proteins facilitates protein cargo loading efficiency. Many EV-enriched proteins are sorted into EVs via an endosomal sorting complex required for transport (ESCRT)-dependent pathway. In parallel, viruses hijack this EV biosynthesis machinery via conserved late domain motifs to promote egress from host cells. Inspired by the similarity of biogenesis between EVs and viruses, we developed a synthetic, Late domain-based EV scaffold protein that enables the display of a set of single chain variable fragments (scFvs) on the EV surface. We named this scaffold the Late domain-based exosomal antibody surface display platform (LEAP). We applied the LEAP scaffold to reprogramme HEK293T cell-derived EVs to elicit T-cell anti-tumor immunity by simultaneously displaying αPD-L1 and αCD3 scFvs on the EV surface (denoted as αPD-L1×αCD3 bispecific T-cell engaging exosomes, BiTExos). We demonstrated that αPD-L1×αCD3 BiTExos actively redirected T cells to bind to PD-L1+ tumor cells, promoting T-cell activation, proliferation and tumoricidal cytokine production. Furthermore, the αPD-L1×αCD3 BiTExos promoted T-cell infiltration into the tumor microenvironment to mitigate the tumor burden in vivo. Our study suggested that the LEAP scaffold may serve as a platform for EV surface display and could be applied for a broad range of EV-based biomedical applications.

Immune modulation permits tolerance and engraftment in a murine model of late-gestation transplantation.

ABSTRACT: In utero hematopoietic cell transplantation is an experimental nonmyeloablative therapy with potential applications in hematologic disorders, including sickle cell disease (SCD). Its clinical utility has been limited due to the early acquisition of T-cell immunity beginning at ∼14 weeks gestation, posing significant technical challenges and excluding treatment fetuses evaluated after the first trimester. Using murine neonatal transplantation at 20 days postcoitum (DPC) as a model for late-gestation transplantation (LGT) in humans, we investigated whether immune modulation with anti-CD3 monoclonal antibody (mAb) could achieve donor-specific tolerance and sustained allogeneic engraftment comparable with that of the early-gestation fetal recipient at 14 DPC. In allogeneic wild-type strain combinations, administration of anti-CD3 mAb with transplantation resulted in transient T-cell depletion followed by central tolerance induction confirmed by donor-specific clonal deletion and skin graft tolerance. Normal immune responses to third-party major histocompatibility complex and viral pathogens were preserved, and graft-versus-host disease did not occur. We further demonstrated the successful application of this approach in the Townes mouse model of SCD. These findings confirm the developing fetal T-cell response as a barrier to LGT and support transient T-cell depletion as a safe and effective immunomodulatory strategy to overcome it.

Informing the Recommended Phase III Dose of Alnuctamab, a CD3 × BCMA T-Cell Engager, Using Population Pharmacokinetics and Exposure-Response Analysis.

Alnuctamab, a B-cell maturation antigen (BCMA)-targeting T-cell engager, has demonstrated encouraging antitumor activity in the phase I study CC-93269-MM-001 treating patients with relapsed or refractory multiple myeloma. Identification of a recommended Phase III dose (RP3D) was a key objective, as such population pharmacokinetic (PopPK) and exposure-response analysis was critical. Intravenous (IV) alnuctamab was administered in fixed doses (0.15-10 mg) or in step-up doses to a maximum 10-mg target dose. Subcutaneous (SC) step-up doses of 3 and 6 mg were followed by a target dose range of 10-60 mg. Concentration data from IV and SC alnuctamab administration was pooled and was well described by a two-compartment PopPK model with first-order absorption and elimination. Covariate analysis determined that the inclusion of baseline soluble BCMA (sBCMA) on clearance significantly improved model fitting. Individual exposure parameters were estimated from the final model to characterize exposure-response relationships. Switching from IV to SC administration improved the safety profile of alnuctamab by limiting the frequency of grade ≥2 CRS events. A significant exposure-CRS relationship was observed after the first SC dose, but not subsequent dose administrations. Exposure-safety analysis did not find a statistically significant relationship between increasing exposure and the probability of key safety events of interest. Logistic regression analysis for patients administered SC alnuctamab identified that increased exposure significantly increased the probability of response, although the additional benefit was minimal at exposures above 30 mg target dose. Considering the totality of exposure-response data, the clinical pharmacology assessment supported a SC RP3D of 3/6/30 mg.

Exploitation of CD3ζ to enhance TCR expression levels and antigen-specific T cell function.

The expression levels of TCRs on the surface of human T cells define the avidity of TCR-HLA/peptide interactions. In this study, we have explored which components of the TCR-CD3 complex are involved in determining the surface expression levels of TCRs in primary human T cells. The results show that there is a surplus of endogenous TCR α/ß chains that can be mobilised by providing T cells with additional CD3γ,δ,ε,ζ chains, which leads to a 5-fold increase in TCR α/ß surface expression. The analysis of individual CD3 chains revealed that provision of additional ζ chain alone was sufficient to achieve a 3-fold increase in endogenous TCR expression. Similarly, CD3ζ also limits the expression levels of exogenous TCRs transduced into primary human T cells. Interestingly, transduction with TCR plus CD3ζ not only increased surface expression of the introduced TCR, but it also reduced mispairing with endogenous TCR chains, resulting in improved antigen-specific function. TCR reconstitution experiments in HEK293T cells that do not express endogenous TCR or CD3 showed that TCRα/ß and all four CD3 chains were required for optimal surface expression, while in the absence of CD3ζ the TCR expression was reduced by 50%. Together, the data show that CD3ζ is a key regulator of TCR expression levels in human T cells, and that gene transfer of exogenous TCR plus CD3ζ improved TCR surface expression, reduced TCR mispairing and increased antigen-specific function.

IL-20 is produced by CD3γδ T cells and induced in the mucosal tissues of grass carp during infection with Aeromonas hydrophila.

Interleukin (IL) 20 is a multifunctional cytokine and plays a vital role in regulating autoimmune diseases, inflammation, and immune responses. IL-20 homologs have been described in fish. However, due to the lack of antibodies, cellular sources and immunological functions of fish IL-20 in response to infections have not been fully characterized. In this study, a monoclonal antibody (mAb) was generated against the recombinant grass carp (Ctenopharyngodon idella) IL-20 protein and characterized by immunoblotting, immunofluorescent microscopy and flow cytometry. It was shown that the IL-20 mAb specifically recognized recombinant IL-20 proteins expressed in the E. coli cells and HEK293 cells. Using confocal microscopy, the IL-20+ cells were identified in the head kidney, gills and intestine of grass carp, and induced after infection with Aeromonas hydrophila. Moreover, the IL-20 protein was found to be secreted mainly by CD3γδ T cells which were located predominantly in the gill filaments and intestinal mucosa. Taken together, our results suggest that IL-20 producing T cells are required for the mucosal immunity against bacterial infection in fish.

PHE1-based IgG-like antibody platform provides a novel strategy for enhanced T-cell immunotherapy.

Introduction: Bispecific 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. Methods: This 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. Results: We 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 ß2 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. Discussion: Moreover, 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.

IMT030122, A novel engineered EpCAM/CD3/4-1BB tri-specific antibody, enhances T-cell recruitment and demonstrates anti-tumor activity in mouse models of colorectal cancer.

Colorectal cancer is a major global health burden, with limited efficacy of traditional treatment modalities in improving survival rates. However, recently advances in immunotherapy has improved treatment outcomes for patients with this cancer. To address the continuing need for improved treatment efficacy, this study introduced a novel tri-specific antibody, IMT030122, that targets EpCAM, 4-1BB, and CD3. We evaluated the pharmacological efficacy and mechanism of action of IMT030122 in vitro and in vivo. In in vitro studies, IMT030122 exhibited differential binding to antigens and cells expressing EpCAM, 4-1BB, and CD3. Moreover, IMT030122 relied on EpCAM-targeted activation of intracellular CD3 and 4-1BB signaling and mediated T cell cytotoxicity specific to HCT116 colorectal cancer cells. In vivo, IMT030122 demonstrated potent anti-tumor activity, significantly inhibiting the growth of colon cancer HCT116 and MC38-hEpCAM subcutaneous grafts. Further pharmacological analysis revealed that IMT030122 recruited lymphocytes from peripheral blood into colorectal cancer tissue and exerted durable anti-tumor activity, predominantly by promoting the activation, proliferation, and differentiation of CD8T cells. Notably, IMT030122 still exhibited anti-tumor efficacy even in the presence of significantly depleted lymphocytes in colorectal cancer tissue. The potent pharmacological activity and anti-tumor effects of IMT030122 suggest it may enhance treatment efficacy and substantially extend the survival of patients with colorectal cancer in the future.

Patient derived cancer organoids model the response to HER2-CD3 bispecific antibody (BsAbHER2) generated from hydroxyapatite gene delivery system.

HER2-positive cancer is a prevalent subtype of malignancy with poor prognosis, yet current targeted therapies, like Trastuzumab and pyrotinib, have resulted in remission in patients with HER2-positive cancer. This study provides a novel approach for immunotherapy based on a hydroxyapatite (HA) gene delivery system producing a bispecific antibody for HER2-positive cancer treatment. An HA nanocarrier has been synthesized by the classical hydrothermal method. Particularly, the HA-nanoneedle system was able to mediate stable gene expression of minicircle DNA (MC) encoding a humanized anti-CD3/anti-HER2 bispecific antibody (BsAbHER2) in vivo. The produced BsAbs exhibited a potent killing effect not only in HER2-positive cancer cells but also in patient-derived organoids in vitro. This HA-nanoneedle gene delivery system features simple large-scale preparation and clinical applicability. Hence, the HA-nanoneedle gene delivery system combined with minicircle DNA vector encoding BsAbHER2 reported here provides a potential immunotherapy strategy for HER2-positive tumors.