Balancing cancer immunotherapy and immune-related adverse events: The emerging role of regulatory T cells

Inosine enhances the efficacy of immune-checkpoint inhibitors in advanced solid tumors: A randomized, controlled, Phase 2 study

BACKGROUND

This study aimed to evaluate whether inosine enhances the efficacy of immune-checkpoint inhibitors in human malignant solid tumors.

METHODS

This single-center, prospective, randomized, open-label study was conducted, from January 2021 to December 2022, in Beijing Friendship Hospital, Capital Medical University, and participants were randomly assigned (1:1) to either the inosine (trial) or non-inosine (control) group that received inosine (dosage: 0.2 g, three times/day) + PD-1/PD-L1 inhibitor or only PD-1/PD-L1 inhibitor ± targeted ± chemotherapy, respectively. Efficacy was assessed every 6 weeks (i.e., after every two-three treatment cycles). The primary endpoint was the objective response rate (ORR); the secondary endpoints were disease control rate, overall survival (OS), and progression-free survival (PFS). The trial was registered at ClinicalTrials.gov (NCT05809336).

RESULTS

Among the 172 participants with advanced malignant solid tumors, 86 each were assigned to the inosine and non-inosine groups, wherein the median PFS (95% CI) was 7.00 (5.31-8.69) and 4.40 (3.10-5.70) months, respectively (hazard ratio [HR] 0.63; 95% CI 0.44-0.90, p = 0.011), and the ORR was 26.7% and 15.1%, respectively (p = 0.061). In the inosine and non-inosine groups, the median OS was not reached and was 29.67 (95% CI 17.40-41.94) months, respectively (HR 1.05 [95% CI 0.59-1.84], p = 0.874). Compared with the non-inosine group, the median PFS and ORR of the inosine group were significantly prolonged and improved in the multiple exploratory subgroup analyses. The safety analysis showed that Grades 3 and 4 adverse reactions occurred in 25 (29%) and 31 (36%) patients in the inosine and non-inosine groups, respectively, and tended to decrease in the inosine group compared with the non-inosine group.

CONCLUSION

Inosine had a tendency to enhance the efficacy of immune-checkpoint inhibitors and reduced immunotherapy-related adverse reactions.

The immunosuppressive landscape in tumor microenvironment

Recent advances in cancer immunotherapy, especially immune checkpoint inhibitors (ICIs), have revolutionized the clinical outcome of many cancer patients. Despite the fact that impressive progress has been made in recent decades, the response rate remains unsatisfactory, and many patients do not benefit from ICIs. Herein, we summarized advanced studies and the latest insights on immune inhibitory factors in the tumor microenvironment. Our in-depth discussion and updated landscape of tumor immunosuppressive microenvironment may provide new strategies for reversing tumor immune evasion, enhancing the efficacy of ICIs therapy, and ultimately achieving a better clinical outcome.

Immunological synapse formation between T regulatory cells and cancer-associated fibroblasts promotes tumour development

Cancer-associated fibroblasts (CAFs) have emerged as a dominant non-hematopoietic cell population in the tumour microenvironment, serving diverse functions in tumour progression. However, the mechanisms via which CAFs influence the anti-tumour immunity remain poorly understood. Here, using multiple tumour models and biopsies from cancer patients, we report that α-SMA+ CAFs can form immunological synapses with Foxp3+ regulatory T cells (Tregs) in tumours. Notably, α-SMA+ CAFs can phagocytose and process tumour antigens and exhibit a tolerogenic phenotype which instructs movement arrest, activation and proliferation in Tregs in an antigen-specific manner. Moreover, α-SMA+ CAFs display double-membrane structures resembling autophagosomes in their cytoplasm. Single-cell transcriptomic data showed an enrichment in autophagy and antigen processing/presentation pathways in α-SMA-expressing CAF clusters. Conditional knockout of Atg5 in α-SMA+ CAFs promoted inflammatory re-programming in CAFs, reduced Treg cell infiltration and attenuated tumour development. Overall, our findings reveal an immunosuppressive mechanism entailing the formation of synapses between α-SMA+ CAFs and Tregs in an autophagy-dependent manner.

Insufficient PD-1 expression during active autoimmune responses: a deep single-cell proteomics analysis in inflammatory arthritis

Objectives

Programmed cell death protein-1 (PD-1) maintains peripheral immune tolerance by preventing T cell continuous activation. Aiming to understand the extent of PD-1 expression in inflammatory arthritis beyond its involvement with T cells, we assess its presence on various circulating single cells.

Methods

Mass cytometry analysis of patients with active seropositive/seronegative rheumatoid (RA; n=9/8) and psoriatic (PsA; n=9) arthritis versus healthy controls (HC; n=13), re-evaluating patients after 3 months of anti-rheumatic treatment.

Results

PD-1 was expressed in all leukocyte subpopulations, with the highest PD-1+ cell frequencies in eosinophils (59-73%) and T cells (50-60%), and the lowest in natural-killer cells (1-3%). PD-1+ cell frequencies and PD-1 median expression were comparable between patient subgroups and HC, in the majority of cell subsets. Exceptions included increases in certain T cell/B cell subsets of seropositive RA and specific monocyte subsets and dendritic cells of PsA; an expanded PD-1+CD4+CD45RA+CD27+CD28+ T subset, denoting exhausted T cells, was common across patient subgroups. Strikingly, significant inverse correlations between individual biomarkers of systemic inflammation (ESR and/or serum CRP) and PD-1+ cell frequencies and/or median expression were evident in several innate and adaptive immunity cell subsets of RA and PsA patients. Furthermore, all inverse correlations noted in individuals with active arthritis were no longer discernible in those who attained remission/low disease activity post-treatment.

Conclusion

PD-1 expression may be insufficient, relative to the magnitude of the concomitant systemic inflammatory response on distinct leukocyte subsets, varying between RA and PsA. Our results point to the potential therapeutic benefits of pharmacological PD-1 activation, to rebalance the autoimmune response and reduce inflammation.

Integrated analysis of single-cell and bulk RNA sequencing data reveals a myeloid cell-related regulon predicting neoadjuvant immunotherapy response across cancers

BACKGROUND

Immunotherapy has brought about a paradigm shift in the treatment of cancer. However, the majority of patients exhibit resistance or become refractory to immunotherapy, and the underlying mechanisms remain to be explored.

METHODS

Sing-cell RNA sequencing (scRNA‑seq) datasets derived from 1 pretreatment and 1 posttreatment achieving pathological complete response (pCR) patient with lung adenocarcinoma (LUAD) who received neoadjuvant immunotherapy were collected, and pySCENIC was used to find the gene regulatory network (GRN) between cell types and immune checkpoint inhibitor (ICI) response. A regulon predicting ICI response was identified and validated using large‑scale pan-cancer data, including a colorectal cancer scRNA‑seq dataset, a breast cancer scRNA‑seq dataset, The Cancer Genome Atlas (TCGA) pan-cancer cohort, and 5 ICI transcriptomic cohorts. Symphony reference mapping was performed to construct the myeloid cell map.

RESULTS

Thirteen major cluster cell types were identified by comparing pretreatment and posttreatment patients, and the fraction of myeloid cells was higher in the posttreatment group (19.0% vs. 11.8%). A PPARG regulon (containing 23 target genes) was associated with ICI response, and its function was validated by a colorectal cancer scRNA‑seq dataset, a breast cancer scRNA‑seq dataset, TCGA pan-cancer cohort, and 5 ICI transcriptomic cohorts. Additionally, a myeloid cell map was developed, and cluster I, II, and III myeloid cells with high expression of PPARG were identified. Moreover, we constructed a website called PPARG ( https://pparg.online/PPARG/ or http://43.134.20.130:3838/PPARG/ ), which provides a powerful discovery tool and resource value for researchers.

CONCLUSIONS

The PPARG regulon is a predictor of ICI response. The myeloid cell map enables the identification of PPARG subclusters in public scRNA-seq datasets and provides a powerful discovery tool and resource value.

PABPC1L Induces IDO1 to Promote Tryptophan Metabolism and Immune Suppression in Renal Cell Carcinoma

The tumor microenvironment (TME) in renal cell carcinomas (RCC) is marked by substantial immunosuppression and immune resistance despite having extensive T-cell infiltration. Elucidation of the mechanisms underlying immune evasion could help identify therapeutic strategies to boost the efficacy of immune checkpoint blockade (ICB) in RCC. This study uncovered a mechanism wherein the polyadenylate-binding protein PABPC1L modulates indoleamine 2,3-dioxygenase 1 (IDO1), a prospective target for immunotherapy. PABPC1L was markedly upregulated in RCC, and high PABPC1L expression correlated with unfavorable prognosis and resistance to ICB. PABPC1L bolstered tryptophan metabolism by upregulating IDO1, inducing T-cell dysfunction and Treg infiltration. PABPC1L enhanced the stability of JAK2 mRNA, leading to increased JAK2-STAT1 signaling that induced IDO1 expression. Additionally, PABPC1L-induced activation of the JAK2-STAT1 axis created a positive feedback loop to promote PABPC1L transcription. Conversely, loss of PABPC1L diminished IDO1 expression, mitigated cytotoxic T-cell suppression, and enhanced responsiveness to anti-PD-1 therapy in patient-derived xenograft models. These findings reveal the crucial role of PABPC1L in facilitating immune evasion in RCC and indicate that inhibiting PABPC1L could be a potential immunotherapeutic approach in combination with ICB to improve patient outcomes.

SIGNIFICANCE

PABPC1L functions as a key factor in renal cell carcinoma immune evasion, enhancing IDO1 and impeding T-cell function, and represents a potential target to enhance the efficacy of immune checkpoint blockade therapy.

Immune checkpoint inhibitor-associated cardiovascular toxicities: A review

Immune checkpoint inhibitors (ICIs) have revolutionary effects on therapeutic strategies for multiple malignancies. Their efficacy depends on their ability to reactivate the host immune system to fight cancer cells. However, adverse reactions to ICIs are common and involve several organs, limiting their use in clinical practice. Although the incidence of cardiovascular toxicity is relatively low, it is associated with serious consequences and high mortality rates. The primary cardiovascular toxicities include myocarditis, pericarditis, Takotsubo syndrome, arrhythmia, vasculitis, acute coronary syndrome, and venous thromboembolism. Currently, the mechanism underlying ICI-associated cardiovascular toxicity remains unclear and underexplored. The diagnosis and monitoring of ICI-associated cardiovascular toxicities mainly include the following indicators: symptoms, signs, laboratory examination, electrocardiography, imaging, and pathology. Treatments are based on the grade of cardiovascular toxicity and mainly include drug withdrawal, corticosteroid therapy, immunosuppressants, and conventional cardiac treatment. This review focuses on the incidence, underlying mechanisms, clinical manifestations, diagnoses, and treatment strategies.

Interleukin-2 signaling in the regulation of T cell biology in autoimmunity and cancer

Interleukin-2 (IL-2) is a critical cytokine for T cell peripheral tolerance and immunity. Here, we review how IL-2 interaction with the high-affinity IL-2 receptor (IL-2R) supports the development and homeostasis of regulatory T cells and contributes to the differentiation of helper, cytotoxic, and memory T cells. A critical element for each T cell population is the expression of CD25 (Il2rα), which heightens the receptor affinity for IL-2. Signaling through the high-affinity IL-2R also reinvigorates CD8+ exhausted T (Tex) cells in response to checkpoint blockade. We consider the molecular underpinnings reflecting how IL-2R signaling impacts these various T cell subsets and the implications for enhancing IL-2-dependent immunotherapy of autoimmunity, other inflammatory disorders, and cancer.

Cardiovascular events after cancer immunotherapy as oncologic emergencies: Analyses of 610 head and neck cancer patients treated with immune checkpoint inhibitors

BACKGROUND

Cardio-oncology and emergency medicine are closely collaborative, as many cardiac events in cancer patients require evaluation and treatment in the emergency department (ED). Immune checkpoint inhibitors (ICIs) have become a common treatment for patients with head and neck cancer (HNC). However, the immune-related adverse events (irAEs) from ICIs can be clinically significant.

METHODS

We reviewed and analyzed cardiovascular diagnoses among HNC patients who received ICI during the period April 1, 2016-December 31, 2020 in a large tertiary cancer center. Demographics, clinical and cancer-related data were abstracted, and billing databases were queried for cardiovascular disease (CVD)-related diagnosis using International Classification of Disease-version10 (ICD-10) codes. We recorded receipt of care at the ED as one of the outcome variables.

RESULTS

A total of 610 HNC patients with a median follow-up time of 12.3 months (median, interquartile range = 5-30 months) comprised our study cohort. Overall, 25.7% of patients had pre-existing CVD prior to ICI treatment. Of the remaining 453 patients without pre-existing CVD, 31.5% (n = 143) had at least one CVD-related diagnosis after ICI initiation. Tachyarrhythmias (91 new events) was the most frequent CVD-related diagnosis after ICI. The time to diagnosis of myocarditis from initiation of ICI occurred the earliest (median 2.5 months, 1.5-6.8 months), followed by myocardial infarction (3.7, 0.5-9), cardiomyopathy (4.5, 1.6-7.3), and tachyarrhythmias (4.9, 1.2-11.4). Patients with myocarditis and tachyarrhythmias mainly presented to the ED for care.

CONCLUSION

The use of ICI in HNC is still expanding and the spectrum of delayed manifestation of ICI-induced cardiovascular toxicities is yet to be fully defined in HNC survivors.

Immune-related adverse events in non-small cell lung cancer: Occurrence, mechanisms and therapeutic strategies

The emergence of immune checkpoint inhibitors (ICIs) has heralded a transformative era in the therapeutic landscape of non-small cell lung cancer (NSCLC). While ICIs have demonstrated clinical efficacy in a portion of patients with NSCLC, these treatments concurrently precipitate a spectrum of immune-related adverse events (irAEs), encompassing mild to severe manifestations, collectively posing a risk of significant organ damage. Consequently, there exists an imperative to augment our comprehension of the pathophysiological underpinnings of irAEs and to formulate more efficacious preventive and ameliorative strategies. In this comprehensive review, we delineate the clinical presentation of organ-specific irAEs in patients with NSCLC and provide an in-depth analysis of recent advancements in understanding the mechanisms driving ICI-induced toxicity. Furthermore, we discuss potential strategies and targets for ameliorating these irAEs. Ultimately, this review aims to furnish valuable insights to guide further research endeavours in the context of irAEs in NSCLC patients.

FSTL3 promotes tumor immune evasion and attenuates response to anti-PD1 therapy by stabilizing c-Myc in colorectal cancer

Programmed cell death 1 ligand 1 (PDL1)/programmed cell death 1 (PD1) blockade immunotherapy provides a prospective strategy for the treatment of colorectal cancer (CRC), but various constraints on the effectiveness of the treatment are still remaining. As reported in previous studies, follistatin-like 3 (FSTL3) could mediate inflammatory response in macrophages by induction lipid accumulation. Herein, we revealed that FSTL3 were overexpressed in malignant cells in the CRC microenvironment, notably, the expression level of FSTL3 was related to tumor immune evasion and the clinical efficacy of anti-PD1 therapy. Further studies determined that hypoxic tumor microenvironment induced the FSTL3 expression via HIF1α in CRC cells, FSTL3 could bind to the transcription factor c-Myc (354-406 amino acids) to suppress the latter's ubiquitination and increase its stability, thereby to up-regulated the expression of PDL1 and indoleamine 2,3-dioxygenase 1 (IDO1). The results in the immunocompetent tumor models verified that FSLT3 knockout in tumor cells increased the proportion of CD8+ T cells in the tumor microenvironment, reduced the proportion of regulatory T cells (CD25+ Foxp3+) and exhausted T cells (PD1+ CD8+), and synergistically improved the anti-PD1 therapy efficacy. To sum up, FSTL3 enhanced c-Myc-mediated transcriptional regulation to promote immune evasion and attenuates response to anti-PD1 therapy in CRC, suggesting the potential of FSTL3 as a biomarker of immunotherapeutic efficacy as well as a novel immunotherapeutic target in CRC.

A case of refractory immune checkpoint inhibitor-induced colitis improved by the treatment with vedolizumab and granulocyte-monocyte apheresis combination therapy

A 68-year-old man developed immune-related adverse event (irAE) colitis after the initiation of nivolumab and ipilimumab combination therapy for malignant melanoma. We diagnosed the patient with grade 3 irAE colitis and started prednisolone (1 mg/kg/day). Although the symptom improved once, it worsened along with the tapering of prednisolone. Therefore, we started infliximab (IFX). However, symptoms did not improve after two doses of IFX. We discontinued IFX and initiated vedolizumab (VED). Because VED alone did not improve the symptom, we started granulocyte-monocyte apheresis (GMA). Twelve weeks after the onset, the colitis was in remission. Therefore, in addition to vedolizumab, GMA may be considered in cases refractory to treatment.

Comparative efficacy and safety of novel immuno-chemotherapy for extensive-stage small-cell lung cancer: a network meta-analysis of randomized controlled trial

Background

Recently, several new first-line immune checkpoint inhibitors (ICIs) plus chemotherapy have been approved for patients with extensive-stage small-cell lung cancer (ES-SCLC). However, direct comparisons between first-line treatments are lacking. Therefore, we indirectly compared the efficacy and safety of specific treatment strategies to inform physicians' and patients' clinical decisions.

Methods

The Pubmed, Cochrane, Embase, and Web of Science databases were searched from 1 January 2000 to 27 November 2022, for randomized clinical trials (RCTs) assessing first-line immuno-chemotherapies for ES-SCLC. A fixed-effect multivariable meta-regression model was established for frequentist network meta-analysis and hazard ratios (HRs) with 95% confidence intervals (95% CI) were computed to compare the effects of immuno-chemotherapies on patient overall survival (OS) and progression-free survival (PFS), while risk ratios with 95% CI were used for treatment- and immune-related adverse events (AEs). The p score values were then used to rank treatments based on their odds of being the best treatment option. The research protocol was registered with the PROSPERO (CRD42022383254).

Results

Seven studies involving 3822 patients were eligible for analysis. Serplulimab plus chemotherapy had better OS outcomes compared to chemotherapy (HR = 0.63; 95% CI: 0.49-0.82) and ipilimumab plus chemotherapy (HR = 0.67; 95% CI: 0.50-0.90). It additionally exhibited better PFS outcomes compared to chemotherapy (HR = 0.48; 95% CI: 0.39-0.60), adebrelimab (HR = 0.72; 95% CI: 0.53-0.97), atezolizumab (HR = 0.62; 0.46-0.85), durvalumab (HR = 0.60; 95% CI: 0.45-0.80), durvalumab and tremelimumab (HR = 0.57; 95% CI: 0.43-0.76), ipilimumab (HR = 0.57; 95% CI: 0.44-0.73), and pembrolizumab (HR = 0.64; 95% CI: 0.48-0.86) plus chemotherapy. Serplulimab plus chemotherapy was linked to the greatest odds of effectively reducing the odds of death (p score = 0.87) and progression (p score = 0.99) while exhibiting a good safety profile.

Conclusion

Serplulimab plus chemotherapy exhibited the best survival outcomes with manageable AEs. Thus, serplulimab plus chemotherapy may represent the optimal best first-line treatment option for ES-SCLC patients.

Prognostic value of systemic inflammation response index in hepatoblastoma patients receiving preoperative neoadjuvant chemotherapy

Introduction

Inflammation is closely associated with tumor development and patient prognosis. The objective of this study is to assess the prognostic value of the preoperative inflammatory indexes in pediatric hepatoblastoma patients who receive neoadjuvant chemotherapy.

Methods

A retrospective analysis was performed on clinical and pathological data of 199 hepatoblastoma patients who underwent hepatectomy with preoperative neoadjuvant chemotherapy from January 2015 to June 2020. The receiver operating characteristic curve was used to evaluate the prognostic value of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI) in predicting OS and EFS. Patients were grouped based on optimal cutoff values of preoperative inflammatory indexes. Survival rates were calculated using the Kaplan-Meier method, and survival outcomes were compared between groups using the log-rank test. Univariate and multivariate Cox proportional hazards regression models were used to identify independent prognostic factors, and a nomogram was constructed using R software to predict the probability of OS.

Results

The receiver operating characteristic curve showed prognostic value for OS, not EFS, in preoperative inflammatory indexes. Patients were categorized into low/high groups: SII ≤ 266.70/higher, NLR ≤ 1.24/higher, PLR ≤ 85.25/higher, and SIRI ≤ 0.72/higher. High NLR, PLR, SII, and SIRI groups had significantly lower 5-year OS than their low counterparts (all p-value < 0.05). The Cox analysis identified four independent prognostic factors: SIRI (HR=2.997, 95% CI: 1.119-8.031), microvascular invasion (HR=2.556, 95% CI: 1.14-5.73), the post-treatment extent of disease (POSTTEXT) staging (IV vs. I: HR=244.204, 95% CI:11.306-5274.556), and alpha-fetoprotein (>100 ng/ml: HR=0.11, 95% CI: 0.032-0.381) for hepatoblastoma patients with neoadjuvant chemotherapy. High SIRI group had more patients with adverse NLR, SII, and POSTTEXT III (all p-value < 0.05). Independent prognostic factors led to an OS nomogram with a concordance index of 0.85 (95% CI: 0.78-0.91, p-value = 1.43e-27) and the calibration curve showed a good fit between the prediction curve and the true curve.

Conclusions

SIRI is an independent prognostic factor of hepatoblastoma patients receiving neoadjuvant chemotherapy. The OS nomogram based on SIRI, POSTTEXT staging, MiVI, and AFP can be used to assess the prognosis of those patients.

Efficacy, safety, and biomarker analysis of nivolumab in combination with abemaciclib plus endocrine therapy in patients with HR-positive HER2-negative metastatic breast cancer: a phase II study (WJOG11418B NEWFLAME trial)

BACKGROUND

Hormone receptor (HR)-positive breast cancer is a disease for which no immune checkpoint inhibitors have shown promise as effective therapies. Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors synergistically increased the effectiveness of antiprogrammed cell death protein-1 (anti-PD-1)/programmed death-ligand 1 (PD-L1) antibodies in preclinical studies.

METHODS

This non-randomized, multicohort, phase II study evaluated the efficacy and safety of the anti-PD-1 antibody nivolumab 240 mg administered every 2 weeks in combination with the CDK4/6 inhibitor abemaciclib 150 mg twice daily and either fulvestrant (FUL) or letrozole (LET) as a first-line or second-line treatment for HR-positive HER2-negative metastatic breast cancer. The primary end point was the objective response rate (ORR), and secondary end points were toxicity, progression-free survival, and overall survival. Blood, tissue, and fecal samples were collected at multiple points for correlative studies to evaluate immunity biomarkers.

RESULTS

From June 2019 to early study termination due to safety concerns on July 2020, 17 patients were enrolled (FUL: n=12, LET: n=5). One patient with a prior treatment history in the FUL cohort was excluded. ORRs were 54.5% (6/11) and 40.0% (2/5) in the FUL and LET cohorts, respectively. Treatment-emergent (TE) adverse events (AEs) of grade ≥3 occurred in 11 (92%) and 5 (100%) patients in the FUL and LET cohorts, respectively. The most common grade ≥3 TEAEs were neutropenia (7 (58.3%) and 3 (60.0%) in the FUL and LET cohorts, respectively), followed by alanine aminotransferase elevation (5 (41.6%) and 4 (80.0%)). One treatment-related death from interstitial lung disease occurred in the LET cohort. Ten patients developed liver-related grade ≥3 AEs. Liver biopsy specimens from 3 patients showed hepatitis characterized by focal necrosis with predominant CD8+ lymphocyte infiltration. Marked elevation of tumor necrosis factor-related cytokines and interleukin-11, and a decrease in peripheral regulatory T cells (Tregs), were observed in patients with hepatotoxicity. These findings suggest that treatment-related toxicities were immune-related AEs likely caused by proinflammatory cytokine production and suppression of Treg proliferation due to the addition of abemaciclib to nivolumab therapy.

CONCLUSIONS

Although the combination of nivolumab and abemaciclib was active, it caused severe and prolonged immune-related AEs.

TRIAL REGISTRATION NUMBER

JapicCTI-194782, jRCT2080224706, UMIN000036970.

Differentiation, regulation and function of regulatory T cells in non-lymphoid tissues and tumors

Regulatory T cells (Tregs) play a substantial role in inhibiting excessive immune response. A large number of studies have focused on the tissue homeostasis maintenance and remodeling characteristics of Tregs in non-lymphoid tissues, such as the skin, colon, lung, brain, muscle, and adipose tissues. Herein, we overview the kinetics of Treg migration to non-lymphoid tissues and adaptation to the specific tissue microenvironment through the development of tissue-specific chemokine receptors, transcription factors, and phenotypes. Additionally, tumor-infiltrating Tregs (Ti-Tregs) play an important role in tumor generation and immunotherapy resistance. The phenotypes of Ti-Tregs are related to the histological location of the tumor and there is a large overlap between the transcripts of Ti-Tregs and those of tissue-specific Tregs. We recapitulate the molecular underpinnings of tissue-specific Tregs, which might shed new light on Treg-based therapeutic targets and biomarkers for inflammatory diseases and cancer.

Lighting Up the Fire in the Microenvironment of Cold Tumors: A Major Challenge to Improve Cancer Immunotherapy

Immunotherapy includes immune checkpoint inhibitors (ICI) such as antibodies targeting cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) or the programmed cell death protein/programmed death ligand 1 (PD-1/PD-L1) axis. Experimental and clinical evidence show that immunotherapy based on immune checkpoint inhibitors (ICI) provides long-term survival benefits to cancer patients in whom other conventional therapies have failed. However, only a minority of patients show high clinical benefits via the use of ICI alone. One of the major factors limiting the clinical benefits to ICI can be attributed to the lack of immune cell infiltration within the tumor microenvironment. Such tumors are classified as "cold/warm" or an immune "desert"; those displaying significant infiltration are considered "hot" or inflamed. This review will provide a brief summary of different tumor properties contributing to the establishment of cold tumors and describe major strategies that could reprogram non-inflamed cold tumors into inflamed hot tumors. More particularly, we will describe how targeting hypoxia can induce metabolic reprogramming that results in improving and extending the benefit of ICI.

Human small intestine contains 2 functionally distinct regulatory T-cell subsets

BACKGROUND

Regulatory T (Treg) CD4 cells in mouse gut are mainly specific for intestinal antigens and play an important role in the suppression of immune responses against harmless dietary antigens and members of the microbiota. However, information about the phenotype and function of Treg cells in the human gut is limited.

OBJECTIVE

We performed a detailed characterization of Foxp3+ CD4 Treg cells in human normal small intestine (SI) as well as from transplanted duodenum and celiac disease lesions.

METHODS

Treg cells and conventional CD4 T cells derived from SI were subjected to extensive immunophenotyping and their suppressive activity and ability to produce cytokines assessed.

RESULTS

SI Foxp3+ CD4 T cells were CD45RA-CD127-CTLA-4+ and suppressed proliferation of autologous T cells. Approximately 60% of Treg cells expressed the transcription factor Helios. When stimulated, Helios-negative Treg cells produced IL-17, IFN-γ, and IL-10, whereas Helios-positive Treg cells produced very low levels of these cytokines. By sampling mucosal tissue from transplanted human duodenum, we demonstrated that donor Helios-negative Treg cells persisted for at least 1 year after transplantation. In normal SI, Foxp3+ Treg cells constituted only 2% of all CD4 T cells, while in active celiac disease, both Helios-negative and Helios-positive subsets expanded 5- to 10-fold.

CONCLUSION

The SI contains 2 subsets of Treg cells with different phenotypes and functional capacities. Both subsets are scarce in healthy gut but increase dramatically in active celiac disease.

Robust IL-2-dependent antitumor immunotherapy requires targeting the high-affinity IL-2R on tumor-specific CD8+ T cells

BACKGROUND

Development of interleukin (IL)-2-dependent antitumor responses focus on targeting the intermediate affinity IL-2R to stimulate memory-phenotypic CD8+ T and natural killer (NK) cells while minimizing regulatory T cell (Treg) expansion. However, this approach may not effectively engage tumor-specific T effector cells. Since tumor-antigen specific T cells upregulate the high-affinity IL-2R, we tested an IL-2 biologic, mouse IL-2/CD25, with selectivity toward the high-affinity IL-2R to support antitumor responses to tumors that vary in their immunogenicity.

METHODS

Mice were first implanted with either CT26, MC38, B16.F10, or 4T1 and after a tumor mass developed, they were treated with high-dose (HD) mouse (m)IL-2/CD25 alone or in combination with anti-programmed cell death protein-1 (PD-1) checkpoint blockade. Tumor growth was monitored and in parallel the immune signature in the tumor microenvironment (TME) was determined by a combination of multiparameter flow cytometry, functional assays, and enumeration of tumor-reactive T cells.

RESULTS

We show that HD mIL-2/CD25, which preferentially stimulates the high-affinity IL-2R, but not IL-2/anti-IL-2 complexes with preferential activity toward the intermediate-affinity IL-2R, supports vigorous antitumor responses to immunogenic tumors as a monotherapy that were enhanced when combined with anti-PD-1. Treatment of CT26-bearing mice with HD mIL-2/CD25 led to a high CD8+:Treg ratio in the TME, increased frequency and function of tumor-specific CD8+ T effector cells with a less exhausted phenotype, and antitumor memory responses.

CONCLUSIONS

Targeting the high-affinity IL-2R on tumor-specific T cells with HD mIL-2/CD25 alone or with PD-1 blockade supports antitumor responses, where the resulting memory response may afford long-term protection against tumor re-emergence.

Molecularly imprinted polymers (MIPs): emerging biomaterials for cancer theragnostic applications

Cancer is a disease caused by abnormal cell growth that spreads through other parts of the body and threatens life by destroying healthy tissues. Therefore, numerous techniques have been employed not only to diagnose and monitor the progress of cancer in a precise manner but also to develop appropriate therapeutic agents with enhanced efficacy and safety profiles. In this regard, molecularly imprinted polymers (MIPs), synthetic receptors that recognize targeted molecules with high affinity and selectivity, have been intensively investigated as one of the most attractive biomaterials for theragnostic approaches. This review describes diverse synthesis strategies to provide the rationale behind these synthetic antibodies and provides a selective overview of the recent progress in the in vitro and in vivo targeting of cancer biomarkers for diagnosis and therapeutic applications. Taken together, the topics discussed in this review provide concise guidelines for the development of novel MIP-based systems to diagnose cancer more precisely and promote successful treatment. Molecularly imprinted polymers (MIPs), synthetic receptors that recognize targeted molecules with high affinity and selectivity, have been intensively investigated as one of the most attractive biomaterials for cancer theragnostic approaches. This review describes diverse synthesis strategies to provide the rationale behind these synthetic antibodies and provides a selective overview of the recent progress in the in vitro and in vivo targeting of cancer biomarkers for diagnosis and therapeutic applications. The topics discussed in this review aim to provide concise guidelines for the development of novel MIP-based systems to diagnose cancer more precisely and promote successful treatment.

Immunoprofiling bronchoalveolar lavage cells reveals multifaceted smoking-associated immune dysfunction

Background

Bronchoalveolar lavage (BAL) is an underutilised tool in the search for pulmonary disease biomarkers. While leukocytes with effector and suppressor function play important roles in airway immunity and tumours, it remains unclear if frequencies and phenotypes of BAL leukocytes can be useful parameters in lung cancer studies and clinical trials. We therefore explored the utility of BAL leukocytes as a source of biomarkers interrogating the impact of smoking, a major lung cancer risk determinant, on pulmonary immunity.

Methods

In this "test case" observational study, BAL samples from 119 donors undergoing lung cancer screening and biopsy procedures were evaluated by conventional and spectral flow cytometry to exemplify the comprehensive immune analyses possible with this biospecimen. Proportions of major leukocyte populations and phenotypic markers levels were found. Multivariate linear rank sum analysis considering age, sex, cancer diagnosis and smoking status was performed.

Results

Significantly increased frequencies of myeloid-derived suppressor cells and PD-L1-expressing macrophages were found in current and former smokers compared to never-smokers. While cytotoxic CD8 T-cells and conventional CD4 helper T-cell frequencies were significantly reduced in current and former smokers, expression of immune checkpoints PD-1 and LAG-3 as well as Tregs proportions were increased. Lastly, the cellularity, viability and stability of several immune readouts under cryostorage suggested BAL samples are useful for correlative end-points in clinical trials.

Conclusions

Smoking is associated with heightened markers of immune dysfunction, readily assayable in BAL, that may reflect a permissive environment for cancer development and progression in the airway.

Kindlin-1 regulates IL-6 secretion and modulates the immune environment in breast cancer models

The adhesion protein Kindlin-1 is over-expressed in breast cancer where it is associated with metastasis-free survival; however, the mechanisms involved are poorly understood. Here, we report that Kindlin-1 promotes anti-tumor immune evasion in mouse models of breast cancer. Deletion of Kindlin-1 in Met-1 mammary tumor cells led to tumor regression following injection into immunocompetent hosts. This was associated with a reduction in tumor infiltrating Tregs. Similar changes in T cell populations were seen following depletion of Kindlin-1 in the polyomavirus middle T antigen (PyV MT)-driven mouse model of spontaneous mammary tumorigenesis. There was a significant increase in IL-6 secretion from Met-1 cells when Kindlin-1 was depleted and conditioned media from Kindlin-1-depleted cells led to a decrease in the ability of Tregs to suppress the proliferation of CD8+ T cells, which was dependent on IL-6. In addition, deletion of tumor-derived IL-6 in the Kindlin-1-depleted tumors reversed the reduction of tumor-infiltrating Tregs. Overall, these data identify a novel function for Kindlin-1 in regulation of anti-tumor immunity, and that Kindlin-1 dependent cytokine secretion can impact the tumor immune environment.

Advances in immune checkpoint inhibitors induced-cardiotoxicity

Immune checkpoint inhibitors (ICIs) are approved as the first-line drug for treating many cancers and has shown significant survival benefits; however, it also causes immune-related adverse events (irAEs) while activating the immune system, involving multiple organs. Among them, cardiovascular immune-related adverse events (CV-irAE) are rare, but common causes of death in ICIs treated cancer patients, which manifest as myocardial, pericardial, vascular and other cardiovascular toxicities. Therefore, it is important that irAEs, especially CV-irAE should be carefully recognized and monitored during the whole ICIs treatment because early detection and treatment of CV-irAE can significantly reduce the mortality of such patients. Consequently, it is urgent to fully understand the mechanism and management strategies of CV-irAE. The effects of ICIs are multifaceted and the exact mechanism of CV-irAE is still elusive. Generally, T cells identify tumor cell antigens as well as antigen in cardiomyocytes that are the same as or homologous to those on tumor cells, thus causing myocardial damage. In addition, ICIs promote formation of cardiac troponin I (cTnI) that induces cardiac dysfunction and myocardial dilatation; moreover, ICIs also increase the production of cytokines, which promote infiltration of inflammation-linked molecules into off-target tissues. Currently, the management and treatment of cardiovascular toxicity are largely dependent on glucocorticoids, more strategies for prevention and treatment of CV-irAE, such as predictive markers are being explored. This review discusses risk factors, potential pathophysiological mechanisms, clinical manifestations, and management and treatment of CV-irAE, guiding the development of more effective prevention, treatment and management strategies in the future.

Efficacy and safety of PD-1/PD-L1 plus CTLA-4 antibodies ± other therapies in lung cancer: a systematic review and meta-analysis

PURPOSE

To investigate the efficacy and safety of programmed cell death 1 (PD-1)/programmed cell death-ligand 1 (PD-L1) plus cytotoxic T lymphocyte antigen-4 (CTLA-4) antibodies ± other therapies in patients with advanced lung cancer.

METHODS

In accordance with the retrieval strategy, we searched electronic databases for randomised controlled trials testing PD-1/PD-L1 plus CTLA-4 antibodies in patients with lung cancer; RR (for objective response rate (ORR), overall survival (OS), progression-free survival (PFS), and immune-related adverse events (irAEs)) from individual studies were calculated and pooled by using random-effects models or fixed-effects models; heterogeneity and publication bias analyses were also performed, using Review Manager 5.3 and Stata 15.1 for statistical analysis.

RESULTS

We included six studies. Four different immune checkpoint inhibitors (nivolumab, pembrolizumab, durvalumab, tremelimumab) were used. Dual checkpoint inhibitors ± other therapies for advanced lung cancer showed significant improvements in ORR (RR 1.49, 95% CI 1.11 to 1.98; p=0.007), OS (HR 0.72, 95% CI 0.63 to 0.83; p<0.00001), and PFS (HR 0.72, 95% CI 0.63 to 0.82; p<0.00001). The subgroup analyses were consistent with the pooled results. The PD-L1 ≥1% (HR 0.67, 95% CI 0.54 to 0.82; p<0.0001) subgroup differences indicated a statistically significant subgroup effect, but the PD-L1 <1% subgroup (HR 0.88, 95% CI 0.75 to 1.05; p=0.15) was not statistically significant. The incidence of adverse events (grade ≥3) was lower than that of the control group (RR 0.90, 95% CI 0.80 to 1.02; p=0.09), but was not significant.

CONCLUSIONS

PD-1/PD-L1 inhibitors combined with CTLA-4 inhibitors ± other therapies can improve the ORR, OS and PFS of patients with advanced or metastatic lung cancer, but the incidence of adverse reactions is high although generally tolerable.

PROSPERO REGISTRATION

CRD42020149216.

Presence of regulatory T-cells in endometrial cancer predicts poorer overall survival and promotes progression of tumor cells

PURPOSE

Endometrial cancer (EC) is one of the most common gynaecologic malignancies. Tumor infiltrating regulatory T-cells (Treg) have been reported to have a prognostic impact in many malignancies. Immunotherapeutic strategies are gaining interest for advanced and recurrent EC cases, where treatment options are rare. Our study was aimed at determining the value of Treg in EC progression.

METHODS

EC specimens from 275 patients and 28 controls were screened immunohistochemically for the presence of Treg represented by FoxP3. Correlations with clinicopathological and survival parameters were performed. Functional assays were performed using EC cell lines Ishikawa + and RL95-2 after co-culturing with isolated CD4 + CD25 + CD127dim Treg. To assess the influence of EC on the composition of peripheral blood mononuclear cells (PBMC), flow cytometric analyses were performed.

RESULTS

We found that an increased infiltration of Treg was associated with high grades and a reduced overall survival. Treg were almost absent in endometrium tissues from healthy control patients. Co-culture of tumor cells with CD4 + CD25 + CD127dim Treg led to functional changes: enhanced invasion, migration and viability indicated that increased levels of Treg in the tumor microenvironment may promote tumor growth. Furthermore, we found that the presence of EC cells led to phenotypic changes in PBMC, showing significantly increased levels of CD25 and FoxP3.

CONCLUSION

Our results indicate that the presence of Treg in the EC tumor environment is associated with a poorer outcome. A remarkable impact of Treg on tumor cell behaviour and vice versa of tumor cells on PBMC subpopulations support this notion mechanistically. Our findings provide a basis for focusing on Treg as potential future therapeutic targets in EC.

The effect of metformin or dipeptidyl peptidase 4 inhibitors on clinical outcomes in metastatic non-small cell lung cancer treated with immune checkpoint inhibitors

BACKGROUND

Preclinical data have shown the immunomodulatory effects of metformin and dipeptidyl peptidase 4 (DPP4) inhibitors in patients with diabetes. However, its clinical impact remains unclear in lung cancer.

METHODS

Between 2017 and 2021, 466 patients received ICI monotherapy. Patients were categorized into concurrent (MET; metformin or combination of metformin and DPP4 inhibitor) and without concomitant (NMET; nonmetformin/DPP4 inhibitors) administration of metformin and DPP4 inhibitors groups at least 8 weeks before and during ICI therapy. The primary objectives were the objective response rate (ORR) and progression-free survival (PFS). The second objective was to evaluate the overall survival (OS) and the occurrence of immune-related adverse events (irAEs).

RESULTS

Among 466 patients, 89 (19.0%) and 377 (81%) were categorized into the MET and NMET groups, respectively. MET group had a significantly higher ORR (MET group: 24.7% vs. NMET group: 14.8%, p = 0.025) and longer PFS than those in the NMET group (MET group 5.1 month vs. NMET group 2.8 months, p = 0.018). After patients were stratified based on the prior line of therapy and PD L1 expression status, the PFS of the second-line therapy and PD L1 ≥50 was significantly higher in the MET than in the NMET group. The proportion of patients experiencing all-grade irAEs was numerically higher in the MET group (19.1%) than in the NMET group (14.3%), without statistical significance (p = 0.382).

CONCLUSIONS

Concurrent use of metformin and DPP4 inhibitors with ICIs significantly improved the clinical outcomes without increasing the incidence of irAEs in NSCLC.

Two novel predictive biomarkers for osteosarcoma and glycolysis pathways: A profiling study on HS2ST1 and SDC3

INTRODUCTION

Prognostic biomarkers for osteosarcoma (OS) are still very few, and this study aims to examine 2 novel prognostic biomarkers for OS through combined bioinformatics and experimental approach.

MATERIALS AND METHODS

Expression profile data of OS and paraneoplastic tissues were downloaded from several online databases, and prognostic genes were screened by differential expression analysis, Univariate Cox analysis, least absolute shrinkage and selection operator regression analysis, and multivariate Cox regression analysis to construct prognostic models. The accuracy of the model was validated using principal component analysis, constructing calibration plots, and column line plots. We also analyzed the relationship between genes and drug sensitivity. Gene expression profiles were analyzed by immunocytotyping. Also, protein expressions of the constructed biomarkers in OS and paraneoplastic tissues were verified by immunohistochemistry.

RESULTS

Heparan sulfate 2-O-sulfotransferase 1 (HS2ST1) and Syndecan 3 (SDC3, met all our requirements after screening. The constructed prognostic model indicated that patients in the high-risk group had a much lower patient survival rate than in the low-risk group. Moreover, these genes were closely related to immune cells (P < .05). Drug sensitivity analysis showed that the 2 genes modeled were strongly correlated with multiple drugs. Immunohistochemical analysis showed significantly higher protein expression of both genes in OS than in paraneoplastic tissues.

CONCLUSIONS

HS2ST1 and SDC3 are significantly dysregulated in OS, and the prognostic models constructed based on these 2 genes have much lower survival rates in the high-risk group than in the low-risk group. HS2ST1 and SDC3 can be used as glycolytic and immune-related prognostic biomarkers in OS.

CD40 monoclonal antibody and OK432 synergistically promote the activation of dendritic cells in immunotherapy

Background

Colorectal cancer (CRC) with pulmonary metastasis usually indicates a poor prognosis, whereas patients may benefit from adoptive cell therapy. Tumor-specific cytotoxic T lymphocytes (CTLs) have been reported as a promising treatment for CRC. However, the antitumor effect of CTLs remains limited partially due to insufficient production of effector cells via the activation by antigen-presenting dendritic cells (DCs).

Method

This study showed that a combination of CD40 mAb and Picibanil (OK-432) could significantly enhance the activation of CTLs by DCs, both in vitro and in vivo. Flow cytometry, colon cancer mouse model, and pathological staining were employed to demonstrate the specific functions.

Results

This approach promoted the maturation of DCs, augmented the production of stimulatory cytokines, and suppressed the secretion of inhibitory cytokines. Additionally, it facilitated the killing efficiency of CTLs via stimulating their proliferation while restraining the number of Tregs, concomitantly with the positive regulation of corresponding cytokines. Furthermore, the combined unit could hurdle the expansion of tumor cells on metastatic lungs in the colon cancer mouse model.

Conclusion

Collectively, the combination of CD40-mAb and OK-432 facilitated the maturation of DCs and enhanced the cytotoxicity of T cells, promising therapeutic approach against CRC.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02630-x.

Emerging Management Approach for the Adverse Events of Immunotherapy of Cancer

Immunotherapy, which stimulates the body’s immune system, has received a considerable amount of press in recent years because of its powerful benefits. Cancer immunotherapy has shown long-term results in patients with advanced disease that are not seen with traditional chemotherapy. Immune checkpoint inhibitors, cytokines like interleukin 2 (IL-2) and interferon-alpha (IFN), and the cancer vaccine sipuleucel-T have all been licensed and approved by the FDA for the treatment of various cancers. These immunotherapy treatments boost anticancer responses by stimulating the immune system. As a result, they have the potential to cause serious, even fatal, inflammatory and immune-related side effects in one or more organs. Immune checkpoint inhibitors (ICPIs) and chimeric antigen receptor (CAR) T-cell therapy are two immunotherapy treatments that are increasingly being used to treat cancer. Following their widespread usage in the clinic, a wave of immune-related adverse events (irAEs) impacting virtually every system has raised concerns about their unpredictability and randomness. Despite the fact that the majority of adverse effects are minimal and should be addressed with prudence, the risk of life-threatening complications exists. Although most adverse events are small and should be treated with caution, the risk of life-threatening toxicities should not be underestimated, especially given the subtle and unusual indications that make early detection even more difficult. Treatment for these issues is difficult and necessitates a multidisciplinary approach involving not only oncologists but also other internal medicine doctors to guarantee quick diagnosis and treatment. This study’s purpose is to give a fundamental overview of immunotherapy and cancer-related side effect management strategies.

Eosinophils and melanoma: Implications for immunotherapy

New therapies such as immune checkpoint blockers (ICB) have offered extended survival to patients affected by advanced melanoma. However, ICBs have demonstrated debilitating side effects on the joints, liver, lungs, skin, and gut. Several biomarkers have been identified for their role in predicting which patients better tolerate ICBs. Still, these biomarkers are limited by immunologic and genetic heterogeneity and the complexity of translation into clinical practice. Recent observational studies have suggested eosinophil counts, and serum levels of eosinophil cationic protein are significantly associated with prolonged survival in advanced-stage melanoma. It is likely that eosinophils thereby modulate treatment response through mechanisms yet to be explored. Here, we review the functionality of eosinophils, their oncogenic role in melanoma and discuss how these mechanisms may influence patient response to ICBs and their implications in clinical practice.

Steatosis, Steatohepatitis and Cancer Immunotherapy: An Intricate Story

Immune checkpoint inhibitors represent one of the most significant recent advances in clinical oncology, since they dramatically improved the prognosis of deadly cancers such as melanomas and lung cancer. Treatment with these drugs may be complicated by the occurrence of clinically-relevant adverse drug reactions, most of which are immune-mediated, such as pneumonitis, colitis, endocrinopathies, nephritis, Stevens Johnson syndrome and toxic epidermal necrolysis. Drug-induced steatosis and steatohepatitis are not included among the typical forms of cancer immunotherapy-induced liver toxicity, which, instead, usually occurs as a panlobular hepatitis with prominent lymphocytic infiltrates. Nonetheless, non-alcoholic fatty liver disease is a risk factor for immunotherapy-induced hepatitis, and steatosis and steatohepatitis are frequently observed in this condition. In the present review we discuss how these pathology findings could be explained in the context of current models suggesting immune-mediated pathogenesis for steatohepatitis. We also review evidence suggesting that in patients with hepatocellular carcinoma, the presence of steatosis or steatohepatitis could predict a poor therapeutic response to these agents. How these findings could fit with immune-mediated mechanisms of these liver diseases will also be discussed.

Therapeutic Targeting of Cancer: Epigenetic Homeostasis

A large number of studies have revealed that epigenetics plays an important role in cancer development. However, the currently-developed epigenetic drugs cannot achieve a stable curative effect. Thus, it may be necessary to redefine the role of epigenetics in cancer development. It has been shown that embryonic development and tumor development share significant similarities in terms of biological behavior and molecular expression patterns, and epigenetics may be the link between them. Cell differentiation is likely a manifestation of epigenetic homeostasis at the cellular level. In this article, we introduced the importance of epigenetic homeostasis in cancer development and analyzed the shortcomings of current epigenetic treatment regimens. Understanding the dynamic process of epigenetic homeostasis in organ development can help us characterize cancer according to its differentiation stages, explore new targets for cancer treatment, and improve the clinical prognosis of patients with cancer.

Regulatory T Cells in Autoimmunity and Cancer: A Duplicitous Lifestyle

Regulatory T (Treg) cells, possess a strategic role in the maintenance of immune homeostasis, and their function has been closely linked to development of diverse pathologies including autoimmunity and cancer. Comprehensive studies in various disease contexts revealed an increased plasticity as a characteristic of Treg cells. Although Treg cell plasticity comes in various flavors, the major categories enclose the loss of Foxp3 expression, which is the master regulator of Treg cell lineage, giving rise to “ex-Treg” cells and the “fragile” Treg cells in which FOXP3 expression is retained but accompanied by the engagement of an inflammatory program and attenuation of the suppressive activity. Treg cell plasticity possess a tremendous therapeutic potential either by inducing Treg cell de-stabilization to promote anti-tumor immunity, or re-enforcing Treg cell stability to attenuate chronic inflammation. Herein, we review the literature on the Treg cell plasticity with lessons learned in autoimmunity and cancer and discuss challenges and open questions with potential therapeutic implications.

[Research Progress of Immune Checkpoint Inhibitor-associated Myocarditis]

免疫检查点抑制剂（immune checkpoint inhibitors, ICIs）是一种负性调节因子抗体，激活T细胞发挥免疫治疗抗肿瘤作用的同时，也可引起免疫相关的不良应答，从而诱导出一系列免疫相关不良反应（immune related adverse events, irAEs）。在这些irAEs中，ICIs相关心肌炎的发病率虽然很低，但致死率却明显高于其他不良反应，接近50%，临床医生应用ICIs时应提高警惕，但目前ICIs相关心肌炎的发病机制仍不明确。本文结合近期ICIs的研究成果对ICIs相关性心肌炎的发生机制及临床表现等方面作一综述，以提高临床医生对该不良反应的认识。

High Levels of Thyroid Hormone Impair Regulatory T Cell Function Via Reduced PD-1 Expression

CONTEXT

Regulatory T cell (Treg) dysfunction plays an important role in the development and progression of Graves' disease (GD). Programmed cell death 1 (PD-1) prompts FoxP3 in Treg expression and enhances the suppressive activity of Tregs. Whether abnormal expression of PD-1 contributes to the breakdown of Tregs and the role of thyroid hormone in the PD-1 expression of Tregs in GD remain substantially undefined.

OBJECTIVE

To evaluate the role of PD-1 in Treg function and triiodothyronine (T3) in PD-1 expression in patients with GD and mice treated with T3.

METHODS

We recruited 30 patients with GD and 30 healthy donors. PD-1 expression in Tregs and Treg function were determined. To evaluate the effects of thyroid hormone on PD-1 expression in Tregs, we used T3 for the treatment of human peripheral blood mononuclear cells (PBMCs). We then treated mice with T3 to confirm the effect of thyroid hormone on PD-1 expression in Tregs and Tregs function in vivo.

RESULTS

PD-1 expression in Tregs and the suppressive function of Tregs significantly decreased in patients with GD. T3 reduced PD-1 expression in human Tregs in a concentration- and time-dependent manner in vitro. High levels of circulating T3 reduced PD-1 expression in Tregs, impaired Treg function, and disrupted T-helper cell (Th1 and Th2) balance in mice treated with T3.

CONCLUSION

Treg dysfunction in GD patients might be due to downregulation of PD-1 expression in Tregs induced by high levels of serum T3.

Autoimmunity in 2019

Based on the PubMed data, we have been performing a yearly evaluation of the publications related to autoimmune diseases and immunology to ascertain the relative weight of the former in the scientific literature. It is particularly intriguing to observe that despite the numerous new avenues of immune-related mechanisms, such as cancer immunotherapy, the proportion of immunology manuscripts related to autoimmunity continues to increase and has been approaching 20% in 2019. As in the previous 13 years, we performed an arbitrary selection of the peer-reviewed articles published by the major dedicated Journals and discussed the common themes which continue to outnumber peculiarites in autoimmune diseases. The investigated areas included systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), psoriatic arthritis (PsA), autoantibodies (autoAbs), and common therapeutic avenues and novel pathogenic mechanisms for autoimmune conditions. Some examples include new pathogenetic evidence which is well represented by IL21 or P2X7 receptor (P2X7R) in SLE or the application of single-cell RNA sequencing (scRNA-seq), mass cytometry, bulk RNA sequencing (RNA-seq), and flow cytometry for the analysis of different cellular populations in RA. Cumulatively and of interest to the clinicians, a large number of findings continue to underline the importance of a strict relationship between basic and clinical science to define new pathogenetic and therapeutic developments. The therapeutic pipeline in autoimmunity continues to grow and maintain a constant flow of new molecules, as well illustrated in RA and PsA, and this is most certainly derived from the new basic evidence and the high-throughput tools applied to autoimmune diseases.

GCH1 induces immunosuppression through metabolic reprogramming and IDO1 upregulation in triple-negative breast cancer

Purpose

Regulatory T cells (Tregs) heavily infiltrate triple-negative breast cancer (TNBC), and their accumulation is affected by the metabolic reprogramming in cancer cells. In the present study, we sought to identify cancer cell-intrinsic metabolic modulators correlating with Tregs infiltration in TNBC.

Experimental design

Using the RNA-sequencing data from our institute (n=360) and the Molecular Taxonomy of Breast Cancer International Consortium TNBC cohort (n=320), we calculated the abundance of Tregs in each sample and evaluated the correlation between gene expression levels and Tregs infiltration. Then, in vivo and in vitro experiments were performed to verify the correlation and explore the underlying mechanism.

Results

We revealed that GTP cyclohydrolase 1 (GCH1) expression was positively correlated with Tregs infiltration and high GCH1 expression was associated with reduced overall survival in TNBC. In vivo and in vitro experiments showed that GCH1 increased Tregs infiltration, decreased apoptosis, and elevated the programmed cell death-1 (PD-1)-positive fraction. Metabolomics analysis indicated that GCH1 overexpression reprogrammed tryptophan metabolism, resulting in L-5-hydroxytryptophan (5-HTP) accumulation in the cytoplasm accompanied by kynurenine accumulation and tryptophan reduction in the supernatant. Subsequently, aryl hydrocarbon receptor, activated by 5-HTP, bound to the promoter of indoleamine 2,3-dioxygenase 1 (IDO1) and thus enhanced the transcription of IDO1. Furthermore, the inhibition of GCH1 by 2,4-diamino-6-hydroxypyrimidine (DAHP) decreased IDO1 expression, attenuated tumor growth, and enhanced the tumor response to PD-1 blockade immunotherapy.

Conclusions

Tumor-cell-intrinsic GCH1 induced immunosuppression through metabolic reprogramming and IDO1 upregulation in TNBC. Inhibition of GCH1 by DAHP serves as a potential immunometabolic strategy in TNBC.

Regulatory T-cell Transcriptomic Reprogramming Characterizes Adverse Events by Checkpoint Inhibitors in Solid Tumors

Immune checkpoint inhibitors (ICI), which target immune regulatory pathways to unleash antitumor responses, have revolutionized cancer immunotherapy. Despite the remarkable success of ICI immunotherapy, a significant proportion of patients whose tumors respond to these treatments develop immune-related adverse events (irAE) resembling autoimmune diseases. Although the clinical spectrum of irAEs is well characterized, their successful management remains empiric. This is in part because the pathogenic mechanisms involved in the breakdown of peripheral tolerance and induction of irAEs remain elusive. Herein, we focused on regulatory T cells (Treg) in individuals with irAEs because these cells are vital for maintenance of peripheral tolerance, appear expanded in the peripheral blood of individuals with cancer, and abundantly express checkpoint molecules, hence representing direct targets of ICI immunotherapy. Our data demonstrate an intense transcriptomic reprogramming of CD4⁺CD25⁺CD127^- Tregs in the blood of individuals with advanced metastatic melanoma who develop irAEs following ICI immunotherapy, with a characteristic inflammatory, apoptotic, and metabolic signature. This inflammatory signature was shared by Tregs from individuals with different types of cancer developing irAEs and individuals with autoimmune diseases. Our findings suggest that inflammatory Treg reprogramming is a feature of immunotherapy-induced irAEs, and this may facilitate translational approaches aiming to induce robust antitumor immunity without disturbing peripheral tolerance.

Immune Check Point Inhibitors and Immune-Related Adverse Events in Small Cell Lung Cancer

Small cell lung cancer (SCLC) is a malignant solid tumor. In recent years, although immune check point inhibitors (ICIs) have achieved important advances in the treatment of SCLC, immune-related adverse events (irAEs) have occurred at the same time during the therapeutic period. Some irAEs lead to dose reduction or treatment rejection. The immune microenvironment of SCLC is complicated, therefore, understanding irAEs associated with ICIs is of great importance and necessity for the clinical management of SCLC. However, the lack of comprehensive understanding of irAEs in patients with SCLC remains remarkable. This review aims to provide an up-to-date overview of ICIs and their associated irAEs in patients with SCLC based on present clinical data.

Effect of P2X purinergic receptors in tumor progression and as a potential target for anti-tumor therapy

The development of tumors is a complex pathological process involving multiple factors, multiple steps, and multiple genes. Their prevention and treatment have always been a difficult problem at present. A large number of studies have proved that the tumor microenvironment plays an important role in the progression of tumors. The tumor microenvironment is the place where tumor cells depend for survival, and it plays an important role in regulating the growth, proliferation, apoptosis, migration, and invasion of tumor cells. P2X purinergic receptors, which depend on the ATP ion channel, can be activated by ATP in the tumor microenvironment, and by mediating tumor cells and related cells (such as immune cells) in the tumor microenvironment. They play an important regulatory role on the effects of the skeleton, membrane fluidity, and intracellular molecular metabolism of tumor cells. Therefore, here, we outlined the biological characteristics of P2X purinergic receptors, described the effect of tumor microenvironment on tumor progression, and discussed the effect of ATP on tumor. Moreover, we explored the role of P2X purinergic receptors in the development of tumors and anti-tumor therapy. These data indicate that P2X purinergic receptors may be used as another potential pharmacological target for tumor prevention and treatment.

Biomarkers for precision immunotherapy in the metastatic setting: hope or reality?

Precision immunotherapy is a crucial approach to improve the efficacy of anti-cancer treatments, particularly in the metastatic setting. In this respect, accurate patient selection takes advantage of the multidimensional integration of patients' clinical information and tumour-specific biomarkers status. Among these biomarkers, programmed death-ligand 1, tumour-infiltrating lymphocytes, microsatellite instability, mismatch repair and tumour mutational burden have been widely investigated. However, novel tumour-specific biomarkers and testing methods will further improve patients' outcomes. Here, we discuss the currently available strategies for the implementation of a precision immunotherapy approach in the clinical management of metastatic solid tumours and highlight future perspectives.

18F-FHBG PET-CT Reporter Gene Imaging of Adoptive CIK Cell Transfer Immunotherapy for Breast Cancer in a Mouse Model

Background

To further improve the efficiency of adoptively transferred cytokine-induced killer (CIK) cell immunotherapy in breast cancer (BC), a reliable imaging method is required to visualize and monitor these transferred cells in vivo.

Methods

Herpes simplex virus 1-thymidine kinase (HSV1-TK) and 9-(4-[¹⁸F]fluoro-3-(hydroxymethyl)butyl)guanine (¹⁸F-FHBG) were used as a pair of reporter gene/reporter probe for positron emission tomography (PET) imaging in this study. Following the establishment of subcutaneous BC xenograft-bearing nude mice models, induced human CIK cells expressing reporter gene HSV1-TK through lentiviral transduction were intravenously injected to nude mice. γ-radioimmunoassay was used to determine the specific uptake of ¹⁸F-FHBG by these genetically engineered CIK cells expressing HSV1-TK in vitro, and ¹⁸F-FHBG micro positron emission tomography-computed tomography (PET-CT) imaging was performed to visualize these adoptively transferred CIK cells in tumor-bearing nude mice.

Results

Specific uptake of ¹⁸F-FHBG by CIK cells expressing HSV1-TK was clearly observed in vitro. Consistently, the localization of adoptively transferred CIK cells in tumor target could be effectively visualized by ¹⁸F-FHBG micro PET-CT reporter gene imaging.

Conclusion

PET-CT reporter gene imaging using ¹⁸F-FHBG as a reporter probe enables the visualization and monitoring of adoptively transferred CIK cells in vivo.

Non-coding RNA derived from extracellular vesicles in cancer immune escape: Biological functions and potential clinical applications

The tumor microenvironment represents a dynamically composed matrix into which cancer cells and many other cell types are embedded to form organ-like structures. The tumor immune microenvironment (TIME), composed of immune cells, is an inseparable part of the tumor microenvironment. Extracellular vesicles (EVs) participate in the occurrence and development of tumors by delivering various biologically active molecules between cells; their role in cancer immune escape in particular has been widely proven. EVs can carry a wide array of cargo, such as non-coding RNAs (ncRNAs), including miRNAs, lncRNAs, and circRNAs, which are selectively loaded by EVs, secreted, and transported to participate in the proliferation of immune cells. Hence, strategies to specifically target EV-ncRNAs could be attractive therapeutic options. In this review, we summarize the current research on the role of EV-ncRNAs in cancer immune escape, and discuss the latest research on the function and regulation mechanism of EV-ncRNAs in cancer immune escape, highlighting and elucidating the potential clinical applications of EV-ncRNAs, including in diagnosis and immunotherapy.

Molecular subtypes based on immune-related genes predict the prognosis for hepatocellular carcinoma patients

BACKGROUND

Hepatocellular carcinoma (HCC) is a malignancy exhibiting the highest lethality. The present study aimed to identify different immune-related clusters in HCC and a robust tumor gene signature to facilitate the prognosis prediction for HCC patients.

METHODS

For the 375 HCC cases collected from the dataset of Cancer Genome Atlas (TCGA), their overall survival (OS) and immune-related genes (IRGs) expression patterns were collected. Thereafter, consensus clustering was employed for grouping and functional enrichment, whereas the ESTIMATE algorithm and the CIBERSORT algorithm were used in subsequent assessment. Immunohistochemistry (IHC) was conducted to verify the protein expression of model genes in HCC and adjacent tissues.

RESULTS

According to consensus clustering with 93-survival related IRGs, a total of five subgroups were found. These five clusters had different prognoses, immune statuses, and expression of immune checkpoints. Afterwards, 11 genes were enrolled for constructing the OS-related prediction model for TCGA HCC cases, which was then validated using the database of International Cancer Genome Consortium (ICGC). The protein expression of LCN2, S100A10, FABP6, PLXNA1, KITLG and OXTR were enhanced in HCC tissues relative to that in normal hepatic tissues, while the protein expression of S100A1, CCL26, CMTM4, IL1RN and RARG were reduced in HCC compared with normal tissues. In addition, different immunocyte infiltration levels between low- and high- groups were further examined.

CONCLUSIONS

According to our results, the IRGs-based classifications assist in explaining the HCC heterogeneity, which may help to develop the more efficient individualized treatments.

Immune-Driven Pathogenesis of Neurotoxicity after Exposure of Cancer Patients to Immune Checkpoint Inhibitors

Over the last decade, immune checkpoint inhibitors (ICIs) have revolutionized the treatment of several cancer types. ICIs work through the blockage of immune inhibitory signals, while increasing the T-cell specific immune antitumoral response. However, due to the fact that ICIs’ mechanism of action is not tissue antigen-specific and not limited to the tumor microenvironment, the use of cancer immunotherapy can produce a broad range of immune-related adverse events (irAEs). Neurological immune-related adverse events (NirAEs) are rare (the overall incidence varies between 1% to 6%), and these adverse events mainly concern the peripheral nervous system, rather than the central nervous system. Due to their potential severity, which could cause interruptions to cancer treatment, NirAEs are of particular clinical importance. Currently, the pathogenesis of these complications is not completely understood, although T-cells seem to play a principal role. Nevertheless, the development of NirAEs is likely to be a multifactorial and complex process. This conclusion can be extracted from the wide range of neurological auto-inflammatory and autoimmune disorders triggered or exacerbated by ICIs, and the extensive variability of the limited histological findings reported. The aim of this review is to summarize the potential immune-driven pathological mechanisms of NirAEs.

Biological Factors behind Melanoma Response to Immune Checkpoint Inhibitors

Modern immunotherapy together with targeted therapy has revolutionized the treatment of advanced melanoma. Inhibition of immune checkpoints significantly improved the median overall survival and gave hope to many melanoma patients. However, this treatment has three serious drawbacks: high cost, serious side effects, and an effectiveness limited only to approximately 50% of patients. Some patients do not derive any or short-term benefit from this treatment due to primary or secondary resistance. The response to immunotherapy depends on many factors that fall into three main categories: those associated with melanoma cells, those linked to a tumor and its microenvironment, and those classified as individual ontogenic and physiological features of the patient. The first category comprises expression of PD-L1 and HLA proteins on melanoma cells as well as genetic/genomic metrics such as mutational load, (de)activation of specific signaling pathways and epigenetic factors. The second category is the inflammatory status of the tumor: “hot” versus “cold” (i.e., high versus low infiltration of immune cells). The third category comprises metabolome and single nucleotide polymorphisms of specific genes. Here we present up-to-date data on those biological factors influencing melanoma response to immunotherapy with a special focus on signaling pathways regulating the complex process of anti-tumor immune response. We also discuss their potential predictive capacity.

Magnetotactic Bacteria and Magnetosomes as Smart Drug Delivery Systems: A New Weapon on the Battlefield with Cancer?

An important direction of research in increasing the effectiveness of cancer therapies is the design of effective drug distribution systems in the body. The development of the new strategies is primarily aimed at improving the stability of the drug after administration and increasing the precision of drug delivery to the destination. Due to the characteristic features of cancer cells, distributing chemotherapeutics exactly to the microenvironment of the tumor while sparing the healthy tissues is an important issue here. One of the promising solutions that would meet the above requirements is the use of Magnetotactic bacteria (MTBs) and their organelles, called magnetosomes (BMs). MTBs are commonly found in water reservoirs, and BMs that contain ferromagnetic crystals condition the magnetotaxis of these microorganisms. The presented work is a review of the current state of knowledge on the potential use of MTBs and BMs as nanocarriers in the therapy of cancer. The growing amount of literature data indicates that MTBs and BMs may be used as natural nanocarriers for chemotherapeutics, such as classic anti-cancer drugs, antibodies, vaccine DNA, and siRNA. Their use as transporters increases the stability of chemotherapeutics and allows the transfer of individual ligands or their combinations precisely to cancerous tumors, which, in turn, enables the drugs to reach molecular targets more effectively.

Tumor infiltrating T cells influence prognosis in stage I-III non-small cell lung cancer

Background

T cell infiltration in non-small cell lung cancer (NSCLC) is essential for the immunological response to malignant tissue, especially in the era of immune-checkpoint inhibition. To investigate the prognostic impact of CD4⁺ T helper cells (T_h), CD8⁺ cytotoxic (T_c) and FOXP3⁺ regulatory T (T_reg) cells in NSCLC, we performed this analysis.

Methods

By counterstaining of CD4, CD8 and FOXP3 we used immunohistochemistry on tissue microarrays (TMA) to evaluate peritumoral T_h cells, T_reg cells and T_c cells in n=294 NSCLC patients with pTNM stage I–III disease.

Results

Strong CD4⁺ infiltration was associated with higher tumor stages and lymphonodal spread. However, strong CD4⁺ infiltration yielded improved overall survival (OS) (P=0.014) in adenocarcinoma (ADC) and large cell carcinoma (LCC) but not in squamous cell carcinoma (SCC). A CD4/CD8 ratio <1 was associated with high grade NSCLC tumors (P=0.020). High CD8⁺ T cell infiltration was an independent prognostic factor for OS (P=0.040) and progression-free survival (PFS) (P=0.012) in the entire study collective. The OS benefit of high CD8⁺ infiltration was especially prominent in PD-L1 negative NSCLC (P=0.001) but not in PD-L1 positive tissue (P=0.335). Moreover, positive FOXP3⁺ expression in tumor infiltrating lymphocytes was associated with increased OS (P=0.007) and PFS (P=0.014) in SCC but not in ADC and LCC (all P>0.05). Here, prognostic effects were prominent in PD-L1 positive SCC (P=0.023) but not in PD-L1 negative SCC (P=0.236).

Conclusions

High proportion of CD8⁺ T_c cells correlated with improved prognostic outcome in stage I–III NSCLC. T_h cells and T_reg cells have implications on outcome with respect to tumor histology and biology.

Immune-based therapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third most frequent cause of cancer-related death. The immune-rich contexture of the HCC microenvironment makes this tumour an appealing target for immune-based therapies. Here, we discuss how the functional characteristics of the liver microenvironment can potentially be harnessed for the treatment of HCC. We will review the evidence supporting a therapeutic role for vaccines, cell-based therapies and immune-checkpoint inhibitors and discuss the potential for patient stratification in an attempt to overcome the series of failures that has characterised drug development in this disease area.