T-cell exhaustion, co-stimulation and clinical outcome in autoimmunity and infection

T-cell exhaustion in multiple myeloma

INTRODUCTION

Chimeric Antigen Receptor (CAR) T-cells and Bispecific Antibodies (BsAb) are the leading platforms for redirecting the immune system against cells expressing the specific antigen, revolutionizing the treatment of hematological malignancies, including multiple myeloma (MM). In MM, drug-resistant relapses are the main therapy-limiting factor and the leading cause of why the disease is still considered incurable. T-cell-engaging therapies hold promise in improving the treatment of MM. However, the effectiveness of these treatments may be hindered by T-cell fitness. T-cell exhaustion is a condition of a gradual decline in effector function, reduced cytokine secretion, and increased expression of inhibitory receptors due to chronic antigen stimulation.

AREAS COVERED

This review examines findings about T-cell exhaustion in MM in the context of T-cell redirecting BsAbs and CAR-T treatment.

EXPERT OPINION

The fitness of T-cells has become an important factor in the development of T-cell redirecting therapies. The way T-cell exhaustion relates to these therapies could affect the further development of CAR and BsAbs technologies, as well as the strategies used for clinical use. Therefore, this review aims to explore the current understanding of T-cell exhaustion in MM and its relationship to these therapies.

Sequential immunotherapy: towards cures for autoimmunity

Despite major progress in the treatment of autoimmune diseases in the past two decades, most therapies do not cure disease and can be associated with increased risk of infection through broad suppression of the immune system. However, advances in understanding the causes of autoimmune disease and clinical data from novel therapeutic modalities such as chimeric antigen receptor T cell therapies provide evidence that it may be possible to re-establish immune homeostasis and, potentially, prolong remission or even cure autoimmune diseases. Here, we propose a 'sequential immunotherapy' framework for immune system modulation to help achieve this ambitious goal. This framework encompasses three steps: controlling inflammation; resetting the immune system through elimination of pathogenic immune memory cells; and promoting and maintaining immune homeostasis via immune regulatory agents and tissue repair. We discuss existing drugs and those in development for each of the three steps. We also highlight the importance of causal human biology in identifying and prioritizing novel immunotherapeutic strategies as well as informing their application in specific patient subsets, enabling precision medicine approaches that have the potential to transform clinical care.

Integrating Omics into Functional Biomarkers of Type 1 Diabetes

Biomarkers are critical to the staging and diagnosis of type 1 diabetes (T1D). Functional biomarkers offer insights into T1D immunopathogenesis and are often revealed using "omics" approaches that integrate multiple measures to identify involved pathways and functions. Application of the omics biomarker discovery may enable personalized medicine approaches to circumvent the more recently appreciated heterogeneity of T1D progression and treatment. Use of omics to define functional biomarkers is still in its early years, yet findings to date emphasize the role of cytokine signaling and adaptive immunity in biomarkers of progression and response to therapy. Here, we share examples of the use of omics to define functional biomarkers focusing on two signatures, T-cell exhaustion and T-cell help, which have been associated with outcomes in both the natural history and treatment contexts.

Interconnected lineage trajectories link conventional and natural killer (NK)-like exhausted CD8+ T cells beneficial in type 1 diabetes

Distinct Natural Killer (NK)-like CD57+ and PD-1+ CD8+ exhausted-like T cell populations (Tex) have both been linked to beneficial immunotherapy response in autoimmune type 1 diabetes (T1D) patients. The origins and relationships between these cell types are poorly understood. Here we show that while PD-1+ and CD57+ Tex populations are epigenetically similar, CD57+ Tex cells display unique increased chromatin accessibility of inhibitory Killer Cell Immunoglobulin-like Receptor (iKIR) and other NK cell genes. PD-1+ and CD57+ Tex also show reciprocal expression of Inhibitory Receptors (IRs) and iKIRs accompanied by chromatin accessibility of Tcf1 and Tbet transcription factor target sites, respectively. CD57+ Tex show unappreciated gene expression heterogeneity and share clonal relationships with PD-1+ Tex, with these cells differentiating along four interconnected lineage trajectories: Tex-PD-1+, Tex-CD57+, Tex-Branching, and Tex-Fluid. Our findings demonstrate new relationships between Tex-like populations in human autoimmune disease and suggest that modulating common precursor populations may enhance response to autoimmune disease treatment.

Disrupting B and T-cell collaboration in autoimmune disease: T-cell engagers versus CAR T-cell therapy?

B and T cells collaborate to drive autoimmune disease (AID). Historically, B- and T-cell (B-T cell) co-interaction was targeted through different pathways such as alemtuzumab, abatacept, and dapirolizumab with variable impact on B-cell depletion (BCD), whereas the majority of patients with AID including rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, and organ transplantation benefit from targeted BCD with anti-CD20 monoclonal antibodies such as rituximab, ocrelizumab, or ofatumumab. Refractory AID is a significant problem for patients with incomplete BCD with a greater frequency of IgD-CD27+ switched memory B cells, CD19+CD20- B cells, and plasma cells that are not directly targeted by anti-CD20 antibodies, whereas most lymphoid tissue plasma cells express CD19. Furthermore, B-T-cell collaboration is predominant in lymphoid tissues and at sites of inflammation such as the joint and kidney, where BCD may be inefficient, due to limited access to key effector cells. In the treatment of cancer, chimeric antigen receptor (CAR) T-cell therapy and T-cell engagers (TCE) that recruit T cells to induce B-cell cytotoxicity have delivered promising results for anti-CD19 CAR T-cell therapies, the CD19 TCE blinatumomab and CD20 TCE such as mosunetuzumab, glofitamab, or epcoritamab. Limited evidence suggests that anti-CD19 CAR T-cell therapy may be effective in managing refractory AID whereas we await evaluation of TCE for use in non-oncological indications. Therefore, here, we discuss the potential mechanistic advantages of novel therapies that rely on T cells as effector cells to disrupt B-T-cell collaboration toward overcoming rituximab-resistant AID.

Assessing Predictive Value of SARS-CoV-2 Epitope-Specific CD8+ T-Cell Response in Patients with Severe Symptoms

Specific T cell responses against SARS-CoV-2 provided an overview of acquired immunity during the pandemic. Anti-SARS-CoV-2 immunity determines the severity of acute illness, but also might be related to the possible persistence of symptoms (long COVID). We retrospectively analyzed ex vivo longitudinal CD8+ T cell responses in 26 COVID-19 patients diagnosed with severe disease, initially (1 month) and long-term (10 months), and in a cohort of 32 vaccinated healthcare workers without previous SARS-CoV-2 infection. We used peptide-human leukocyte antigen (pHLA) dextramers recognizing 26 SARS-CoV-2-derived epitopes of viral and other non-structural proteins. Most patients responded to at least one of the peptides studied, mainly derived from non-structural ORF1ab proteins. After 10 months follow-up, CD8+ T cell responses were maintained at long term and reaction against certain epitopes (A*01:01-ORF1ab1637) was still detected and functional, showing a memory-like phenotype (CD127+ PD-1+). The total number of SARS-CoV-2-specific CD8+ T cells was significantly associated with protection against long COVID in these patients. Compared with vaccination, infected patients showed a less effective immune response to spike protein-derived peptides restricted by HLA. So, the A*01:01-S865 and A*24:02-S1208 dextramers were only recognized in vaccinated individuals. We conclude that initial SARS-CoV-2-specific CD8+ T cell response could be used as a marker to understand the evolution of severe disease and post-acute sequelae after SARS-CoV-2 infection.

Factors associated with immune responses to SARS-CoV-2 vaccination in individuals with autoimmune diseases

Patients with autoimmune diseases are at higher risk for severe infection due to their underlying disease and immunosuppressive treatments. In this real-world observational study of 463 patients with autoimmune diseases, we examined risk factors for poor B and T cell responses to SARS-CoV-2 vaccination. We show a high frequency of inadequate anti-spike IgG responses to vaccination and boosting in the autoimmune population but minimal suppression of T cell responses. Low IgG responses in B cell-depleted patients with multiple sclerosis (MS) were associated with higher CD8 T cell responses. By contrast, patients taking mycophenolate mofetil (MMF) exhibited concordant suppression of B and T cell responses. Treatments with highest risk for low anti-spike IgG response included B cell depletion within the last year, fingolimod, and combination treatment with MMF and belimumab. Our data show that the mRNA-1273 (Moderna) vaccine is the most effective vaccine in the autoimmune population. There was minimal induction of either disease flares or autoantibodies by vaccination and no significant effect of preexisting anti-type I IFN antibodies on either vaccine response or breakthrough infections. The low frequency of breakthrough infections and lack of SARS-CoV-2-related deaths suggest that T cell immunity contributes to protection in autoimmune disease.

The immunology of type 1 diabetes

Following the seminal discovery of insulin a century ago, treatment of individuals with type 1 diabetes (T1D) has been largely restricted to efforts to monitor and treat metabolic glucose dysregulation. The recent regulatory approval of the first immunotherapy that targets T cells as a means to delay the autoimmune destruction of pancreatic β-cells highlights the critical role of the immune system in disease pathogenesis and tends to pave the way for other immune-targeted interventions for T1D. Improving the efficacy of such interventions across the natural history of the disease will probably require a more detailed understanding of the immunobiology of T1D, as well as technologies to monitor residual β-cell mass and function. Here we provide an overview of the immune mechanisms that underpin the pathogenesis of T1D, with a particular emphasis on T cells.

Targeting pro-inflammatory T cells as a novel therapeutic approach to potentially resolve atherosclerosis in humans

Atherosclerosis (AS), a leading cause of cardio-cerebrovascular disease worldwide, is driven by the accumulation of lipid contents and chronic inflammation. Traditional strategies primarily focus on lipid reduction to control AS progression, leaving residual inflammatory risks for major adverse cardiovascular events (MACEs). While anti-inflammatory therapies targeting innate immunity have reduced MACEs, many patients continue to face significant risks. Another key component in AS progression is adaptive immunity, but its potential role in preventing AS remains unclear. To investigate this, we conducted a retrospective cohort study on tumor patients with AS plaques. We found that anti-programmed cell death protein 1 (PD-1) monoclonal antibody (mAb) significantly reduces AS plaque size. With multi-omics single-cell analyses, we comprehensively characterized AS plaque-specific PD-1+ T cells, which are activated and pro-inflammatory. We demonstrated that anti-PD-1 mAb, when captured by myeloid-expressed Fc gamma receptors (FcγRs), interacts with PD-1 expressed on T cells. This interaction turns the anti-PD-1 mAb into a substitute PD-1 ligand, suppressing T-cell functions in the PD-1 ligands-deficient context of AS plaques. Further, we conducted a prospective cohort study on tumor patients treated with anti-PD-1 mAb with or without Fc-binding capability. Our analysis shows that anti-PD-1 mAb with Fc-binding capability effectively reduces AS plaque size, while anti-PD-1 mAb without Fc-binding capability does not. Our work suggests that T cell-targeting immunotherapy can be an effective strategy to resolve AS in humans.

CD8 is down(regulated) for tolerance

Activated CD8+ T cells directly kill target cells. Therefore, the regulation of their function is central to avoiding immunopathology. Mechanisms that curb effector functions in CD4+ and CD8+ T cells are mostly shared, yet important differences occur. Here, we focus on the control of CD8+ T cell activity and discuss the importance of a poorly understood aspect of tolerance that directly impairs engagement of target cells: the downregulation of CD8. We contextualize this process and propose that it represents a key element during CD8+ T cell modulation.

Expanding the role of CAR T-cell therapy: From B-cell hematological malignancies to autoimmune rheumatic diseases

Chimeric antigen receptor (CAR) T-cell therapy is a form of immunotherapy where the lymphocytes, mostly T-cells, are redirected to specifically recognize and eliminate a target antigen by coupling them with CARs. The binding of CAR and target cell surface antigens leads to vigorous T cell activation and robust anti-tumor immune responses. Areas of implication of CAR T-cell therapies include mainly hematological malignancies (i.e., advanced B-cell cancers); however, recent studies have proven the unprecedented success of the new immunotherapy also in autoimmune rheumatic diseases. We aim to review the recent advances in CAR T-cell therapies in rheumatology but also to address the limitations of their use in the real clinical practice based on the data on their efficacy and safety.

A biomarker-stratified comparison of top-down versus accelerated step-up treatment strategies for patients with newly diagnosed Crohn's disease (PROFILE): a multicentre, open-label randomised controlled trial

BACKGROUND

Management strategies and clinical outcomes vary substantially in patients newly diagnosed with Crohn's disease. We evaluated the use of a putative prognostic biomarker to guide therapy by assessing outcomes in patients randomised to either top-down (ie, early combined immunosuppression with infliximab and immunomodulator) or accelerated step-up (conventional) treatment strategies.

METHODS

PROFILE (PRedicting Outcomes For Crohn's disease using a moLecular biomarker) was a multicentre, open-label, biomarker-stratified, randomised controlled trial that enrolled adults with newly diagnosed active Crohn's disease (Harvey-Bradshaw Index ≥7, either elevated C-reactive protein or faecal calprotectin or both, and endoscopic evidence of active inflammation). Potential participants had blood drawn to be tested for a prognostic biomarker derived from T-cell transcriptional signatures (PredictSURE-IBD assay). Following testing, patients were randomly assigned, via a secure online platform, to top-down or accelerated step-up treatment stratified by biomarker subgroup (IBDhi or IBDlo), endoscopic inflammation (mild, moderate, or severe), and extent (colonic or other). Blinding to biomarker status was maintained throughout the trial. The primary endpoint was sustained steroid-free and surgery-free remission to week 48. Remission was defined by a composite of symptoms and inflammatory markers at all visits. Flare required active symptoms (HBI ≥5) plus raised inflammatory markers (CRP >upper limit of normal or faecal calprotectin ≥200 μg/g, or both), while remission was the converse-ie, quiescent symptoms (HBI <5) or resolved inflammatory markers (both CRP ≤ the upper limit of normal and calprotectin <200 μg/g) or both. Analyses were done in the full analysis (intention-to-treat) population. The trial has completed and is registered (ISRCTN11808228).

FINDINGS

Between Dec 29, 2017, and Jan 5, 2022, 386 patients (mean age 33·6 years [SD 13·2]; 179 [46%] female, 207 [54%] male) were randomised: 193 to the top-down group and 193 to the accelerated step-up group. Median time from diagnosis to trial enrolment was 12 days (range 0-191). Primary outcome data were available for 379 participants (189 in the top-down group; 190 in the accelerated step-up group). There was no biomarker-treatment interaction effect (absolute difference 1 percentage points, 95% CI -15 to 15; p=0·944). Sustained steroid-free and surgery-free remission was significantly more frequent in the top-down group than in the accelerated step-up group (149 [79%] of 189 patients vs 29 [15%] of 190 patients, absolute difference 64 percentage points, 95% CI 57 to 72; p<0·0001). There were fewer adverse events (including disease flares) and serious adverse events in the top-down group than in the accelerated step-up group (adverse events: 168 vs 315; serious adverse events: 15 vs 42), with fewer complications requiring abdominal surgery (one vs ten) and no difference in serious infections (three vs eight).

INTERPRETATION

Top-down treatment with combination infliximab plus immunomodulator achieved substantially better outcomes at 1 year than accelerated step-up treatment. The biomarker did not show clinical utility. Top-down treatment should be considered standard of care for patients with newly diagnosed active Crohn's disease.

FUNDING

Wellcome and PredictImmune Ltd.

Assessment of biological organ age using molecular pathology in pre-transplant kidney biopsies

Organ shortage is a major challenge in kidney transplantation but the use of older donors, often with co-morbidities, is hampered by inconsistent outcomes. Methods of accurately stratifying marginal donor organs by clinical and histological assessment are lacking. To better understand organ variability, we profiled the transcriptomes of 271 kidneys from deceased donors at retrieval. Following correction for biopsy composition, we assessed molecular pathways that associated with delayed, and sub-optimal one-year graft function. Analysis of cortical biopsies identified an adaptive immune gene-rich module that significantly associated with increasing age and worse outcomes. Cellular deconvolution using human kidney reference single cell transcriptomes confirmed an increase in kidney-specific B and T cell signatures, as well as kidney macrophage, myofibroblast and fibroblast gene sets in this module. Surprisingly, innate immune pathway and neutrophil gene signature enrichment was associated with better outcomes. Thus, our work uncovers cellular molecular features of pathological organ ageing, identifiable at kidney retrieval, with translational potential.

Signaling by Type I Interferons in Immune Cells: Disease Consequences

This review addresses interferon (IFN) signaling in immune cells and the tumor microenvironment (TME) and examines how this affects cancer progression. The data reveal that IFNs exert dual roles in cancers, dependent on the TME, exhibiting both anti-tumor activity and promoting cancer progression. We discuss the abnormal IFN signaling induced by cancerous cells that alters immune responses to permit their survival and proliferation.

T cell expressions of aberrant gene signatures and Co-inhibitory receptors (Co-IRs) as predictors of renal damage and lupus disease activity

BACKGROUND

Systemic lupus erythematosus (SLE) is distinguished by an extensive range of clinical heterogeneity with unpredictable disease flares and organ damage. This research investigates the potential of aberrant signatures on T cell genes, soluble Co-IRs/ligands, and Co-IRs expression on T cells as biomarkers for lupus disease parameters.

METHODS

Comparative transcriptome profiling analysis of non-renal and end-stage renal disease (ESRD) phenotypes of SLE was performed using CD4 + and CD8 + cDNA microarrays of sorted T cells. Comparing the expression of Co-IRs on T cells and serum soluble mediators among healthy and SLE phenotypes.

RESULTS

SLE patients with ESRD were downregulated CD38, PLEK, interferon-γ, CX3CR1, FGFBP2, and SLCO4C1 transcripts on CD4 + and CD8 + T cells simultaneously and NKG7, FCRL6, GZMB/H, FcγRIII, ITGAM, Fas ligand, TBX21, LYN, granulysin, CCL4L1, CMKLR1, HLA-DRβ, KIR2DL3, and KLRD1 in CD8 T cells. Pathway enrichment and PPI network analyses revealed that the overwhelming majority of Differentially Expressed Genes (DEGs) have been affiliated with novel cytotoxic, antigen presentation, and chemokine-cell migration signature pathways. CD8 + GZMK + T cells that are varied in nature, including CD161 + Mucosal-associated invariant T (MAIT) cells and CD161- aged-associated T (Taa) cells and CD161-GZMK + GZMB + T cells might account for a higher level of GZMK in CD8 + T cells associated with ESRD. SLE patients have higher TIGIT + , PD1 + , and lower CD127 + cell percentages on CD4 + T cells, higher TIM3 + , TIGIT + , HLA-DR + cell frequency, and lower MFI expression of CD127, CD160 in CD8 T cells. Co-IRs expression in T cells was correlated with soluble PD-1, PDL-2, and TIM3 levels, as well as SLE disease activity, clinical phenotypes, and immune-therapy responses.

CONCLUSION

The signature of dysfunctional pathways defines a distinct immunity pattern in LN ESRD patients. Expression levels of Co-IRs in peripheral blood T cells and serum levels of soluble PD1/PDL-2/TIM3 can serve as biomarkers for evaluating clinical parameters and therapeutic responses.

MLXIPL associated with tumor-infiltrating CD8+ T cells is involved in poor prostate cancer prognosis

Introduction

Within tumor microenvironment, the presence of preexisting antitumor CD8+ T Q7 cells have been shown to be associated with a favorable prognosis in most solid cancers. However, in the case of prostate cancer (PCa), they have been linked to a negative impact on prognosis.

Methods

To gain a deeper understanding of the contribution of infiltrating CD8+ T cells to poor prognosis in PCa, the infiltration levelsof CD8+ T cells were estimated using the TCGA PRAD (The Cancer Genome Atlas Prostate Adenocarcinoma dataset) and MSKCC (Memorial Sloan Kettering Cancer Center) cohorts.

Results

Bioinformatic analyses revealed that CD8+ T cells likely influence PCa prognosis through increased expression of immune checkpoint molecules and enhanced recruitment of regulatory T cells. The MLXIPL was identified as the gene expressed in response to CD8+ T cell infiltration and was found to be associated with PCa prognosis. The prognostic role of MLXIPL was examined in two cohorts: TCGA PRAD (p = 2.3E-02) and the MSKCC cohort (p = 1.6E-02). Subsequently, MLXIPL was confirmed to be associated with an unfavorable prognosis in PCa, as evidenced by an independent cohort study (hazard ratio [HR] = 2.57, 95% CI: 1.42- 4.65, p = 1.76E-03).

Discussion

In summary, the findings suggested that MLXIPL related to tumor-infiltrating CD8+ T cells facilitated a poor prognosis in PCa.

Prognostic effect of TCF1+ CD8+ T cell and TOX+ CD8+ T cell infiltration in lung adenocarcinoma

Recent studies have highlighted the pivotal roles of T cell transcription factors TCF-1 and TOX in modulating the immune response in cancer, with TCF-1 maintaining CD8+ T cell stemness and TOX promoting T cell exhaustion. The prognostic significance of these factors in lung adenocarcinoma (LUAD) remains a critical area of investigation. The retrospective study included 191 patients with LUAD who underwent surgery, of whom 83% were in stages II and III. These patients were divided into exploratory (n = 135) and validation (n = 56) groups based on the time of diagnosis. Multiplex fluorescence immunohistochemistry was used to examine the infiltration levels of CD8+ T cells, TCF1+ CD8+ T cells, and TOX+ CD8+ T cells. The percentage of CD8+ T cells in tumor was markedly lower than that in stroma (p < 0.05). In tumor-draining lymph nodes (TDLNs) invaded by tumor, the proportion of stem-like TCF1+ CD8+ T cells was significantly decreased (p < 0.01). Importantly, higher infiltration levels of CD8+ T cells and TCF1+ CD8+ T cells were associated with improved disease-free survival (DFS) (p = 0.009 and p = 0.006, respectively) and overall survival (OS) (p = 0.018 and p = 0.010, respectively). This study underscores the potential of TCF1+ CD8+ T cells as prognostic biomarkers in LUAD, providing insights into the tumor immune microenvironment and guiding future therapeutic strategies.

Abatacept increases T cell exhaustion in early RA individuals who carry HLA risk alleles

Exhausted CD8 T cells (TEX) are associated with worse outcome in cancer yet better outcome in autoimmunity. Building on our past findings of increased TIGIT+KLRG1+ TEX with teplizumab therapy in type 1 diabetes (T1D), in the absence of treatment we found that the frequency of TIGIT+KLRG1+ TEX is stable within an individual but differs across individuals in both T1D and healthy control (HC) cohorts. This TIGIT+KLRG1+ CD8 TEX population shares an exhaustion-associated EOMES gene signature in HC, T1D, rheumatoid arthritis (RA), and cancer subjects, expresses multiple inhibitory receptors, and is hyporesponsive in vitro, together suggesting co-expression of TIGIT and KLRG1 may broadly define human peripheral exhausted cells. In HC and RA subjects, lower levels of EOMES transcriptional modules and frequency of TIGIT+KLRG1+ TEX were associated with RA HLA risk alleles (DR0401, 0404, 0405, 0408, 1001) even when considering disease status and cytomegalovirus (CMV) seropositivity. Moreover, the frequency of TIGIT+KLRG1+ TEX was significantly increased in RA HLA risk but not non-risk subjects treated with abatacept (CTLA4Ig). The DR4 association and selective modulation with abatacept suggests that therapeutic modulation of TEX may be more effective in DR4 subjects and TEX may be indirectly influenced by cellular interactions that are blocked by abatacept.

Sex differences in CD8+ T cell responses during adaptive immunity

Biological sex is an important variable that influences the immune system's susceptibility to infectious and non-infectious diseases and their outcomes. Sex dimorphic features in innate and adaptive immune cells and their activities may help to explain sex differences in immune responses. T lymphocytes in the adaptive immune system are essential to providing protection against infectious and chronic inflammatory diseases. In this review, T cell responses are discussed with focus on the current knowledge of biological sex differences in CD8+ T cell mediated adaptive immune responses in infectious and chronic inflammatory diseases. Future directions aimed at investigating the molecular and cellular mechanisms underlying sex differences in diverse T cell responses will continue to underscore the significance of understanding sex differences in protective immunity at the cellular level, to induce appropriate T cell-based immune responses in infection, autoimmunity, and cancer. This article is categorized under: Immune System Diseases > Molecular and Cellular Physiology Infectious Diseases > Molecular and Cellular Physiology.

Prognosis of immune checkpoint inhibitor-induced myasthenia gravis: a single center experience and systematic review

Background

Immune checkpoint inhibitors (ICI)-induced myasthenia gravis (MG) is an uncommon but potentially fatal neurotoxicity. We aim to help physicians familiarize themselves with the clinical characteristics of ICI-induced MG, facilitating early diagnosis and prompt intervention.

Methods

We searched the Chinese People's Liberation Army General Hospital medical record system from January 2017 to August 2023 for patients diagnosed with ICI-induced MG. We systematically reviewed the literature until August 2023 to identify all similar patients. We collected clinical information on these patients.

Results

110 patients were identified, 9 from our institution and 101 from case reports. In our institution, Median age was 66 years (range: 49-79 years). 6 were males. The most common was lung cancer (n = 4). All patients had no previous history of MG and received PD-1 or PD-L1 inhibitors. The median time from ICI initiation to first MG symptoms was 4 weeks (range: 2-15 weeks). ICIs were discontinued in all patients. Most patients initially received high-dose corticosteroids, and their symptoms improved. Some patients are discharged with corticosteroids maintenance therapy. In addition, 55 patients (50%) with concomitant myositis and/or myocarditis and MG-induced mortality were more common in the myositis and/or myocarditis group (10.9% vs. 34.5%, p = 0.016). Overlap of myositis with MG (OR = 3.148, p = 0.009) and anti-AChR antibody positivity (OR = 3.364, p = 0.005) were both significantly associated with poor outcomes.

Conclusion

Our study reveals the prognosis of ICI-induced MG and suggests that myositis and/or myocarditis are severe comorbidities of ICI-induced MG, emphasizing the importance of early diagnosis and clinical intervention.

Sustained post-rituximab B-cell depletion is common in ANCA-associated vasculitis and is affected by sex and renal function

OBJECTIVE

Despite the increasing use of rituximab in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), it remains unclear what the optimal dosing is, especially for maintenance of remission. A deeper understanding of post-rituximab B-cell repopulation patterns may aid better-tailored treatment.

METHODS

This is a monocentric, retrospective study including ANCA-positive AAV patients receiving a single course of rituximab induction. CD19+ B cells were longitudinally monitored with flow cytometry. B-cell repopulation was defined as CD19+ >10 cells/μL.

RESULTS

Seventy-one patients were included, the majority with microscopic polyangiitis (75%), myeloperoxidase-ANCA positivity (75%) and with renal involvement (79%). During a median follow-up of 54 months since the first rituximab infusion, 44 patients (62%) repopulated B cells, with a median time to repopulation of 39 months (range 7-102). Patients experiencing B-cell depletion lasting longer than the overall median time to repopulation (39 months) exhibited a lower risk of flare and higher risk of serious infection. In multivariate Cox regression, higher estimated glomerular filtration rate (eGFR) [hazard ratio (HR) 1.84, 95% confidence interval (CI) 1.13-2.98 per 30 mL/min/1.73 m2 eGFR] and female sex (HR 2.70, 95% CI 1.37-5.31) were independent predictors of increased rate of B-cell repopulation.

CONCLUSION

A subset of AAV patients develop sustained post-rituximab B-cell depletion, which associates with reduced risk of flare and increased risk of serious infection in the long term. Preserved renal function and female sex are associated with faster B-cell repopulation. These observations further highlight the need to personalize immunosuppression to improve clinical outcomes.

Diabetes mellitus and idiopathic pulmonary fibrosis: a Mendelian randomization study

BACKGROUND

The question as to whether or not diabetes mellitus increases the risk of idiopathic pulmonary fibrosis (IPF) remains controversial. This study aimed to investigate the causal association between type 1 diabetes (T1D), type 2 diabetes (T2D), and IPF using Mendelian randomization (MR) analysis.

METHODS

We used two-sample univariate and multivariate MR (MVMR) analyses to investigate the causal relationship between T1D or T2D and IPF. We obtained genome-wide association study (GWAS) data for T1D and T2D from the European Bioinformatics Institute, comprising 29,652 T1D samples and 101,101 T1D single nucleotide polymorphisms (SNPs) and 655,666 T2D samples and 5,030,727 T2D SNPs. We also used IPF GWAS data from the FinnGen Biobank comprising 198,014 IPF samples and 16,380,413 IPF SNPs. All cases and controls in these datasets were derived exclusively from European populations. In the univariate MR analysis, we employed inverse variance-weighted (IVW), weighted median (WM), and MR-Egger regression methods. For the MVMR analysis, we used the multivariate IVW method primarily, and supplemented it with multivariate MR-Egger and multivariate MR- least absolute shrinkage and selection operator methods. Heterogeneity tests were conducted using the MR-IVW and MR-Egger regression methods, whereas pleiotropic effects were assessed using the MR-Egger intercept. The results of MR and sensitivity analyses were visualized using forest, scatter, leave-one-out, and funnel plots.

RESULTS

Univariate MR revealed a significant causal relationship between T1D and IPF (OR = 1.118, 95% CI = 1.021-1.225, P = 0.016); however, no significant causal relationship was found between T2D and IPF (OR = 0.911, 95% CI = 0.796-1.043, P = 0.178). MVMR analysis further confirmed a causal association between T1D and IPF (OR = 1.133, 95% CI = 1.011-1.270, P = 0.032), but no causal relationship between T2D and IPF (OR = 1.009, 95% CI = 0.790-1.288, P = 0.950). Sensitivity analysis results validated the stability and reliability of our findings.

CONCLUSION

Univariate and multivariate analyses demonstrated a causal relationship between T1D and IPF, whereas no evidence was found to support a causal relationship between T2D and IPF. Therefore, in clinical practice, patients with T1D should undergo lung imaging for early detection of IPF.

Altered immune co-inhibitory receptor expression and correlation of LAG-3 expression to disease severity in NMOSD

Co-inhibitory receptors (CIR)s regulate T cell-mediated immune responses and growing evidence links co-inhibitory receptors to the progression of neuroimmunological diseases. We studied the expression levels of CIRs: TIM-3, TIGIT, PD-1 and LAG-3 in the peripheral blood mononuclear cells (PBMCs) of 30 patients with Neuromyelitis optica spectrum disorder (NMOSD), 11 Multiple sclerosis (MS) patients and 31 Healthy controls (HC). We found that the mRNA expression levels of TIM-3 were significantly increased in NMOSD compared with HC, and increased LAG-3 surface protein expression was also observed on T-cells of NMOSD patients. Moreover, we observed a negative correlation between LAG-3 expression and disease severity in NMOSD. Our findings suggest a protective effect of LAG-3 in the setting of NMOSD, and that the differential expression of CIRs observed in this study may play a role in the pathological process of NMOSD.

Expression of lymphocyte activation gene-3 on CD4+T cells is regulated by cytokine interleukin-18 in myasthenia gravis

Myasthenia gravis (MG) is a T cell-dependent, B cell-mediated, and complement-dependent autoimmune disease. Lymphocyte activation gene-3 (LAG-3; CD223) is an immune checkpoint protein that plays an important role in maintaining autoimmune tolerance and homeostasis. To investigate the cytokine-regulated expression pattern of LAG-3, CD4+T cells were sorted from the peripheral blood of healthy volunteers by density gradient centrifugation and stimulated with various cytokines in vitro. The expression of membrane LAG-3 (mLAG-3), membrane a disintegrin and metallopeptidase domain10 (mADAM10) and membrane ADAM17 (mADAM17) on CD4+T cells was detected by flow cytometry; the concentration of soluble LAG-3 (sLAG-3) was detected by ELISA; and the relative expression of genes at the transcriptional level was detected by fluorescence quantitative RT-PCR (qRT-PCR). sLAG-3 levels were significantly increased in the peripheral plasma of AChR Ab-positive patients with MG compared to healthy volunteers, while the percentage of mLAG-3 expression on CD4+T lymphocytes in the peripheral blood of patients with MG was significantly reduced. IL-18 inhibited mLAG-3 levels on CD4+T cells in a concentration-dependent manner. Additionally, the concentration of sLAG-3 in the supernatant increased. After PHA and IL-18 stimulation, ADAM10 and ADAM17 also increased compared to those in the PHA-active group. Moreover, there were significant differences in the expression of mADAM10 and mADAM17 in CD4+T lymphocytes between patients with MG and healthy volunteers. These results suggest that IL-18 may regulate the expression pattern of mLAG-3 in CD4+T cells and sLAG-3 via ADAM10- and ADAM17-mediated pathways, thus affecting the immune effects of CD4+T cells. This study provides a preliminary exploration of the upstream regulatory molecules of the LAG-3 and IL-18/LAG-3 signalling pathways for potential targeted therapy of autoimmune diseases in the future.

Transcriptional reprogramming via signaling domains of CD2, CD28, and 4-1BB

Costimulatory signals provided to T cells during antigen encounter have a decisive role in the outcome of immune responses. Here, we used chimeric receptors harboring the extracellular domain of mouse inducible T cell costimulator (mICOS) to study transcriptional activation mediated by cytoplasmic sequences of the major T cell costimulatory receptors CD28, 4-1BB, and CD2. The chimeric receptors were introduced in a T cell reporter platform that allows to simultaneously evaluate nuclear factor κB (NF-κB), NFAT, and AP-1 activation. Engagement of the chimeric receptors induced distinct transcriptional profiles. CD28 signaling activated all three transcription factors, whereas 4-1BB strongly promoted NF-κB and AP-1 but downregulated NFAT activity. CD2 signals resulted in the strongest upregulation of NFAT. Transcriptome analysis revealed pronounced and distinct gene expression signatures upon CD2 and 4-1BB signaling. Using the intracellular sequence of CD28, we exemplify that distinct signaling motifs endow chimeric receptors with different costimulatory capacities.

CD7 activation regulates cytotoxicity-driven pathology in systemic sclerosis, yielding a target for selective cell depletion

OBJECTIVES

Cytotoxic T cells and natural killer (NK) cells are central effector cells in cancer and infections. Their effector response is regulated by activating and inhibitory receptors. The regulation of these cells in systemic autoimmune diseases such as systemic sclerosis (SSc) is less defined.

METHODS

We conducted ex vivo analysis of affected skin and blood samples from 4 SSc patient cohorts (a total of 165 SSc vs 80 healthy individuals) using single-cell transcriptomics, flow cytometry and multiplex immunofluorescence staining. We further analysed the effects of costimulatory modulation in functional assays, and in a severely affected SSc patient who was treated on compassionate use with a novel anti-CD3/CD7 immunotoxin treatment.

RESULTS

Here, we show that SSc-affected skin contains elevated numbers of proliferating T cells, cytotoxic T cells and NK cells. These cells selectively express the costimulatory molecule CD7 in association with cytotoxic, proinflammatory and profibrotic genes, especially in recent-onset and severe disease. We demonstrate that CD7 regulates the cytolytic activity of T cells and NK cells and that selective depletion of CD7+ cells prevents cytotoxic cell-induced fibroblast contraction and inhibits their profibrotic phenotype. Finally, anti-CD3/CD7 directed depletive treatment eliminated CD7+ skin cells and stabilised disease manifestations in a severely affected SSc patient.

CONCLUSION

Together, the findings imply costimulatory molecules as key regulators of cytotoxicity-driven pathology in systemic autoimmune disease, yielding CD7 as a novel target for selective depletion of pathogenic cells.

Cytotoxic Tph subset with low B-cell helper functions and its involvement in systemic lupus erythematosus

T peripheral helper (Tph) cells are thought to contribute to extra-follicular B cell activation and play a pathogenic role in autoimmune diseases. However, the role of Tph subsets is not fully elucidated. Here, we investigate the immunological functions of Tph subsets and their involvement in systemic lupus erythematosus (SLE). We have defined four Tph subsets (Tph1: CXCR3+CCR6-, Tph2: CXCR3-CCR6-, Tph17: CXCR3-CCR6+, and Tph1-17: CXCR3+CCR6+) and performed RNA sequencing after cell sorting. Tph1 and Tph17 subsets express substantial levels of IL21, indicating B cell helper functions. However, Tph2 and Tph1-17 subsets express low IL21. Interestingly, we have found Tph2 subset express high levels of CX3CR1, GZMB, PRF1, GLNY, S1PR5, TBX21, EOMES, ZNF863, and RUNX3, indicating a feature of CD4+ cytotoxic T lymphocytes. In SLE patients, the frequency of Tph1 and Tph2 subsets are significantly increased and positively correlated with SLE disease activity indexes. Tph1 cells expansion has been observed in patients with cutaneous and musculoskeletal manifestations. On the other hand, Tph2 cell expansion has been found in patients with lupus nephritis in addition to the above manifestations. Our findings imply that Tph1 and Tph2 subsets exert distinct immunological functions and are contributed to the complexity of clinical manifestations in SLE.

[Influence of underlying disease and immunosuppression on the immunocompetence in inflammatory rheumatic diseases]

Patients with inflammatory rheumatic diseases have a higher risk of infections in comparison to the general population. For this patient group, in addition to cardiovascular diseases, infections play an important role with respect to morbidity and mortality. Even if it is difficult to make concrete statements with respect to individual diseases, it can be assumed that there is a lower risk of infections in inflammatory joint diseases in comparison to connective tissue diseases and vasculitides. The increased risk of infections is determined by multiple factors, whereby the underlying factors are classified into three main categories: patient-related factors (age, comorbidities, lifestyle), disease-related factors (immunological dysfunction as part of the disease pathophysiology) and drug-related factors (type and dosage of the immunosuppression and/or immunomodulation). An improved understanding of the complexity of these associations enables the optimization of treatment and disease control taking the individual risk factors into account, with the aim of a significant reduction in the risk of infections.

Inhibition of CD38 enzymatic activity enhances CAR-T cell immune-therapeutic efficacy by repressing glycolytic metabolism

Chimeric antigen receptor (CAR)-T therapy has shown superior efficacy against hematopoietic malignancies. However, many patients failed to achieve sustainable tumor control partially due to CAR-T cell exhaustion and limited persistence. In this study, by performing single-cell multi-omics data analysis on patient-derived CAR-T cells, we identify CD38 as a potential hallmark of exhausted CAR-T cells, which is positively correlated with exhaustion-related transcription factors and further confirmed with in vitro exhaustion models. Moreover, inhibiting CD38 activity reverses tonic signaling- or tumor antigen-induced exhaustion independent of single-chain variable fragment design or costimulatory domain, resulting in improved CAR-T cell cytotoxicity and antitumor response. Mechanistically, CD38 inhibition synergizes the downregulation of CD38-cADPR -Ca2+ signaling and activation of the CD38-NAD+-SIRT1 axis to suppress glycolysis. Collectively, our findings shed light on the role of CD38 in CAR-T cell exhaustion and suggest potential clinical applications of CD38 inhibition in enhancing the efficacy and persistence of CAR-T cell therapy.

CXCR5+TIM-3-PD-1+ stem-like cytotoxic CD8+ T cells: elevated in chronic rhinosinusitis and associated with disease severity

Background

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease with an autoimmune background. Altered expression levels of T cell immunoglobulin and mucin-domain containing-3 (TIM-3), C-X-C chemokine receptor type 5 (CXCR5), and programmed cell death protein 1 (PD-1) are implicated in the progression of inflammatory and autoimmune diseases. Moreover, CXCR5+TIM-3-PD-1+ stem-like cytotoxic T cells function as memory stem cells during chronic disease processes and retain cytotoxicity-related gene networks.

Objectives

To explore the expressions of CXCR5, TIM-3, and PD-1 on T cells and their correlation with clinical parameters in CRS.

Methods

Flow cytometry was used to assess the expressions and co-expressions of CXCR5, TIM-3, and PD-1 on T cells in the tissues of the paranasal sinus and peripheral blood of patients with CRS as well as healthy controls. Immunofluorescence was used to assess the co-localization of TIM-3, CXCR5, and PD-1 with T cells. The disease severity of our patients with CRS was evaluated using the Lund-Mackay score. A complete blood count was also performed for the patients with CRS.

Results

Expression levels of CXCR5 and PD-1 on T cells were significantly increased in the nasal tissues of patients with CRS. Compared with those in healthy controls, patients with CRS had high percentages of CXCR5+TIM-3-PD-1+ CD8+ and CD4+ T cells in nasal tissues, while no significant difference was observed in peripheral blood levels. Patients with CRS had a higher density of nasal CXCR5+TIM-3-PD-1+ T cells than that in healthy controls. CXCR5+TIM-3-PD-1+ CD8+ T cell levels in the nasal polyps of patients with CRS were negatively correlated with the patients' Lund-Mackay scores. The levels of CXCR5+TIM-3-PD-1+ T cells in nasal tissues were also negatively associated with disease duration and positively associated with the chronic inflammatory state of CRS.

Conclusions

The level of CXCR5+TIM-3-PD-1+ stem cell-like T cells, especially CXCR5+TIM-3-PD-1+ CD8+ T cells, is increased in CRS. Therefore, inducing CXCR5+TIM-3-PD-1+ T cell exhaustion may be an effective immunotherapy for CRS.

LAG-3, TIM-3, and TIGIT: Distinct functions in immune regulation

LAG-3, TIM-3, and TIGIT comprise the next generation of immune checkpoint receptors being harnessed in the clinic. Although initially studied for their roles in restraining T cell responses, intense investigation over the last several years has started to pinpoint the unique functions of these molecules in other immune cell types. Understanding the distinct processes that these receptors regulate across immune cells and tissues will inform the clinical development and application of therapies that either antagonize or agonize these receptors, as well as the profile of potential tissue toxicity associated with their targeting. Here, we discuss the distinct functions of LAG-3, TIM-3, and TIGIT, including their contributions to the regulation of immune cells beyond T cells, their roles in disease, and the implications for their targeting in the clinic.

Superantigen-fused T cell engagers for tumor antigen-mediated robust T cell activation and tumor cell killing

Inadequate T cell activation has severely limited the success of T cell engager (TCE) therapy, especially in solid tumors. Enhancing T cell activity while maintaining the tumor specificity of TCEs is the key to improving their clinical efficacy. However, currently, there needs to be more effective strategies in clinical practice. Here, we design novel superantigen-fused TCEs that display robust tumor antigen-mediated T cell activation effects. These innovative drugs are not only armed with the powerful T cell activation ability of superantigens but also retain the dependence of TCEs on tumor antigens, realizing the ingenious combination of the advantages of two existing drugs. Superantigen-fused TCEs have been preliminarily proven to have good (>30-fold more potent) and specific (>25-fold more potent) antitumor activity in vitro and in vivo. Surprisingly, they can also induce the activation of T cell chemotaxis signals, which may promote T cell infiltration and further provide an additional guarantee for improving TCE efficacy in solid tumors. Overall, this proof-of-concept provides a potential strategy for improving the clinical efficacy of TCEs.

Extraislet expression of islet antigen boosts T cell exhaustion to partially prevent autoimmune diabetes

Persistent antigen exposure results in the differentiation of functionally impaired, also termed exhausted, T cells which are maintained by a distinct population of precursors of exhausted T (TPEX) cells. T cell exhaustion is well studied in the context of chronic viral infections and cancer, but it is unclear whether and how antigen-driven T cell exhaustion controls progression of autoimmune diabetes and whether this process can be harnessed to prevent diabetes. Using nonobese diabetic (NOD) mice, we show that some CD8+ T cells specific for the islet antigen, islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) displayed terminal exhaustion characteristics within pancreatic islets but were maintained in the TPEX cell state in peripheral lymphoid organs (PLO). More IGRP-specific T cells resided in the PLO than in islets. To examine the impact of extraislet antigen exposure on T cell exhaustion in diabetes, we generated transgenic NOD mice with inducible IGRP expression in peripheral antigen-presenting cells. Antigen exposure in the extraislet environment induced severely exhausted IGRP-specific T cells with reduced ability to produce interferon (IFN)γ, which protected these mice from diabetes. Our data demonstrate that T cell exhaustion induced by delivery of antigen can be harnessed to prevent autoimmune diabetes.

Single-cell analysis of refractory anti-SRP necrotizing myopathy treated with anti-BCMA CAR-T cell therapy

Immune-mediated necrotizing myopathy (IMNM) is an autoimmune disorder associated with the presence of autoantibodies, characterized by severe clinical presentation with rapidly progressive muscular weakness and elevated levels of creatine kinase, while traditional pharmacological approaches possess varying and often limited effects. Considering the pathogenic role of autoantibodies, chimeric antigen receptor (CAR)-T cells targeting B cell maturation antigen (BCMA) have emerged as a promising therapeutic strategy. We reported here a patient with anti-signal recognition particle IMNM refractory to multiple available therapies, who was treated with BCMA-targeting CAR-T cells, exhibited favorable safety profiles, sustained reduction in pathogenic autoantibodies, and persistent clinical improvements over 18 mo. Longitudinal single-cell RNA, B cell receptor, T cell receptor sequencing analysis presented the normalization of immune microenvironment after CAR-T cell infusion, including reconstitution of B cell lineages, replacement of T cell subclusters, and suppression of overactivated immune cells. Analysis on characteristics of CAR-T cells in IMNM demonstrated a more active expansion of CD8+ CAR-T cells, with a dynamic phenotype shifting pattern similar in CD4+ and CD8+ CAR-T cells. A comparison of CD8+ CAR-T cells in patients with IMNM and those with malignancies collected at different timepoints revealed a more NK-like phenotype with enhanced tendency of cell death and neuroinflammation and inhibited proliferating ability of CD8+ CAR-T cells in IMNM while neuroinflammation might be the distinct characteristics. Further studies are warranted to define the molecular features of CAR-T cells in autoimmunity and to seek higher efficiency and longer persistence of CAR-T cells in treating autoimmune disorders.

Early allogeneic immune modulation after establishment of donor hematopoietic cell-induced mixed chimerism in a nonhuman primate kidney transplant model

Background

Mixed lymphohematopoietic chimerism is a proven strategy for achieving operational transplant tolerance, though the underlying immunologic mechanisms are incompletely understood.

Methods

A post-transplant, non-myeloablative, tomotherapy-based total lymphoid (TLI) irradiation protocol combined with anti-thymocyte globulin and T cell co-stimulatory blockade (belatacept) induction was applied to a 3-5 MHC antigen mismatched rhesus macaque kidney and hematopoietic cell transplant model. Mechanistic investigations of early (60 days post-transplant) allogeneic immune modulation induced by mixed chimerism were conducted.

Results

Chimeric animals demonstrated expansion of circulating and graft-infiltrating CD4+CD25+Foxp3+ regulatory T cells (Tregs), as well as increased differentiation of allo-protective CD8+ T cell phenotypes compared to naïve and non-chimeric animals. In vitro mixed lymphocyte reaction (MLR) responses and donor-specific antibody production were suppressed in animals with mixed chimerism. PD-1 upregulation was observed among CD8+ T effector memory (CD28-CD95+) subsets in chimeric hosts only. PD-1 blockade in donor-specific functional assays augmented MLR and cytotoxic responses and was associated with increased intracellular granzyme B and extracellular IFN-γ production.

Conclusions

These studies demonstrated that donor immune cell engraftment was associated with early immunomodulation via mechanisms of homeostatic expansion of Tregs and early PD-1 upregulation among CD8+ T effector memory cells. These responses may contribute to TLI-based mixed chimerism-induced allogenic tolerance.

PD-1/PD-L1 governed cross-talk of exhausted CD8+ T and memory B cells in systemic lupus erythematosus

BACKGROUND

Indeterminate readout of the quantitative interferon-γ release test (QFT) for Mycobacterium tuberculosis screening is a specific laboratory finding for systemic lupus erythematosus (SLE), which may be due to T-cell exhaustion and abnormal programmed death receptor 1 (PD-1)/programmed death-ligand 1 (PD-L1) signalling.

METHODS

We enrolled 104 patients with SLE and 225 with other rheumatic musculoskeletal diseases (RMDs) who presented to the outpatient clinic between 2020 and 2023. Twenty healthy donors served as the controls. The QFT was performed in all participants, and those with indeterminate results were compared among the groups. Immunophenotyping and functional assays were performed using blood mononuclear cells. Interferon (IFN)-γ was detected in vitro and ex vivo in patients with SLE with indeterminate or negative QFT results, before or after rituximab therapy.

RESULTS

104 patients with SLE had a significantly higher rate of indeterminate QFT results was significantly higher (17.31%) than that of 225 patients with RMD (3.56%). Patients with SLE with indeterminate QFT had more active disease (SLEDAI-2K, mean 10.94 vs 4.02, p<0.0001), including a higher incidence of active nephritis (55.56% vs 29.07%). Indeterminate QFT in SLE is mainly caused by an insufficient IFN-γ response in CD8+T cells with exhausted immunophenotypes. The abnormal interaction between exhausted PD-1 high CD8+ T cells and activated PD-L1 low memory B cells in SLE can be reversed with a PD-1 agonist or increased PD-L1 expression. Rituximab treatment indirectly reversed this IFN-γ response.

CONCLUSION

The PD-1/PD-L1 signalling pathway, which governs the crosstalk between exhausted CD8+ T cells and activated memory B cells, is a mechanistic explanation for insufficient interferon-γ response in patients with SLE.

Comparison of efficacy discrepancy between early-phase clinical trials and phase III trials of PD-1/PD-L1 inhibitors

BACKGROUND

Phase III clinical trials are pivotal for evaluating therapeutics, yet a concerning failure rate has been documented, particularly impacting oncology where accelerated approvals of immunotherapies are common. These failures are predominantly attributed to a lack of therapeutic efficacy, indicating overestimation of results from phase II studies. Our research aims to systematically assess overestimation in early-phase trials involving programmed cell death-1 (PD-1)/programmed cell death-ligand 1(PD-L1) inhibitors compared with phase III trials and identify contributing factors.

METHODS

We matched 51 pairs of early-phase and phase III clinical trials from a pool of over 9,600 PD-1/PD-L1 inhibitor trials. The matching criteria included identical treatment regimens, cancer types, treatment lines, and biomarker enrichment strategies. To assess overestimation, we compared the overall response rates (ORR) between early-phase and phase III trials. We established independent variables related to eligibility criteria, and trial design features of participants to analyze the factors influencing the observed discrepancy in efficacy between the two phases through univariable and multivariable logistic analyses.

RESULT

Early-phase trial outcomes systematically overestimated the subsequent phase III results, yielding an odds ratio (OR) comparing ORR in early-phase versus phase III: 1.66 (95% CI: 1.43 to 1.92, p<0.05). This trend of inflated ORR was consistent across trials testing PD-1/PD-L1 monotherapies and combination therapies involving PD-1/PD-L1. Among the examined factors, the exclusion of patients with autoimmune diseases was significantly associated with the disparity in efficacy between early-phase trials and phase III trials (p=0.023). We calculated a Ward statistic of 2.27 to validate the effectiveness of the model.

CONCLUSION

These findings underscore the tendency of overestimation of efficacy in early-phase trials involving immunotherapies. The observed differences could be attributed to variations in the inclusion of patients with autoimmune disorders in early-phase trials. These insights have the potential to inform stakeholders in the future development of cancer immunotherapies.

COVID-19 mRNA Vaccines: Lessons Learned from the Registrational Trials and Global Vaccination Campaign

Our understanding of COVID-19 vaccinations and their impact on health and mortality has evolved substantially since the first vaccine rollouts. Published reports from the original randomized phase 3 trials concluded that the COVID-19 mRNA vaccines could greatly reduce COVID-19 symptoms. In the interim, problems with the methods, execution, and reporting of these pivotal trials have emerged. Re-analysis of the Pfizer trial data identified statistically significant increases in serious adverse events (SAEs) in the vaccine group. Numerous SAEs were identified following the Emergency Use Authorization (EUA), including death, cancer, cardiac events, and various autoimmune, hematological, reproductive, and neurological disorders. Furthermore, these products never underwent adequate safety and toxicological testing in accordance with previously established scientific standards. Among the other major topics addressed in this narrative review are the published analyses of serious harms to humans, quality control issues and process-related impurities, mechanisms underlying adverse events (AEs), the immunologic basis for vaccine inefficacy, and concerning mortality trends based on the registrational trial data. The risk-benefit imbalance substantiated by the evidence to date contraindicates further booster injections and suggests that, at a minimum, the mRNA injections should be removed from the childhood immunization program until proper safety and toxicological studies are conducted. Federal agency approval of the COVID-19 mRNA vaccines on a blanket-coverage population-wide basis had no support from an honest assessment of all relevant registrational data and commensurate consideration of risks versus benefits. Given the extensive, well-documented SAEs and unacceptably high harm-to-reward ratio, we urge governments to endorse a global moratorium on the modified mRNA products until all relevant questions pertaining to causality, residual DNA, and aberrant protein production are answered.

Uncovering the flip side of immune checkpoint inhibitors: a comprehensive review of immune-related adverse events and predictive biomarkers

Immune checkpoint inhibitors (ICIs) have generated considerable excitement as a novel class of immunotherapeutic agents due to their remarkable efficacy in treating various types of cancer. However, the widespread use of ICIs has brought about a number of safety concerns, especially the development of immune-related adverse events (irAEs). These serious complications could result in treatment discontinuation and even life-threatening consequences, making it critical to identify high-risk groups and predictive markers of irAEs before initiating therapy. To this end, the current article examines several potential predictive markers of irAEs in important organs affected by ICIs. While retrospective studies have yielded some promising results, limitations such as small sample sizes, variable patient populations, and specific cancer types and ICIs studied make it difficult to generalize the findings. Therefore, prospective cohort studies and real-world investigations are needed to validate the potential of different biomarkers in predicting irAEs risk. Overall, identifying predictive markers of irAEs is a crucial step towards improving patient safety and enhancing the management of irAEs. With ongoing research efforts, it is hoped that more accurate and reliable biomarkers will be identified and incorporated into clinical practice to guide treatment decisions and prevent the development of irAEs in susceptible patients.

Might maintenance therapy be discontinued once clinical remission is achieved in ANCA-associated vasculitis?

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) encompasses a group of rare, multisystem autoimmune disorders characterised by the occurrence of inflammation and damage to small blood vessels, leading to a wide range of clinical manifestations. They include granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). Outcomes for patients with MPA and GPA have been transformed over recent years. However, the establishment of effective maintenance therapy aiming to balance the risks of disease relapse with those related to prolonged immunosuppression has become a clinical priority. This review aims to explore two differing perspectives on this unsolved problem. Pros and Cons of the following approaches will be discussed: "Biomarker-guided personalised approach on top of generic maintenance strategy guidelines" or "ANCA specificity-related personalised maintenance treatment after intensive B-cell depletion"?

Noninvasive approach to indicate risk factors of nonalcoholic steatohepatitis overlapping autoimmune hepatitis based on peripheral lymphocyte pattern

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) clinically includes autoimmunity as indicated by antinuclear antibody (ANA) positivity and overlap of autoimmune hepatitis (AIH). Discriminating AIH-overlap NASH from NAFLD/NASH is required for proper treatment, and typically involves pathological diagnosis by invasive liver biopsy. Differential patterns of peripheral lymphocytes in NAFLD and AIH were assessed to noninvasively indicate risk factors of AIH-overlap NASH by flow cytometry (FCM).

METHODS

We assessed the differential frequencies of peripheral lymphocytes in 115 patients: 70 NASH (ANA negative:positive:AIH-overlap = 36:20:14), 18 NAFL, and 27 AIH (acute:chronic = 12:15) patients diagnosed by FCM. We focused on the following populations of lymphocytes: T cells, B cells, natural killer (NK) cells, NKT cells, helper T cell (Th) subsets (Th1, Th2, and Th17), and regulatory T cells; we also examined programmed cell death (PD) 1 and cytotoxic T-lymphocyte antigen levels.

RESULTS

Several significant differences in laboratory parameters and peripheral lymphocyte frequencies were found among the NAFLD and AIH subgroups. In univariate and multivariate analyses, hyaluronic acid level, liver stiffness, and the frequencies of Th17 and CD8+ PD1+ T cells were independent risk factors of NASH in NAFLD. Regarding overlap of AIH, only the frequency of CD8+ PD1+ T cells (odds ratio, 0.01; 95% CI 0.00-38.9, p = 0.004) was an independent risk factor in NASH and significantly decreased in AIH.

CONCLUSIONS

The decreased frequency of peripheral CD8+ PD1+ T cells is an independent risk factor of NASH overlapping with AIH in the present cohort. Our findings will facilitate development of a new noninvasive FCM method for indicating risk factors of NASH, including autoimmunity.

Precision medicine in inflammatory bowel disease

Inflammatory bowel disease (IBD) is an incurable disease characterized by remission-relapse cycles throughout its course. Both Crohn's disease (CD) and ulcerative colitis (UC), the two main forms of IBD, exhibit tendency to develop complications and substantial heterogeneity in terms of frequency and severity of relapse, thus posing great challenges to the clinical management for IBD. Current treatment strategies are effective in different ways in induction and maintenance therapies for IBD. Recent advances in studies of genetics, pharmacogenetics, proteomics and microbiome provide a strong driving force for identifying molecular markers of prognosis and treatment response, which should help clinicians manage IBD patients more effectively, and then, improve clinical outcomes and reduce treatment costs of patients. In this review, we summarize and discuss precision medicine in IBD, focusing on predictive markers of disease course and treatment response, and monitoring indices during therapeutic drug monitoring.

The plethora of immunomodulatory drugs: opportunities for immune-mediated kidney diseases

In recent decades, insights into the molecular pathways involved in disease have revolutionized the treatment of autoimmune diseases. A plethora of targeted therapies have been identified and are at varying stages of clinical development in renal autoimmunity. Some of these agents, such as rituximab or avacopan, have been approved for the treatment of immune-mediated kidney disease, but kidney disease lags behind more common autoimmune disorders in new drug development. Evidence is accumulating as to the importance of adaptive immunity, including abnormalities in T-cell activation and signaling, and aberrant B-cell function. Furthermore, innate immunity, particularly the complement and myeloid systems, as well as pathologic responses in tissue repair and fibrosis, play a key role in disease. Collectively, these mechanistic studies in innate and adaptive immunity have provided new insights into mechanisms of glomerular injury in immune-mediated kidney diseases. In addition, inflammatory pathways common to several autoimmune conditions exist, suggesting that the repurposing of some existing drugs for the treatment of immune-mediated kidney diseases is a logical strategy. This new understanding challenges the clinical investigator to translate new knowledge into novel therapies leading to better disease outcomes. This review highlights promising immunomodulatory therapies tested for immune-mediated kidney diseases as a primary indication, details current clinical trials and discusses pathways that could be targeted in the future.

Introducing Molecular Chaperones into the Causality and Prospective Management of Autoimmune Hepatitis

Molecular chaperones influence the immunogenicity of peptides and the activation of effector T cells, and their pathogenic roles in autoimmune hepatitis are unclear. Heat shock proteins are pivotal in the processing and presentation of peptides that activate CD8+ T cells. They can also induce regulatory B and T cells and promote immune tolerance. Tapasin and the transporter associated with antigen processing-binding protein influence the editing and loading of high-affinity peptides for presentation by class I molecules of the major histocompatibility complex. Their over-expression could enhance the autoimmune response, and their deficiency could weaken it. The lysosome-associated membrane protein-2a isoform in conjunction with heat shock cognate 70 supports the importation of cytosolic proteins into lysosomes. Chaperone-mediated autophagy can then process the peptides for activation of CD4+ T cells. Over-expression of autophagy in T cells may also eliminate negative regulators of their activity. The human leukocyte antigen B-associated transcript three facilitates the expression of class II peptide receptors, inhibits T cell apoptosis, prevents T cell exhaustion, and sustains the immune response. Immunization with heat shock proteins has induced immune tolerance in experimental models and humans with autoimmune disease by inducing regulatory T cells. Therapeutic manipulation of other molecular chaperones may promote T cell exhaustion and induce tolerogenic dendritic cells. In conclusion, molecular chaperones constitute an under-evaluated family of ancillary proteins that could affect the occurrence, severity, and outcome of autoimmune hepatitis. Clarification of their contributions to the immune mechanisms and clinical activity of autoimmune hepatitis could have therapeutic implications.

Immune Checkpoints in Solid Organ Transplantation

Allogenic graft acceptance is only achieved by life-long immunosuppression, which comes at the cost of significant toxicity. Clinicians face the challenge of adapting the patients' treatments over long periods to lower the risks associated with these toxicities, permanently leveraging the risk of excessive versus insufficient immunosuppression. A major goal and challenge in the field of solid organ transplantation (SOT) is to attain a state of stable immune tolerance specifically towards the grafted organ. The immune system is equipped with a set of inhibitory co-receptors known as immune checkpoints (ICs), which physiologically regulate numerous effector functions. Insufficient regulation through these ICs can lead to autoimmunity and/or immune-mediated toxicity, while excessive expression of ICs induces stable hypo-responsiveness, especially in T cells, a state sometimes referred to as exhaustion. IC blockade has emerged in the last decade as a powerful therapeutic tool against cancer. The opposite action, i.e., subverting IC for the benefit of establishing a state of specific hypo-responsiveness against auto- or allo-antigens, is still in its infancy. In this review, we will summarize the available literature on the role of ICs in SOT and the relevance of ICs with graft acceptance. We will also discuss the possible influence of current immunosuppressive medications on IC functions.

Umbilical Cord-Derived Mesenchymal Stem Cells Attenuate S100-Induced Autoimmune Hepatitis via Modulating Th1 and Th17 Cell Responses in Mice

Currently, the first-line treatment for autoimmune hepatitis (AIH) is still the combination of glucocorticoids or immunosuppressants. However, hormone and immunosuppressive therapy can cause serious side effects, such as Cushing syndrome and bone marrow suppression. Previous studies reported on the applicability and safety of mesenchymal stem cells (MSCs) to ameliorate liver inflammation and fibrosis. However, the characteristics of MSCs sources directly contribute to the different conclusions on the mechanisms underlying MSC-mediated immunoregulation. Bone marrow-derived MSCs can exert an immunosuppression effect to ameliorate the S100-induced AIH model by inhibiting several proinflammatory cytokines and upregulating of PD-L1 in liver tissue. It is not clear whether human umbilical cord-derived MSCs (hUC-MSCs) could directly inhibit liver inflammation and ultimately alleviate the dysfunction of hepatocytes in the AIH model. First, hUC-MSCs were extracted from umbilical cord tissue, and the basic biological properties and multilineage differentiation potential were examined. Second, 1 × 106 hUC-MSCs were administered intravenously to AIH mice. At the peak of the disease, serum levels of alanine aminotransferase and aspartate aminotransferase and pathologic damage to liver tissue were measured to evaluate liver function and degree of inflammation. We also observed that the infiltration of CD4+ T cells in the liver was significantly reduced. Furthermore, the frequency of the splenic IFNγ- and IL-17A- producing CD4+ T cells were also significantly decreased, while we only observed an increasing trend in Treg cells in liver tissue. Third, an RNA sequencing analysis of liver tissue was performed, which showed that in the UC-MSC-treated group, the transcriptional profiles of inflammation-related signaling pathways were significantly negatively regulated compared to those of phosphate-buffered saline-treated mice. Collectively, these findings indicated the potential of hUC-MSC to suppress immune responses in immune anomaly mediated liver disease, thus offering a potential clinical option to improve AIH.

Possibility of PD-1/PD-L1 Inhibitors for the Treatment of Patients with Chronic Hepatitis B Infection

BACKGROUND

Chronic hepatitis B (CHB) infection is still a major global public health problem, with nearly two billion patients. Although current antiviral drugs can inhibit viral replication and reduce hepatitis B virus (HBV) related complications, it is difficult to achieve clinical endpoints due to drug resistance.

SUMMARY

Immune checkpoint inhibitors (ICIs) are an important strategy to reverse T-cell exhaustion, and rebuilding an effective functional T-cell response is a promising immunomodulatory approach for CHB patients. However, ICIs may lead to viral reactivation or immune-related adverse effects. There are still many controversies in the application of ICIs in treating patients with CHB.

KEY MESSAGES

This article reviews the research progress of ICIs in CHB infection and related issues. The goal of this paper was to summarize the possible impact of new therapies for CHB with the aim of reducing potential clinical risks.

Bibliometric analysis of rheumatic immune related adverse events associated with immune checkpoint inhibitors

Background

Immune checkpoint inhibitors (ICIs) has emerged as a popular cancer treatment approach. However, non-specific activation of T cells by ICIs can lead to immune-related adverse events (irAEs), including specific rheumatic manifestations. The study aimed to explore the current trend of ICIs associated rheumatic irAEs and summarize the knowledge structure through bibliometric methods.

Methods

The Web of Science Core Collection database (WoSCC) was selected for retrieving literature on ICIs associated rheumatic irAEs. To evaluate contributions from different countries/regions, institutions, journals, and authors, bibliometric analysis software, including VOSviewer and CiteSpace, as well as bibliometric online platforms, were utilized to construct and visualize bibliometric networks. Through the systematic review of this knowledge domain, future research directions were determined.

Results

In This study, a total of 803 publications on ICIs-associated rheumatic irAEs were included for analysis. The distribution of these publications revealed two distinct growth phases: a stable phase between 2007 to 2015 followed by rapid growth from 2016 to 2020. The United States emerged as the top contributor in terms of publications, citations, and h-index, with the majority of leading institutions and funding agencies located there. Apart from government funding, pharmaceutical companies such as Bristol Myers Squibb and Merck Company also play a significant role in drug development and research. Analysis of keywords and citation bursts indicated that the initial burst was related to "monoclonal antibody," "anti-CLTA4 antibody," and "melanoma". This was followed by a rise in interest related to "sarcoidosis," "safety," "inflammatory arthritis," and "preexisting autoimmune."

Conclusion

This study summarized the global research trends concerning ICIs associated rheumatic irAEs. The findings can provide valuable insights into the current understanding of rheumatic irAEs, highlight the research trend and developments in the field. Future efforts should focus on developing classification criteria and guidelines, conducting prospective studies, investigating the mechanisms involved, and identifying biomarkers for prediction and monitoring of these events.

Differential Immune Infiltration Profiles in Colitis-Associated Colorectal Cancer versus Sporadic Colorectal Cancer

BACKGROUND

Chronic inflammation is a significant factor in colorectal cancer (CRC) development, especially in colitis-associated CRC (CAC). T-cell exhaustion is known to influence inflammatory bowel disease (IBD) progression and antitumor immunity in IBD patients. This study aimed to identify unique immune infiltration characteristics in CAC patients.

METHODS

We studied 20 CAC and 20 sporadic CRC (sCRC) patients, who were matched by tumor stage, grade, and location. Immunohistochemical staining targeted various T-cell markers (CD3, CD4, CD8, and FOXP3), T-cell exhaustion markers (TOX and TIGIT), a B-cell marker (CD20), and a neutrophil marker (CD66b) in tumor and tumor-free mucosa from both groups. The quantification of the tumor immune stroma algorithm assessed immune-infiltrating cells.

RESULTS

CAC patients had significantly lower TOX+ cell infiltration than sCRC in tumors (p = 0.02) and paracancerous tissues (p < 0.01). Right-sided CAC showed increased infiltration of TOX+ cells (p = 0.01), FOXP3+ regulatory T-cells (p < 0.01), and CD20+ B-cells (p < 0.01) compared to left-sided CAC. In sCRC, higher tumor stages (III and IV) had significantly lower TIGIT+ infiltrate than stages I and II. In CAC, high CD3+ (p < 0.01) and CD20+ (p < 0.01) infiltrates correlated with improved overall survival. In sCRC, better survival was associated with decreased TIGIT+ cells (p < 0.038) and reduced CD8+ infiltrates (p = 0.02).

CONCLUSION

In CAC, high CD3+ and CD20+ infiltrates relate to improved survival, while this association is absent in sCRC. The study revealed marked differences in TIGIT and TOX expression, emphasizing distinctions between CAC and sCRC. T-cell exhaustion appears to have a different role in CAC development.