PD-L1 gene polymorphisms and low serum level of PD-L1 protein are associated to type 1 diabetes in Chile

Human immune phenotyping reveals accelerated aging in type 1 diabetes

The proportions and phenotypes of immune cell subsets in peripheral blood undergo continual and dramatic remodeling throughout the human life span, which complicates efforts to identify disease-associated immune signatures in type 1 diabetes (T1D). We conducted cross-sectional flow cytometric immune profiling on peripheral blood from 826 individuals (stage 3 T1D, their first-degree relatives, those with ≥2 islet autoantibodies, and autoantibody-negative unaffected controls). We constructed an immune age predictive model in unaffected participants and observed accelerated immune aging in T1D. We used generalized additive models for location, shape, and scale to obtain age-corrected data for flow cytometry and complete blood count readouts, which can be visualized in our interactive portal (ImmScape); 46 parameters were significantly associated with age only, 25 with T1D only, and 23 with both age and T1D. Phenotypes associated with accelerated immunological aging in T1D included increased CXCR3+ and programmed cell death 1-positive (PD-1+) frequencies in naive and memory T cell subsets, despite reduced PD-1 expression levels on memory T cells. Phenotypes associated with T1D after age correction were predictive of T1D status. Our findings demonstrate advanced immune aging in T1D and highlight disease-associated phenotypes for biomarker monitoring and therapeutic interventions.

Endocrine immune-related adverse effects of immune-checkpoint inhibitors

INTRODUCTION

Immune-checkpoint inhibitor therapy modulates the response of the immune system acting against cancer. Two pathways impacted by this kind of treatment are the CTLA4 and the PD-1/PD-L1 pathways. ICI therapy can trigger autoimmune adverse effects, known as immune-related Adverse Events (irAEs).

AREAS COVERED

This review focuses on irAEs which affect the endocrine system. This review elucidates the pathways used by these drugs with a focus on the hypothetical pathogenesis at their basis. In fact, the pathophysiology of irAEs concerns the possibility of an interaction between cellular autoimmunity, humoral immunity, cytokines, chemokines, and genetics. The endocrine irAEs examined are thyroid dysfunctions, immune related-hypophysitis, diabetes, peripheral adrenal insufficiency, and hypoparathyroidism.

EXPERT OPINION

There is still much to investigate in endocrine irAES of checkpoint inhibitors. In the future, checkpoint inhibitors will be increasingly utilized therapies, and therefore it is crucial to find the proper diagnostic-therapeutic program for irAEs, especially as endocrine irAEs are nonreversible and require lifelong replacement therapies.

Immune cells and their inflammatory mediators modify β cells and cause checkpoint inhibitor-induced diabetes

Checkpoint inhibitors (CPIs) targeting programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) and cytotoxic T lymphocyte antigen 4 (CTLA-4) have revolutionized cancer treatment but can trigger autoimmune complications, including CPI-induced diabetes mellitus (CPI-DM), which occurs preferentially with PD-1 blockade. We found evidence of pancreatic inflammation in patients with CPI-DM with shrinkage of pancreases, increased pancreatic enzymes, and in a case from a patient who died with CPI-DM, peri-islet lymphocytic infiltration. In the NOD mouse model, anti-PD-L1 but not anti-CTLA-4 induced diabetes rapidly. RNA sequencing revealed that cytolytic IFN-γ+CD8+ T cells infiltrated islets with anti-PD-L1. Changes in β cells were predominantly driven by IFN-γ and TNF-α and included induction of a potentially novel β cell population with transcriptional changes suggesting dedifferentiation. IFN-γ increased checkpoint ligand expression and activated apoptosis pathways in human β cells in vitro. Treatment with anti-IFN-γ and anti-TNF-α prevented CPI-DM in anti-PD-L1-treated NOD mice. CPIs targeting the PD-1/PD-L1 pathway resulted in transcriptional changes in β cells and immune infiltrates that may lead to the development of diabetes. Inhibition of inflammatory cytokines can prevent CPI-DM, suggesting a strategy for clinical application to prevent this complication.

PD-L1 rs2890658 Polymorphism Increases Risk for Non-Small-Cell Lung Cancer in Northern China Population Based on Experimental Data and Meta-Analysis

Purpose

To dig the PD-L1 rs2890658 polymorphism with susceptibility of non-small-cell lung cancer (NSCLC) in northern China.

Patients and Methods

There were 600 NSCLC patients and 600 age and sex matched controls from the same ethnic origin recruited in the present research. Polymerase chain reaction-restriction fragment length polymorphism method genotyped PD-L1 rs2890658 polymorphism. PubMed and Embase were searched to get eligible literature for meta-analysis. The association between PD-L1 rs2890658 polymorphism and NSCLC risk was calculated with odds ratio and 95% confidence interval.

Results

It is more likely that individuals who have CC genotype and C allele are 2.15 and 1.41 times to develop NSCLC compared with individuals with AA genotype and A allele, respectively. Meta-analysis showed that the individuals who have C allele and CA genotype increased the risk of suffering from NSCLC.

Conclusion

PD-L1 rs2890658 polymorphism increased NSCLC risk in northern China population and it might predict the occurrence of NSCLC.

The genetic influence of PD-1/PD-L1 axis single nucleotide polymorphisms on the incidence of type 1 diabetes mellitus in pediatric Egyptian patients

Background

The increasing prevalence of diabetes mellitus (DM) is one of the most challenging public health issues. The destruction of insulin-producing cells in the islets of Langerhans is the hallmark of type 1 diabetes mellitus (T1DM) as an autoimmune disease. In the current case–control study, the role of single nucleotide polymorphisms (SNPs) was investigated within the programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) inhibitory axis and their association with T1DM susceptibility in a sample of Egyptian pediatric patients. The study included 80 T1DM pediatric patients and 76 healthy control subjects. The patients were recruited from Beni-Suef University Hospital’s Pediatric Endocrinology Outpatient Clinic. Genotyping of PD-1 SNP (rs 34819629) and PD-L1 SNPs (rs 2297137 and rs 4143815) was performed by TaqMan allelic discrimination technique via real-time polymerase chain reaction (RT-PCR). The patients were subjected to a thorough clinical examination and history taking.

Result

Genotyping of PD-1 (rs 34819629) revealed that all of the enrolled patients and the control group inherited the same genotype (GG genotype). With regard to PDL-1 rs4143815 SNP and the risk of T1DM occurrence, our comparison did not reveal the presence of an association between the different genetic models (general, dominant, and recessive) of the SNP and the risk of T1DM (p = 0.078 and p = 0.055; for the general genetic model, p = 0.061 and p = 0.169 for the dominant and the recessive types, respectively). Regarding PDL-1 rs2297137 SNP, the results of this study demonstrated that the risk of T1DM was significantly associated with the recessive genetic model (p = 0.007) as the diabetic group’s predominant G allele was higher compared to the control group.

Conclusion

The findings obtained supported the hypothesis that the predominant G allele of PD-L1 rs2297137 is associated with the development of T1DM. Chronic hyperglycemia and long-standing diabetes problems are linked to both PD-L1 SNPs (rs4143815 and rs2297137). Future studies with a more significant number of patients are required to support our results.

Sintilimab-induced autoimmune diabetes: A case report and review of the literature

BACKGROUND

With the widespread application of immune checkpoint inhibitor (ICI) therapy, the number of immune-related adverse effects (irAEs) has increased over the years. Autoimmune diabetes mellitus (DM) is a rare irAEs of ICIs and can be troublesome and life threatening.

CASE SUMMARY

We report a 78-year-old woman with no history of diabetes who presented with hyperglycemia up to 23.4 mmol/L (random blood glucose level) after 14 courses of sintilimab. Hemoglobin A1c was 8.2%, fasting insulin was 0.29 mIU/mL, and fasting C-peptide was decreased to a level with negative autoantibodies. Combing her medical history and laboratory examination, she was diagnosed with programmed cell death (PD)-1-inhibitor-induced, new-onset autoimmune DM. After controlling her blood glucose, she was treated with daily insulin by subcutaneous injection. She was allowed to continue anti-PD-1 therapy and she still obtained some therapeutic efficacy. We also reviewed some published cases (n = 36) of PD-1/PD-ligand 1 (PD-L1) inhibitor-induced DM. We also discuss potential pathogenic mechanisms, clinical features, prognostic markers (β cell antibodies, human leukocyte antigen type, PD-L1 Level) of this rare adverse effect.

CONCLUSION

It is important for all clinicians to be aware of DM as an irAEs of ICIs.

Biomarkers Associated with Immune-Related Adverse Events under Checkpoint Inhibitors in Metastatic Melanoma

Simple Summary

Our aim was to check for possible associations between clinical parameters or NGS-based genetic alterations and the occurrence of immune-related adverse events (IRAE) in melanoma patients with immune checkpoint inhibitors (ICI). We analyzed 95 melanoma patients with ICI and were able to identify several biomarkers associated with the development of IRAE. Female sex was significantly associated with the development of hepatitis, increased total and relative monocytes at ICI initiation were significantly associated with the development of pancreatitis, the same, pre-existing autoimmune diseases. Furthermore, the following genetic alterations were identified being associated with IRAE: SMAD3 (pancreatitis); CD274, SLCO1B1 (hepatitis); PRDM1, CD274 (encephalitis); PRDM1, CD274, TSHR, FAN1 (myositis). Myositis and encephalitis, both, were associated with alterations of PRDM1 and CD274, which might explain their joined appearance in clinical practice. Our findings can help to assess the risk for the development of IRAE in melanoma patients with ICI.

Abstract

Immune checkpoint inhibitors (ICI) have revolutionized the therapeutic landscape of metastatic melanoma. However, ICI are often associated with immune-related adverse events (IRAE) such as colitis, hepatitis, pancreatitis, hypophysitis, pneumonitis, thyroiditis, exanthema, nephritis, myositis, encephalitis, or myocarditis. Biomarkers associated with the occurrence of IRAE would be desirable. In the literature, there is only little data available and furthermore mostly speculative, especially in view of genetic alterations. Our major aim was to check for possible associations between NGS-based genetic alterations and IRAE. We therefore analyzed 95 melanoma patients with ICI and evaluated their NGS results. We checked the data in view of potential associations between copy number variations (CNVs), small variations (VARs), human leucocyte antigen (HLA), sex, blood count parameters, pre-existing autoimmune diseases and the occurrence of IRAE. We conducted a literature research on genetic alterations hypothesized to be associated with the occurrence of IRAE. In total, we identified 39 genes that have been discussed as hypothetical biomarkers. We compared the list of these 39 genes with the tumor panel that our patients had received and focused our study on those 16 genes that were also included in the tumor panel used for NGS. Therefore, we focused our analyses on the following genes: AIRE, TERT, SH2B3, LRRK2, IKZF1, SMAD3, JAK2, PRDM1, CTLA4, TSHR, FAN1, SLCO1B1, PDCD1, IL1RN, CD274, UNG. We obtained relevant results: female sex was significantly associated with the development of hepatitis, combined immunotherapy with colitis, increased total and relative monocytes at therapy initiation were significantly associated with the development of pancreatitis, the same, pre-existing autoimmune diseases. Further significant associations were as follows: HLA homozygosity (hepatitis), and VARs on SMAD3 (pancreatitis). Regarding CNVs, significant markers included PRDM1 deletions and IL1RN (IRAE), CD274 duplications and SLCO1B1 (hepatitis), PRDM1 and CD274 (encephalitis), and PRDM1, CD274, TSHR, and FAN1 (myositis). Myositis and encephalitis, both, were associated with alterations of PRDM1 and CD274, which might explain their joined appearance in clinical practice. The association between HLA homozygosity and IRAE was clarified by finding HLA-A homozygosity as determining factor. We identified several genetic alterations hypothesized in the literature to be associated with the development of IRAE and found significant results concerning pre-existing autoimmune diseases and specific blood count parameters. Our findings can help to better understand the development of IRAE in melanoma patients. NGS might be a useful screening tool, however, our findings have yet to be confirmed in larger studies.

The Price of Success: Immune-Related Adverse Events from Immunotherapy in Lung Cancer

Cancer immunotherapy has the goal of enhancing a patient’s intrinsic immune processes in order to mount a successful immune response against tumor cells. Cancer cells actively employ tactics to evade, delay, alter, or attenuate the anti-tumor immune response. Immune checkpoint inhibitors (ICIs) modulate endogenous regulatory immune mechanisms to enhance immune system activation, and have become the mainstay of therapy in many cancer types. This activation occurs broadly and as a result, activation is supraphysiologic and relatively non-specific, which can lead to immune-related adverse events (irAEs), the frequency of which depends on the patient, the cancer type, and the specific ICI antibody. Careful assessment of patients for irAEs through history taking, physical exam, and routine laboratory assessments are key to identifying irAEs at early stages, when they can potentially be managed more easily and before progressing to higher grades or more serious effects. Generally, most patients with low grade irAEs are eligible for re-challenge with ICIs, and the use of corticosteroids to address an irAE is not associated with poorer patient outcomes. This paper reviews immune checkpoint inhibitors (ICIs) including their mechanisms of action, usage, associated irAEs, and their management.

A Patient with Atezolizumab-Induced Autoimmune Diabetes Mellitus Presenting with Diabetic Ketoacidosis

Background: Atezolizumab, an immune checkpoint inhibitor, is a humanized monoclonal, anti-programmed death ligand 1 (PD-L1) antibody used for the treatment of metastatic urothelial carcinoma that has progressed after chemotherapy.Case Presentation: We describe a patient with a known history of urothelial carcinoma who presented with diabetic ketoacidosis 6 weeks following his second cycle of atezolizumab. His serum lactate level was slightly elevated (2 mM) and his β-hydroxybutyrate level was elevated (3.9 mM). High anion gap metabolic acidosis secondary to diabetic ketoacidosis was diagnosed. Subsequent testing demonstrated hemoglobin A1c level of 9.9%, positivity for anti-glutamic acid decarboxylase antibody (0.03 nM, reference range <0.02 nM), and suppressed C-peptide level (0.1 μg/L, reference range 0.9‐7.1 μg/L) in the absence of detectable anti-islet antigen 2 (IA-2) or anti-insulin antibodies. His initial management included cessation of atezolizumab treatment, intravenous sodium chloride administration, and insulin pump infusion, after which metabolic acidosis gradually resolved. The insulin pump was subsequently switched to Protaphane at 18 units before breakfast and 8 units before dinner, together with metformin at 1000 mg twice daily. Four weeks later his medication was changed to human isophane insulin plus neutral insulin (70%/30%; Mixtard 30 HM; 26 units/4 units). Linagliptin at 5 mg was added 1 month later. His hemoglobin A1c level declined to 8.1% 1 year later.Conclusions: PD-L1 inhibitors can induce type 1 diabetes, and patients can present with diabetic ketoacidosis. Blood glucose levels should be regularly monitored in patients who are prescribed these medications.

Neurological Immunotoxicity from Cancer Treatment

The emergence of immune-based treatments for cancer has led to a growing field dedicated to understanding and managing iatrogenic immunotoxicities that arise from these agents. Immune-related adverse events (irAEs) can develop as isolated events or as toxicities affecting multiple body systems. In particular, this review details the neurological irAEs from immune checkpoint inhibitors (ICI) and chimeric antigen receptor (CAR) T cell immunotherapies. The recognition and treatment of neurological irAEs has variable success, depending on the severity and nature of the neurological involvement. Understanding the involved mechanisms, predicting those at higher risk for irAEs, and establishing safety parameters for resuming cancer immunotherapies after irAEs are all important fields of ongoing research.

Type 1 diabetes induced by immune checkpoint inhibitors

With the increasing use of immune checkpoint inhibitors (ICI) including anti-cytotoxic T lymphocyte associated antigen-4 (CTLA-4) and anti-programmed cell death-1 (PD-1) in cancers, ICI-induced type 1 diabetes has been reported throughout the world. In this review, we aim to summarize the characteristics of this disease and discuss the mechanism of it. As an immune-related adverse event, type 1 diabetes developed after the administration of anti-PD-1 or anti-PD-ligand 1 (PD-L1) in the combination with or without anti-CTLA-4. It usually presented with acute onset, and 62.1% of the reported cases had diabetic ketoacidosis. Only a third of them had positive autoantibodies associated with type 1 diabetes. Susceptible HLA genotypes might be associated. T-cell-stimulation by blocking of the interaction of PD-1 and PD-L1 in pancreatic β cells was the main mechanism involved in the pathology. Insulin was the only effective treatment of ICI-induced type 1 diabetes. In conclusions, ICI-induced type 1 diabetes is a potentially life-threating adverse event after the immunotherapy of cancers. Screening and early recognition is important. Further investigation of the mechanism may help to better understand the pathology of type 1 diabetes.

The Role of Programmed Death-1 in Type 1 Diabetes

PURPOSE OF REVIEW

Programmed death-1 (PD-1) is an inhibitory receptor that controls T and B cell proliferation and function through interacting with its ligand PD-L1 or PD-L2. PD-1/PD-L1 blockade reboots anti-tumor immunity and is currently used to treat > 15 different types of cancer. However, the response rate is not at 100% and some patients relapse. Importantly, up to 37% of patients treated with PD-1/PD-L1 blocking antibodies develop immune-related adverse events, including overt autoimmunity, such as type 1 diabetes (T1D). Herein, we discuss the role of PD-1, PD-L1, and PD-L2 signaling in pre-clinical models of T1D, including recent work from our laboratory.

RECENT FINDINGS

We highlight ongoing efforts to harness PD-1/PD-L1 signaling and treat autoimmunity. We also evaluate studies aimed at defining biomarkers that could reliably predict the development of immune-related adverse events after clinical PD-1/PD-L1 blockade. With increasing use of PD-1 blockade in the clinic, onset of autoimmunity is a growing health concern. In this review, we discuss what is known about the role of PD-1 pathway signaling in T1D and comment on ongoing efforts to identify patients at risk of T1D development after PD-1 pathway blockade.

Programmed death-ligand 1 single nucleotide polymorphism affects breast cancer chemosensitivity and adverse events in the neoadjuvant setting

OBJECTIVE

We aimed to determine whether single nucleotide polymorphisms in the PD-L1 gene are related to the response and adverse events of patients receiving neoadjuvant therapy and to explore the mechanism.

METHODS

Nine single nucleotide polymorphisms of PD-L1 were selected and tested among patients before neoadjuvant therapy. Four models were used in single nucleotide polymorphism genotype analysis: the addictive model compared TT vs TA vs AA; the dominant model compared TT vs TA+AA; the recessive model compared TT+TA vs AA; and the over-dominant model compared TT+AA vs TA (A as the minor allele). We analyzed the associations between single nucleotide polymorphism genotypes and pathological complete response, disease-free survival, and adverse events. Overexpression of the targeted microRNA was carried out using microRNA mimics. Logistic regression was used to analyze the associations between different single nucleotide polymorphism genotypes and pathological complete response outcome. Kaplan-Meier plots and log-rank tests were used to compare disease-free survival between groups with different single nucleotide polymorphism genotypes. The Cox proportional hazards model was used to calculate the adjusted hazard ratio. The Spearman's correlation test was used to determine the correlations between different genotypes and adverse events.

RESULTS

rs4143815C>G was associated with better pathological complete response in the addictive and over-dominant models and with poorer disease-free survival in the recessive model. Patients with different genotypes had different adverse events. Overexpression of miR34c resulted in the downregulation of PD-L1 mRNA expression.

CONCLUSION

The PD-L1 single nucleotide polymorphism rs4143815 was associated with the pathological complete response rate, disease-free survival, and adverse events in breast cancer patients receiving neoadjuvant therapy. The interaction between miR34c and PD-L1 might be affected by rs4143815.

Immune checkpoint inhibitors and diabetes: Mechanisms and predictors

The emergence of immune checkpoint inhibitors in the arsenal of cancer immunotherapy was a breakthrough which provided hope to many cancer patients. However, not long has passed since their discovery that some adverse effects were associated with these promising therapeutic agents. Immune checkpoint inhibitors dysregulate host immunity and may precipitate autoimmune diseases including diabetes mellitus. In this review, we go beyond the case reports towards understanding the underlying mechanisms by which Programmed cell death 1 (PD-1) and Programmed death ligand-1 (PD-L1) inhibitors precipitate diabetes. We discuss the role of PD-1/PD-L1 in autoimmunity and the use of mice models to describe their involvement in diabetes. We also reviewed the genetic anomalies in PD-1/PD-L1genes and their link to diabetes. Finally, we present the studies conducted to identify patients at risk of developing autoimmune diseases as an adverse effect for PD-1/PD-L1 use. Understanding these issues can guide researchers to find a way to circumvent the autoimmune adverse reactions seen with PD-1/PD-L1 inhibitors without affecting their antitumor activity.

Atezolizumab-induced type 1 diabetes mellitus in a patient with metastatic renal cell carcinoma

Checkpoint inhibitor immunotherapy has revolutionised cancer treatment since its inception. During an inflammatory response, activated cytotoxic T cells expressing programmed cell death protein 1 (PD-1) interact with programmed cell death-ligand 1 (PD-L1) on peripheral tissues to thwart an autoimmune reaction. Cancer cells upregulate PD-L1 expression to evade the immune system and are vulnerable to attack in the presence of PD-1 or PD-L1 checkpoint inhibitors. However, blockade of this pathway also contributes to the unintended side effect of autoimmune endocrinopathies. Atezolizumab, a checkpoint inhibitor against PD-L1, is associated with the rare complication of type 1 diabetes. We present a case of glutamic acid decarboxylase antibody-positive type 1 diabetes developing in a patient with a long-standing history of well-controlled type 2 diabetes following treatment with atezolizumab for metastatic renal cell carcinoma.

Immune-related adverse events of checkpoint inhibitors

Cancer immunotherapies have changed the landscape of cancer treatment during the past few decades. Among them, immune checkpoint inhibitors, which target PD-1, PD-L1 and CTLA-4, are increasingly used for certain cancers; however, this increased use has resulted in increased reports of immune-related adverse events (irAEs). These irAEs are unique and are different to those of traditional cancer therapies, and typically have a delayed onset and prolonged duration. IrAEs can involve any organ or system. These effects are frequently low grade and are treatable and reversible; however, some adverse effects can be severe and lead to permanent disorders. Management is primarily based on corticosteroids and other immunomodulatory agents, which should be prescribed carefully to reduce the potential of short-term and long-term complications. Thoughtful management of irAEs is important in optimizing quality of life and long-term outcomes.

The role of programed death-ligand 1 in renal diseases

Programed death-ligand 1 (PD-L1, B7-H1, CD274) is a coinhibitory molecule that plays a vital role in the pathogenesis of both neoplastic and nonneoplastic diseases. However, the role of PD-L1 in primary and secondary renal diseases remains to be clarified. Previous studies have shown that both intracellular and intercellular PD-L1 participate in renal diseases via complex mechanisms. PD-L1 plays a dual role in lupus nephritis and has a protective effect in renal ischemia reperfusion injury and nephrotoxic nephritis but not in proliferative immune complex glomerulonephritis. PD-L1 supplementation, anti-PD-L1 antibodies, and D-peptide antagonists have promising application prospects in the treatment of renal diseases. In this review, we summarize the available data published on PD-L1 in renal diseases for the first time.

Association of apoptosis genes in PDCD1 but not PDCD1LG2, FAS, and FASLG with pediatric idiopathic uveitis in Han Chinese

BACKGROUND

Previous studies have shown that aberrant T lymphocyte apoptosis is involved in the pathogenesis of uveitis. Genetic variants of apoptotic pathway-related factors (including PDCD1, PDCD1LG2, FAS, and FASLG) may affect apoptosis and in turn predict susceptibility to autoimmune disease. This has not yet been studied in pediatric idiopathic uveitis (PIU) and juvenile idiopathic arthritis (JIA)-associated uveitis and was therefore the subject of the study presented here.

METHODS

Fourteen single-nucleotide polymorphisms (SNPs) of several apoptosis-related pathway genes were analyzed in 1238 PIU patients, 128 JIA-associated uveitis patients and 1114 healthy controls using the iPLEX Gold Assay and MassARRAY platform.

RESULTS

A lower frequency of the PDCD1/rs6710479 CC genotype in PIU patients was found when compared to controls (Pc = 3.42 × 10^-3). A higher frequency of the PDCD1/rs7421861 A allele (Pc = 4.85 × 10^-3) was observed in PIU patients as compared with controls. Stratification analysis showed a positive association of band keratopathy with the PDCD1/rs7565639 CT genotype (Pc = 1.05 × 10^-2) and a negative association of this parameter with the PDCD1/rs7565639 C allele (Pc = 3.76 × 10^-2).

CONCLUSIONS

This study revealed that rs6710479 and rs7421861 in the PDCD1 gene confer susceptibility to PIU in Han Chinese. A stratified analysis showed that PDCD1/rs7565639 is associated with band keratopathy in PIU patients.

Type 1 diabetes pathogenesis and the role of inhibitory receptors in islet tolerance

Type 1 diabetes (T1D) affects over a million Americans, and disease incidence is on the rise. Despite decades of research, there is still no cure for this disease. Exciting beta cell replacement strategies are being developed, but in order for such approaches to work, targeted immunotherapies must be designed. To selectively halt the autoimmune response, researchers must first understand how this response is regulated and which tolerance checkpoints fail during T1D development. Herein, we discuss the current understanding of T1D pathogenesis in humans, genetic and environmental risk factors, presumed roles of CD4+ and CD8+ T cells as well as B cells, and implicated autoantigens. We also highlight studies in non-obese diabetic mice that have demonstrated the requirement for CD4+ and CD8+ T cells and B cells in driving T1D pathology. We present an overview of central and peripheral tolerance mechanisms and comment on existing controversies in the field regarding central tolerance. Finally, we discuss T cell- and B cell-intrinsic tolerance mechanisms, with an emphasis on the roles of inhibitory receptors in maintaining islet tolerance in humans and in diabetes-prone mice, and strategies employed to date to harness inhibitory receptor signaling to prevent or reverse T1D.

Association of a PD-L2 Gene Polymorphism with Chronic Lymphatic Filariasis in a South Indian Cohort

Lymphatic filariasis (LF) is a parasitic infection, caused by three closely related nematodes, namely Wuchereria bancrofti, Brugia malayi, and Brugia timori. Previously, we have shown that lysate from B. malayi microfilariae induces the expression of interleukin (IL)-10 and programmed death-ligand (PD-L) 1 on monocytes, which lead to inhibition of CD4⁺ T-cell responses. In this study, we investigated associations of IL-10 and programmed cell death (PD)-1 pathway gene polymorphisms with clinical manifestation in LF. We evaluated the frequency of alleles and genotypes of IL-10 (rs3024496, rs1800872), IL-10RA (rs3135932), IL-10RB (rs2834167), PD-1 (rs2227982, rs10204525), PD-L1 (rs4143815), PD-L2 (rs7854413), and single-nucleotide polymorphisms (SNPs) in 103 patients with chronic pathology (CP), such as elephantiasis or hydrocele and 106 endemic normal (EN) individuals from a South Indian population living in an area endemic for LF. Deviations from the Hardy-Weinberg equilibrium were tested, and we found a significant difference between the frequency of polymorphisms in PD-L2 (rs7854413; P < 0.001) and IL-10RB (rs2834167; P = 0.012) between the CP and the EN group, whereas there were no significant differences found among IL-10, IL-10RA, PD-1, and PD-L1 SNPs. A multivariate analysis showed that the existence of a CC genotype in PD-L2 SNP rs7854413 is associated with a higher risk of developing CP (OR: 2.942; 95% confidence interval [CI]: 0.957-9.046; P = 0.06). Altogether, these data indicate that a genetically determined individual difference in a non-synonymous missense SNP of PD-L2 might influence the susceptibility to CP.

Stimulatory and Inhibitory Co-signals in Autoimmunity

Co-receptors cooperatively regulate the function of immune cells to optimize anti-infectious immunity while limiting autoimmunity by providing stimulatory and inhibitory co-signals. Among various co-receptors, those in the CD28/CTLA-4 family play fundamental roles in the regulation of lymphocytes by modulating the strength, quality, and/or duration of the antigen receptor signal. The development of the lethal lymphoproliferative disorder and various tissue-specific autoimmune diseases in mice deficient for CTLA-4 and PD-1, respectively, clearly demonstrates their pivotal roles in the development and the maintenance of immune tolerance. The recent success of immunotherapies targeting CTLA-4 and PD-1 in the treatment of various cancers highlights their critical roles in the regulation of cancer immunity in human. In addition, the development of multifarious autoimmune diseases as immune-related adverse events of anti-CTLA-4 and anti-PD-1/PD-L1 therapies and the successful clinical application of the CD28 blocking therapy using CTLA-4-Ig to the treatment of arthritis assure their crucial roles in the regulation of autoimmunity in human. Accumulating evidences in mice and humans indicate that genetic and environmental factors strikingly modify effects of the targeted inhibition and potentiation of co-signals. In this review, we summarize our current understanding of the roles of CD28, CTLA-4, and PD-1 in autoimmunity. Deeper understandings of the context-dependent and context-independent functions of co-signals are essential for the appropriate usage and the future development of innovative immunomodulatory therapies for a diverse array of diseases.

Clinical impact of low serum free T4 in patients with non-small cell lung cancer treated with nivolumab

Nivolumab improves the prognosis of non-small cell lung cancer (NSCLC) but can cause immune-related adverse events (irAEs). Reports have indicated longer progression-free survivals (PFSs) in patients with irAEs than in those without irAEs. We reported associations between programmed death ligand-1 (PD-L1) single nucleotide polymorphisms (SNPs) and PFS after nivolumab treatment. We hypothesized that adverse events might be associated with the SNPs of PD-L1. We analyzed data from 111 patients with NSCLC treated with nivolumab. The response rate was 14%, and the median PFS was 68 days. We found patients with the adverse event of low free tetraiodothyronine (fT4) had significantly longer PFSs than those without low fT4 (not reached vs 67 days; hazard ratio [HR], 0.297; P = 0.010). Moreover, median overall survival was longer in patients with low fT4 than those without low fT4 (not reached vs 556 days, HR, 0.139; P = 0.020). Patients with the T allele of rs1411262 (P = 0.0073) and with the A allele of rs822339 (P = 0.0204) developed low fT4. Patients with the T/T genotype had longer PFSs than with those with the C/T and C/C genotypes of rs1411262 (165 vs. 67 days, HR, 1.65; P = 0.040), and those with the A/A genotype had longer PFSs than those with the A/G and G/G genotypes of rs822339 (182 vs. 67 days, HR, 1.76; P = 0.025). In the patients with advanced NSCLC, low fT4 after nivolumab treatment was associated with significantly longer PFSs. The SNPs of PD-L1 may be associated with the adverse events of nivolumab.

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.

Endocrine Toxicity of Cancer Immunotherapy Targeting Immune Checkpoints

Immune checkpoints are small molecules expressed by immune cells that play critical roles in maintaining immune homeostasis. Targeting the immune checkpoints cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed death 1 (PD-1) with inhibitory antibodies has demonstrated effective and durable antitumor activity in subgroups of patients with cancer. The US Food and Drug Administration has approved several immune checkpoint inhibitors (ICPis) for the treatment of a broad spectrum of malignancies. Endocrinopathies have emerged as one of the most common immune-related adverse events (irAEs) of ICPi therapy. Hypophysitis, thyroid dysfunction, insulin-deficient diabetes mellitus, and primary adrenal insufficiency have been reported as irAEs due to ICPi therapy. Hypophysitis is particularly associated with anti-CTLA-4 therapy, whereas thyroid dysfunction is particularly associated with anti-PD-1 therapy. Diabetes mellitus and primary adrenal insufficiency are rare endocrine toxicities associated with ICPi therapy but can be life-threatening if not promptly recognized and treated. Notably, combination anti-CTLA-4 and anti-PD-1 therapy is associated with the highest incidence of ICPi-related endocrinopathies. The precise mechanisms underlying these endocrine irAEs remain to be elucidated. Most ICPi-related endocrinopathies occur within 12 weeks after the initiation of ICPi therapy, but several have been reported to develop several months to years after ICPi initiation. Some ICPi-related endocrinopathies may resolve spontaneously, but others, such as central adrenal insufficiency and primary hypothyroidism, appear to be persistent in most cases. The mainstay of management of ICPi-related endocrinopathies is hormone replacement and symptom control. Further studies are needed to determine (i) whether high-dose corticosteroids in the treatment of ICPi-related endocrinopathies preserves endocrine function (especially in hypophysitis), and (ii) whether the development of ICPi-related endocrinopathies correlates with tumor response to ICPi therapy.

Fulminant Type 1 Diabetes Mellitus Accompanied by Positive Conversion of Anti-insulin Antibody after the Administration of Anti-CTLA-4 Antibody Following the Discontinuation of Anti-PD-1 Antibody

An 80-year-old woman with malignant melanoma received 20 cycles of anti-programmed death 1 (PD-1) antibody (nivolumab) treatment and showed normal glucose tolerance. Three weeks after switching to anti-cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) antibody (ipilimumab), her plasma glucose level was elevated to 639 mg/dL, her HbA1c was 7.7%, and her fastening serum C-peptide immunoreactivity was undetectable. Anti-glutamic acid decarboxylase and insulinoma-associated protein-2 antibodies were negative. She was diagnosed with fulminant type 1 diabetes mellitus (F1DM). Remarkably, her anti-insulin antibody was positively converted, and her Sialylated Carbohydrate Antigen, Krebs von den Lungen-6 levels increased after ipilimumab therapy. She possessed F1DM-susceptible Human Leukocyte Antigen-DR4. A fluorescence activated cell sorting analysis showed an altered T-cell population. This case of F1DM highlights specific mechanisms underlying pancreatic beta cell immunity.

Novel minor HLA DR associated antigens in type 1 diabetes

Type 1 diabetes is an autoimmune disease leading to insulin deficiency. Autoantibodies to beta cell proteins are already present in the asymptomatic phase of type 1 diabetes. Recent findings have suggested a number of additional minor autoantigens in patients with type 1 diabetes. We have established luciferase immunoprecipitation systems (LIPS) for anti-MTIF3, anti-PPIL2, anti-NUP50 and anti-MLH1 and analyzed samples from 500 patients with type 1 diabetes at onset of clinical disease and 200 healthy individuals who had a family history of type 1 diabetes but no evidence of beta cell autoantibodies. We show significantly higher frequencies of anti-MTIF3, anti-PPIL2 and anti-MLH1 in recent onset type 1 diabetes patients in comparison to controls. In addition, antibodies to NUP50 were associated with HLA-DRB1*03 and antibodies to MLH1 were associated with HLA-DRB1*04 genotypes.

Interferon-gamma drives programmed death-ligand 1 expression on islet β cells to limit T cell function during autoimmune diabetes

Type 1 diabetes is caused by autoreactive T cell-mediated β cell destruction. Even though co-inhibitory receptor programmed death-1 (PD-1) restrains autoimmunity, the expression and regulation of its cognate ligands on β cell remains unknown. Here, we interrogated β cell-intrinsic programmed death ligand-1 (PD-L1) expression in mouse and human islets. We measured a significant increase in the level of PD-L1 surface expression and the frequency of PD-L1+ β cells as non-obese diabetic (NOD) mice aged and developed diabetes. Increased β cell PD-L1 expression was dependent on T cell infiltration, as β cells from Rag1-deficient mice lacked PD-L1. Using Rag1-deficient NOD mouse islets, we determined that IFN-γ promotes β cell PD-L1 expression. We performed analogous experiments using human samples, and found a significant increase in β cell PD-L1 expression in type 1 diabetic samples compared to type 2 diabetic, autoantibody positive, and non-diabetic samples. Among type 1 diabetic samples, β cell PD-L1 expression correlated with insulitis. In vitro experiments with human islets from non-diabetic individuals showed that IFN-γ promoted β cell PD-L1 expression. These results suggest that insulin-producing β cells respond to pancreatic inflammation and IFN-γ production by upregulating PD-L1 expression to limit self-reactive T cells.

Biomarkers for immune-related toxicities of checkpoint inhibitors: current progress and the road ahead

INTRODUCTION

Immune checkpoint pathways are key immune regulatory pathways that play a physiologic role in maintaining immune-homeostasis and are often co-opted by cancer cells to evade the host immune system. Recent developments in cancer immunotherapy, mainly drugs blocking the immune checkpoint pathways, have revolutionized the treatment paradigm for many solid tumors. A wide spectrum of immune-related adverse events (irAEs) have been described with the use of these agents which necessitate treatment with immunosuppression, lead to disruption of therapy and can on occasion be life-threatening. There are currently no clinically validated biomarkers to predict the risk of irAEs. Areas covered: In this review, the authors describe the current progress in identifying biomarkers for irAEs and potential future directions. Literature search was conducted using PubMed-MEDLINE, Embase and Scopus. In addition, abstracts from major conference proceedings were reviewed for relevant content. Expert commentary: The discovery of biomarkers for irAEs is currently in its infancy, however there are a lot of promising candidate biomarkers that are currently being investigated. Biomarkers that can identify patients at a higher risk of developing irAEs or lead to early detection of autoimmune toxicities are crucial to optimize patient selection for immune-oncology agents and to minimize toxicity with their use.

Association of PD-1 and PD-L1 Genetic Polymorphyisms with Type 1 Diabetes Susceptibility

AIMS

The programmed death- (PD-) 1/PD-1 ligand (PD-L) pathway plays an important role in regulating T cell activation and maintaining peripheral tolerance. Accumulated studies showed that PD-1/PD-L1 pathway was involved in the development of type 1 diabetes (T1DM). Since the genetic background of type 1 diabetes differs greatly among the different population, we aim to investigate the association of genetic polymorphisms in PD-1 and PD-L1 with T1DM susceptibility in Chinese population.

METHODS

In total, 166 T1DM patients and 100 healthy controls were enrolled into the study. Genomic DNA was extracted from 4 mL peripheral blood samples collected from each subject. Genotyping of 8 selected SNPs of PD-1 and PD-L1 was carried out by the pyrosequencing PSQ 24 System using PyroMark Gold reagents (QIAGEN).

RESULTS

SNP rs4143815 in PD-L1 was significantly associated with T1DM. People carrying the C allele of rs4143815 suffering less risk of T1DM and T1DM patients with G/G genotype showed higher levels of autoantibody (AAB) positive incidence compared with C allele carriers. No significant associations were found in other SNPs.

CONCLUSIONS

Our results indicate that rs4143815 of PD-L1 is significantly associated with T1DM and may serve as a new biomarker to predict the T1DM susceptibility.

Clinical Impact of Single Nucleotide Polymorphism in PD-L1 on Response to Nivolumab for Advanced Non-Small-Cell Lung Cancer Patients

This study was intended to determine the efficacy of nivolumab, we evaluated treatment response with respect to PD-1/PD-L1 SNPs among patients with NSCLC. A total of 50 patients with NSCLC were treated with nivolumab and were also evaluated for PD-1/PD-L1 single nucleotide polymorphisms (SNPs) from plasma DNA. We investigated the association among PD-1/PD-L1 SNPs, objective response rate (ORR) and progression-free survival (PFS). Two of seven SNPs studied showed association with ORR and PFS, with maximum evidence at the marker rs2282055. The ORR was 25%, 15%, and 0% for the G/G, G/T and T/T genotypes of PD-L1 rs2282055, respectively. The G allele of PD-L1 rs2282055 was significantly associated with better clinical response compared with the T allele (P = 0.0339 [Cochran-Armitage trend test]). The median PFS time was 2.6 months (95% confidence interval [CI], 1.8 months to 4.3 months) for the G/G and G/T genotypes and 1.8 months (95% confidence interval [CI], 0.4 months to 2.2 months) for the T/T genotype (P = 0.0163). Moreover, the C/C and C/G genotypes of PD-L1 rs4143815 were significantly associated with better ORR and PFS in NSCLC patients treated with nivolumab. These results suggest that rs2282055 and rs4143815 may be a biomarker for the efficacy of nivolumab.

Counter-regulation of rejection activity against human liver grafts by donor PD-L1 and recipient PD-1 interaction

BACKGROUND & AIMS

Co-inhibitory receptor-ligand interactions fine-tune immune responses by negatively regulating T cell functions. Our aim is to examine the involvement of co-inhibitory receptor-ligand pair PD-1/PD-L1 in regulating rejection after liver transplantation (LT) in humans.

METHODS

PD-L1/PD-1 expression in liver allograft was determined by immunohistochemistry or flow cytometry, and the effect of blockade was studied using graft-infiltrating T cells ex vivo. Five single nucleotide polymorphisms within PD-1 and PD-L1 genes were genotyped in 528 LT recipients and 410 donors, and associations with both early (⩽6months) and late (>6months) acute rejection were analyzed using Cox proportional-hazards regression model. The effect of PD-L1 rs4143815 on PD-L1 expression was analyzed using donor hepatic leukocytes.

RESULTS

PD-L1 was expressed by hepatocytes, cholangiocytes and along the sinusoids in post-transplant liver allografts, and PD-1 was abundantly expressed on allograft-infiltrating T cells. PD-L1 blockade enhanced allogeneic proliferative responses of graft-infiltrating T cells. In the genetic association analysis, donor PD-L1 rs4143815 (CC/CG vs. GG; HR=0.230; p=0.002) and recipient PD-1 rs11568821 (AA/AG vs. GG; HR=3.739; p=0.004) were associated with acute rejection late after LT in multivariate analysis. Recipients carrying the PD-1 rs11568821 A allele who were transplanted with liver grafts of PD-L1 rs4143815 GG homozygous donors showed the highest risk for late acute rejection. PD-L1 rs4143815 is associated with differential PD-L1 expression on donor hepatic dendritic cells upon IFN-γ stimulation.

CONCLUSION

Our data suggest that interplay between donor PD-L1 and recipient PD-1 counter-regulates rejection activity against liver grafts in humans.

PD-1 pathway-mediated regulation of islet-specific CD4+ T cell subsets in autoimmune diabetes

Type 1 diabetes (T1D) is a CD4⁺ T cell-driven autoimmune disease resulting from the destruction of insulin-producing pancreatic beta cells. Clinical evidence and studies in non-obese diabetic (NOD) mice suggest that insulin is a major autoantigen. With this in mind, we developed insulin B_10-23:IA^g7 tetramer reagents to track insulin-specific CD4⁺ T cells in mice and interrogated the role of Programmed death-1 (PD-1) for peripheral tolerance. PD-1 is a T cell inhibitory receptor necessary to maintain tolerance and prevent T1D in NOD mice. PD-1 pathway inhibitors are increasingly used in the clinic for treating malignancies, and while many patients benefit, some develop adverse autoimmune events, including T1D. We therefore sought to understand the role of PD-1 in maintaining islet-specific tolerance in diabetes-resistant strains. B6.g7 mice express the same MHC Class II allele as NOD mice, have predominantly naïve insulin-specific CD4⁺ T cells in the periphery, and remain diabetes-free even after PD-1 pathway blockade. Here, we examined the trafficking potential of insulin-specific CD4⁺ T cells in NOD and B6.g7 mice with or without anti-PD-L1 treatment, and found that PD-L1 blockade preferentially increased the number of CD44^highCXCR3⁺ insulin-specific cells in NOD but not B6.g7 mice. Additionally, we investigated whether pancreatic islets in NOD and B6.g7 mice expressed CXCL10, a lymphocyte homing chemokine and ligand for CXCR3. Anti-PD-L1 treated and control NOD mice had detectable CXCL10 expression in the islets, while B6.g7 islets did not. These data suggest that islet tolerance may be in part attributed to the pancreatic environment and in the absence of pancreas inflammation, chemotactic cytokines may be missing. This, together with our previous data showing that PD-1 pathway blockade preferentially affects effector but not anergic self-specific T cells has implications for the use of checkpoint blockade in treating tumor patients. Our work suggests that determining tumor- and self-specific CD4⁺ T cell activation status (naïve, effector or anergic) prior to initiation of immunotherapy would likely help to stratify individuals who would benefit from this therapy versus those who might have adverse effects or incomplete tumor control.

PD-L1 Gene Polymorphism and High Level of Plasma Soluble Pd-L1 Protein may be aSsociated with Non-Small Cell Lung Cancer

Background

PD-1 and its ligand PD-L1 belong to the co-inhibition molecules, which can downregulate immune responses. The PD-L1 polymorphism and the level of soluble PD-L1 (sPD-L1) were investigated in non-small cell lung cancer (NSCLC).

Methods

A total of 288 NSCLC patients and 300 controls were enrolled. An A/C polymorphism at position 8923 in the PD-L1 gene was genotyped using the polymerase chain reaction-restriction fragment length polymorphism method.

Results

The prevalence of the 8923C allele was significantly higher in NSCLC patients than controls (10.2% versus 5.3%, p = 0.002, odds ratio 2.03, 95% confidence interval 1.30-3.17; data were adjusted for age and sex). NSCLC patients also showed increased plasma levels of sPD-L1 compared to controls (1.92 ng/mL versus 0.91 ng/mL, p<0.001). Furthermore, lung adenocarcinoma patients had higher sPD-L1 levels than patients with squamous cell carcinoma (p<0.01). However, no association was observed between the different genetic variants and plasma concentrations of sPD-L1.

Conclusions

The PD-L1 8923A/C polymorphism could be associated with increased susceptibility to NSCLC. Plasma levels of sPD-L1 are significantly increased in NSCLC patients, especially those with adenocarcinoma.

Variations in genes involved in immune response checkpoints and association with outcomes in patients with resected colorectal liver metastases

In patients with colorectal liver metastases (CLM), liver resection offers the possibility of cure and long-term survival. The liver is a highly immunogenic organ harboring ~80% of the body's tissue macrophages. Emerging data demonstrate a critical role of the immune response for cancer treatment. We investigated variations within genes involved in immune response checkpoints and their association with outcomes in patients with CLM who underwent neoadjuvant chemotherapy including bevacizumab and liver resection. Single-nucleotide polymorphisms (SNPs) in nine genes (CCL2, CCR2, LAG3, NT5E, PDCD1, CD274, IDO1, CTLA4 and CD24) were analyzed in genomic DNA from 149 patients with resected bevacizumab-pretreated CLM by direct Sanger DNA sequencing, and correlated with response, recurrence-free survival (RFS), overall survival (OS), probability of cure and recurrence patterns. IDO1 (indoleamine 2, 3-dioxygenase) rs3739319 G>A and CD24 rs8734 G>A showed a significant difference in 3-year OS rates. In addition, IDO1 rs3739319 G>A was significantly associated with extrahepatic recurrence. Recursive partitioning analyses revealed that IDO1 rs3739319 G>A was the dominant SNP predicting RFS and OS. Our data suggest that variants within genes involved in immune response checkpoints are associated with outcomes in patients with resected CLM and might lead to improved treatment strategies modulating anti-tumor immune response by targeting novel immune checkpoints.