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Despite demonstrating promising outcomes in treating hematologic malignancies, the efficacy of chimeric antigen receptor-modified T (CAR-T) cell therapy remains limited when applied to solid tumors due to tumor immune microenvironment (TIME). Strategies to augment CAR-T cell efficacy against solid tumors have been investigated by ameliorating TIME to a certain extent. In this study, Cabozantinib was utilized in combination with CAR-T cells targeting carbonic anhydrase IX (CAIX) for the treatment of renal cancer. Our findings indicate that combination therapy with CAIX-CAR-T and Cabozantinib demonstrated synergistic efficacy against an orthotopic xenograft tumor model and a subcutaneous tumor model of renal cell carcinoma in mice. Mechanistically, it was observed that CAR-T cells combined with Cabozantinib led to an increase in the infiltration of tumor-infiltrating T cells, while reducing tumor-associated macrophages and M2 polarization. Additionally, Cabozantinib blocked the programmed cell death-1 (PD-1)/programmed death-ligand 1 (PD-L1) axis by decreasing the expression of PD-L1 in tumor cells and PD-1 in T cells. Furthermore, Cabozantinib promoted CAR-T cell effector function and reduced T cell exhaustion. This combination therapy represents a novel approach to enhancing CAR-T cell efficacy against solid tumors and holds significant promise for advancing CAR-T cell therapy in clinical settings., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Psoriasis, characterized by chronic inflammation, is a persistent skin condition that is notoriously challenging to manage and prone to relapse. Despite significant advancements in its treatment, many adverse reactions still occur. Therefore, exploring the mechanisms behind the occurrence and development of psoriasis is extremely important., Methods: The weighted correlation network analysis (WGCNA) algorithm was used to identify phenotype-related genes in patients with psoriasis. We recruited clinical samples of patients with psoriasis, and used single-cell RNA sequencing (scRNA-seq) to visualize divergent genes and metabolisms of varied cells for the psoriasis. Various machine-learning methods were used to identify core genes, and molecular docking was used to analyze the stability of leptomycin B targeting pituitary tumor transforming 1 (PTTG1). Immunofluorescence (IHC) analysis, multiplex immunofluorescence (mIF) analysis, and quantitative reverse transcription polymerase chain reaction (qRT-PCR) were used to validate the results., Results: Our results identified 1391 genes associated with the phenotype in patients with psoriasis and highlighted the significant alterations in T-cell functionality observed in the disease by WGCNA. There were nine distinct cellular clusters in psoriasis analyzed with the aid of scRNA-seq data. Each subtype of cell exhibited distinct genetic profiles, functional roles, signaling mechanisms, and metabolic characteristics. Machine-learning methods further demonstrated the potential diagnostic value of T cell-derived PTTG1 and its relationship with T-cell exhaustion in psoriasis. Lastly, the leptomycin B was scrutinized and verified had high stability targeting PTTG1., Conclusions: This study elucidates the biological basis of psoriasis. At the same time, it was discovered that PTTG1 derived from exhausted T cells serves as a diagnostic biomarker for psoriasis. Leptomycin B could be a potential drug for targeted treatment of psoriasis on PTTG1., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Chimeric antigen receptor T (CAR-T) cells show remarkable efficacy for some hematological malignancies. However, CAR targets that are expressed at high level and selective to tumors are scarce. Several strategies have been proposed to tackle the on-target off-tumor toxicity of CAR-T cells that arise from suboptimal selectivity, but these are complicated, with many involving dual gene expression for specificity. In this study, we show that switchable CAR-T cells with a tumor targeting adaptor can mitigate on-target off-tumor toxicity against a low selectivity tumor antigen that cannot be targeted by conventional CAR-T cells, such as CD40. Our system is composed of anti-cotinine murine CAR-T cells and cotinine-labeled anti-CD40 single chain variable fragments (scFv), with which we show selective tumor killing while sparing CD40-expressing normal cells including macrophages in a mouse model of lymphoma. Simple replacement of the tumor-targeting adaptor with a suicidal drug-conjugated tag may further enhance safety by enabling permanent in vivo depletion of the switchable CAR-T cells when necessary. In summary, our switchable CAR system can control CAR-T cell toxicity while maintaining therapeutic efficacy, thereby expanding the range of CAR targets., Competing Interests: Competing interests K.C. and E.Y.C. are founders and shareholders of Ticaros Inc. H.B.P., J.E.L., and G.R.J. are currently employees of Ticaros. K.C., J.C., H.B.P., K.H.K., S.I.K., and G.R.J. are co-inventors on the pending patent for anti-CD40 switchable CAR T cells. The other authors declare no competing interests., (© 2024. The Author(s).)

The redirection of T lymphocytes against tumor-associated or tumor-specific antigens, using bispecific antibodies or chimeric antigen receptors (CAR), has shown therapeutic success against certain hematological malignancies. However, this strategy has not been effective against solid tumors. Here, we describe the development of CAR T cells targeting p95HER2, a tumor-specific antigen found in HER2-amplified solid tumors. These CAR T cells display robust activity against p95HER2-expressing cell lines but demonstrate limited efficacy against patient-derived xenografts. As p95HER2 is invariably detectable on tumor cells that overexpress HER2, but not those that express HER2 at normal levels, we arm p95HER2-specific CAR T cells with affinity-tuned bispecific antibodies against HER2 and CD3 in order to redirect them only to HER2-amplified cells. The combination of p95HER2.CAR T cells and HER2 x CD3 bispecific antibodies lead to a complete regression in three HER2-positive, patient-derived mouse xenografts tumor models. This combination represents a promising strategy to redirect T cells against a subset of HER2-positive tumors., Competing Interests: Competing interests J.A. has received research funds from Roche, Byondis, Menarini and Molecular Partners and consultancy honoraria from Menarini, Mnemo and ARKIN. J.A. is an inventor of patent applications EP22382294, EP20382457, EP16191933.7, EP0930183.5 and P200801652. M.R.A., I.R.R., C.K., E.M., are inventors of patent application EP20382457. M.R.A., S.D., A.G.E., I.R.R., V.N. are inventors of patent application EP22382294. C.K. declares employment, patents and stock ownership with Roche. E.M. declares employment with Roche. E.G. reports: research agreements with Novartis, Roche, Thermo Fisher, AstraZeneca, Taiho, BeiGene, Janssen; consultant/advisor at Roche, Ellipses Pharma, Boehringer Ingelheim, Janssen Global Services, Seattle Genetics, Thermo Fisher, MabDiscovery, Anaveon, F-Star Therapeutics, Hengrui, Sanofi, Incyte; and payment or honoraria for speakers’ bureaus from Merck Sharp & Dohme, Roche, Thermo Fisher, Lilly, Novartis, SeaGen. The remaining authors declare no competing interests., (© 2024. The Author(s).)

Context: Low magnesium levels, which are common in people with type 2 diabetes, are associated with increased levels of proinflammatory molecules. It is unknown whether magnesium supplementation decreases this low-grade inflammation in people with type 2 diabetes., Objective: We performed multidimensional immunophenotyping to better understand the effect of magnesium supplementation on the immune system of people with type 2 diabetes and low magnesium levels., Methods: Using a randomized, double-blind, placebo-controlled, 2-period, crossover study, we compared the effect of magnesium supplementation (15 mmol/day) with placebo on the immunophenotype, including whole blood immune cell counts, T-cell and CD14+ monocyte function after ex vivo stimulation, and the circulating inflammatory proteome., Results: We included 12 adults with insulin-treated type 2 diabetes (7 males, mean ± SD age 67 ± 7 years, body mass index 31 ± 5 kg/m2, HbA1c 7.5 ± 0.9%) and low magnesium levels (0.73 ± 0.05 mmol/L). Magnesium treatment significantly increased serum magnesium and urinary magnesium excretion compared with placebo. Interferon-γ production from phorbol myristate acetate/ionomycin stimulated CD8+ T-cells and T-helper 1 cells, as well as interleukin (IL) 4/IL5/IL13 production from T-helper 2 cells was lower after treatment with magnesium compared with placebo. Magnesium supplementation did not affect immune cell numbers, ex vivo monocyte function, and circulating inflammatory proteins, although we found a tendency for lower high sensitivity C-reactive protein levels after magnesium supplementation compared with placebo., Conclusion: In conclusion, magnesium supplementation modulates the function of CD4+ and CD8+ T-cells in people with type 2 diabetes and low serum magnesium levels., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)

Background: Chimeric antigen receptor T (CAR-T) cell therapy has been shown remarkable efficacy in the treatment of hematological malignancies in recent years. However, a considerable proportion of patients would experience tumor recurrence and deterioration. Insufficient CAR-T cell persistence is the major reason for relapse. Multiple strategies to enhance the long-term antitumor effects of CAR-T cells have been explored and developed. In this study, we focused on tyrosine kinase inhibitors (TKIs), which have emerged immunomodulatory potential besides direct tumoricidal effects., Methods: Here, we screened 50 approved TKIs drugs and identified that afatinib (AFA) markedly enhanced the expressing of CD62L and inhibited reactive oxygen species level in T cells. And the underlying mechanisms of AFA medicating T cells were explored by detecting signal transduction, and metabolism pattern. Furthermore, we co-cultured AFA with CAR-T cells during the preparation stage and multianalyses of differentiation characteristics, metabolic profiling, and RNA sequencing revealed that AFA induce comprehensive metabolism remodeling and fate reprogramming. Based on it, we finally identified the antitumor efficacy of AFA-pretreatment CAR-T compared with negative-control CAR-T., Results: We identified that AFA blocked the T-cell receptor (TCR) and phosphoinositide 3-kinase-protein kinase B-mechanistic target of rapamycin signaling pathways, induced metabolic reprogramming and modulated T-cell differentiation. When combined with CAR-T cells, AFA inhibited the exhaustion and enhanced the persistence and cytotoxicity. Our results revealed that the pretreatment of AFA enables to boost CAR-T cells with strong antitumor cytotoxicity in leukemia mouse model., Conclusions: Our study systematically demonstrated that AFA pretreatment effectively enhanced CAR-T cells antitumor performance, which presents a novel optimization strategy for potent and durable CAR-T cell therapy., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Current therapies for systemic lupus erythematosus that target a particular factor or cell type exhibit limited effectiveness. To address this limitation, our focus was on CD132, a subunit common to six inflammatory factor receptors implicated in SLE. Our study revealed heightened CD132 expression in SLE patients' lymphocytes, contributing to the production of pro-inflammatory cytokines and immunoglobulins. We developed a novel humanized anti-CD132 monoclonal antibody, named as 2D4. 2D4 efficiently blocked IL-21 and IL-15, with limited effectiveness against IL-2, thereby suppressing T and B cells without disrupting immune tolerance. In the mouse immunization model, 2D4 virtually inhibited T cell-dependent, antigen-specific B-cell response. In lupus murine models, 2D4 mitigated inflammation by suppressing multiple pro-inflammatory cytokines and anti-dsDNA antibody titers, also diminishing proteinuria and glomerulonephritis. Compared to Belimumab, 2D4 exhibited superior efficacy in ameliorating the inflammatory state and preserving renal function. Moreover, 2D4 exhibited the ability to inhibit the production of pro-inflammatory factors and autoantibodies in PBMCs from individuals with SLE, highlighting its therapeutic potential for SLE individuals. Potent, 2D4 has the potential to significantly improve clinical outcomes in SLE and other complex autoimmune disorders., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

X-irradiation of blood products is an alternative for gamma-ray to prevent post-transfusion GvHD. However, commercial X-irradiators are not widely available while little is known about their safety and efficacy for platelet products. This study introduces an efficient, accessible and cost-effective "X irradiation system" for platelet concentrates (PCs). By constructing a suitable radiation box (phantom) for a clinically available linear accelerator, an "X irradiation system" was designed specifically for PCs. PCs were divided into three equal bags either exposed to X- and gamma-irradiation or kept unirradiated (control). Irradiation-induced inhibition of T cells proliferation was examined by MTT and cell cycle assays on mononuclear cells (MNCs) obtained from PCs. The inhibitory effect of irradiation on allorecognition ability of MNCs was assessed by mixed lymphocyte reaction where MTT evaluated lymphocyte proliferation responses and flowcytometry examined CD8 + T lymphocytes activity. Platelet activation was also examined with P-selectin expression and PAC-1 binding by flowcytometry. X- and gamma-irradiation reduced T cell proliferation while disturbing the cell-cycle with reduced entry of T-cells into the S phase and their G2 arrest. Both types of irradiations also effectively reduced "lymphocyte allorecognition responses" while inactivating CD8 + T lymphocytes in platelet products but with no significant effect on platelet activity. This is the first study that showed "X irradiation system" effectively suppresses T cell proliferation and CD8 + T lymphocyte activity in platelet products, with no effect to platelet quality and activation markers. This may suggest the LINAC-based "X irradiation system" with a dose of 30Gy as efficient and safe as gamma-irradiation for platelet products., Competing Interests: Declarations Competing interests The authors declare no competing interests. Ethics approval This study was approved by the Ethics Committee of the High Institute for Research and Education in Transfusion Medicine, Tehran, Iran (Ethic approval numbers: IR.TMI.REC.1401.017& IR.TMI.REC.1402.001)., (© 2024. The Author(s).)

Purpose of Review: There is a growing recognition of plaque erosion as a cause of acute coronary syndrome. This review aims to examine the potential involvement of T cells in this process., Recent Findings: Immune-vascular interactions have been identified in the development of plaque erosions. Up to one-third of eroded plaques show evidence of active immune infiltration, with the presence of T cells. We propose that microerosions may frequently occur in association with the infiltration of T cells and macrophages in early atherosclerotic lesions. Healing of erosions could trigger the deposition of excessive extracellular matrix. The pro-inflammatory and cytotoxic actions of T cells, along with reduced endothelial integrity and other mechanisms, may subsequently give rise to clinical symptoms. To gain a better understanding of the role of T cells in plaque erosion, it is crucial to develop improved models for conducting controlled experiments and to study atherosclerosis in younger individuals., Competing Interests: Declarations Conflict Interests The authors declare no conflict of interest. Human and Animal Rights and Informed Consent All reported studies/experiments with human or animal subjects performed by the authors have been previously published and complied with all applicable ethical standards (including the Helsinki Declaration and its amendments, institutional/national research committee standards, and international/national/institutional guidelines)., (© 2024. The Author(s).)

Diabetic kidney disease (DKD) is a prevalent microvascular complication of diabetes mellitus and a primary cause of end-stage renal disease (ESRD). Increasing studies suggest that immune cells are involved in regulating renal inflammation, which contributes to the progression of DKD. Compared with conventional methods, single-cell sequencing technology is more developed technique that has advantages in resolving cellular heterogeneity, parallel multi-omics studies, and discovering new cell types. ScRNA-seq helps researchers to analyze specifically gene expressions, signaling pathways, intercellular communication as well as their regulations in various immune cells of kidney biopsy and urine samples. It is still challenging to investigate the function of each cell type in the pathophysiology of kidney due to its complex and heterogeneous structure and function. Here, we discuss the application of single-cell transcriptomics in the field of DKD and highlight several recent studies that explore the important role of immune cells including macrophage, T cells, B cells etc. in DKD through scRNA-seq analyses. Through combing the researches of scRNA-seq on immune cells in DKD, this review provides novel perspectives on the pathogenesis and immune therapeutic strategy for DKD., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

To examine the possible causative association between Crohn disease (CD) and the T-cell surface glycoprotein CD5 and to ascertain whether sphingomyelin (SM) functions as a mediator. We conducted a two-step Mendelian randomization (MR) study to further explore the pathogenesis of Crohn and its related targets. MR study was performed on CD5 and CD using summary-level data from a genome-wide association study. Additionally, by employing a two-step MR study method, we determined that SM might mediate the causal effect of CD5 on CD. There was a favorable correlation between the surface glycoprotein CD5 on T cells and vulnerability to CD, and SM mediated the causal effect of CD5 on CD (the mediating effect accounts for 9.2%). Our study revealed that CD5 and CD are causally related, with SM mediating a small fraction of the impact (approximately 9.2%). The mediating function of SM in the link between CD5 and CD is anticipated to be realized through the regulation of immune cell transportation, apoptosis of intestinal barrier cells, and maintenance of the intestinal microenvironment., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

The role of tumor microenvironment (TME)-associated inadequate protein modification and trafficking due to insufficiency in Golgi function, leading to Golgi stress, in the regulation of T cell function is largely unknown. Here, we show that disruption of Golgi architecture under TME stress, identified by the decreased expression of GM130, was reverted upon treatment with hydrogen sulfide (H 2 S) donor GYY4137 or overexpressing cystathionine β-synthase (CBS), an enzyme involved in the biosynthesis of endogenous H 2 S, which also promoted stemness, antioxidant capacity, and increased protein translation, mediated in part by endoplasmic reticulum-Golgi shuttling of Peroxiredoxin-4. In in vivo models of melanoma and lymphoma, antitumor T cells conditioned ex vivo with exogenous H 2 S or overexpressing CBS demonstrated superior tumor control upon adoptive transfer. Further, T cells with high Golgi content exhibited unique metabolic and glycation signatures with enhanced antitumor capacity. These data suggest that strategies to mitigate Golgi network stress or using Golgi hi tumor-reactive T cells can improve tumor control upon adoptive transfer.

B cell maturation depends on cognate interactions between the T and B cells. Upon interaction with CD40 ligand (CD40L) on T cells, CD40 delivers costimulatory signals alongside B cell antigen receptor (BCR) signaling to regulate affinity maturation and antibody class switch. Mutations affecting CD40-CD40L interactions cause abnormal antibody responses in immunodeficiencies known as X-linked hyper-IgM syndrome (X-HIgM). Here, we study the CD40-mediated mechanotransduction in B cells, which likely occurs during their physical contacts with T cells. We found that CD40 forms catch bond with CD40L that lasts longer at larger forces, both B and T cells exert tension on CD40-CD40L bonds, and force enhances CD40 signaling and antibody class switch. X-HIgM CD40L mutations impair catch bond formation, suppress endogenous tension, and reduce force-enhanced CD40 signaling, leading to deficiencies in antibody class switch. Our findings highlight the role of mechanotransduction in CD40 function and provide insights into the mechanisms underlying X-HIgM syndrome.

In this prospective longitudinal study, we evaluated the durability of humoral responses to SARS-CoV-2 mRNA booster vaccination in 93 people with HIV, exploring the possible role of T-cell dysfunction and inflammaging biomarkers in predicting antibody waning. We found that, despite a negligible influence of the inflammaging milieu, low CD4/CD8 ratio and CD4+CD127+ percentage as well as high CD8+CD38+CD45RO+ percentage are associated with faster antibody waning, in turn contributing to our understanding of the determinants of COVID-19 vaccine-elicited immune response in this population., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

IL-7 is a cytokine produced by stromal cells, which binds to IL-7Rα and plays an important role for homeostasis of T lymphocytes. Excessive activities of IL-7-triggered signaling pathways causes autoimmune diseases. How IL-7-triggered signaling and immune effects are regulated is not fully understood. In this study, we show that the membrane-associated RING-CH (MARCH) E3 ligase family member MARCH8 mediates K27-linked polyubiquitination of IL-7Rα, leading to its lysosomal degradation. Site-directed mutagenesis suggests that MARCH8 meditates polyubiquitination of IL-7Rα at K265/K266, and mutation of these residues renders IL-7Rα resistance to MARCH8-mediated polyubiquitination and degradation. MARCH8 deficiency increases IL-7-triggered activation of the downstream transcription factor STAT5 and transcriptional induction of the effector genes in human T lymphoma cells. MARCH8 deficiency also promotes IL-7-triggered T cell proliferation and splenic memory CD8+ T cell differentiation in mice. Our findings suggest that MARCH8 negatively regulates IL-7-triggered signaling by mediating K27-linked polyubiquitination and lysosomal degradation of IL-7Rα, which reveals a negative regulatory mechanism of IL-7-triggered T cell homeostasis., (Copyright © 2024 by The American Association of Immunologists, Inc.)

In the tumor microenvironment, macrophages exhibit different phenotypes and functions in response to various signals, playing a crucial role in the initiation and progression of tumors. Several studies have indicated that intervention in the functions of different phenotypes of tumor-associated macrophages causes significant changes in the crosstalk between tumor cells and immune-related cells, such as T, NK, and B cells, markedly altering the course of tumor development. However, only a few specific therapeutic strategies targeting macrophages are yet available. This article comprehensively reviews the molecular biology mechanisms through which tumor-associated macrophages mediate the crosstalk between tumor cells and immune-related cells. Also, various treatment methods currently used in clinical practice and those in the clinical trial phase have been summarized, and the novel strategies for targeting tumor-associated macrophages have been categorized accordingly., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Oxaliplatin is currently used for chemotherapy in patients with hepatocellular carcinoma, but its increasing tolerance to tumours over time limits its clinical application. Studies have shown that high PD-L1 expression promotes the polarization of M2 macrophages. The increased infiltration of M2 macrophages, including those in HCC, is positively correlated with poor prognosis in various solid tumours. We found that oxaliplatin promoted the expression of PD-L1 in liver cancer cells, which might be attributed partly to the tolerance of tumours to oxaliplatin. Therefore, in this study, we explored the antitumour effect of attenuated Salmonella carrying siRNA-PD-L1 combined with oxaliplatin via Western blotting, immunohistochemistry, immunofluorescence, and flow cytometry. The results revealed that attenuated Salmonella carrying siRNA-PD-L1 combined with oxaliplatin more significantly inhibited tumour growth in tumour-bearing mice, suppressed the expression of PD-L1 in tumour tissue, increased the apoptosis of tumour cells and the expression of the tumour-related protein cleaved-caspase3, and increased the infiltration of M1 macrophages and T lymphocytes in tumour tissues. Moreover, the combination therapy increased the activation of T cells and the number of T lymphocytes and NK cells in the spleens of the mice and improved the overall antitumour immune response in the mice. Our results confirmed that attenuated Salmonella harbouring siRNA-PD-L1 combined with oxaliplatin had a significant antitumour effect and did not increase the incidence of toxic side effects, providing a theoretical reference for addressing oxaliplatin tolerance in the treatment of hepatocellular carcinoma., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The prognosis for esophageal squamous cell carcinoma (ESCC), a prevalent and aggressive form of cancer, remains poor despite advancements in treatment options. Addressing the gap in comprehensive prognostic information derived from circRNA expression profiles for ESCC, our study aimed to establish a linkage between circRNA expressions and ESCC prognosis. To achieve this, we first developed an optimized prognostic model named T cell-related risk score (TRRS), which integrates T cell-associated features with machine learning algorithms. In parallel, we re-analyzed existing RNA-seq datasets to redefine the expression profiles of circRNAs and mRNAs. Utilizing the TRRS as a foundational "bridge," we identified circRNAs correlated with TRRS, leading to the development of a novel circRNA pair-based prognostic model, the TCRS, which is independent of specific expression levels. Further investigations uncovered two circRNAs, circNLK(5,6,7).1 and circRC3H1(2).1, with potential functional significance. These findings underscore the utility of these risk scores as tools for predicting overall survival and identifying potential therapeutic targets for ESCC patients., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Ethnopharmacological Relevance: HLA-B*35:01 has been identified as a risk allele for Polygonum multiflorum Thunb.-induced liver injury (PMLI). However, the immune mechanism underlying HLA-B*35:01-mediated PMLI remains unknown., Aim of the Study: To characterize the immune mechanism of HLA-B*35:01-mediated PMLI., Materials and Methods: Components of P. multiflorum (PM) bound to the HLA-B*35:01 molecule was screened by immunoaffinity chromatography. Both wild-type mice and HLA-B*35:01 transgenic (TG) mice were treated with emodin. The levels of transaminases, histological changes and T-cell response were assessed. Splenocytes from emodin-treated mice were isolated and cultured in vitro. Phenotypes and functions of T cells were characterized upon drug restimulation using flow cytometry or ELISA. Emodin-pulsed antigen-presenting cells (APCs) or glutaraldehyde-fixed APCs were co-cultured with splenocytes from emodin-treated transgenic mice to detect their effect on T-cell activation., Results: Emodin, the main component of PM, could non-covalently bind to the HLA-B*35:01-peptide complexes. TG mice were more sensitive to emodin-induced immune hepatic injury, as manifested by elevated aminotransferase levels, infiltration of inflammatory cells, increased percentage of CD8+T cells and release of effector molecules in the liver. However, these effects were not observed in wild-type mice. An increase in percentage of T cells and the levels of interferon-γ, granzyme B, and perforin was detected in emodin-restimulated splenocytes from TG mice. Anti-HLA-I antibodies inhibited the secretion of these effector molecules induced by emodin. Mechanistically, emodin-pulsed APCs failed to stimulate T cells, while fixed APCs in the presence of emodin could elicit the secretion of T cell effector molecules., Conclusion: The HLA-B*35:01-mediated CD8 + T cell reaction to emodin through the P-I mechanism may contribute to P. multiflorum-induced liver injury., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest regarding the publication of this article., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Systemic lupus erythematosus (SLE) is an autoimmune disease with protean manifestations. There is little understanding of why some organs are specifically impacted in patients and the mechanisms of disease persistence remain unclear. While much work has been done characterizing the DNA methylation status in SLE, there is less information on histone modifications, a more dynamic epigenetic feature. This study identifies two histone marks of activation and the binding of p300 genome-wide in three cell types and three clinical subsets to better understand cell-specific effects and differences across clinical subsets., Results: We examined 20 patients with SLE and 8 controls and found that individual chromatin marks varied considerably across T cells, B cells, and monocytes. When pathways were examined, there was far more concordance with conservation of TNF, IL-2/STAT5, and KRAS pathways across multiple cell types and ChIP data sets. Patients with cutaneous lupus and lupus nephritis generally had less dramatically altered chromatin than the general SLE group. Signals also demonstrated significant overlap with GWAS signals in a manner that did not implicate one cell type more than the others., Conclusions: The pathways identified by altered histone modifications and p300 binding are pathways known to be important from RNA expression studies and recognized pathogenic mechanisms of disease. NFκB and classical inflammatory pathways were strongly associated with increased peak heights across all cell types but were the highest-ranking pathway for all three antibodies in monocytes according to fgsea analysis. IL-6 Jak/STAT3 signaling was the most significant pathway association in T cells marked by H3K27ac change. Therefore, each cell type experiences the disease process distinctly although in all cases there was a strong theme of classical inflammatory pathways. Importantly, this NFκB pathway, so strongly implicated in the patients with generalized SLE, was much less impacted in monocytes when cutaneous lupus was compared to the general SLE cohort and also less impacted in lupus nephritis compared to general SLE. These studies define important cell type differences and emphasize the breadth of the inflammatory effects in SLE., Competing Interests: Declarations Ethical approval and consent to participate The Johns Hopkins University School of Medicine Institutional Review Board approved this study. IRB00216558. UPENN Institutional Review Board for healthy controls was 705906. Patient consent All patients consented for this study. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Due to the higher risk of medical complications posed by influenza infection, patients with type 1 diabetes (T1D) are strongly recommended to receive the influenza vaccine. However, it remains unclear if hyperglycemia in patients with T1D affects vaccine-induced immune responses. In this study, we investigated the humoral and cellular immune responses of prediabetic and diabetic, nonobese diabetic (NOD) mice following influenza vaccination to determine the effects of hyperglycemia on influenza vaccine-induced responses. In diabetic NOD mice, vaccine-specific IgG and IgM levels, as well as IgG-producing cells, were comparable to those in prediabetic NOD mice. However, the diabetic NOD mice exhibited reduced percentages of memory T cells and activated T cells in the spleen, along with reduced number of vaccine-specific interferon (IFN)-γ-secreting cells. Thus, these findings suggest that in patients with T1D, hyperglycemia could lead to impaired cell-mediated immune responses following influenza vaccination., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Abstract: Extramedullary disease (EMD) is a high-risk feature of multiple myeloma (MM) and remains a poor prognostic factor, even in the era of novel immunotherapies. Here, we applied spatial transcriptomics (RNA tomography for spatially resolved transcriptomics [tomo-seq] [n = 2] and 10x Visium [n = 12]) and single-cell RNA sequencing (n = 3) to a set of 14 EMD biopsies to dissect the 3-dimensional architecture of tumor cells and their microenvironment. Overall, infiltrating immune and stromal cells showed both intrapatient and interpatient variations, with no uniform distribution over the lesion. We observed substantial heterogeneity at the copy number level within plasma cells, including the emergence of new subclones in circumscribed areas of the tumor, which is consistent with genomic instability. We further identified the spatial expression differences between GPRC5D and TNFRSF17, 2 important antigens for bispecific antibody therapy. EMD masses were infiltrated by various immune cells, including T cells. Notably, exhausted TIM3+/PD-1+ T cells diffusely colocalized with MM cells, whereas functional and activated CD8+ T cells showed a focal infiltration pattern along with M1 macrophages in tumor-free regions. This segregation of fit and exhausted T cells was resolved in the case of response to T-cell-engaging bispecific antibodies. MM and microenvironment cells were embedded in a complex network that influenced immune activation and angiogenesis, and oxidative phosphorylation represented the major metabolic program within EMD lesions. In summary, spatial transcriptomics has revealed a multicellular ecosystem in EMD with checkpoint inhibition and dual targeting as potential new therapeutic avenues., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Among new vaccine technologies contributed to the control of the COVID-19 pandemic, ChAdOx1 nCoV-19, a chimpanzee adenovirus (ChAd)-vector vaccine expressing the SARS-CoV-2 spike protein, could be administered globally owing to its low production cost and lack of a requirement for frozen storage. Despite its benefits, most recipients have reported immediate inflammatory reactions after the initial dose vaccination. We comprehensively examined the immune landscape following ChAdOx1 nCoV-19 vaccination based on the single-cell transcriptomes of immune cells and epigenomic profiles of monocytes. Monocyte and innate-like activated T cell populations expressing interferon-stimulated genes (ISGs) increased 1 day post-vaccination with appearance of distinct subtype of ISG-activated cells, returning to baseline by day 14. Pre-treatment with oral corticosteroids effectively curtailed these ISG-associated inflammatory responses by decreasing chromatin accessibility of major ISGs, without hampering vaccine immunogenicity. Our findings provide insights into the human immune response following ChAd-based vaccination and propose a method to reduce inflammatory side effects., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Jeong Seok Lee reports financial support was provided by Korea Advanced Institute of Science and Technology. Jeong Seok Lee reports a relationship with Korea Advanced Institute of Science and Technology that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.]., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Adoptive cell therapies (ACT) exhibit excellent efficacy in hematological malignancy. However, its application in solid tumors still has many challenges partly due to the tumor immune microenvironment. Cryo-thermal therapy (CTT) can induce an acute inflammatory response and remold the immune environment, providing an appropriate environment for the activation of adaptive immunity. However, it remains unclear whether CTT can enhance the efficacy of ACT., Methods: A bilateral B16F10 tumor-bearing mouse model was used to assess whether CTT could enhance the efficacy of ACT. The right large tumor was subjected to CTT, and the left small tumor was collected for flow cytometry, RNA-seq, immunohistochemistry and TCR Vβ sequencing. Finally, bilateral B16F10 tumor-bearing mice and 4T1 tumor-bearing mice were used to assess the efficacy after CTT combined with ACT., Results: CTT dramatically reshaped the immune microenvironment in distal tumors to an acute inflammatory state by promoting innate cell infiltration, increasing cytokine production by macrophages and DCs. The remodeling of the tumor immune microenvironment further enhanced the antitumor efficiency of ACT by increasing the proliferation of T cells, promoting activation of the effector functions of T cells and boosting the expansion of TCR clones., Conclusions: Our results suggest that CTT can significantly reshape the tumor immunosuppressive microenvironment and convert "cold tumors" into "hot tumors," thereby enhancing ACT-induced immune responses and maximizing the therapeutic effect of ACT., Competing Interests: Declarations Conflict of interest The authors declare no competing interests. Ethics approval All animal experiments were approved by the Animal Welfare Committee of Shanghai Jiao Tong University, and experimental methods were performed in accordance with the guidelines of Shanghai Jiao Tong University Animal Care (approved by Shanghai Jiao Tong University Scientific Ethics Committee, Registration No. 2020017)., (© 2024. The Author(s).)

Background: Immunotherapy, such as chimeric antigen receptor T (CAR-T) cells targeting CD33 or CD123, has been well developed over the past decade for the treatment of acute myeloid leukemia (AML). However, the inability to sustain tumor-free survival and the possibility of relapse due to antigen loss have raised concerns. A dual targeting of CD33 and CD123 is needed for better outcomes., Methods: Based on our previously constructed CD33 and CD123 monovalent CAR-T, Loop33 × 123 and Loop123 × 33 CAR-T were constructed with molecular cloning techniques. All CAR-T cells were generated by lentivirus transduction of T cells from healthy donors. Phenotype detection was evaluated on day 7 concerning activation, exhaustion, and subtype proportions. Coculture killing assays were conducted using various AML cell lines and primary AML cells. Degranulation and cytokine secretion levels were detected by flow cytometry. Cell-derived xenograft models were established using wild-type Molm 13 cell lines, or a mixture of Molm 13-KO33 and Molm 13-KO123 cells as an ideal model of immune escape. By monitoring body weight and survival of tumor-bearing mice, Loop33 × 123 and Loop123 × 33 CAR-T cells were further assessed for their efficacy in vivo., Results: In vitro study, our results demonstrated that Loop33 × 123 CAR-T cells could efficiently eliminate AML cell lines and primary AML cells with elevated degranulation and cytokine secretion levels. Compared with our previously constructed monovalent CD33 or CD123 CAR-T cells, Loop33 × 123 CAR-T cells showed superior advantages in an immune escape model. In vivo studies further confirmed that Loop33 × 123 CAR-T cells could effectively prolong the survival of mice without significant toxicity. However, Loop123 × 33 CAR-T cells failed to show the same effects. Furthermore, Loop33 × 123 CAR-T cells efficiently circumvented potential immune escape, a challenge where monovalent CAR-T cells failed., Conclusions: Loop33 × 123 CAR-T targeting CD33 and CD123 could efficiently eliminate AML cells and prolong survival of tumor-bearing mice, while addressing the issue of immune escape., Competing Interests: Declarations Conflict of interest The authors declare no competing interests., (© 2024. The Author(s).)

Congenital heart disease (CHD) is the most common birth defect in newborns, often requiring cardiac surgery with concomitant thymectomy that is known to increase disease susceptibility later in life. Studies of γδ T cells, which are one of the dominant T cells in the early fetal human thymus, are rare. Here, we provide a comprehensive analysis of the γδ T cell compartment via flow cytometry and next-generation sequencing in children and infants with CHD, who underwent cardiac surgery shortly after birth. A perturbation of the γδ T cell repertoire is evident, and Vδ1 T cell numbers are reduced. However, those cells that are present, do retain cytotoxicity. In contrast, GZMA+CD28+CD161hi innate effector Vγ9Vδ2 T cells are found in higher proportions. TCR-seq identifies an increase in TRDJ3+ γδ T cell clones in children with CHD, but not in a confirmatory group of neonates prior to CHD surgery, which overall points to a persistence of fetal-derived effector γδ T cells in children with CHD., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

As a model organism in the study of immunity to infection, Toxoplasma gondii has been instrumental in establishing key principles of host anti-microbial defense and its regulation. Here, we employed an attenuated uracil auxotroph strain of Type I Toxoplasma designated OMP to further untangle the early immune response to this parasitic pathogen. Experiments using αβ T cell-deficient Tcrb -/- mice unexpectedly revealed that an intact αβ T lymphocyte compartment was essential to survive infection with OMP. Subsequent antibody depletion and knockout mouse experiments demonstrated contributions from CD4 + T cells and most predominantly CD8 + T cells in resistance. Using transgenic knockout mice, we found only a partial requirement for IFN-γ and a lack of requirement for Toll-like receptor (TLR) adaptor MyD88 in resistance. In contrast to other studies on Toxoplasma , the ability to survive OMP infection did not require IL-12p40. Surprisingly, T cell-dependent IL-10 was found to be critical for survival, and deficiency of this cytokine triggered an abnormally high systemic inflammatory response. We also found that parasite molecule GRA24, a dense granule protein that triggers TLR-independent IL-12 production, acts as a virulence factor contributing to death of OMP-infected Tcrb -/- and IL-10 -/- mice. Furthermore, resistance against OMP was restored in Tcrb -/- mice via monoclonal depletion of IL-12p40, suggesting that GRA24-induced IL-12 underlies the fatal immunopathology observed. Collectively, our studies provide insight into a novel and rapidly arising T lymphocyte-dependent anti-inflammatory response to T. gondii which operates independently of MyD88 and IL-12 and that depends on the function of parasite-dense granule protein GRA24.IMPORTANCEAs a model infectious microbe and an important human pathogen, the apicomplexan Toxoplasma gondii has provided many important insights into innate and adaptive immunity to infection. We show here that a low virulence uracil auxotrophic Toxoplasma strain emerges as a virulent parasite in the absence of an intact T cell compartment. Both CD4 + and CD8 + T lymphocytes are required for optimal protection, in line with previous findings in other models of Toxoplasma infection. Nevertheless, several novel aspects of the response were identified in our study. Protection occurs independently of IL-12 and MyD88 and only partially requires IFN-γ. This is noteworthy particularly because the cytokines IL-12 and IFN-γ have previously been regarded as essential for protective immunity to T. gondii . Instead, we identified the anti-inflammatory effects of T cell-dependent IL-10 as the critical factor enabling host survival. The parasite dense granule protein GRA24, a host-directed mitogen-activated protein kinase activator, was identified as a major virulence factor in T cell-deficient hosts. Collectively, our results provide new and unexpected insights into host resistance to Toxoplasma ., Competing Interests: The authors declare no conflict of interest.

Insufficient influx of T cells into the tumor microenvironment, including brain metastasis, dramatically limits efficacy of conventional immunotherapy. In this issue of Immunity, Messmer et al. interrogate spatiotemporal dependencies of melanoma brain metastasis T cell infiltration by intravital microscopy. They find that T cells enter these brain tumors through peritumoral venous vessels and can be stimulated with immunotherapy., Competing Interests: Declaration of interests J.R. and A.B. are inventors of provisional patent applications related to leptomeningeal metastasis. A.B. is an inventor of patents related to treatment of brain and leptomeningeal metastases., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Tissue-resident memory T (T RM ) cells are integral to tissue immunity, persisting in diverse anatomical sites where they adhere to a common transcriptional framework. How these cells integrate distinct local cues to adopt the common T RM cell fate remains poorly understood. Here, we show that whereas skin T RM cells strictly require transforming growth factor β (TGF-β) for tissue residency, those in other locations utilize the metabolite retinoic acid (RA) to drive an alternative differentiation pathway, directing a TGF-β-independent tissue residency program in the liver and synergizing with TGF-β to drive T RM cells in the small intestine. We found that RA was required for the long-term maintenance of intestinal T RM populations, in part by impeding their retrograde migration. Moreover, enhanced RA signaling modulated T RM cell phenotype and function, a phenomenon mirrored in mice with increased microbial diversity. Together, our findings reveal RA as a fundamental component of the host-environment interaction that directs immunosurveillance in tissues., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

To improve immunotherapy for brain tumors, it is important to determine the principal intracranial site of T cell recruitment from the bloodstream and their intracranial route to brain tumors. Using intravital microscopy in mouse models of intracranial melanoma, we discovered that circulating T cells preferably adhered and extravasated at a distinct type of venous blood vessel in the tumor vicinity, peritumoral venous vessels (PVVs). Other vascular structures were excluded as alternative T cell routes to intracranial melanomas. Anti-PD-1/CTLA-4 immune checkpoint inhibitors increased intracranial T cell motility, facilitating migration from PVVs to the tumor and subsequently inhibiting intracranial tumor growth. The endothelial adhesion molecule ICAM-1 was particularly expressed on PVVs, and, in samples of human brain metastases, ICAM-1 positivity of PVV-like vessels correlated with intratumoral T cell infiltration. These findings uncover a distinct mechanism by which the immune system can access and control brain tumors and potentially influence other brain pathologies., Competing Interests: Declaration of interests F.W. reports receiving research grants from Boehringer, Genentech, Roche, and Divide and Conquer Ltd., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Abstract: Besides genetic influences, nongenetic factors such as graft-versus-host disease and viral infections have been shown to be important shapers of the immune reconstitution and diversification processes after hematopoietic stem cell transplantation (HSCT). However, differential susceptibility to immune modulation by nongenetic factors is not fully understood. We determined to follow the reconstitution of the T-cell receptor (TCR) repertoire through immune sequencing of natural killer (NK) cells using a 35-marker spectral flow cytometry panel and in relation to clinical events. A longitudinal investigation was performed on samples derived from 54 HSCT recipients during the first year after HSCT. We confirmed a significant contraction in TCR repertoire diversity, with remarkable stability over time. Cytomegalovirus (CMV) reactivation had the ability to significantly change TCR repertoire clonality and composition, with a long-lasting imprint. Our data further revealed skewing of NK-cell reconstitution in CMV reactivated recipients, with an increased frequency of KIR2DL2L3S2+ adaptive, cytolytic, and functional CD107a+ NK cells, concomitant with a reduced pool of NKG2A+ NK cells. We provided support that CMV might act as an important driver of peripheral homeostatic proliferation of circulating specific T and NK cells, which can be viewed as a compensatory mechanism to establish a new peripheral repertoire., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

To address immune escape, multi-specific CAR-T-cell strategies use natural ligands that specifically bind multiple receptors on malignant cells. In this context, we propose a split CAR design comprising a universal receptor expressed on T cells and ligand-based switch molecules, which preserves the natural trimeric structure of ligands like APRIL and BAFF. Following optimization of the hinges and switch labeling sites, the split-design CAR-T cells ensure the native conformation of ligands, facilitating the optimal formation of immune synapses between target cancer cells and CAR-T cells. Our CAR-T-cell strategy demonstrates antitumor activities against various B-cell malignancy models in female mice, potentially preventing immune escape following conventional CAR-T-cell therapies in the case of antigen loss or switching. This ligand-based split CAR design introduces an idea for optimizing CAR recognition, enhancing efficacy and potentially improving safety in clinical translation, and may be broadly applicable to cellular therapies based on natural receptors or ligands., Competing Interests: Competing interests The Chinese patent “A method to prepare natural ligand-mediated switchable gene-modified immune cells against multiple targets” with the application number CN202010073487.1 is related to the present work. The applicant for the patent is Peking University Shenzhen Graduate School. The authors declare that they have no competing interests., (© 2024. The Author(s).)

Background: For best efficacy, vaccines must provide long-lasting immunity. To measure longevity, memory from B and T cells are surrogate endpoints for vaccine efficacy. When antibodies are insufficient for protection, the immune response must rely on T cells. The magnitude and differentiation of effective, durable immune responses depend on antigen-specific precursor frequencies. However, development of vaccines that induce durable T-cell responses for cancer treatment has remained elusive., Methods: To address long-lasting immunity, patients with HER2+ (human epidermal growth factor receptor 2) advanced stage cancer received HER2/neu targeted vaccines. Interferon-gamma (IFN-γ) enzyme-linked immunosorbent spot measuring HER2/neu IFN-γ T cells were analyzed from 86 patients from three time points: baseline, 1 month after vaccine series, and long-term follow-up at 1 year, following one in vitro stimulation. The baseline and 1-month post-vaccine series responses were correlated with immunity at long-term follow-up by logistic regression. Immunity was modeled by non-linear functions using generalized additive models., Results: Antigen-specific T-cell responses at baseline were associated with a 0.33-log increase in response at long-term follow-up, 95% CI (0.11, 0.54), p=0.003. 63% of patients that had HER2/neu specific T cells at baseline continued to have responses at long-term follow-up. Increased HER2/neu specific T-cell response 1 month after the vaccine series was associated with a 0.47-log increase in T-cell response at long-term follow-up, 95% CI (0.27, 0.67), p=2e-5. 74% of patients that had an increased IFN-γ HER2 response 1 month after vaccines retained immunity long-term. As the 1-month post-vaccination series precursor frequency of HER2+IFN-γ T-cell responses increased, the probability of retaining these responses long-term increased (OR=1.49 for every one natural log increase of precursor frequency, p=0.0002), reaching an OR of 20 for a precursor frequency of 1:3,000 CONCLUSIONS: Patients not destined to achieve long-term immunity can be identified immediately after completing the vaccine series. Log-fold increases in antigen-specific precursor frequencies after vaccinations correlate with increased odds of retaining long-term HER2 immune responses. Further vaccine boosting or immune checkpoint inhibitors or other immune stimulator therapy should be explored in patients that do not develop antigen-specific T-cell responses to improve overall response rates., Competing Interests: Competing interests: JBL has received grant funding from Merck, AstraZeneca, Precigen, ArsenalBio, Volastra, Nurix, Aminex Therapeutics through his institution and is a consultant for Verismo Therapeutics. JD is employed by Grail. SS has received grant funding from Veana, IMV Inc, and Stanford Burnham Prebys. MLD has grant funding from Precigen, Veanna, Bavarian Nordic, and Aston Sci. MLD also holds shares in Epithany and is an inventor on patents held by the University of Washington. The authors declare there are no other competing interests., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

A significant challenge for chimeric antigen receptor (CAR) T cell therapy against glioblastoma (GBM) is its immunosuppressive microenvironment, which is densely populated by protumoral glioma-associated microglia and macrophages (GAMs). Myeloid immune checkpoint therapy targeting the CD47-signal regulatory protein alpha (SIRPα) axis induces GAM phagocytic function, but CD47 blockade monotherapy is associated with toxicity and low bioavailability in solid tumors. In this work, we engineer a CAR T cell against epidermal growth factor receptor variant III (EGFRvIII), constitutively secreting a signal regulatory protein gamma-related protein (SGRP) with high affinity to CD47. Anti-EGFRvIII-SGRP CAR T cells eradicate orthotopic EGFRvIII-mosaic GBM in vivo, promoting GAM-mediated tumor cell phagocytosis. In a subcutaneous CD19 + lymphoma mouse model, anti-CD19-SGRP CAR T cell therapy is superior to conventional anti-CD19 CAR T. Thus, combination of CAR and SGRP eliminates bystander tumor cells in a manner that could overcome main mechanisms of CAR T cell therapy resistance, including immune suppression and antigen escape., (© 2024. The Author(s).)

BACKGROUNDInhibition of Bruton's tyrosine kinase with ibrutinib blocks the function of myeloid-derived suppressor cells (MDSC). The combination of ibrutinib and nivolumab was tested in patients with metastatic solid tumors.METHODSSixteen patients received ibrutinib 420 mg p.o. daily with nivolumab 240 mg i.v. on days 1 and 15 of a 28-day cycle. The effect of ibrutinib and nivolumab on MDSC, the immune profile, and cytokine levels were measured. Single-cell RNA-Seq and T cell receptor sequencing of immune cells was performed.RESULTSCommon adverse events were fatigue and anorexia. Four patients had partial responses and 4 had stable disease at 3 months (average 6.5 months, range 3.5-14.6). Median overall survival (OS) was 10.8 months. Seven days of Bruton's tyrosine kinase (BTK) inhibition significantly increased the proportion of monocytic-MDSC (M-MDSC) and significantly decreased chemokines associated with MDSC recruitment and accumulation (CCL2, CCL3, CCL4, CCL13). Single-cell RNA-Seq revealed ibrutinib-induced downregulation of genes associated with MDSC-suppressive function (TIMP1, CXCL8, VEGFA, HIF1A), reduced MDSC interactions with exhausted CD8+ T cells, and decreased TCR repertoire diversity. The addition of nivolumab significantly increased circulating NK and CD8+ T cells and increased CD8+ T cell proliferation. Exploratory analyses suggest that MDSC and T cell gene expression and TCR repertoire diversity were differentially affected by BTK inhibition according to patient response.CONCLUSIONIbrutinib and nivolumab were well tolerated and affected MDSC and T cell function in patients with solid metastatic tumors.TRIAL REGISTRATIONClinicalTrials.gov NCT03525925.FUNDINGNIH; National Cancer Institute Cancer; National Center for Advancing Translational Sciences; Pelotonia.

Research has demonstrated the high mortality and morbidity associated with B-Acute lymphoblastic lymphoma (B-ALL). Researchers have developed several therapeutic approaches to combat the disorder. Recently, researchers developed chimeric antigen receptors (CARs)-T cells, which recognize antigens independently of major histocompatibility complexes (MHCs) and activate at a higher level with additional persistence. However, relapsing B-ALL has been reported in several cases. This review article was aimed to collecting recent information regarding the mechanisms used by B-ALL-related lymphocytes to escape from CAR-T cells and the plausible resolution projects., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

An enhanced vaccine is immediately required to swap the more than 100 year-old bacillus Calmette-Guerin (BCG) vaccine against tuberculosis. Here, trimethyl chitosan-loaded inactivated Mycobacterium smegmatis (MST), along with potent adenovirus hexon protein (AdHP), and toll-like receptor (TLR)-1/2 as a nanovaccine, was developed against tuberculosis (TB). The nanoformulation increased the bioavailability of MST and elicited the targeting ability. Nanovaccines have a size range of 183.5 ± 9.5 nm with a spherical morphology and uniform distribution. The nanovaccine exhibited a higher release of antigen in acidic pH, and this is mainly due to protonation of ionizable groups in polymeric materials. The nanovaccine facilitated the effective cellular uptake of bone-marrow-derived dendritic cells and progressive endosomal escape in a shorter period. In vitro analyses indicated that the nanovaccine activated cytokine and T-cell production and also assisted in humoral immunity by producing antibodies. The nanovaccine was able to induce more cellular and humoral memory cells and a better protective immune response. Nanomaterials effectively delivered the MST, AdHP, and TLR1/2 antigens to the major histocompatibility complex class I and II pathways to generate protective cytotoxic CD8 + and CD4 + T-cells. In vivo experiments, compared with free MST and BCG, showed that mice immunized with the nanovaccine induced more specific CD4 + , CD8 + , and memory T-cell activations. Overall, the fabricated nanovaccine was able to control the release of antigens and adjuvants and enhance memory cell activation and humoral immunity against TB.

Tumor cell-derived prostaglandin E2 (PGE2) is a tumor cell-intrinsic factor that supports immunosuppression in the tumor microenvironment (TME) by acting on the immune cells, but the impact of PGE2 signaling in tumor cells on the immunosuppressive TME is unclear. We demonstrate that deleting the PGE2 synthesis enzyme or disrupting autocrine PGE2 signaling through EP4 receptors on tumor cells reverses the T cell-low, myeloid cell-rich TME, activates T cells, and suppresses tumor growth. Knockout (KO) of Ptges (the gene encoding the PGE2 synthesis enzyme mPGES-1) or the EP4 receptor gene (Ptger4) in KPCY (KrasG12D P53R172H Yfp CrePdx) pancreatic tumor cells abolished growth of implanted tumors in a T cell-dependent manner. Blockade of the EP4 receptor in combination with immunotherapy, but not immunotherapy alone, induced complete tumor regressions and immunological memory. Mechanistically, Ptges- and Ptger4-KO tumor cells exhibited altered T and myeloid cell attractant chemokines, became more susceptible to TNF-α-induced killing, and exhibited reduced adenosine synthesis. In hosts treated with an adenosine deaminase inhibitor, Ptger4-KO tumor cells accumulated adenosine and gave rise to tumors. These studies reveal an unexpected finding - a nonredundant role for the autocrine mPGES-1/PGE2/EP4 signaling axis in pancreatic cancer cells, further nominating mPGES-1 inhibition and EP4 blockade as immune-sensitizing therapy in cancer.

The function of PD-1/PD-L1 axis have been intensively studied for immune escape of various cancers. However, the underlying function of PD-L2 remains poorly understood. Here, we demonstrate that PD-L2 is majorly expressed in exosomes with surface localization by clear cell renal cell carcinoma (ccRCC) cells. Tumor cell-derived exosome PD-L2 (TDE-PD-L2) exhibits high expression compared with TDE-PD-L1 in various cancers. In the absence of adaptive immune, TDE-PD-L2 suppresses tumor growth and metastasis. Under immune competence condition, TDE-PD-L2 is hijacked by immune cells in a PD-1-dependent manner to systematically dampen function of T cells via the increased proportion of the regulatory T cells and the decreased proportion of cytotoxic CD8 + T cells in both tumor-infiltrating T cells and spleen. The effects of TDE-PD-L2 on tumor is restored by antibodies targeting PD-L2. Collectively, we demonstrate that PD-1/TDE-PD-L2 axis systematically suppresses T cell functions, representing a potentially therapeutic strategy for ccRCC treatment., (© 2024. The Author(s).)

Modern cancer management comprises a variety of treatment strategies. Immunotherapy, while successful at treating many cancer subtypes, is often hindered by tumor immune evasion and T cell exhaustion as a result of an immunosuppressive tumor microenvironment (TME). In solid malignancies, the extracellular matrix (ECM) embedded within the TME plays a central role in T cell recognition and cancer growth by providing structural support and regulating cell behavior. Relative to healthy tissues, tumor associated ECM signatures include increased fiber density and alignment. These and other differentiating features contributed to variation in clinically observed tumor-specific ECM configurations, collectively referred to as Tumor-Associated Collagen Signatures (TACS) 1-3. TACS is associated with disease progression and immune evasion. This review explores our current understanding of how ECM geometry influences the behaviors of both immune cells and tumor cells, which in turn impacts treatment efficacy and cancer evolutionary progression. We discuss the effects of ECM remodeling on cancer cells and T cell behavior and review recent in silico models of cancer-immune interactions.

Although significant progress has been achieved in elucidating the genetic architecture of systemic lupus erythematosus (SLE), identifying genes underlying the pathogenesis has been challenging. The NZM2410-derived lupus susceptibility Sle3 locus is associated with T cell hyperactivity and activated myeloid cells. However, candidate genes associated with these phenotypes have not been identified. Here, we narrow the Sle3 locus to a smaller genomic segment (Sle3k) and show that mice carrying Sle3k and Sle1 loci developed lupus nephritis. We identify Klf13 as the primary candidate gene that is associated with genome-wide transcription changes resulting in higher levels of proinflammatory cytokines, enhanced T cell activation, and hyperresponsiveness of myeloid cells. Correspondingly, Klf13 -/- mice display repression of genes involved in mediating immune activation, including key proinflammatory cytokines/chemokines in T cells and dysregulation in cytokine signaling pathways in myeloid cells in response to toll receptor ligands. Klf13 upregulation is associated with increased production of RANTES, a key chemokine in lupus nephritis, in activated T cells and the kidneys of lupus-prone mice. In sum, our findings reveal Klf13 as a key gene in the Sle3 interval in mediating lupus pathogenesis that may have implications in the rational design of new therapies for SLE., (© 2024. The Author(s).)

Specificity of a T cell receptor (TCR) is determined by the combination of its interactions to the peptide and human leukocyte antigen (HLA). TCR-based therapeutic molecules have to date targeted a single peptide in the context of a single HLA allele. Some peptides are presented on multiple HLA alleles, and by engineering TCRs for specific recognition of more than one allele, there is potential to expand the targetable patient population. Here, as a proof of concept, we studied two TCRs, S2 and S8, binding to the PRAME peptide antigen (ELFSYLIEK) presented by HLA alleles HLA-A*03:01 and HLA-A*11:01. By structure-guided affinity maturation targeting a specific residue on the HLA surface, we show that the affinity of the TCR can be modulated for different alleles. Using a combination of affinity maturation and functional T cell assay, we demonstrate that an engineered TCR can target the same peptide on two different HLA alleles with similar affinity and potency. This work highlights the importance of engineering alloselectivity for designing TCR based therapeutics suitable for differing global populations., (© 2024. The Author(s).)

Enzymopathy disorders are the result of missing or defective enzymes. Among these enzymopathies, mucopolysaccharidosis type I is a rare genetic lysosomal storage disorder caused by mutations in the gene encoding alpha-L-iduronidase (IDUA), which ultimately causes toxic buildup of glycosaminoglycans (GAGs). There is currently no cure and standard treatments provide insufficient relief to the skeletal structure and central nervous system (CNS). Human memory T (Tm) cells migrate throughout the body's tissues and can persist for years, making them an attractive approach for cellular-based, systemic enzyme replacement therapy. Here, we tested genetically engineered, IDUA-expressing Tm cells as a cellular therapy in an immunodeficient mouse model of MPS I. Our results demonstrate that a single dose of engineered Tm cells leads to detectable IDUA enzyme levels in the blood for up to 22 weeks and reduced urinary GAG excretion. Furthermore, engineered Tm cells take up residence in nearly all tested tissues, producing IDUA and leading to metabolic correction of GAG levels in the heart, lung, liver, spleen, kidney, bone marrow, and the CNS, although only minimal improved cognition was observed. Our study indicates that genetically engineered Tm cells hold great promise as a platform for cellular-based enzyme replacement therapy for the treatment of mucopolysaccharidosis type I and potentially many other enzymopathies and protein deficiencies., Competing Interests: Declaration of interests A patent has been filed by the University of Minnesota covering technologies described in this manuscript., (Published by Elsevier Inc.)

Chimeric antigen receptor T cell (CAR-T) therapy has emerged as a revolutionary approach in the treatment of malignancies. Despite its remarkable successes, this field continues to grapple with challenges such as scalability, safety concerns, limited therapeutic effect, in vivo persistence, and the need for precise control over CAR expression. In the post-pandemic era of COVID-19 vaccine immunization, the application of messenger RNA (mRNA) encapsulated within lipid nanoparticles (LNPs) has recently garnered significant attention as a potential solution to address these challenges. This review delves into the dynamic landscape of mRNA-LNP technology and its potential implications for CAR-engineered immune cell-based immunotherapy., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.)

Under compassionate use, chimeric antigen receptor (CAR) T cells have elicited durable remissions in patients with refractory idiopathic inflammatory myopathies (IIMs). Here, we report on the safety, efficacy, and correlative data of the first subject with the immune-mediated necrotizing myopathy (IMNM) subtype of IIM who received a fully human, 4-1BBz anti-CD19-CAR T cell therapy (CABA-201) in the RESET-Myositis phase I/II trial (NCT06154252). CABA-201 was well-tolerated following infusion. Notably, no evidence of cytokine release syndrome or immune effector cell-associated neurotoxicity syndrome was observed. Creatine kinase levels decreased, and muscular strength improved post-infusion. Peripheral B cells were depleted rapidly following infusion, and the subject achieved peripheral B cell aplasia by day 15 post-infusion. Peripheral B cells returned at 2 months post-infusion and were almost entirely transitional. Autoantibodies to SRP-9, SRP-72, SRP-54, and Ro-52, decreased relative to baseline, whereas antibodies associated with pathogens and vaccinations remained stable. The infusion product consisted of predominantly CD4 + effector memory T cells and exhibited in vitro cytolytic activity. Post-infusion, CABA-201 expansion peaked at day 15 and was preceded by a serum IFN-γ peak on day 8 with peaks in serum IL-12p40 and IP-10 on day 15. These data detail the safety, efficacy, and pharmacodynamics of CABA-201 in the first IMNM subject., Competing Interests: Declaration of interests J.V., D.N., J.S., M.W., Z.V., A.E., J.W., J.C., Q.L., T.F., C.S., F.H.-N., D.T., C.M., C.L., D.C., and S.B. are employees of Cabaletta Bio., (Copyright © 2024 Cabaletta Bio. Published by Elsevier Inc. All rights reserved.)

Adoptive cell therapy using chimeric antigen receptor (CAR) T cells has proven to be lifesaving for many cancer patients. However, its therapeutic efficacy has been limited in solid tumors. One key factor for this is cancer-associated fibroblasts (CAFs) that modulate the tumor microenvironment (TME) to inhibit T cell infiltration and induce "T cell dysfunction." Additionally, the sparsity of tumor-specific antigens (TSA) and expression of CAR-directed tumor-associated antigens (TAA) on normal tissues often results in "on-target off-tumor" cytotoxicity, raising safety concerns. Using TALEN-mediated gene editing, we present here an innovative CAR T cell engineering strategy to overcome these challenges. Our allogeneic "Smart CAR T cells" are designed to express a constitutive CAR, targeting FAP + CAFs in solid tumors. Additionally, a second CAR targeting a TAA such as mesothelin is specifically integrated at a TCR signaling-inducible locus like PDCD1. FAPCAR-mediated CAF targeting induces expression of the mesothelin CAR, establishing an IF/THEN-gated circuit sensitive to dual antigen sensing. Using this approach, we observe enhanced anti-tumor cytotoxicity, while limiting "on-target off-tumor" toxicity. Our study thus demonstrates TALEN-mediated gene editing capabilities for design of allogeneic IF/THEN-gated dual CAR T cells that efficiently target immunotherapy-recalcitrant solid tumors while mitigating potential safety risks, encouraging clinical development of this strategy., Competing Interests: Declaration of interests S.Dharani, H.C., A.J., J.V., P.D., L.P., and S.Das are current employees and equity holders at Cellectis. TALEN is a Cellectis patented technology. J.P.F. is a former Cellectis employee and is a current employee of Bristol Myers Squibb., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Immune cell metabolism governs the outcome of immune responses and contributes to the development of autoimmunity by controlling lymphocyte pathogenic potential. In this study, we evaluated the metabolic profile of myelin-specific murine encephalitogenic T cells, to identify novel therapeutic targets for autoimmune neuroinflammation., Methods: We performed metabolomics analysis on actively-proliferating encephalitogenic T cells to study their overall metabolic profile in comparison to resting T cells. Metabolomics, phosphoproteomics, in vitro functional assays, and in vivo studies in experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS), were then implemented to evaluate the effect of metabolic targeting on autoreactive T cell pathogenicity. Finally, we confirmed the translational potential of our targeting approach in human pro-inflammatory T helper cell subsets and in T cells from MS patients., Results: We found that autoreactive encephalitogenic T cells display an altered coenzyme A (CoA) synthesis pathway, compared to resting T cells. CoA fueling with the CoA precursor pantethine (PTTH) affected essential immune-related processes of myelin-specific T cells, such as cell proliferation, cytokine production, and cell adhesion, both in vitro and in vivo. Accordingly, pre-clinical treatment with PTTH before disease onset inhibited the development of EAE by limiting T cell pro-inflammatory potential in vivo. Importantly, PTTH also significantly ameliorated the disease course when administered after disease onset in a therapeutic setting. Finally, PTTH reduced pro-inflammatory cytokine production by human T helper 1 (Th1) and Th17 cells and by T cells from MS patients, confirming its translational potential., Conclusion: Our data demonstrate that CoA fueling with PTTH in pro-inflammatory and autoreactive T cells may represent a novel therapeutic approach for the treatment of autoimmune neuroinflammation., (© 2024. The Author(s).)

Chimeric antigen receptor (CAR)-T cell therapy demonstrates substantial efficacy in various hematological malignancies. However, its application in solid tumors is still limited. Clinical studies report suboptimal outcomes such as reduced cytotoxicity of CAR-T cells and tumor evasion, underscoring the need to address the challenges of sliding cytotoxicity in CAR-T cells. Despite improvements from fourth and next-generation CAR-T cells, new challenges include systemic toxicity from continuously secreted proteins, low productivity, and elevated costs. Recent research targets genetic modifications to boost killing potential, metabolic interventions to hinder tumor progression, and diverse combination strategies to enhance CAR-T cell therapy. Efforts to reduce the duration and cost of CAR-T cell therapy include developing allogenic and in-vivo approaches, promising significant future advancements. Concurrently, innovative technologies and platforms enhance the potential of CAR-T cell therapy to overcome limitations in treating solid tumors. This review explores strategies to optimize CAR-T cell therapies for solid tumors, focusing on enhancing cytotoxicity and overcoming application restrictions. We summarize recent advances in T cell subset selection, CAR-T structural modifications, infiltration enhancement, genetic and metabolic interventions, production optimization, and the integration of novel technologies, presenting therapeutic approaches that could improve CAR-T cell therapy's efficacy and applicability in solid tumors., (© 2024. The Author(s).)

Autoimmunity underlies many painful disorders, such as enthesopathies, which localize to the enthesis. From infiltration of the synovium and axial skeleton by B cells, to disturbances in the ratio of M1/M2 enthesis macrophages, to CD8 + T cell mediated inflammation, autoimmune dysregulation is becoming increasingly well characterized in enthesopathies. Tissue resident B cells, macrophages, neutrophils, and T cells have also been localized in healthy human entheses. However, the potential developmental origins, presence, and role of immune cells (ICs) in enthesis development is not known. Here, we use single-cell RNA-sequencing analysis to describe IC subtypes present in the enthesis before, during, and after mineralization, and to infer regulatory interactions between ICs and mesenchymal cells (MCs). We report the presence of nine phenotypically distinct IC subtypes, including B cells, macrophages, neutrophils, and T cells. We find that specific IC subtypes may promote MC-proliferation and differentiation, and that MCs may regulate IC phenotype and autoimmunity. Our findings suggest that bidirectional regulatory interactions between ICs and MCs may be important to enthesis mineralization, and suggest that progenitor MCs have a unique ability to limit autoimmunity during development., (© 2024. The Author(s).)

Although tumor immunotherapy has achieved significant success in recent years, tackling solid tumors remains a formidable challenge. Here, we present an approach that utilizes outer membrane vesicles (OMVs) from bacterial cells as scaffolds to engage immune cells in solid tumor immunotherapy. Two types of nanobodies targeting CD47/SIRPα and PD-1/PD-L1 pathways were simultaneously conjugated onto the surfaces of the OMVs in divalent and trivalent forms using orthogonal SpyCatcher-SpyTag and SnoopCatcher-SnoopTag chemistry. This resulted in the generation of an OMV-based nanosized immune cell engager (OMV-NICE) with dual-targeting abilities. In vitro assays confirmed the retention of the function of the two nanobodies on the OMV-NICE, as evidenced by the synergistically enhanced macrophage phagocytosis and T cell cytotoxicity against tumor cells. In vivo studies using a B16-F10 melanoma mouse model also revealed the superior antitumor activity of OMV-NICE compared to those of unconjugated nanobodies and OMVs alone. Subsequent mechanistic investigations further supported the enhanced recruitment of macrophages and T cells to the tumor region by OMV-NICE. Overall, this work expands the current repertoire of immune cell engagers, and the developed OMV-NICE platform holds great promise for broad applications, particularly in solid tumor immunotherapy.