Tuned activation of MSLN-CAR T cells induces superior antitumor responses in ovarian cancer models

B4M3 CAR-T cell enhance antitumor activity and non-tumor toxicity in ovarian cancer

Chimeric antigen receptor (CAR) T cells have demonstrated promising therapeutic outcomes in hematologic malignancies, but efficacy against most solid tumors, including ovarian cancer (OC). To address CAR-T challenges, we generated CAR-T cells (B4M3 CAR-T) targeting two tumor-associated antigens, B7H3 and MSLN, simultaneously. Immunohistochemistry and proteomics technologies, were employed to analyze the xenograft tumor tissues and key organ tissues at the end of the treatment in vivo assays. B4M3 CAR-T cells demonstrated rapid antitumor effects under in vivo stress conditions, protected against organ damage, and exhibited favorable safety and tolerability. Molecular and signaling studies indicated that B4M3 CAR-T promoted tumor cell death by activating the NF-κB and TNF signaling pathways. Furthermore, B4M3 CAR-T cells enhancing the innate immune response and altering the metabolic profile. Collectively, our study successfully developed B4M3 CAR-T cells, which exhibited significant antitumor effects in ovarian cancer and it provide a novel strategy for the immunotherapy of OC.

Chimeric antigen receptor T cell immunotherapy for gynecological malignancies

Gynecologic malignancies pose a serious threat to women's health worldwide. Although immunotherapy has significantly revolutionized cancer treatment strategies, effective therapeutic options for recurrent or advanced gynecologic malignancies are still deficient, posing significant challenges to clinical therapy. Chimeric antigen receptor (CAR) T cell therapy has achieved remarkable efficacy in treating hematologic malignancies, marking a significant change in the oncology treatment paradigm. However, despite the gradual increase in CAR T cell therapy used in treating solid tumors in recent years, its efficacy in treating gynecologic malignancies still needs further validation. This review will thoroughly examine CAR-T cell engineering and its mechanism of action on specific antigens associated with gynecologic malignancies, systematically assess the current application of CAR T cell therapy in gynecologic tumors and the advancements in clinical trials, and discuss the significant challenges and corresponding strategies, thereby offering a scientific foundation and guidance for future research in this area.

Results From First-in-Human Phase I Study of a Novel CD19-1XX Chimeric Antigen Receptor With Calibrated Signaling in Large B-Cell Lymphoma

PURPOSE

We designed a CD19-targeted chimeric antigen receptor (CAR) comprising a calibrated signaling module, termed 1XX, that differs from that of conventional CD28/CD3ζ and 4-1BB/CD3ζ CARs. Preclinical data demonstrated that 1XX CARs generated potent effector function without undermining T-cell persistence. We hypothesized that 1XX CAR T cells may be effective at low doses and elicit minimal toxicities.

METHODS

In this first-in-human, phase I, dose escalation and expansion clinical trial, patients with relapsed or refractory large B-cell lymphoma received 19(T2)28z-1XX CAR T cells at four dose levels (DLs), ranging from 25 to 200 × 106.

RESULTS

Twenty-eight patients underwent apheresis and received CAR T cells. Sixteen and 12 patients were treated in the dose escalation and expansion cohorts, respectively. The overall response rate (ORR) was 82% and complete response (CR) rate was 71% in the entire cohort. The lowest dose of 25 × 106 was selected for dose expansion. In 16 patients treated at this DL, 88% achieved ORR and 75% CR. With the median follow-up of 24 months, the 1-year event-free survival was 61% (95% CI, 45 to 82) and 14 patients remain in continuous CR beyond 12 months. In all cohorts, grade ≥3 cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome rates were low at 4% and 7%, respectively. 1XX CAR T-cell products contain a higher proportion of CD8 T cells with memory features, and CAR T-cell persistence has been detected beyond 1-2 years in patients with ongoing remission.

CONCLUSION

The calibrated potency of the 1XX CAR affords excellent efficacy at low cell doses with favorable toxicity profiles and may benefit the treatment of other hematologic malignancies, solid tumors, and autoimmunity.

Treponema denticola major surface protein (Msp): a key player in periodontal pathogenicity and immune evasion

Treponema denticola, a bacterium that forms a "red complex" with Porphyromonas gingivalis and Tannerella forsythia, is associated with periodontitis, pulpitis, and other oral infections. The major surface protein (Msp) is a surface glycoprotein with a relatively well-established overall domain structure (N-terminal, central and C-terminal regions) and a controversial tertiary structure. As one of the key virulence factors of T. denticola, Msp is associated with adherence, immune response, and pore formation by the microorganism. It also mediates several pathological changes in histocytes, such as cytoskeleton disruption, neutrophil phagocytosis, and phosphoinositide balance interruption. In addition, the Msp of T. denticola is also an ortholog of the Treponema pallidum repeat (Tpr) proteins and Msp or Msp-like proteins that have been detected in other oral treponeme species. This review will discuss the structure, pathogenicity and homologs of Msp produced by T. denticola, illuminate the controversy regarding the structure and membrane topology of native Msp, explore the potential roles of Msp in the mechanism of T. denticola immune escape and provide an overview of the cytotoxicity and adherence ability of Msp. Further understanding of the structure and functions of Msp will offer new insights that will help promote further investigations of the pathogenic mechanisms of T. denticola and other treponemes, leading to more effective prophylactic or therapeutic treatments for relevant diseases.

SMAD4 Regulates the Expression of LCK Affecting Chimeric Antigen Receptor-T Cells Proliferation Through PI3K/Akt Signaling Pathway

The proliferation of CAR-T cells was hindered and cannot play its killing function well in solid tumors. And yet the regulatory mechanism of CAR-T cell proliferation is not fully understood. Here, we showed that recombinant expression of CD19CAR in T cells significantly increased the basal activation level of CAR-T cells and LCK activation. Both LCK and SMAD4 were essential for CAR-T cells proliferation since over-express LCK or SMAD4 significantly promotes CAR-T cells proliferation, while knock-down LCK or SMAD4 expression inhibited the proliferation of CAR-T cells seriously. More cells go into apoptosis when knock-down LCK or SMAD4 expression, and the cell cycle was arrested in G2/M or S phase, respectively. Over-express LCK or SMAD4 significantly promotes phosphorylation of PI3K and Akt, while it was inhibited when cells were treated with PI3K and Akt inhibitors (LY294002 or MK2206). Further mechanism exploration experiments showed that SMAD4 bound on the promoter region of LCK regulating its expression. Taken together, we reported that the transcription factor SMAD4 regulated the expression of LCK and further involved in the PI3K/Akt signaling pathway to affect the proliferation of CAR-T cells.

CAR T-cell therapy for systemic lupus erythematosus: current status and future perspectives

Systemic lupus erythematosus (SLE) and lupus nephritis (LN) are debilitating autoimmune disorders characterized by pathological autoantibodies production and immune dysfunction, causing chronic inflammation and multi-organ damage. Despite current treatments with antimalarial drugs, glucocorticoids, immunosuppressants, and monoclonal antibodies, a definitive cure remains elusive, highlighting an urgent need for novel therapeutic strategies. Recent studies indicate that chimeric antigen receptor T-cell (CAR-T) therapy has shown promising results in treating B-cell malignancies and may offer a significant breakthrough for non-malignant conditions like SLE. In this paper, we aim to provide an in-depth analysis of the advancements in CAR-T therapy for SLE, focusing on its potential to revolutionize treatment for this complex disease. We explore the fundamental mechanisms of CAR-T cell action, the rationale for its application in SLE, and the immunological underpinnings of the disease. We also summarize clinical data on the safety and efficacy of anti-CD19 and anti-B cell maturation antigen (BCMA) CAR-T cells in targeting B-cells in SLE. We discuss the clinical implications of these findings and the potential for CAR-T therapy to improve outcomes in severe or refractory SLE cases. The integration of CAR-T therapy into the SLE treatment paradigm presents a new horizon in autoimmunity research and clinical practice. This review underscores the need for continued exploration and optimization of CAR-T strategies to address the unmet needs of SLE patients.

Comprehensive Analysis and Verification of the Prognostic Significance of Cuproptosis-Related Genes in Colon Adenocarcinoma

Colon adenocarcinoma (COAD) is a frequently occurring and lethal cancer. Cuproptosis is an emerging type of cell death, and the underlying pathways involved in this process in COAD remain poorly understood. Transcriptomic and clinical data for COAD patients were collected from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. We investigated alterations in DNA and chromatin of cuproptosis-related genes (CRGs) in COAD. In order to identify predictive differentially expressed genes (DEGs) and various molecular subtypes, we used consensus cluster analysis. Through univariate, multivariate, and Lasso Cox regression analyses, four CRGs were identified. A risk prognostic model for cuproptosis characteristics was constructed based on four CRGs. This study also examined the association between the risk score and the tumor microenvironment (TME), the immune landscape, and drug sensitivity. We distinguished two unique molecular subtypes using consensus clustering analysis. We discovered that the clinical characteristics, prognosis, and TME cell infiltration characteristics of patients with multilayer CRG subtypes were all connected. The internal and external evaluations of the predicted accuracy of the prognostic model built using data derived from a cuproptosis risk score were completed at the same time. A nomogram and a clinical pathological analysis make it more useful in the field of medicine. A significant rise in immunosuppressive cells was observed in the high cuproptosis risk score group, with a correlation identified between the cuproptosis risk score and immune cell infiltration. Despite generally poor prognoses, the patients with a high cuproptosis risk but low tumor mutation burden (TMB), cancer stem cell (CSC) index, or microsatellite instability (MSI) may still benefit from immunotherapy. Furthermore, the cuproptosis risk score positively correlated with immune checkpoint gene expression. Analyzing the potential sensitivity to medications could aid in the development of clinical chemotherapy regimens and decision-making. CRGs are the subject of our in-depth study, which exposed an array of regulatory mechanisms impacting TME. In addition, we performed additional data mining into clinical features, prognosis effectiveness, and possible treatment medications. COAD's molecular pathways will be better understood, leading to more precise treatment options.

Three-dimensional dynamics of mesothelin-targeted CAR.CIK lymphocytes against ovarian cancer peritoneal carcinomatosis

Intraperitoneal cellular immunotherapy with CAR-redirected lymphocytes is an intriguing approach to target peritoneal carcinomatosis (PC) from ovarian cancer (OC), which is currently evaluated in clinical trials. PC displays a composite structure with floating tumor cells within ascites and solid-like masses invading the peritoneum. Therefore, a comprehensive experimental model is crucial to optimize CAR-cell therapies in such a peculiar environment. Here, we explored the activity of cytokine-induced killer lymphocytes (CIK), redirected by CAR against mesothelin (MSLN-CAR.CIK), within reductionistic 3D models resembling the structural complexity of both liquid and solid components of PC. MSLN-CAR.CIK effectively killed and were functionally efficient against OC targets. In a "floating-like" 3D context with floating OC spheroids, both tumor localization and killing by MSLN-CAR.CIK were significantly boosted by fluid flow. In a "solid-like" context, MSLN-CAR.CIK were recruited through the extracellular matrix on embedded tumor aggregates, with variable kinetics depending on the effector-target distance. Furthermore, MSLN-CAR.CIK penetrated the inner levels of OC spheroids exerting effective tumor killing. Our findings provide currently unknown therapeutically relevant information on intraperitoneal approaches with CAR.CIK, supporting further developments and improvements for clinical studies in the context of locoregional cell therapy approaches for patients with PC from OC.

DC-derived CXCL10 promotes CTL activation to suppress ovarian cancer

This study investigates the role of dendritic cells (DCs), with a focus on their CXCL10 marker gene, in the activation of cytotoxic T lymphocytes (CTLs) within the ovarian cancer microenvironment and its impact on disease progression. Utilizing scRNA-seq data and immune infiltration analysis, we identified a diminished DC presence in ovarian cancer. Gene analysis pinpointed CXCL10 as a key regulator in OV progression via its influence on DCs and CTLs. Prognostic analysis and in vitro experiments substantiated this role. Our findings reveal that DC-derived CXCL10 significantly affects CTL activation and proliferation. Reduced CXCL10 levels hinder CTL cytotoxicity, promoting ovarian cancer cell migration and invasion. Experimental studies using animal models have provided further evidence that the capacity of CTLs to suppress tumor development is significantly diminished when treated with DCs that have low expression of CXCL10. Dendritic cell-derived CXCL10 emerges as a pivotal factor in restraining ovarian cancer growth and metastasis through the activation of cytotoxic T lymphocytes. This study sheds light on the crucial interplay within the ovarian cancer microenvironment, offering potential therapeutic targets for ovarian cancer treatment.

Mesothelin expression correlates with elevated inhibitory immune activity in patients with colorectal cancer

The expression of the protein Mesothelin (MSLN) is highly variable in several malignancies, including colorectal cancer (CRC), and high levels are associated with aggressive clinicopathological features and worse patient survival. Colorectal cancer is both a common and deadly cancer; being the third most common in incidence and second most common cause of cancer-related death. While systemic therapy remains the primary therapeutic option for most patients with stage IV (metastatic; m) CRC, their disease eventually becomes treatment refractory, and 85% succumb within 5 years. Microsatellite-stable (MSS) CRC tumors, which constitute more than 90% of patients with mCRC, are generally refractory to immunotherapeutic interventions. In our current work, we characterize MSLN levels in CRC, specifically correlating expression with clinical outcomes in relevant CRC subtypes, and explore how MSLN expression impacts the status of immune activation and suppression in the peritumoral microenvironment. Higher MSLN expression is prevalent in CMS1 and CMS4 CRC subtypes and correlates with higher gene mutation rates across the patient cohorts. Further, MSLN-high patients exhibit increased M1/M2 macrophage infiltration, PD-L1 staining, immune-inhibitory gene expression, enrichment in inflammatory, TGF-β, IL6/JAK/STAT3, IL2/STAT5 signaling pathways, and mutation in KRAS and FBXW7. Together, these results suggest that MSLN protein is a potential target for antigen-specific therapy and supports investigation into its tumorigenic effects to identify possible therapeutic interventions for patients with high MSLN expressing MSS CRC.

CD8+ T cell exhaustion and its regulatory mechanisms in the tumor microenvironment: key to the success of immunotherapy

A steady dysfunctional state caused by chronic antigen stimulation in the tumor microenvironment (TME) is known as CD8+ T cell exhaustion. Exhausted-like CD8+ T cells (CD8+ Tex) displayed decreased effector and proliferative capabilities, elevated co-inhibitory receptor generation, decreased cytotoxicity, and changes in metabolism and transcription. TME induces T cell exhaustion through long-term antigen stimulation, upregulation of immune checkpoints, recruitment of immunosuppressive cells, and secretion of immunosuppressive cytokines. CD8+ Tex may be both the reflection of cancer progression and the reason for poor cancer control. The successful outcome of the current cancer immunotherapies, which include immune checkpoint blockade and adoptive cell treatment, depends on CD8+ Tex. In this review, we are interested in the intercellular signaling network of immune cells interacting with CD8+ Tex. These findings provide a unique and detailed perspective, which is helpful in changing this completely unpopular state of hypofunction and intensifying the effect of immunotherapy.

Reshaping the tumor immune microenvironment to improve CAR-T cell-based cancer immunotherapy

In many hematologic malignancies, the adoptive transfer of chimeric antigen receptor (CAR) T cells has demonstrated notable success; nevertheless, further improvements are necessary to optimize treatment efficacy. Current CAR-T therapies are particularly discouraging for solid tumor treatment. The immunosuppressive microenvironment of tumors affects CAR-T cells, limiting the treatment's effectiveness and safety. Therefore, enhancing CAR-T cell infiltration capacity and resolving the immunosuppressive responses within the tumor microenvironment could boost the anti-tumor effect. Specific strategies include structurally altering CAR-T cells combined with targeted therapy, radiotherapy, or chemotherapy. Overall, monitoring the tumor microenvironment and the status of CAR-T cells is beneficial in further investigating the viability of such strategies and advancing CAR-T cell therapy.

CAR-T therapy for ovarian cancer: Recent advances and future directions

Ovarian cancer (OC) is a common gynecological tumor with high mortality, which is difficult to control its progression with conventional treatments and is prone to recurrence. Recent studies have identified OC as an immunogenic tumor that can be recognized by the host immune system. Immunotherapy for OC is being evaluated, but approaches such as immune checkpoint inhibitors have limited efficacy, adoptive cell therapy is an alternative therapy, in which CAR(chimeric antigen receptor)-T therapy has been applied to the clinical treatment of hematological malignancies. In addition, CAR-NK and CAR-macrophage (CAR-M) have also shown great potential in the treatment of solid tumors. Here, we discuss recent advances in preclinical and clinical studies of CAR-T for OC treatment, introduce the efforts made by researchers to modify the structure of CAR in order to achieve effective OC immunotherapy, as well as the research status of CAR-NK and CAR-M, and highlight emerging therapeutic opportunities that can be utilized to improve the survival of patients with OC using CAR-based adoptive cell therapy.

Application of CAR-T cell therapy targeting mesothelin in solid tumor treatment

Chimeric antigen receptor (CAR)-T-cell therapy is one of the most effective immunotherapies. CAR-T-cell therapy has achieved great success in the treatment of hematological malignancies. However, due to the characteristics of solid malignant tumors, such as on-target effects, off-tumor toxicity, an immunosuppressive tumor microenvironment (TME), and insufficient trafficking, CAR-T-cell therapy for solid tumors is still in the exploration stage. Mesothelin (MSLN) is a molecule expressed on the surface of various solid malignant tumor cells that is suitable as a target of tumor cells with high MSLN expression for CAR-T-cell therapy. This paper briefly described the development of CAR-T cell therapy and the structural features of MSLN, and especially summarized the strategies of structure optimization of MSLN-targeting CAR-T-cells and the enhancement methods of MSLN-targeting CAR-T cell anti-tumor efficacy by summarizing some preclinical experiment and clinical trials. When considering MSLN-targeting CAR-T-cell therapy as an example, this paper summarizes the efforts made by researchers in CAR-T-cell therapy for solid tumors and summarizes feasible treatment plans by integrating the existing research results.

Calibrated CAR Signaling Enables Low-Dose Therapy in Large B-Cell Lymphoma

We designed a CD19-targeted CAR comprising a calibrated signaling module, termed 1XX, that differs from that of conventional CD28/CD3z and 4-1BB/CD3z CARs. Here we report the first-in-human, phase 1 clinical trial of 19(T2)28z-1XX CAR T cells in relapsed/refractory large B-cell lymphoma. We hypothesized that 1XX CAR T cells may be effective at low doses and investigated 4 doubling dose levels starting from 25×106 CAR T cells. The overall response rate (ORR) was 82% and complete response (CR) rate 71% in the entire cohort (n=28) and 88% ORR and 75% CR in 16 patients treated at 25×106. With the median follow-up of 24 months, the 1-year EFS was 61% (95% CI: 45-82%). Overall, grade ≥3 CRS and ICANS rates were low at 4% and 7%. The calibrated potency of the 1XX CAR affords excellent efficacy at low cell doses and may benefit the treatment of other hematological malignancies, solid tumors and autoimmunity.

Impact of fludarabine and treosulfan on ovarian tumor cells and mesothelin chimeric antigen receptor T cells

In addition to their immunosuppressive effect, cytostatics conditioning prior to adoptive therapy such as chimeric antigen receptor (CAR) T cells may play a role in debulking and remodeling the tumor microenvironment. We investigated in vitro the killing efficacy and impact of treosulfan and fludarabine on ovarian cancer cells expressing mesothelin (MSLN) and effect on MSLN-targeting CAR T cells. Treosulfan and fludarabine had a synergetic effect on killing of SKOV3 and OVCAR4 cells. Sensitivity to the combination of treosulfan and fludarabine was increased when SKOV3 cells expressed MSLN and when OVCAR4 cells were tested in hypoxia, while MSLN cells surface expression by SKOV3 and OVCAR4 cells was not altered after treosulfan or fludarabine exposure. Exposure to treosulfan or fludarabine (10 µM) neither impacted MSLN-CAR T cells degranulation, cytokines production upon challenge with MSLN + OVCAR3 cells, nor induced mitochondrial defects. Combination of treosulfan and fludarabine decreased MSLN-CAR T cells anti-tumor killing in normoxia but not hypoxia. In conclusion, treosulfan and fludarabine killed MSLN + ovarian cancer cells without altering MSLN-CAR T cells functions (at low cytostatics concentration) even in hypoxic conditions, and our data support the use of treosulfan and fludarabine as conditioning drugs prior to MSLN-CAR T cell therapy.

Recent advances in understanding the immune microenvironment in ovarian cancer

The occurrence of ovarian cancer (OC) is a major factor in women's mortality rates. Despite progress in medical treatments, like new drugs targeting homologous recombination deficiency, survival rates for OC patients are still not ideal. The tumor microenvironment (TME) includes cancer cells, fibroblasts linked to cancer (CAFs), immune-inflammatory cells, and the substances these cells secrete, along with non-cellular components in the extracellular matrix (ECM). First, the TME mainly plays a role in inhibiting tumor growth and protecting normal cell survival. As tumors progress, the TME gradually becomes a place to promote tumor cell progression. Immune cells in the TME have attracted much attention as targets for immunotherapy. Immune checkpoint inhibitor (ICI) therapy has the potential to regulate the TME, suppressing factors that facilitate tumor advancement, reactivating immune cells, managing tumor growth, and extending the survival of patients with advanced cancer. This review presents an outline of current studies on the distinct cellular elements within the OC TME, detailing their main functions and possible signaling pathways. Additionally, we examine immunotherapy rechallenge in OC, with a specific emphasis on the biological reasons behind resistance to ICIs.

TOP CAR with TMIGD2 as a safe and effective costimulatory domain in CAR cells treating human solid tumors

Chimeric antigen receptor (CAR)-T cell therapy shows impressive efficacy treating hematologic malignancies but requires further optimization in solid tumors. Here, we developed a TMIGD2 optimized potent/persistent (TOP) CAR that incorporated the costimulatory domain of TMIGD2, a T and NK cell costimulator, and monoclonal antibodies targeting the IgV domain of B7-H3, an immune checkpoint expressed on solid tumors and tumor vasculature. Comparing second- and third-generation B7-H3 CARs containing TMIGD2, CD28, and/or 4-1BB costimulatory domains revealed superior antitumor responses in B7-H3.TMIGD2 and B7-H3.CD28.4-1BB CAR-T cells in vitro. Comparing these two constructs using in vivo orthotopic human cancer models demonstrated that B7-H3.TMIGD2 CAR-T cells had equivalent or superior antitumor activity, survival, expansion, and persistence. Mechanistically, B7-H3.TMIGD2 CAR-T cells maintained mitochondrial metabolism; produced less cytokines; and established fewer exhausted cells, more central memory cells, and a larger CD8/CD4 T cell ratio. These studies demonstrate that the TOP CAR with TMIGD2 costimulation offered distinct benefits from CD28.41BB costimulation and is effective against solid tumors.

CAR-based immunotherapy for breast cancer: peculiarities, ongoing investigations, and future strategies

Surgery, chemotherapy, and endocrine therapy have improved the overall survival and postoperative recurrence rates of Luminal A, Luminal B, and HER2-positive breast cancers but treatment modalities for triple-negative breast cancer (TNBC) with poor prognosis remain limited. The effective application of the rapidly developing chimeric antigen receptor (CAR)-T cell therapy in hematological tumors provides new ideas for the treatment of breast cancer. Choosing suitable and specific targets is crucial for applying CAR-T therapy for breast cancer treatment. In this paper, we summarize CAR-T therapy's effective targets and potential targets in different subtypes based on the existing research progress, especially for TNBC. CAR-based immunotherapy has resulted in advancements in the treatment of breast cancer. CAR-macrophages, CAR-NK cells, and CAR-mesenchymal stem cells (MSCs) may be more effective and safer for treating solid tumors, such as breast cancer. However, the tumor microenvironment (TME) of breast tumors and the side effects of CAR-T therapy pose challenges to CAR-based immunotherapy. CAR-T cells and CAR-NK cells-derived exosomes are advantageous in tumor therapy. Exosomes carrying CAR for breast cancer immunotherapy are of immense research value and may provide a treatment modality with good treatment effects. In this review, we provide an overview of the development and challenges of CAR-based immunotherapy in treating different subtypes of breast cancer and discuss the progress of CAR-expressing exosomes for breast cancer treatment. We elaborate on the development of CAR-T cells in TNBC therapy and the prospects of using CAR-macrophages, CAR-NK cells, and CAR-MSCs for treating breast cancer.

Mesothelin expression correlates with elevated inhibitory immune activity in patients with colorectal cancer

The expression of the protein Mesothelin (MSLN) is highly variable in several malignancies including colorectal cancer (CRC) and high levels are associated with aggressive clinicopathological features and worse patient survival. CRC is both a common and deadly cancer; being the third most common in incidence and second most common cause of cancer related death. While systemic therapy remains the primary therapeutic option for most patients with stage IV (metastatic; m) CRC, their disease eventually becomes treatment refractory, and 85% succumb within 5 years. Microsatellite-stable (MSS) CRC tumors, which affect more than 90% of patients with mCRC, are generally refractory to immunotherapeutic interventions. In our current work, we characterize MSLN levels in CRC, specifically correlating expression with clinical outcomes in relevant CRC subtypes and explore how MSLN expression impacts the status of immune activation and suppression in the peritumoral microenvironment. High MSLN expression is highly prevalent in CMS1 and CMS4 CRC subtypes as well as in mCRC tissue and correlates with higher gene mutation rates across the patient cohorts. Further, MSLN-high patients exhibit increased M1/M2 macrophage infiltration, PD-L1 staining, immune-inhibitory gene expression, enrichment in inflammatory, TGF-β, IL6/JAK/STAT3, IL2/STAT5 signaling pathways and mutation in KRAS and FBXW7. Together, these results suggest MSLN protein is a potential target for antigen-specific therapy and supports investigation into its tumorigenic effects to identify possible therapeutic interventions for patients with high MSLN expressing MSS CRC.

Effect of neoadjuvant chemotherapy on the immune microenvironment of gynaecological tumours

Purpose: To assess the impact of neoadjuvant chemotherapy (NACT) on the tumor immune microenvironment (TIME) in gynaecological tumors, with a focus on understanding the potential for enhanced combination therapies.Methods: We systematically queried the PubMed, Embase, and Cochrane databases, encompassing reviews, clinical trials, and case studies, to undertake a thorough analysis of the impact of NACT on the TIME of gynaecological tumors.Results: NACT induces diverse immune microenvironment changes in gynaecological tumors. In cervical cancer, NACT boosts immune-promoting cells, enhancing tumor clearance. Ovarian cancer studies yield variable outcomes, influenced by patient-specific factors and treatment regimens. Limited research exists on NACT's impact on endometrial cancer's immune microenvironment, warranting further exploration. In summary, NACT-induced immune microenvironment changes display variability. Clinical trials highlight personalized immunotherapy's positive impact on gynaecological tumor prognosis, suggesting potential avenues for future cancer treatments. However, rigorous investigation is needed to determine the exact efficacy and safety of combining NACT with immunotherapy.Conclusion: This review provides a solid foundation for the development of late-stage immunotherapy and highlights the importance of therapeutic strategies targeting immune cells in TIME in anti-tumor therapy.

CAR designs for solid tumors: overcoming hurdles and paving the way for effective immunotherapy

Chimeric antigen receptor T cell (CAR-T) therapy has revolutionized immunotherapy by modifying patients' immune cells genetically. By expressing CARs, these modified cells can specifically identify and eliminate tumor cells. The success of CAR-T therapy in hematological malignancies, such as leukemia and lymphoma, has been remarkable. Numerous studies have reported improved patient outcomes and increased survival rates. However, the application of CAR-T therapy in treating solid tumors faces significant challenges. Solid tumors possess complex microenvironments containing stromal cells, extracellular matrix components, and blood vessels. These factors can impede the infiltration and persistence of CAR-T cells within the tumor. Additionally, the lack of target antigens exclusively expressed on tumor cells raises concerns about off-target effects and potential toxicity. This review aims to discuss advancements achieved by CAR-T therapy in solid tumors and the clinical outcomes in the realm of solid tumors.

Targeting LAG-3, TIM-3, and TIGIT for cancer immunotherapy

In one decade, immunotherapy based on immune checkpoint blockades (ICBs) has become a new pillar of cancer treatment following surgery, radiation, chemotherapy, and targeted therapies. However, not all cancer patients benefit from single or combination therapy with anti-CTLA-4 and anti-PD-1/PD-L1 monoclonal antibodies. Thus, an increasing number of immune checkpoint proteins (ICPs) have been screened and their effectiveness evaluated in preclinical and clinical trials. Lymphocyte activation gene-3 (LAG-3), T cell immunoglobulin and mucin-domain-containing-3 (TIM-3), and T cell immunoreceptor with immunoglobulin and tyrosine-based inhibitory motif (ITIM) domain (TIGIT) constitute the second wave of immunotherapy targets that show great promise for use in the treatment of solid tumors and leukemia. To promote the research and clinical application of ICBs directed at these targets, we summarize their discovery, immunotherapy mechanism, preclinical efficiency, and clinical trial results in this review.

Fine-Tuning through Generations: Advances in Structure and Production of CAR-T Therapy

Chimeric antigen receptor (CAR)-T cell therapy is a promising form of immunotherapy that has seen significant advancements in the past few decades. It involves genetically modifying T cells to target cancer cells expressing specific antigens, providing a novel approach to treating various types of cancer. However, the initial success of first-generation CAR-T cells was limited due to inadequate proliferation and undesirable outcomes. Nonetheless, significant progress has been made in CAR-T cell engineering, leading to the development of the latest fifth-generation CAR-T cells that can target multiple antigens and overcome individual limitations. Despite these advancements, some shortcomings prevent the widespread use of CAR-T therapy, including life-threatening toxicities, T-cell exhaustion, and inadequate infiltration for solid tumors. Researchers have made considerable efforts to address these issues by developing new strategies for improving CAR-T cell function and reducing toxicities. This review provides an overview of the path of CAR-T cell development and highlights some of the prominent advances in its structure and manufacturing process, which include the strategies to improve antigen recognition, enhance T-cell activation and persistence, and overcome immune escape. Finally, the review briefly covers other immune cells for cancer therapy and ends with the discussion on the broad prospects of CAR-T in the treatment of various diseases, not just hematological tumors, and the challenges that need to be addressed for the widespread clinical application of CAR-T cell therapies.

Self-delivery of TIGIT-blocking scFv enhances CAR-T immunotherapy in solid tumors

Chimeric antigen receptor T cell therapy has become an important immunotherapeutic tool for overcoming cancers. However, the efficacy of CAR-T cell therapy in solid tumors is relatively poor due to the complexity of the tumor microenvironment and inhibitory immune checkpoints. TIGIT on the surface of T cells acts as an immune checkpoint by binding to CD155 on the tumor cells' surface, thereby inhibiting tumor cell killing. Blocking TIGIT/CD155 interactions is a promising approach in cancer immunotherapy. In this study, we generated anti-MLSN CAR-T cells in combination with anti-α-TIGIT for solid tumors treatment. The anti-α-TIGIT effectively enhanced the efficacy of anti-MLSN CAR-T cells on the killing of target cells in vitro. In addition, we genetically engineered anti-MSLN CAR-T cells with the capacity to constitutively produce TIGIT-blocking single-chain variable fragments. Our study demonstrated that blocking TIGIT significantly promoted cytokine release to augment the tumor-killing effect of MT CAR-T cells. Moreover, the self-delivery of TIGIT-blocking scFvs enhanced the infiltration and activation of MT CAR-T cells in the tumor microenvironments to achieve better tumor regression in vivo. These results suggest that blocking TIGIT effectively enhances the anti-tumor effect of CAR-T cells and suggest a promising strategy of combining CAR-T with immune checkpoints blockade in the treatment of solid tumors.