Immune checkpoints and rheumatic diseases: what can cancer immunotherapy teach us?

Immune checkpoint inhibitors in cancer patients with autoimmune disease: Safety and efficacy

The utilization of immune-checkpoint inhibitors (ICIs) in cancer immunotherapy frequently leads to the occurrence of immune-related adverse events (irAEs), making it generally not recommended for patients with preexisting autoimmune diseases. Hence, we conducted a meta-analysis on safety and efficacy of ICIs in cancer patients with preexisting autoimmune diseases to provide further insights. PubMed, EMBASE, and Cochrane Library were systematically searched until December 20, 2024. The main summary measures used were pooled rate and risk ratio (RR) with 95% confidential interval (CI), which were analyzed using R statistic software. A total of 52 articles were included in the study. When cancer patients with preexisting autoimmune diseases received ICIs treatment, the overall incidence was 0.610 (95% CI: 0.531-0.686) for any grade irAEs, 0.295 (95% CI: 0.248-0.343) for flares, 0.325 (95% CI: 0.258-0.396) for de novo irAEs, 0.238 (95% CI: 0.174-0.309) for grade ≥3 irAEs, and 0.143 (95% CI: 0.109-0.180) for discontinuation due to immunotoxicity. Compared with those without autoimmune diseases, cancer patients with autoimmune diseases experienced a higher risk of any-grade irAEs (RR: 1.23, 95% CI: 1.12-1.35) and discontinuation due to immunotoxicity (1.40, 95% CI: 1.11-1.78). However, no statistically significant differences were observed in the incidence of grade ≥3 irAEs, objective response rate (ORR), disease control rate (DCR), overall survival (OS), and progression-free survival (PFS) between the two groups. During ICIs treatment, irAEs are common among cancer patients with autoimmune diseases, but severe irAEs is relatively low. ICIs are effective in this population, but should be strictly monitored when used to avoid immunotoxicity.

Circulating PD-1hi CXCR5- and CXCR5+ CD4 T cells are elevated in patients with newly diagnosed giant cell arteritis, and predict relapse

OBJECTIVES

GCA is a large/medium-vessel granulomatous vasculitis, and the Programmed Cell Death 1/Programmed Cell Death-ligand-1 (PD-1/PD-L1) coinhibitory pathway seems to be implicated in its pathogenesis. CD4 T cells expressing high PD-1 levels, CD4+CXCR5-PD-1hi peripheral helper (Tph) and CD4+CXCR5+PD-1hi follicular helper T cells (Tfh) are key mediators of autoimmunity. Their frequencies are elevated in the peripheral blood of subjects with several autoimmune conditions but have not been investigated in GCA. Our objective was to study the frequency of circulating Tph (cTph) and Tfh (cTfh) in patients with newly diagnosed GCA (nGCA).

METHODS

Prospective, non-interventional study on consecutive patients referred to our US GCA fast-track clinic over a period of 24 months. Peripheral blood was drawn immediately upon initial diagnosis. For each patient, an age- and gender-matched healthy control (HC) was included. Peripheral blood mononuclear cells isolated by Ficoll-Hypaque were examined by cytometry. Patients were subsequently treated with standard therapy according to the updated 2018 EULAR recommendations.

RESULTS

Sixty-five nGCA patients were included. As compared with HC, nGCA patients presented at baseline with an increased frequency of cTph and cTfh cells. Among the 46 patients who could be followed up for 12 months, 19 experienced a relapse. The baseline frequency of cTph and cTfh cells had been significantly lower in patients who relapsed as compared with those who did not. A cTph cell frequency <1.0 predicted relapse with a sensitivity of 90% and specificity of 93%.

CONCLUSION

nGCA patients demonstrate increased baseline cTph and cTfh cell frequencies. Lower baseline proportions of cTph and cTfh cells associate with relapse.

Prospects for the application of pathological response rate in neoadjuvant therapy for gastric cancer

With the annual increase in the incidence and mortality rates of gastric cancer, it has gradually become one of the significant threats to human health. Approximately 90% of gastric cancer patients are diagnosed with adenocarcinoma. Although the 5-year survival rate for early-stage gastric cancer can exceed 90%, due to its concealed symptoms, less than half of the patients are eligible for radical surgical treatment upon diagnosis. For gastric cancer patients receiving palliative treatment, the current expected survival time is only about one year. In China, the majority of gastric cancer patients, accounting for about 80% of the total, are in the locally advanced stage. For these patients, radical surgery remains the primary treatment option; however, surgery alone is often inadequate in controlling tumor progression. In the pivotal MAGIC study, the recurrence rate was as high as 75%, and similar results were obtained in the French ACCORD07-FFCD9703 study. Numerous clinical trials are currently exploring preoperative neoadjuvant therapy for patients with locally advanced gastric cancer. Data indicates that preoperative neoadjuvant therapy can not only reduce the size of the local tumor but also shrink surrounding lymph nodes, thereby downstaging the tumor and improving the R0 resection rate. Additionally, it can decrease tumor cell activity and eliminate potential micrometastases. The emergence of various immunotherapies has ushered in a new era for neoadjuvant treatment options for gastric cancer.

Promising New Anti-TIGIT Agents: Stealthy Allies in Cancer Immunotherapy

TIGIT (T cell immunoreceptor with immunoglobulin and tyrosine-based inhibitory motif (ITIM) domain), Vstm3, and VSIG9, are newly recognized immunological checkpoints. They are prominently expressed on CD4+ and CD8+ T cells, tumor-infiltrating lymphocytes (TILs), natural killer (NK) cells, and regulatory T cells (Tregs). The TIGIT (TIGIT) protein is crucial for immune modulation since it diminishes NK cell populations and hinders T cell activity in cancer patients and experimental models. CD155, the principal ligand of TIGIT in humans, has been recognized as a pivotal target for immunotherapy owing to its interaction with TIGIT. CD155 is linked to the efficacy of anti-programmed cell death protein 1 (PD-1) therapy, even without TIGIT expression, underscoring its importance in immune checkpoint suppression. Anti-TIGIT medicines, either independently or in conjunction with anti-PD-1 treatments, have demonstrated potential in augmenting immune responses to malignancies. This review examines the structural and functional characteristics of the TIGIT protein, new developments in anti-TIGIT drugs, and their prospective use in cancer immunotherapy.

PD-1 immunology in the kidneys: a growing relationship

In recent years, knowledge regarding immune regulation has expanded rapidly, and major advancements have been made in immunotherapy for immune-associated disorders, particularly cancer. The programmed cell death 1 (PD-1) pathway is a cornerstone in immune regulation. It comprises PD-1 and its ligands mediating immune tolerance mechanisms and immune homeostasis. Accumulating evidence demonstrates that the PD-1 axis has a crucial immunosuppressive role in the tumor microenvironment and autoimmune diseases. PD-1 receptors and ligands on immune cells and renal parenchymal cells aid in maintaining immunological homeostasis in the kidneys. Here, we present a comprehensive review of PD-1 immunology in various kidney disorders, including renal cell carcinoma, glomerulonephritis, kidney transplantation, renal aging, and renal immune-related adverse events secondary to PD-1 immunotherapy.

Cancer immunotherapy of Wilms tumor: a narrative review

Wilms tumor (WT) is the most common malignant tumor of the urinary system in children. Though the traditional treatment of surgery plus radiotherapy and chemotherapy achieves exciting clinical efficacy, in relapsed and refractory cases, the long-term overall survival rates are poor. Besides, chemotherapy and radiation have serious long-term toxic side effects on children. Cancer immunotherapy is a new tumor therapy that works by activating the body's immune system to allow immune cells to kill tumor cells more efficiently. Currently, cancer immunotherapy has been tested in clinical trials or basic studies in WT. This article reviews the current status of clinical trials and basic research of cancer immunotherapy in WT to promote the application of cancer immunotherapy in WT patients.

Exploration of the combined role of immune checkpoints and immune cells in the diagnosis and treatment of ankylosing spondylitis: a preliminary study immune checkpoints in ankylosing spondylitis

OBJECTIVE

Immune checkpoints have emerged as promising therapeutic targets for autoimmune diseases. However, the specific roles of immune checkpoints in the pathophysiology of ankylosing spondylitis (AS) remain unclear.

METHODS

Hip ligament samples were obtained from two patient groups: those with AS and femoral head deformity, and those with femoral head necrosis but without AS, undergoing hip arthroplasty. Label-Free Quantification (LFQ) Protein Park Analysis was used to identify the protein composition of the ligaments. Peripheral blood samples of 104 AS patients from public database were used to validate the expression of key proteins. KEGG, GO, and GSVA were employed to explore potential pathways regulated by immune checkpoints in AS progression. xCell was used to calculate cell infiltration levels, LASSO regression was applied to select key cells, and the correlation between immune checkpoints and immune cells was analyzed. Drug sensitivity analysis was conducted to identify potential therapeutic drugs targeting immune checkpoints in AS. The expression of key genes was validated through immunohistochemistry (IHC).

RESULTS

HLA-DMB and HLA-DPA1 were downregulated in the ligaments of AS and this has been validated through peripheral blood datasets and IHC. Significant differences in expression were observed in CD8 + Tcm, CD8 + T cells, CD8 + Tem, osteoblasts, Th1 cells, and CD8 + naive T cells in AS. The infiltration levels of CD8 + Tcm and CD8 + naive T cells were significantly positively correlated with the expression levels of HLA-DMB and HLA-DPA1. Immune cell selection using LASSO regression showed good predictive ability for AS, with AUC values of 0.98, 0.81, and 0.75 for the three prediction models, respectively. Furthermore, this study found that HLA-DMB and HLA-DPA1 are involved in Th17 cell differentiation, and both Th17 cell differentiation and the NF-kappa B signaling pathway are activated in the AS group. Drug sensitivity analysis showed that AS patients are more sensitive to drugs such as doramapimod and GSK269962A.

CONCLUSION

Immune checkpoints and immune cells could serve as avenues for exploring diagnostic and therapeutic strategies for AS.

Tackling TNF-α in autoinflammatory disorders and autoimmune diseases: From conventional to cutting edge in biologics and RNA- based nanomedicines

Autoinflammatory disorders and autoimmune diseases result from abnormal deviations of innate and adaptive immunity that heterogeneously affect organs and clinical phenotypes. Despite having etiologic and phenotypic differences, these two conditions share the onset of an aberrant inflammatory process. Targeting the main drivers controlling inflammation is useful to treat both autoimmune and autoinflammatory syndromes. TNF-α is a major player in the inflammatory immune response, and anti-TNF-α antibodies have been a revolutionary treatment in many autoimmune disorders. However, production difficulties and high development costs hinder their implementation, and accessibility to their use is still limited. Innovative strategies aimed at overcoming the limitations associated with anti-TNF-α antibodies are being explored, including RNA-based therapies. Here we summarize the central role of TNF-α in immune disorders and how anti-TNF-based immunotherapies changed the therapeutic landscape, albeit with important limitations related to side effects, tolerance, and resistance to therapies. We then outline how nanotechnology has provided the final momentum for the use of nucleic acids in the treatment of autoimmune and autoinflammatory diseases, with a focus on inflammatory bowel diseases (IBDs). The example of IBDs allows the evaluation and discussion of the nucleic acids-based treatments that have been developed, to identify the role that innovative approaches possess in view of the treatment of autoinflammatory disorders and autoimmune diseases.

Immune Checkpoint Inhibitor Related Rheumatological Complications: Cooperation between Rheumatologists and Oncologists

In cancer, immune checkpoint inhibitors (ICIs) improve patient survival but may lead to severe immune-related adverse events (irAEs). Rheumatic irAEs are a distinct entity that are much more common in a real-life than in clinical trial reports due to their unspecific symptoms and them being a rare cause of hospitalization. This review focuses on an interdisciplinary approach to the management of rheumatic irAEs, including cooperation between oncologists, rheumatologists, and immunologists. We discuss the immunological background of rheumatic irAEs, as well as their unique clinical characteristics, differentiation from other irAEs, and treatment strategies. Importantly, steroids are not the basis of therapy, and nonsteroidal anti-inflammatory drugs should be administered in the front line with other antirheumatic agents. We also address whether patients with pre-existing rheumatic autoimmune diseases can receive ICIs and how antirheumatic agents can interfere with ICIs. Interestingly, there is a preclinical rationale for combining ICIs with immunosuppressants, particularly tumor necrosis factor α and interleukin 6 inhibitors. Regardless of the data, the mainstay in managing irAEs is interdisciplinary cooperation between oncologists and other medical specialties.

Can Soluble Immune Checkpoint Molecules on Exosomes Mediate Inflammation?

Immune checkpoints (ICPs) are major co-signaling pathways that trigger effector functions in immune cells, with isoforms that are either membrane bound, engaging in direct cell to cell activation locally, or soluble, acting at distant sites by circulating freely or potentially via extracellular vesicles (EVs). Exosomes are small EVs secreted by a variety of cells carrying various proteins and nucleic acids. They are distributed extensively through biological fluids and have major impacts on infectious diseases, cancer, and neuroinflammation. Similarly, ICPs play key roles in a variety of disease conditions and have been extensively utilized as a prognostic tool for various cancers. Herein, we explored if the association between exosomes and ICPs could be a significant contributor of inflammation, particularly in the setting of cancer, neuroinflammation and viral infections, wherein the up regulation in both exosomal proteins and ICPs correlate with immunosuppressive effects. The detailed literature review of existing data highlights the significance and complexity of these two important pathways in mediating cancer and potentiating neuroinflammation via modulating overall immune response. Cells increasingly secret exosomes in response to intracellular signals from invading pathogens or cancerous transformations. These exosomes can carry a variety of cargo including proteins, nucleic acids, cytokines, and receptors/ligands that have functional consequences on recipient cells. Illustration generated using BioRender software.

MALAT-1/p53/miR-155/miR-146a ceRNA circuit tuned by methoxylated quercitin glycoside alters immunogenic and oncogenic profiles of breast cancer

Triple-Negative Breast Cancer (TNBC) is one of the most aggressive and hot BC subtypes. Our research group has recently shed the light on the utility of natural compounds as effective immunotherapeutic agents. The aim of this study is to investigate the role of a methoxylated quercetin glycoside (MQG) isolated from Cleome droserifolia in harnessing TNBC progression and tuning the tumor microenvironment and natural killer cells cytotoxicity. Results showed that MQG showed the highest potency (IC₅₀ = 12 µM) in repressing cellular proliferation, colony-forming ability, migration, and invasion capacities. Mechanistically, MQG was found to modulate a circuit of competing endogenous RNAs where it was found to reduce the oncogenic MALAT-1 lncRNA and induce TP53 and its downstream miRNAs; miR-155 and miR-146a. Accordingly, this leads to alteration in several downstream signaling pathways such as nitric oxide synthesizing machinery, natural killer cells' cytotoxicity through inducing the expression of its activating ligands such as MICA/B, ULBP2, CD155, and ICAM-1 and trimming of the immune-suppressive cytokines such as TNF-α and IL-10. In conclusion, this study shows that MQG act as a compelling anti-cancer agent repressing TNBC hallmarks, activating immune cell recognition, and alleviating the immune-suppressive tumor microenvironment experienced by TNBC patients.

Cytokine Release Syndrome in Cancer Patients Receiving Immune Checkpoint Inhibitors: A Case Series of 25 Patients and Review of the Literature

Cytokine release syndrome (CRS) is a phenomenon of immune hyperactivation described in the setting of immunotherapy. Unlike other immune-related adverse events, CRS triggered by immune checkpoint inhibitors (ICIs) is not well described. The clinical characteristics and course of 25 patients with ICI-induced CRS from 2 tertiary hospitals were abstracted retrospectively from the medical records and analyzed. CRS events were confirmed by 2 independent reviewers and graded using the Lee et al. scale. The median duration of CRS was 15.0 days (Q1; Q3 6.3; 29.8) and 10 (40.0%) had multiple episodes of CRS flares. Comparing the clinical factors and biomarkers in Grades 1-2 and 3-5 CRS, we found that patients with Grades 3-5 CRS had following: (i) had longer time to fever onset [25.0 days (Q1; Q3 13.0; 136.5) vs. 3.0 days (Q1; Q3 0.0; 18.0), p=0.027]; (ii) more cardiovascular (p=0.002), neurologic (p=0.001), pulmonary (p=0.044) and rheumatic (p=0.037) involvement; (iii) lower platelet count (p=0.041) and higher urea (p=0.041) at presentation compared to patients with Grades 1-2 CRS. 7 patients (28.0%) with Grades 1-2 CRS were rechallenged using ICIs without event. 9 patients (36.0%) were treated with pulse methylprednisolone and 6 patients (24.0%) were treated with tocilizumab. Despite this, 3 patients (50%) who received tocilizumab had fatal (Grade 5) outcomes from ICI-induced CRS. Longer time to fever onset, lower platelet count and higher urea at presentation were associated with Grade 3-5 CRS. These parameters may be used to predict which patients are likely to develop severe CRS.

T cells and monocyte-derived myeloid cells mediate immunotherapy-related hepatitis in a mouse model

BACKGROUND & AIMS

Immune checkpoint inhibitors (ICIs) are associated with immune-related adverse events (irAEs) which are more severe when ICIs are used in combination. We aimed to use a mouse model to elucidate the molecular mechanisms of immune-related hepatitis, one of the common irAEs associated with ICIs.

METHODS

Immune phenotyping and molecular profiling were performed on Pdcd1^-/- mice treated with anti-CTLA4 and/or the IDO1 inhibitor epacadostat or a 4-1BB agonistic antibody.

RESULTS

ICI combination-induced hepatitis and 4-1BB agonist-mediated hepatitis share similar features yet maintain distinct immune signatures. Both were characterized by an expansion of periportal infiltrates and pan-zonal inflammation albeit with different morphologic characteristics. In both cases, infiltrates were predominantly CD4+ and CD8+ T cells with upregulated T-cell activation markers, ICOS and CD44. Depletion of CD8+ T cells abolished ICI-mediated hepatitis. Single-cell transcriptomics revealed that the hepatitis induced by combination ICIs is associated with a robust immune activation signature in all subtypes of T cells and T helper 1 skewing. Expression profiling revealed a central role for IFNγ and liver monocyte-derived macrophages in promoting a pro-inflammatory T-cell response to ICI combination and 4-1BB agonism.

CONCLUSION

We developed a novel mouse model which offers significant value in yielding deeper mechanistic insight into immune-mediated liver toxicity associated with various immunotherapies.

LAY SUMMARY

Hepatitis is one of the common immune-related adverse events in cancer patients receiving immune checkpoint inhibitor (ICI) therapy. The mechanisms of ICI-induced hepatitis are not well understood. In this paper, we identify key molecular mechanisms mediating immune intracellular crosstalk between liver T cells and macrophages in response to ICI in a mouse model.

Multifunctional Nanocarriers-Mediated Synergistic Combination of Immune Checkpoint Inhibitor Cancer Immunotherapy and Interventional Oncology Therapy

Immune checkpoint inhibitor (ICI) cancer immunotherapies are becoming one of the standard therapies for cancer patients. However, ICI cancer immunotherapy's overall response rate is still moderate and even combinational ICI cancer immunotherapies are not showing significant improvement in therapeutic outcomes. Only a subset of patients responds to the therapy due to the resistance and ignorance to the ICI cancer immunotherapy. Following immune-related adverse events (irAEs) are also limiting the whole therapeutic regimens. New approaches that can increase the immunotherapeutic efficacy and reduce systemic irAEs are required. Recently, multifunctional nanocarriers, which can extend the half-life of ICIs and modulate tumor microenvironment (TME), have shown a substantial opportunity to enhance ICI cancer immunotherapies. Interventional oncology (IO) allowing simultaneous diagnosis, immunogenic loco-regional therapeutic delivery, and real-time monitoring of the treatment efficacy have advanced to demonstrate the effective conversion of TME. The use of multifunctional nanocarriers with the IO therapies amplify the image guidance capability and immunogenic therapeutic localization for the potential combinational ICI cancer immunotherapy. This article will discuss the emerging opportunity of multifunctional nanocarriers mediated synergistic combination of ICI cancer immunotherapy and IO local therapy.

Signal inhibitory receptor on leukocytes-1 recognizes bacterial and endogenous amphipathic α-helical peptides

Signal inhibitory receptor on leukocytes-1 (SIRL-1) is a negative regulator of myeloid cell function and dampens antimicrobial responses. We here show that different species of the genus Staphylococcus secrete SIRL-1-engaging factors. By screening a library of single-gene transposon mutants in Staphylococcus aureus, we identified these factors as phenol-soluble modulins (PSMs). PSMs are amphipathic α-helical peptides involved in multiple aspects of staphylococcal virulence and physiology. They are cytotoxic and activate the chemotactic formyl peptide receptor 2 (FPR2) on immune cells. Human cathelicidin LL-37 is also an amphipathic α-helical peptide with antimicrobial and chemotactic activities, structurally and functionally similar to α-type PSMs. We demonstrate that α-type PSMs from multiple staphylococcal species as well as human cathelicidin LL-37 activate SIRL-1, suggesting that SIRL-1 recognizes α-helical peptides with an amphipathic arrangement of hydrophobicity, although we were not able to show direct binding to SIRL-1. Upon rational peptide design, we identified artificial peptides in which the capacity to ligate SIRL-1 is segregated from cytotoxic and FPR2-activating properties, allowing specific engagement of SIRL-1. In conclusion, we propose staphylococcal PSMs and human LL-37 as a potential new class of natural ligands for SIRL-1.

Clinical outcome of renal cancer patients who early interrupted immunotherapy due to serious immune-related adverse events. Meet-Uro 13 trial on behalf of the MeetUro investigators

BACKGROUND

Severe immune-related Adverse Events (irAEs) develop in 10-27% of patients treated with Immune-Oncology (IO) [Powles (Lancet 391:748-757, 2018); Galsky (Lancet 395:1547-1557, 2020); Haanen (Ann Oncol 28:119-142, 2017)]. The aim of our study was to evaluate efficacy and clinical outcome of metastatic renal cell carcinoma (mRCC) patients who stopped Immune Checkpoint Inhibitors (ICIs) due to early Grade (G) 3-G4 irAEs.

METHODS

We retrospectively collected data from 204 mRCC patients treated with ICIs in 6 Italian referral centers adhering to the Meet-Uro group, between February 2017 and January 2020. To properly weight the results, patients who did not report early G3-G4 toxicities have been included as control group. Primary endpoint was to evaluate 6 months Progression Free Survival (PFS) after early treatment interruption for Grade (G) 3-4 toxicities compared to the control group. Secondary endpoints were to evaluate Time to treatment failure (TTF) and overall survival (OS) in both groups. All statistical analyses were performed using SPSS software (version 19.00, SPSS, Chicago).

RESULTS

18/204 (8.8%) patients had early treatment interruption for serious (G3-G4) irAEs. Early was defined as interruption of IO after only one or two administrations. Immune related nephritis and pancreatitis were the most common irAE that lead to treatment interruption. 6/18 patients received IO-IO combination whereas 12/18 patients antiPD1. In the study group, 12/18 (66.6%) were free from progression at 6 months since IO interruption, TTF was 1.6 months (95% CI 1.6-2.1), mPFS was 7.4 months (95% CI 3.16-11.6) and mOS was 15.5 months (5.1-25.8). In the control group 111/184 (60.3%) patients were free from progression at 6 months, TTF was 4.6 months (95% CI 3.5-5.6), mPFS was 4.6 months (95% CI 3.5-5.6) and mOS was 19.6 months (95% CI 15.1-24.0). In the overall population, mPFS was 5.0 months (95% CI 4.0-5.9) and mOS was 19.6 months (95% CI 15.1-24.0).

CONCLUSIONS

ICIs seem to maintain efficacy even after early interruption due to severe irAE.

Carbon nanotubes (CNT)-loaded ginsenosides Rb3 suppresses the PD-1/PD-L1 pathway in triple-negative breast cancer

Carbon nanotubes (CNTs), as advanced nanotechnology with specific properties and structures, have presented practical drug delivery properties. Ginsenoside Rg3 is a component of puffed ginseng and demonstrates anti-cancer activities. To explore the effect of CNTs-loaded Rg3 (Rg3-CNT) on the PD-1/PD-L1 signaling and the development of triple-negative breast cancer (TNBC). Our data revealed that Rg3 inhibited the cell viability of TNBC cells, in which Rg3-CNT further enhanced this effect in the system. Similarly, the colony formation of TNBC cells was decreased by Rg3, while Rg3-CNT could reinforce its effect in the cells. Besides, the treatment of Rg3 induced apoptosis of TNBC cells, in which Rg3-CNT treatment further increased the phenotype in the cells. Remarkably, Rg3-CNT, but not Rg3, attenuated PD-L1 expression in TNBC cells. Rg3-CNT decreased the PD-L1 upregulation induced by interferon-γ (IFN-γ) in breast cancer cells. Importantly, Rg3-CNT was able to reduce PD-1 expression in activated T cells. Specifically, Rg3-CNT reduced the PD-1/PD-L1 axis in a T cell/triple-negative TNBC cell co-culture system. Moreover, the levels of IFN-γ, interleukins-2 (IL-2), interleukins-9 (IL-9), interleukins-10 (IL-10), interleukins-22 (IL-22), and interleukins-23 (IL-23) were significantly stimulated in the activated T cells, while the treatment of Rg3-CNT could reverse these phenotypes in the cells. Rg3-CNT attenuated the TNBC cell growth in vivo. The Rg3-CNT improved the anti-cancer effect of Rg3 toward TNBC by inhibiting the PD-1/PD-L1 axis. Our finding provides new insights into the mechanism by which Rg3-CNT attenuates the development of TNBC. Rg3-CNT may be applied as the potential therapeutic strategy for immunotherapy of TNBC.

The safety and efficacy of immune-checkpoint inhibitors in patients with cancer and pre-existing autoimmune diseases

Objective: This study aims at investigating the safety and efficacy of immune-checkpoint inhibitors (ICIs) in patients with cancer and pre-existing autoimmune disease (AID). Materials & methods: PubMed, Embase and Cochrane Library were searched for relevant studies. The primary end points of the study were immunotoxicity and cancer response. Results: At the early use of ICIs, compared with those with active AID, grade 3-4 AID flare occurred more frequently in patients with inactive AID after treatment with ICIs; and the incidence of grade 3-4 immunotoxic effects was significantly lower in patients undergoing immunosuppressive therapy than those without corresponding treatment. In addition, patients with worsening AID generally obtained a better objective response than those without a flare. Conclusion: This study demonstrates that the toxic effects induced by immunotherapy are generally manageable in patients with cancer and pre-existing AID, some of whom even achieve satisfactory antitumor effects in clinical practice.

Metabolic and Nutritional Disorders Following the Administration of Immune Checkpoint Inhibitors: A Pharmacovigilance Study

BACKGROUND

Although several metabolic and nutritional disorders (MNDs) have been reported in the recipients of immune checkpoint inhibitors (ICIs), these events have not been fully captured and comprehensively characterized in real-world population.

OBJECTIVES

To provide complete metabolic and nutritional toxicity profiles after ICIs (single and combined) initiation through an integrated big database.

METHODS

Reporting odds ratios (ROR) and information component (IC) based on statistical shrinkage transformation were utilized to perform disproportionality analysis using the US Food and Drug Administration Adverse Events Reporting System. Both ROR and IC were used to calculate disproportionality when compared with the whole database, but only ROR was used when comparison was made for different ICI strategies. Only when both the lower limits of 95% confidence intervals (CIs) for ROR (ROR₀₂₅) and IC (IC₀₂₅) exceeded specified threshold values (1 and 0, respectively) was regarded as a signal.

RESULTS

A total of 29,294,335 records were involved and 8,662 records were for MNDs in patients exposed to ICIs. Statistically significant association was detected between ICIs use and total MNDs (IC₀₂₅/ROR₀₂₅ = 1.06/2.19). For monotherapy, three ICI monotherapies (anti-PD-1, anti-PDL-1, and anti-CTLA-4) were all disproportionately associated with MNDs. Statistically significant differences in reporting frequencies also emerged when comparing anti-PD-1 with anti-PD-L1/anti-CTLA-4 monotherapy, with RORs of 1.11 (95%CI 1.01-1.21), and 1.35 (95%CI 1.23-1.48), respectively. Notably, combination therapy was associated with a higher reporting frequency of theses toxicities compared to monotherapy with a ROR of 1.56 (95%CI 1.48-1.64). Additionally, disproportionality analysis at High-level Group Term level highlighted eight broad entities of MNDs. Further disproportionality analysis at Preferred Term level indicated a wide range and varied strength of signals. For ICI monotherapy, nivolumab and pembrolizumab showed the broadest spectrum of MNDs. For combination therapy, a variety of signals were detected for nivolumab + ipilimumab therapy even comparable to two PD-1 monotherapies.

CONCLUSION

Metabolic and nutritional complications could be provoked by ICI monotherapy (especially anti-PD-1) and further reinforced by combination therapy. Clinicians and patients should be informed about these potential risks that might be encountered in real-world practice. Aforehand education and regular monitoring of related biochemical parameters (calcium, sodium, potassium, protein) are recommended to ensure better cancer survivorship.

Lung Cancer Survival in Patients With Autoimmune Disease

IMPORTANCE

Patients with autoimmune disease and lung cancer pose a multidisciplinary treatment challenge, particularly with the advent of immunotherapy. However, the association between autoimmune disease and lung cancer survival is largely unknown.

OBJECTIVE

To determine the association between autoimmune disease and lung cancer survival.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study between 2003 and 2019 at a single academic medical center (Northwestern University). A query of the Northwestern Medicine Enterprise Data Warehouse identified 349 patients with lung cancer and several autoimmune diseases. Types of lung cancers included small cell, adenocarcinoma, squamous cell carcinoma, non-small cell not otherwise specified, and large cell carcinoma. Autoimmune diseases included rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, mixed connective tissue disease, myositis, and Sjögren syndrome. Inclusion criteria were biopsy-confirmed lung cancer, autoimmune diagnosis confirmed by a rheumatologist, and death or an encounter listed in the electronic medical record within 2 years of study end. A control group of patients with biopsy-proven lung cancer but without autoimmune disease was identified. Data analysis was conducted from March to July 2020.

EXPOSURE

Presence of autoimmune disease.

MAIN OUTCOMES AND MEASURES

Overall survival and progression-free survival in patients with autoimmune disease. The hypothesis was that patients with autoimmune disease would have worse progression-free survival and overall survival compared with patients in the control group.

RESULTS

Of the original 349 patients, 177 met inclusion criteria. Mean (SD) age at lung cancer diagnosis was 67.0 (10.0) years and 136 (76.8%) were women. Most common autoimmune diseases were rheumatoid arthritis (97 [54.8%]), systemic sclerosis (43 [24.3%]), and systemic lupus erythematous (15 [8.5%]). Most common lung cancers were adenocarcinoma (99 [55.9%]), squamous cell carcinoma (29 [16.4%]), and small cell lung cancer (17 [9.6%]). A total of 219 patients (mean [SD] age at diagnosis, 65.9 [4.1] years; 173 [79.0%]) were identified as having lung cancer without autoimmune disease and included in the control cohort. Compared with patients in the control group, patients with autoimmune disease experienced no difference in overall survival (log-rank P = .69). A total of 126 patients (69.5%) with autoimmune disease received standard of care vs 213 patients (97.3%) in the control group (P < .001). No individual autoimmune disease was associated with worse prognosis, even among patients with underlying interstitial lung disease.

CONCLUSIONS AND RELEVANCE

Compared with institutional controls, patients with autoimmune disease experienced no difference in survival despite the fact that fewer patients in this group received standard-of-care treatment. No individual autoimmune disease was associated with worse prognosis. Future multicenter prospective trials are needed to further evaluate autoimmune disease and lung cancer survival.

Co-inhibitory Receptor Signaling in T-Cell-Mediated Autoimmune Glomerulonephritis

Autoimmune glomerulonephritis occurs as a consequence of autoantibodies and T-cell effector functions that target autoantigens. Co-signaling through cell surface receptors profoundly influences the optimal activation of T cells. The scope of this review is signaling mechanisms and the functional roles of representative T-cell co-inhibitory receptors in the regulation of autoimmune glomerulonephritis, along with current therapeutic challenges mainly on preclinical trials. Co-inhibitory receptors utilize both shared and unique signaling pathway, suggesting specialized functions that provide the rationale behind therapies for autoimmune glomerulonephritis by targeting these inhibitory receptors. These receptors largely suppress Th1 immunity, modify Th17 and Th2 immune response, and enhance Treg function. Anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4) immunoglobulin (Ig), which is able to block both activating CD28 and inhibitory CTLA4 signaling, has been shown in preclinical and clinical investigations to have effects on glomerular disease. Other inhibitory receptors for treating glomerulonephritis have not been clinically tested, and efficacy of manipulating these pathways requires further preclinical investigation. While immune checkpoint inhibition using anti-CTLA4 antibodies and anti-programmed cell death 1 (PD-1)/PD-L1 antibodies has been approved for the treatment of several cancers, blockade of CTLA4 and PD-1/PD-L1 is associated with adverse effects that resemble autoimmune disorders, including systemic vasculitis. A renal autoimmune vasculitis model features an initial Th17 dominancy followed later by a Th1-dominant outcome and Treg cells that attenuate autoreactive T-cell function. Toward the development of effective therapies for T-cell-mediated autoimmune glomerulonephritis, it would be preferable to pay attention to the impact of the inhibitory pathways in immunological renal disease settings.

Regulation of PD-L1 Expression by NF-κB in Cancer

Immune checkpoints are inhibitory receptor/ligand pairs regulating immunity that are exploited as key targets of anti-cancer therapy. Although the PD-1/PD-L1 pair is one of the most studied immune checkpoints, several aspects of its biology remain to be clarified. It has been established that PD-1 is an inhibitory receptor up-regulated by activated T, B, and NK lymphocytes and that its ligand PD-L1 mediates a negative feedback of lymphocyte activation, contributing to the restoration of the steady state condition after acute immune responses. This loop might become detrimental in the presence of either a chronic infection or a growing tumor. PD-L1 expression in tumors is currently used as a biomarker to orient therapeutic decisions; nevertheless, our knowledge about the regulation of PD-L1 expression is limited. The present review discusses how NF-κB, a master transcription factor of inflammation and immunity, is emerging as a key positive regulator of PD-L1 expression in cancer. NF-κB directly induces PD-L1 gene transcription by binding to its promoter, and it can also regulate PD-L1 post-transcriptionally through indirect pathways. These processes, which under conditions of cellular stress and acute inflammation drive tissue homeostasis and promote tissue healing, are largely dysregulated in tumors. Up-regulation of PD-L1 in cancer cells is controlled via NF-κB downstream of several signals, including oncogene- and stress-induced pathways, inflammatory cytokines, and chemotherapeutic drugs. Notably, a shared signaling pathway in epithelial cancers induces both PD-L1 expression and epithelial–mesenchymal transition, suggesting that PD-L1 is part of the tissue remodeling program. Furthermore, PD-L1 expression by tumor infiltrating myeloid cells can contribute to the immune suppressive features of the tumor environment. A better understanding of the interplay between NF-κB signaling and PD-L1 expression is highly relevant to cancer biology and therapy.

Innate B Cells: the Archetype of Protective Immune Cells

The innate B cell (IBC) population is heterogeneous and involved in the primary immune response. IBC functions include a high ability to produce natural antibodies with IgM isotype, the elimination of apoptotic cells, and a capacity to be cognate help to T cells. Among IBC subsets, B-1 cells and marginal zone B cells are the main producers of IgM, act as rapid immune responders that may relocate to follicular lymphoid and differentiate to cytokine and antibody-secreting cells shortly after infection. IBCs functions are highly dependent on their localization site and the nature of their B cell receptor repertoire, suggesting a high plasticity range of different immune responses. In this review, we will describe the nature and functions of the different innate-like B cell subsets, first in mice and then in humans. Besides this, we will emphasize the strong ability of these cells to undertake different protective functions from the first line of defense against pathogens to the regulatory role of the broader immune response.

PD-1H (VISTA)-mediated suppression of autoimmunity in systemic and cutaneous lupus erythematosus

Systemic lupus erythematosus (SLE) and discoid lupus erythematosus (DLE) of the skin are autoimmune diseases characterized by inappropriate immune responses against self-proteins; the key elements that determine disease pathogenesis and progression are largely unknown. Here, we show that mice lacking immune inhibitory receptor VISTA or programmed death-1 homolog (PD-1H KO) on a BALB/c background spontaneously develop cutaneous and systemic autoimmune diseases resembling human lupus. Cutaneous lupus lesions of PD-1H KO mice have clustering of plasmacytoid dendritic cells (pDCs) similar to human DLE. Using mass cytometry, we identified proinflammatory neutrophils as critical early immune infiltrating cells within cutaneous lupus lesions of PD-1H KO mice. We also found that PD-1H is highly expressed on immune cells in human SLE, DLE lesions, and cutaneous lesions of MRL/lpr mice. A PD-1H agonistic monoclonal antibody in MRL/lpr mice reduces cutaneous disease, autoantibodies, inflammatory cytokines, chemokines, and immune cell expansion. Furthermore, PD-1H on both T cells and myeloid cells including neutrophils and pDCs could transmit inhibitory signals, resulting in reduced activation and function, establishing PD-1H as an inhibitory receptor on T cells and myeloid cells. On the basis of these findings, we propose that PD-1H is a critical element in the pathogenesis and progression of lupus, and PD-1H activation could be effective for treatment of systemic and cutaneous lupus.

Leukocyte Associated Immunoglobulin Like Receptor 1 Regulation and Function on Monocytes and Dendritic Cells During Inflammation

Inhibitory receptors are crucial immune regulators and are essential to prevent exacerbated responses, thus contributing to immune homeostasis. Leukocyte associated immunoglobulin like receptor 1 (LAIR-1) is an immune inhibitory receptor which has collagen and collagen domain containing proteins as ligands. LAIR-1 is broadly expressed on immune cells and has a large availability of ligands in both circulation and tissues, implicating a need for tight regulation of this interaction. In the current study, we sought to examine the regulation and function of LAIR-1 on monocyte, dendritic cell (DC) and macrophage subtypes, using different in vitro models. We found that LAIR-1 is highly expressed on intermediate monocytes as well as on plasmacytoid DCs. LAIR-1 is also expressed on skin immune cells, mainly on tissue CD14⁺ cells, macrophages and CD1c⁺ DCs. In vitro, monocyte and type-2 conventional DC stimulation leads to LAIR-1 upregulation, which may reflect the importance of LAIR-1 as negative regulator under inflammatory conditions. Indeed, we demonstrate that LAIR-1 ligation on monocytes inhibits toll like receptor (TLR)4 and Interferon (IFN)-α- induced signals. Furthermore, LAIR-1 is downregulated on GM-CSF and IFN-γ monocyte-derived macrophages and monocyte-derived DCs. In addition, LAIR-1 triggering during monocyte derived-DC differentiation results in significant phenotypic changes, as well as a different response to TLR4 and IFN-α stimulation. This indicates a role for LAIR-1 in skewing DC function, which impacts the cytokine expression profile of these cells. In conclusion, we demonstrate that LAIR-1 is consistently upregulated on monocytes and DC during the inflammatory phase of the immune response and tends to restore its expression during the resolution phase. Under inflammatory conditions, LAIR-1 has an inhibitory function, pointing toward to a potential intervention opportunity targeting LAIR-1 in inflammatory conditions.

Functional categories of immune inhibitory receptors

The human genome encodes more than 300 potential immune inhibitory receptors. The reason for this large number of receptors remains unclear. We suggest that inhibitory receptors operate as two distinct functional categories: receptors that control the signalling threshold for immune cell activation and receptors involved in the negative feedback of immune cell activation. These two categories have characteristic receptor expression patterns: 'threshold' receptors are expressed at steady state and their expression remains high or is downregulated upon activation, whereas 'negative feedback' receptors are induced upon immune cell activation. We use mathematical models to illustrate their possible modes of operation in different scenarios for different purposes. We discuss how this categorization may impact the choice of therapeutic targets for immunotherapy of malignant, infectious and autoimmune diseases.

Mechanisms of immune-related adverse events during the treatment of cancer with immune checkpoint inhibitors

Immune checkpoint inhibitors are novel biologic agents to treat cancer by inhibiting the regulatory interactions that limit T cell cytotoxicity to tumours. Current agents target either CTLA-4 or the PD-1/PD-L1 axis. Because checkpoints may also regulate autoreactivity, immune checkpoint inhibitor therapy is complicated by side effects known as immune-related adverse events (irAEs). The aim of this article is to review the mechanisms of these events. irAEs can involve different tissues and include arthritis and other rheumatic manifestations. The frequency of irAEs is related to the checkpoint inhibited, with the combination of agents more toxic. Because of their severity, irAEs can limit therapy and require immunosuppressive treatment. The mechanisms leading to irAEs are likely similar to those promoting anti-tumour responses and involve expansion of the T cell repertoire; furthermore, immune checkpoint inhibitors can affect B cell responses and induce autoantibody production. Better understanding of the mechanisms of irAEs will be important to improve patient outcome as well as quality of life during treatment.

Clinical characteristics of rheumatic syndromes associated with checkpoint inhibitors therapy

Compared with conventional cancer therapies, the spectrum of toxicities observed with checkpoint inhibitors is unique and can affect any organ system. Arthralgia and myalgia were by far the most commonly reported rheumatic immune-related adverse events in clinical trials, and there is now a growing number of case series and reports describing clinical features of de novo rheumatic immune-related adverse events, which will be the focus of this review. Some patients develop genuine classic rheumatic and musculoskeletal diseases, but a number of rheumatic immune-related adverse events mimic rheumatic and musculoskeletal diseases with atypical features, mainly polymyalgia rheumatica, rheumatoid arthritis and myositis, as well as several systemic conditions, including sicca syndrome, vasculitis, sarcoidosis, systemic sclerosis and lupus.

Immune-related adverse events of checkpoint inhibitors: Insights into immunological dysregulation

Immune checkpoint inhibitors (ICIs) targeting against programmed cell death-1(PD-1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) have shown efficacy in cancer treatment. However, a spectrum of immune-related adverse events (irAEs) have raised concerns about their clinical application. IrAEs are distinct from traditional chemo- and radiotherapy-induced toxicities, as they are related in particular to the dysregulation of immune system and autoimmunity. The underlying pathogenesis of irAEs remains elusive. Understanding of the potential underlying mechanism is of great importance for the management of irAEs and the development of new ICIs with insignificant irAEs. In this review, we summarize the current evidence to provide insights into the biological basis of irAEs and provide a potential explanation for their pathogenesis, with focus on the relationship between checkpoint molecules and immune cell regulation.

Pembrolizumab-Induced Seronegative Arthritis and Fasciitis in a Patient with Lung Adenocarcinoma

BACKGROUND

Immune checkpoint inhibitors (CPIs) are new promising anti-cancer drugs that block negative costimulation of T-cells leading to an enhanced anti-tumor immune response. Pembrolizumab, an a monoclonal antibody, targeting the programmed cell death protein 1 (PD-1) pathway. CPIs have been associated with a number of immune-related adverse events (AEs), including musculoskeletal and rheumatic disease.

OBJECTIVE

To present a case with lung adenocarcinoma treated with pembrolizumab, which developed inflammatory arthritis and fasciitis.

CASE REPORT

A 73-year-old male patient was referred to the rheumatology outpatient clinic with complaints of pain in the pretibial area, pain and swelling in both ankles joints and the right fırst metacarpophalangeal (MCP) joint. Three months ago he had diagnosed with lung adenocarcinoma and pembrolizumab was started. Locomotor system complaints were started after receiving two infusions of pembrolizumab. Physical examination revealed both ankle arthritis, mild edema in the pretibial region, tenderness in the muscles and arthritis in the right fırst MCP joint. Laboratory examinations showed mild acute phase reactants elevation. Lower extremity MRI showed diffuse edema in both gastrocnemius muscle and fascia, compatible with fasciitis. Pembrolizumab-related fasciitis and seronegative arthritis were diagnosed. Low dose corticosteroid was started and a significant regression was observed in the patient's complaints.

CONCLUSION

Inflammatory myositis with fasciitis and inflammatory arthritis in lower extremities appears to be a new adverse effect of pembrolizumab therapy.

The immunopathogenesis of rheumatic immune adverse events from checkpoint inhibitors: prospects for targeted therapy

PURPOSE OF REVIEW

The introduction of checkpoint inhibitors as well as other allied advances in cancer immunology has made immunotherapy a pillar in the treatment of cancer. At the same time, these therapies have been associated with a remarkable array of immune-mediated toxicities observed in virtually every organ system, a portion of which are rheumatic in nature or multisystem in expression making them of particular relevance for rheumatologists.

RECENT FINDINGS

Most of our knowledge of these immune-related adverse events (irAEs) stems from clinical descriptive reports; we lack detailed understanding on immunopathogenesis for most complications. Therapeutic approaches are currently empiric and rely heavily on glucocorticoids and inhibitors of tumor necrosis factor. Serious consideration must now be given to advance our understanding of the immunopathogenesis of this emergent field and to exploit the full depth and breadth of the rich armamentarium of targeted therapies currently available to treat autoimmune and autoinflammatory diseases.

SUMMARY

irAEs are and will continue to increase in incidence and pose major hurdles to the continuing success and evolution of cancer immunotherapy. Basic and translational research into pathogenesis of irAEs and clinical trials of targeted therapies for these complications is urgently needed. Rheumatologists are well poised to actively contribute to the care and research of these complications.

What did we learn from CTLA-4 insufficiency on the human immune system?

Cytotoxic-T-lymphocyte-antigen-4 (CTLA-4) is a negative immune regulator constitutively expressed on regulatory T (Treg) cells and upregulated on activated T cells. CTLA-4 inhibits T cell activation by various suppressive functions including competition with CD28, regulation of the inhibitory function of Treg cells, such as transendocytosis, and the control of adhesion and motility. Intrinsic CTLA-4 signaling has been controversially discussed, but so far no distinct signaling pathway has been identified. The CTLA-4-mediated Treg suppression plays an important role in the maintenance of peripheral tolerance and the prevention of autoimmune diseases. Human CTLA-4 insufficiency is caused by heterozygous germline mutations in CTLA4 and characterized by a complex immune dysregulation syndrome. Clinical studies on CTLA4 mutation carriers showed a reduced penetrance and variable expressivity, suggesting modifying factor(s). One hundred and forty-eight CTLA4 mutation carriers have been reported; patients showed hypogammaglobulinemia, recurrent infectious diseases, various autoimmune diseases, and lymphocytic infiltration into multiple organs. The CTLA-4 expression level in Treg cells was reduced, while the frequency of Treg cells was increased in CTLA-4-insufficient patients. The transendocytosis assay is a specific functional test for the assessment of newly identified CTLA4 gene variants. Immunoglobulin substitution, corticosteroids, immunosuppressive therapy, and targeted therapy such as with CTLA-4 fusion proteins and mechanistic target of rapamycin (mTOR) inhibitors were applied; patients with life-threatening, treatment-resistant symptoms underwent hematopoietic stem cell transplantation. The fact that in humans CTLA-4 insufficiency causes severe disease taught us that the amount of CTLA-4 molecules present in/on T cells matters for immune homeostasis. However, whether the pathology-causing activated T lymphocytes in CTLA-4-insufficient patients are antigen-specific is an unsolved question. CTLA-4, in addition, has a role in autoimmune diseases and cancer. Anti-CTLA-4 drugs are employed as checkpoint inhibitors to target various forms of cancer. Thus, clinical research on human CTLA-4 insufficiency might provide us a deeper understanding of the mechanism(s) of the CTLA-4 molecule and immune dysregulation disorders.

The Role of Immune Checkpoint Receptors in Regulating Immune Reactivity in Lupus

Immune checkpoint receptors with co-stimulatory and co-inhibitory signals are important modulators for the immune system. However, unrestricted co-stimulation and/or inadequate co-inhibition may cause breakdown of self-tolerance, leading to autoimmunity. Systemic lupus erythematosus (SLE) is a complex multi-organ disease with skewed and dysregulated immune responses interacting with genetics and the environment. The close connections between co-signaling pathways and SLE have gradually been established in past research. Also, the recent success of immune checkpoint blockade in cancer therapy illustrates the importance of the co-inhibitory receptors in cancer immunotherapy. Moreover, immune checkpoint blockade could result in substantial immune-related adverse events that mimic autoimmune diseases, including lupus. Together, immune checkpoint regulators represent viable immunotherapeutic targets for the treatment of both autoimmunity and cancer. Therefore, it appears reasonable to treat SLE by restoring the out-of-order co-signaling axis or by manipulating collateral pathways to control the pathogenic immune responses. Here, we review the current state of knowledge regarding the relationships between SLE and the co-signaling pathways of T cells, B cells, dendritic cells, and neutrophils, and highlight their potential clinical implications. Current clinical trials targeting the specific co-signaling axes involved in SLE help to advance such knowledge, but further in-depth exploration is still warranted.

The Diverse Function of PD-1/PD-L Pathway Beyond Cancer

The recent success of PD-1 and PD-L1 blockade in cancer therapy illustrates the important role of the PD-1/PD-L1 pathway in the regulation of antitumor immune responses. However, signaling regulated by the PD-1/PD-L pathway is also associated with substantial inflammatory effects that can resemble those in autoimmune responses, chronic infection, and sepsis, consistent with the role of this pathway in balancing protective immunity and immunopathology, as well as in homeostasis and tolerance. Targeting PD-1/PD-L1 to treat cancer has shown benefits in many patients, suggesting a promising opportunity to target this pathway in autoimmune and inflammatory disorders. Here, we systematically evaluate the diverse biological functions of the PD-1/PD-L pathway in immune-mediated diseases and the relevant mechanisms that control these immune reactions.

Rheumatoid arthritis-relevant DNA methylation changes identified in ACPA-positive asymptomatic individuals using methylome capture sequencing

Objective

To compare DNA methylation in subjects positive vs negative for anti-citrullinated protein antibodies (ACPA), a key serological marker of rheumatoid arthritis (RA) risk.

Methods

With banked serum from a random subset (N = 3600) of a large general population cohort, we identified ACPA-positive samples and compared them to age- and sex-matched ACPA-negative controls. We used a custom-designed methylome panel to conduct targeted bisulfite sequencing of 5 million CpGs located in regulatory or hypomethylated regions of DNA from whole blood (red blood cell lysed). Using binomial regression models, we investigated the differentially methylated regions (DMRs) between ACPA-positive vs ACPA-negative subjects. An independent set of T cells from RA patients was used to “validate” the differentially methylated sites.

Results

We measured DNA methylation in 137 subjects, of whom 63 were ACPA-positive, 66 were ACPA-negative, and 8 had self-reported RA. We identified 1303 DMRs of relevance, of which one third (402) had underlying genetic effects. These DMRs were enriched in intergenic CpG islands (CGI) and CGI shore regions. Furthermore, the genes associated with these DMRs were enriched in pathways related to Epstein-Barr virus infection and immune response. In addition, 80 (38%) of 208 RA-specific DMRs were replicated in T cells from RA samples.

Conclusions

Sequencing-based high-resolution methylome mapping revealed biologically relevant DNA methylation changes in asymptomatic individuals positive for ACPA that overlap with those seen in RA. Pathway analyses suggested roles for viral infections, which may represent the effect of environmental triggers upstream of disease onset.

Electronic supplementary material

The online version of this article (10.1186/s13148-019-0699-9) contains supplementary material, which is available to authorized users.

Immune Checkpoint Inhibitors-related Rheumatic Diseases: What Rheumatologist Should Know?

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Immune checkpoint inhibitors are revolutionized drugs for cancer immunotherapy in the last years. The mechanism of action of CPIs including the limitation of the activation of Tcells, and thus enhancing the self-immune response against tumour cells. Checkpointinhibitors( CPIs) may dysregulate the immune system, resulting in some toxicities. These toxicities or side effects are called Immune-related Adverse Events (IRAEs) that can potentially affect any organ and tissue. Rheumatic diseases due to checkpoint inhibitors are also reported in the literature. The spectrum of rheumatic manifestations are quite wide; the most common are arthralgia/arthritis, myalgia/myositis, polimyalgia rheumatica, lupus, rheumatoid arthritis, Sjögren’s syndrome. At the same time, these drugs can also cause an exacerbation of known rheumatologic disease. Treatment approaches for developing rheumatic findings due to checkpoint inhibitors should be multidisciplinary. There should be a close relationship between oncologists who follow-up these patients and rheumatologists. The rheumatic manifestations should be defined and treated early. In general, the musculoskeletal side effects are transient and may regress after stopping CPIs. The most commonly used medications are corticosteroids. Immunosuppressive drugs (HQ, MTX, anti-TNF-alpha, anti-IL-6) should be preferred when treatment is unresponsive or as steroid-sparing agents.

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The aim of this review was to evaluate the checkpoint inhibitors-related rheumatologic findings and therapeutic strategies in light of recent literature data.

Immune inhibitory proteins and their pathogenic and therapeutic implications in autoimmunity and autoimmune hepatitis

Key inhibitory proteins can blunt immune responses to self-antigens, and deficiencies in this repertoire may promote autoimmunity. The goals of this review are to describe the key immune inhibitory proteins, indicate their possible impact on the development of autoimmune disease, especially autoimmune hepatitis, and encourage studies to clarify their pathogenic role and candidacy as therapeutic targets. English abstracts were identified in PubMed by multiple search terms. Full length articles were selected for review, and secondary and tertiary bibliographies were developed. Cytotoxic T lymphocyte antigen-4 impairs ligation of CD28 to B7 ligands on antigen presenting cells and inhibits the adaptive immune response by increasing anti-inflammatory cytokines, generating regulatory T cells, and reducing T cell activation and proliferation. Programed cell death antigen-1 inhibits T cell selection, activation, and proliferation by binding with two ligands at different phases and locations of the immune response. A soluble alternatively spliced variant of this protein can dampen the inhibitory signal. Autoimmune hepatitis has been associated with polymorphisms of the cytotoxic T lymphocyte antigen-4 gene, reduced hepatic expression of a ligand of programed cell death antigen-1, an interfering soluble variant of this key inhibitory protein, and antibodies against it. Findings have been associated with laboratory indices of liver injury and suboptimal treatment response. Abatacept, belatacept, CD28 blockade, and induction of T cell exhaustion are management considerations that require scrutiny. In conclusion, deficiencies in key immune inhibitory proteins may promote the occurrence of autoimmune diseases, such as autoimmune hepatitis, and emerging interventions may overcome these deficiencies. Investigations should define the nature, impact and management of these inhibitory disturbances in autoimmune hepatitis.

Two populations of circulating PD-1hiCD4 T cells with distinct B cell helping capacity are elevated in early rheumatoid arthritis

Objective

A novel population of B helper cells, phenotypically CD4+CXCR5−PD-1hi, has been described in the synovial tissues and peripheral blood of seropositive RA patients, and termed ‘peripheral helper T’ (Tph) cells. Contrary to CD4+CXCR5+PD-1hi follicular helper T (Tfh), Tph cells are not located in lymphoid organs but accumulate in inflamed tissues. Our objective was to study the frequency of circulating Tph (cTph) and circulating Tfh cell counterparts (cTfh) in patients with early RA (eRA).

Methods

Freshly isolated peripheral blood mononuclear cells from 56 DMARD-naïve eRA patients and 56 healthy controls were examined by flow cytometry. Autologous cocultures of naïve or memory B cells were established with isolated peripheral blood Tph or Tfh cells.

Results

Seropositive (RF+ and/or ACPA+, n = 38) but not seronegative eRA patients (n = 18) demonstrated increased frequencies and absolute numbers of cTph and cTfh cells. cTph but not cTfh cells expressed CCR2. Those eRA patients who experienced a significant clinical improvement at 12 months demonstrated a marked decrease of their cTph cell numbers whereas their cTfh cell numbers remained unchanged. Both isolated Tph and isolated Tfh cells were able to induce maturation of memory B cells, whereas only Tfh cells could differentiate naïve B cells.

Conclusion

Two populations of PD-1hiCD4 T cells with distinct phenotype and B cell helping capacity are increased in the peripheral blood of seropositive eRA patients. Whereas cTph cells are present only in patients with an active disease, cTfh cells seem to be constitutively elevated.

The role of ocular dendritic cells in uveitis

Dendritic cells (DCs) act as a bridge between innate and adoptive immunity. They are widely distributed in various tissues and organs. Resident ocular DCs are found in the peripheral margins and juxtapapillary areas of the retina, usually in an immature state. During inflammation, DCs are activated and participate in the development of uveitis, an ocular inflammatory disease. Herein, the characteristics and status of DCs in uveitis, the possible factors affecting the status of DCs, and the clinical methods for detecting the DCs in patients are described.

Targeting the tumor microenvironment to overcome immune checkpoint blockade therapy resistance

The ability of immune checkpoint inhibitors (ICIs) to reactivate the killing function of the immune system to tumor cells has led to long lasting immune response presenting highly promising clinical advances. Recently, immune checkpoint inhibitors related resistance due to the specialized tumor microenvironment has also drawn a widely attention. To overcome resistance to immune checkpoint blockade therapy, understanding the relationship of this type of therapy and tumor microenvironment is necessary and critical. This review will focus on how the tumor environment influences the effectiveness of the immunotherapeutic check inhibitors. Finally, we provide a briefly succinct glimpse into the most exciting pre-clinical discoveries and ongoing clinical trials to overcome the resistance of ICIs.

Immune checkpoint inhibitor-induced rheumatoid arthritis: insights into an increasingly common aetiology of polyarthritis

Nivolumab is an immune checkpoint inhibitor that is used in the treatment of a variety of cancers in the adjuvant or metastatic setting. Adverse effects include non-specific activation of T cells, leading to immune-related adverse events in downstream organs. We present a case of a 36-year-old man with unresectable oropharyngeal squamous cell carcinoma who developed nivolumab-induced rheumatoid arthritis. As immune checkpoint inhibitor use is becoming widespread in the medical oncology domain, the purpose of this case report is to increase awareness of an increasingly common cause of rheumatic disease and to alert clinicians to consider immunotherapy in their differential diagnosis of polyarthritis. This case also highlights the importance of working in an interdisciplinary manner to enhance cancer care for the patient as well as to increase awareness of the potential adverse effects of immunotherapy in patients with cancer.

Amelioration of amyloid β-FcγRIIb neurotoxicity and tau pathologies by targeting LYN

SRC-family kinases (SFKs) have been implicated in Alzheimer's disease (AD), but their mode of action was scarcely understood. Here, we show that LYN plays an essential role in amyloid β (Aβ)-triggered neurotoxicity and tau hyperphosphorylation by phosphorylating Fcγ receptor IIb2 (FcγRIIb2). We found that enzyme activity of LYN was increased in the brain of AD patients and was promoted in neuronal cells exposed to Aβ 1-42 (Aβ_1-42). Knockdown of LYN expression inhibited Aβ_1-42-induced neuronal cell death. Of note, LYN interacted with FcγRIIb2 upon exposure to Aβ_1-42 and phosphorylated FcγRIIb2 at Tyr273 within immunoreceptor tyrosine-based inhibitory motif in neuronal cells. With the use of the structure-based drug design, we isolated KICG2576, an ATP-competitive inhibitor of LYN. Determination of cocrystal structure illustrated that KICG2576 bound to the cleft in the LYN kinase domain and inhibited LYN with a half-maximal inhibitory concentration value of 0.15 μM. KICG2576 inhibited Aβ- or FcγRIIb2-induced cell death, and this effect was better than pyrazolopyrimidine 1, a widely used inhibitor of SFK. Upon exposure to Aβ, KICG2576 blocked the phosphorylation of FcγRIIb2 and translocation of phosphatidylinositol 3,4,5-trisphosphate 5-phosphatase 2, a binding protein to the phosphorylated FcγRIIb2, to the plasma membrane, resulting in the inhibition of tau hyperphosphorylation, the downstream event of Aβ_1-42-FcγRIIb2 binding. Furthermore, intracerebroventricular injection of KICG2576 into mice ameliorated Aβ-induced memory impairment. These results suggest that LYN plays a crucial role in Aβ_1-42-mediated neurotoxicity and tau pathology, providing a therapeutic potential of LYN in AD.-Gwon, Y., Kim, S.-H., Kim, H. T., Kam, T.-I., Park, J., Lim, B., Cha, H., Chang, H.-J., Hong, Y. R., Jung, Y.-K. Amelioration of amyloid β-FcγRIIb neurotoxicity and tau pathologies by targeting LYN.