Evaluación de la expresión de PD-L1 e infiltración linfocitaria intratumoral en carcinoma de mama invasivo triple negativo / Evaluation of PD-L1 expression and intratumoral lym phocytic infiltration in triple-negative invasive breast car cinoma

Resumen Introducción : El endofenotipo de cáncer de mama triple negativo (TNBC) es uno de los menos frecuentes y sin diana terapéutica, por tanto, se plantea estudiar la correlación del punto de control inmunológico PD-L1 con el establecimiento de microambiente tumoral evaluado por la infiltración linfocitaria intratumoral estromal (TILs) y su importancia en la práctica clínica. Métodos : Se realizó un estudio retrospectivo de casos y controles, con 31 casos de carcinoma infiltrante de la mama triple negativo y 57 controles no pareados de endofenotipo Luminal A, Luminal B y HER-2 atendidos en un año. Se evaluaron las variables: tipo y grado his tológico, expresión PD-L1 con el clon 22C3, TILs, invasión linfovascular, tamaño tumoral, compromiso de ganglios linfáticos y metástasis. El análisis estadístico se ejecutó con la prueba de chi cuadrado y prueba de coeficiente de correlación de Spearman. Resultados : Se encontró una correlación negativa estadísticamente significativa entre TILs y PD-L1 (rho - 0.106, p 0.025), indicando que a mayor expresión de PD-L1, es menor la infiltración linfocitaria intratumo ral. En los grupos de TILs B (10-40% TILs) y C (40-90% TILs) donde se presenta marcado infiltrado inflamatorio intratumoral se evidenció mayor número de pacientes negativos para PD-L1 (CPS <10) con 16 y 10 casos res pectivamente. Para los casos TNBC se logró identificar un coeficiente de asociación negativa (rho -0.378) y con significancia estadística (p 0.01). Discusión : Se estableció la asociación de TNBC, TILs y expresión de PDL1, lo cual es importante para la instau ración de terapias diana y el desarrollo de la medicina de precisión.

Abstract Introduction : Triple negative breast cancer endophe notype (TNBC) is one of the least frequent and without therapeutic target; therefore we propose to study the correlation of PD-L1 immune checkpoint with the es tablishment of tumor microenvironment assessed by intratumoral stromal lymphocyte infiltration (TILS) and its importance in clinical practice. Methods : A retrospective case-control study was performed, with 31 cases of triple-negative infiltrat ing breast carcinoma and 57 unmatched controls of Luminal A, Luminal B and HER-2 endophenotype seen in one year. The following variables were evaluated: histologic type and grade, PD-L1 expression with clone 22C3, TILS, lymphovascular invasion, tumor size, lymph node involvement and metastasis. Statistical analysis was performed with the chi-square test and Spearman correlation coefficient test. Results : a statistically significant negative correlation was found between TILS and PD-L1 (rho - 0.106, p 0.025), indicating that the higher the expression of PD-L1, the lower the intratumoral lymphocytic infiltration. In the TILS B (10-40% TILS) and C (40-90% TILS) groups where there was a marked intratumoral inflammatory infiltrate, a greater number of patients were negative for PD-L1 (CPS <10) with 16 and 10 cases, respectively. For TNBC cases a negative association coefficient was identified (rho -0.378) with statistical significance (p 0.01). Discussion : The association between TNBC, TILS and PDL1 expression was established, which is important for the establishment of target therapies and the develop ment of precision medicine.

Cancer immunotherapy with enveloped self-amplifying mRNA CARG-2020 that modulates IL-12, IL-17 and PD-L1 pathways to prevent tumor recurrence

Targeting multiple immune mechanisms may overcome therapy resistance and further improve cancer immunotherapy for humans. Here, we describe the application of virus-like vesicles (VLV) for delivery of three immunomodulators alone and in combination, as a promising approach for cancer immunotherapy. VLV vectors were designed to deliver single chain interleukin (IL)-12, short-hairpin RNA (shRNA) targeting programmed death ligand 1 (PD-L1), and a dominant-negative form of IL-17 receptor A (dn-IL17RA) as a single payload or as a combination payload. Intralesional delivery of the VLV vector expressing IL-12 alone, as well as the trivalent vector (designated CARG-2020) eradicated large established tumors. However, only CARG-2020 prevented tumor recurrence and provided long-term survival benefit to the tumor-bearing mice, indicating a benefit of the combined immunomodulation. The abscopal effects of CARG-2020 on the non-injected contralateral tumors, as well as protection from the tumor cell re-challenge, suggest immune-mediated mechanism of protection and establishment of immunological memory. Mechanistically, CARG-2020 potently activates Th1 immune mechanisms and inhibits expression of genes related to T cell exhaustion and cancer-promoting inflammation. The ability of CARG-2020 to prevent tumor recurrence and to provide survival benefit makes it a promising candidate for its development for human cancer immunotherapy.

Construction and self-activation detection of yeast two-hybrid bait plasmid of human programmed cell death ligand 1 immunoglobulin variable region domain gene / 中国生物制品学杂志

@#Objective To construct a yeast two-hybrid recombinant bait plasmid of human programmed cell death ligand 1(PD-L1)immunoglobulin variable region(IgV)domain gene,detect its expression in yeast and detect the cytotoxicity and self-activation of PD-L1 IgV protein as well as the interaction between PD-L1 IgV and human thioredoxin(hTrx).Methods Human PD-L1 was analyzed by bioinformatics method,and primers were designed to amplify PD-L1 IgV domain based on the coding region of PD-L1 gene registered in NCBI GenBank database. PCR amplification was carried out with pENTERPD-L1 plasmid as template,and then cloned into yeast two-hybrid bait vector pGBKT7. The recombinant bait plasmid and pGBKT7 empty vector were transformed into Y2HGold yeast cells respectively,and the PD-L1 IgV gene and its expression were detected by PCR and Western blot;Meanwhile,the protein toxicity and self-activation of PD-L1 IgV were detected,and the interaction between PD-L1 IgV and hTrx was detected by drip plate method.Results The bioinformatics analysis results of PD-L1 were consistent with related reports. The recombinant bait plasmid pGBKT7-PD-L1 IgV was correctly constructed,and Y2HGold positive clone was obtained,in which PD-L1 IgV was stably expressed. The empty vector pGBKT7 and recombinant bait plasmid pGBKT7-PD-L1 IgV grew well on SD/-Trp and SD/-Trp/X-α-Gal plates with the same colony size and number and white colony,but they did not grow on SD/-Trp/X-α-Gal/AbA plates,which indicated that PD-L1 IgV protein had no toxicity and no self-activation effect on yeast. The results of drip plates test showed that all experimental groups grew well on SD/-Trp/-Leu plate,while only positive control group grew on SD/-Trp/-Leu/X-α-Gal/AbA plate and showed blue color,which indicated that bait protein PD-L1 IgV and hTrx did not self-activate,and there was no interaction between them.Conclusion Recombinant human PD-L1 IgV bait plasmid was successfully constructed. PD-L1 IgV protein showed no toxicity and self-activation effect on yeast cells,and there was no interaction between PD-L1 IgV and hTrx. Subsequently,hTrx can be used to construct a peptide aptamer library,from which peptide aptamers that specifically bind to PD-L1 IgV can be screened.

The expression mechanism of programmed cell death 1 ligand 1 and its role in immunomodulatory ability of mesenchymal stem cells / 中华创伤杂志(英文版)

Programmed cell death 1 ligand 1 (PD-L1) is an important immunosuppressive molecule, which inhibits the function of T cells and other immune cells by binding to the receptor programmed cell death-1. The PD-L1 expression disorder plays an important role in the occurrence, development, and treatment of sepsis or other inflammatory diseases, and has become an important target for the treatment of these diseases. Mesenchymal stem cells (MSCs) are a kind of pluripotent stem cells with multiple differentiation potential. In recent years, MSCs have been found to have a strong immunosuppressive ability and are used to treat various inflammatory insults caused by hyperimmune diseases. Moreover, PD-L1 is deeply involved in the immunosuppressive events of MSCs and plays an important role in the treatment of various diseases. In this review, we will summarize the main regulatory mechanism of PD-L1 expression, and discuss various biological functions of PD-L1 in the immune regulation of MSCs.

Effects of Ophiopogonis Root Decoction on a mouse model of idiopathic pulmonary fibrosis based on PD-1/PD-L1 signaling pathway / 中成药

AIM To investigate the effects of Ophiopogonis Root Decoction on bleomycin(BLM)-induced idiopathic pulmonary fibrosis(IPF)in mice and to explore its metabolic modulation of immunity.METHODS The IPF mouse model was constructed by tracheal drip injection of BLM,and the mice were randomly divided into the control group,the model group,the pirfenidone group(0.3 g/kg)and the high,medium and low dose groups of Ophiopogonis Root Decoction(18,9,4.5 g/kg).HE and Masson staining,ELISA,flow cytometry and immunohistochemistry were used to detect the histopathological changes of the lung,the levels of Collagen I,HYP and TGF-β1,the proportion of PD-1+ CD4+T cells in plasma,and the expressions of p-STAT3,PD-1,PD-L1 and IL-17A in lung tissue,respectively.RESULTS Compared with the control group,the model group displayed significantly higher level of lung coefficients(P<0.01),more severe pulmonary inflammatory cell infiltration and collagen fiber deposition,and increased pulmonary fibrosis score(P<0.01),increased levels of Collagen I,HYP and TGF-β1(P<0.01),increased proportion of PD-1+ CD4+ T cells in plasma(P<0.01),increased pulmonary expression of p-STAT3,PD-1,PD-L1 and IL-17A(P<0.01).Compared with the model group,the Ophiopogonis Root Decoction groups shared lower levels of lung coefficients(P<0.05),less pulmonary inflammatory cell infiltration and collagen fiber deposition,decreased pulmonary fibrosis score(P<0.05),decreased levels of Collagen I,HYP and TGF-β1(P<0.05),decreased proportion of PD-1+ CD4+T cells in plasma(P<0.05),and decreased pulmonary expression of p-STAT3,PD-1,PD-L1,and IL-17A(P<0.05).CONCLUSION Ophiopogonis Root Decoction can significantly reduce extracellular matrix(ECM)deposition and curb the progression of IPF via inhibition of STAT3/PD-1/PD-L1 immunomodulatory signaling pathway.

Immune checkpoint inhibitor related tuberculosis:a case report and literature analysis / 复旦学报（医学版）

With the increasing application of immune checkpoint inhibitors(ICI)in anti-tumor therapy,ICI related infections are often neglected.Mycobacterium tuberculosis(MTB)is also a common pathogen.We reported a case of ICI related pulmonary tuberculosis from Zhongshan Hospital,Fudan University.Meanwhile,18 cases of ICI related tuberculosis infection were collected through literature search,and the characteristics of ICI related tuberculosis were analyzed to improve the understanding in clinic practice.All the cases were confirmed TB including 15 cases of pulmonary tuberculosis(1 case with complication of intestinal tuberculosis)and 4 cases of extra-pulmonary tuberculosis(1 case of disseminated tuberculosis,bone tuberculosis,tuberculous pericarditis and tuberculous pleurisy,respectively).The chest CT characteristics of pulmonary tuberculosis mainly included centrilobular nodules,ground glass nodules,empty lesions,patchy shadows,consolidation and large infiltration.Eighteen cases started anti-tuberculosis treatment,while 4 cases continued ICI treatment.Three cases suspended ICI(2 cases had remission after reuse)and 11 cases stopped ICI,and 1 case was not mentioned.ICI related tuberculosis may be a direct complication of tumor immunotherapy.It is necessary to screen tuberculosis infection and exclude active tuberculosis before immunotherapy.If there are suspected symptoms such as fever,cough and sputum during ICI treatment,active tuberculosis should be taken into account.

Retrospective Analysis of Advanced Hepatocellular Carcinoma in the Elderly Treated with Domestic PD-1 Inhibitors combined with Lenva-tinib / 医学研究杂志

Objective To explore the clinical efficacy and safety of domestic programmed death-1(PD-1)ingibitor combined with lenvatinib in the treatment of advanced hepatocellular carcinoma in the elderly.Methods The clinical data of 37 elderly patients(o-ver 60 years old)with advanced hepatocellular carcinoma,who received domestic PD-1 inhibitors combined with lenvatinib in Zhengzhou Yihe Hospital from September 2021 to July 2022 were collected.Modified Response Evaluation Criteria in Solid Tumors(mRECIST)was used to evaluate the efficacy of intrahepatic lesions,and Response Evaluation Criteria in Solid Tumors(RECIST)1.1 was used to evaluate the efficacy of extrahepatic metastatic lesions.Kaplan-Meier method was used to evaluate the survival curve.Results Among the 37 elderly patients with hepatocellular carcinoma,8 patients achieved partial response,15 patients achieved stabilization,and 14 patients a-chieved disease progression.The objective response rate and the disease control rate were 21.6％(8/37)and 62.2％(23/37),respec-tively,and the median progression-free survival time was 5.885months(95％CI:5.374-6.397 months).The overall incidence rate of treatment-related adverse events was 51.4％(19/37).The most common adverse events were fatigue 27.0％(10/37),rash 27.0％(10/37)and hypertension 21.6％(8/37).Conclusion Domestic PD-1 inhibitors combined with lenvatinib is an effective and safe therapy for elderly patients with advanced hepatocellular carcinoma.

Research progress of immune checkpoint inhibitor associated pneumonia in non-small cell lung cancer and integrated TCM and Western medicine treatment / 中国免疫学杂志

Immune checkpoint inhibitors(ICIs)mainly including the CTL antigen 4(CTLA-4)and PD-1/PD-L1,which would offer a notable clinical benefit for non-small cell lung cancer(NSCLC)patients.By strengthening the antitumor immune re-sponse of the body,ICIs lead to immune-related adverse events(irAEs),including checkpoint inhibitor pneumitis(CIP).Although the clinical incidence of CIP is relatively low,some serious cases may prolong or terminate of immunotherapy,even life threateing.This article tries to summarize the clinical manifestations,pathological characteristics,biological mechanism,susceptible population,diagnosis and differential diagnosis,and integrated traditional Chinese and Western medicine treatment of CIP,in order to understand CIP more clearly.

ERK mediated C-Myc/PD-L1 synergy to investigate tumor suppression effect of Shenqi Yiliu decoction combined with cisplatin in combination with H22 hepatocellular carcinoma tumor bearing mice / 中国免疫学杂志

Objective:To investigate the tumor suppressing effect of Shenqi Yiliu decoction combined with cisplatin via ERK-mediated C-Myc/PD-L1 phase-coordinated pathway on H22 hepatocellular carcinoma tumor-bearing mice and its mechanism.Meth-ods:In 60 SPF-grade male Kunming mice,10 mice were taken as blank group by random number table method,and the other 50 mice were replicated as H22 hepatocellular carcinoma tumor-bearing mouse model.After successful replication of the model,the model mice were randomly divided into model group,cisplatin group[2.5×10-3 g/(kg·3 d)],Shenqi Yiliu decoction low[13.515 g/(kg·d)],me-dium[27.03 g/(kg·d-1)],and high dose[27.030 g/(kg·d)]combined with cisplatin group[2.5×10-3 g/(kg·3 d)],10 mice in each group were treated for 13 d.After 24 h of the last dose,the mice were anesthetized and sacrificed,and the tumor inhibition rate,spleen index and thymus index of each drug group were determined;HE staining was performed to observe the histopathological changes of tumor in mice;ELISA kit was used to detect the contents of EGF and IFN-γ in tumor tissue homogenate;p-ERK1/2,C-Myc and PD-L1 protein expression in tumor tissue were detected by IHC and Western blot;ERK,C-Myc and PD-L1 mRNA expression levels in tumor tissue were detected by RT-PCR.Results:Compared with blank group,the average body mass and spleen index of mice in model group were decreased(P<0.05).Compared with model group,the tumor inhibition effect of each treatment group was obvious,and Shenqi Yiliu decoction combined with cisplatin group inhibited tumor growth in liver cancer mice in a dose-dependent way,im-proved the average body mass,spleen index and thymus index of mice,promoted the necrosis of tumor cells and increased the necrotic area.EGF and IFN-γ contents,P-ERK1/2,C-Myc,PD-L1 protein expressions and ERK,C-Myc,PD-L1 mRNA expression levels were decreased in tumor tissues(P<0.05).Compared with cisplatin group,the therapeutic effect of Shenqi decoction combined with cisplatin in medium and high dose groups was significant,and the difference was statistically significant(P<0.05).Conclusion:Shenqi Yiliu decoction combined with cisplatin effectively inhibited the tumor growth of H22 liver cancer tumor-bearing mice and significantly reduces the expression of C-Myc and PD-L1 proteins in the tumor tissues,which may be through the regulation of ERK signaling path-way-related protein expression to exert tumor suppressive effect.

New strategies for targeting PD-1/PD-L1:degraders,bifunctional molecules and covalent inhibitors / 中国药科大学学报

Programmed cell death protein-1(PD-1)/programmed cell death ligand-1(PD-L1)has been considered to be one of the most promising targets for tumor immunotherapy.At present,both monoclonal antibody drugs and small molecule inhibitors targeting PD-1/PD-L1 are facing bottlenecks.Numerous researchers have tried to explore different strategies to block the PD-L1/PD-L1 pathway,hoping to improve the effects of tumor immunotherapy.This review focuses on the degraders,bifunctional molecules and covalent inhibitors that target PD-L1,aiming to provide inspiring insights for the development of anti-PD-1/PD-L1 drugs.

Effects of Apatinib combined with Temozolomide on levels of sPD-1 and sPD-L1 in patients with drug-resistant recurrent glioblastoma

Abstract Objective This study aimed to explore the effects of Apatinib combined with Temozolomide (TMZ) on the levels of Soluble PD-1 (sPD-1) and Soluble Programmed Death-1 Ligand (sPD-L1) in patients with drug-resistant recurrent Glioblastoma (GB). Study design A total of 69 patients with recurrent GB from September 2020 to March 2022 were recruited and assigned to the control group (n = 34) and observation group (n = 35) according to different treatment options after tumor recurrence. The control group was treated with TMZ, and the observation group was treated with Apatinib combined with TMZ. Levels of sPD-1 and spd-l1, clinical efficacy, survival time and adverse reactions were observed and compared between the two groups. Results General data including gender, age, body mass index, and combined diseases indicated no statistical significance between groups (p > 0.05). Before the intervention, sPD-1 and sPD-L1 levels were not significantly different in the two groups (p > 0.05). After interventions, levels of PD-1 and sPD-L1 levels decreased significantly (p < 0.05). The objective remission rate and clinical benefit rate of the observation group were higher and overall survival and progression-free survival were longer than those of the control group (p < 0.05). No significant difference was observed in major adverse reactions among patients (p > 0.05). Conclusions Apatinib combined with TMZ is safe and effective in the treatment of recurrent GB. The combined application of the two can reduce the levels of sPD-1 and sPD-L1, which has important clinical application value.

Analysis of PD-1/PD-L1 variations in lung cancer and association with immunotherapeutic efficacy and prognosis: A nonrandomized controlled trial

Abstract Introduction This study aims to explore Programmed Death Receptor-1 (PD-1) and Programmed Death Ligand-1 (PD-L1) variations in Lung Cancer (LC) tissues and Peripheral Blood (PPB) and their association with immunotherapy efficacy and prognosis. Method 72 patients with LC were included in the LC group and 39 patients with concurrent benign lung disease were included in the benign group. PD-1/PDL-1 was compared in PPB and lung tissue. All LC patients were treated with immunotherapy. The relationship between PD-1/PDL-1 in LC tissue and PPB and immunotherapy efficacy was analyzed. Patients were divided into death and survival groups, and PD-1/PDL-1 in tumor tissues and PPB were compared. Results The authors found that PD-1 and PDL-1 positive expression in lung tissue and PPB in LC patients was elevated. Combined detection of PD-1 and PDL-1 was effective in diagnosing LC and evaluating the prognosis of LC patients. PD-1 and PDL-1 positive expression was reduced after disease remission while elevated in dead patients. The 3-year survival rate of patients with PD-1 positive expression was 45.45 % (25/55), which was lower (82.35 %, 14/17) than those with PD-1 negative expression. The 3-year survival rate of patients with positive and negative expression of PDL-1 was 48.78 % (20/41) and 61.29 % (19/31), respectively. Discussion The present results demonstrated that PD-1 and PDL-1 are abnormal in cancer tissue and PPB of LC patients. The combined detection of PD-1 and PDL-1 has diagnostic value for LC and evaluation value for the efficacy and prognosis of immunotherapy.

Toxicidad pulmonar por pembrolizumab / Pulmonary Toxicity of Pembrolizumab

Se presenta el caso de un paciente con diagnóstico de adenocarcinoma de pulmón metastásico que, luego de realizar cinco meses de tratamiento con pembrolizumab, presentó neumonitis grado 2, interpretada como toxicidad por pembrolizumab con buena respuesta y resolución de los infiltrados con la suspensión del inmunomodulador y la administración de corticoides(AU)

We present the case of a patient diagnosed with metastatic lung adenocarcinoma who, after five months of treatment with pembrolizumab, presented grade 2 pneumonitis, interpreted as pembrolizumab toxicity, with a good response and resolution of the infiltrates with the suspension of the immunomodulator and the administration of corticosteroids(AU)

PD-L1 and PD-L2 expression in colorectal cancer

Context: The programmed death-1 (PD-1) is an immune checkpoint molecule that suppresses T-cell response. The binding of PD-1 to PD-L1/PD-L2 results cytokine production, and T-cell proliferation are reduced. Tumors expressing PD-L1 and PD-L2 escape from cytotoxic T-cells and are exposed to tumor progression. For this reason, immunotherapy has become a new option in the treatment of cancer. Aims: In this study, we examined the PD-L1 and PD-L2 expression in colorectal carcinoma (CRC), and evaluated the relationship between clinicopathological parameters and CD8+ T cells. Methods and Material: We evaluated CD8 expression in tumor-infiltrating lymphocytes and surrounding tumor lymphocytes with PD-L1, PD-L2 staining in tumor cells and immune cells formalin-fixed paraffin embedded samples of 124 patient diagnosed with CRC. Statistical Analysis Used: Pearson Chi-Square, Fisher Exact Chi-Square, and Pearson Exact Chi-Square analyses were used in the analysis of the cross tables. Survival distributions predicted Kaplan--Meier method and it was evaluated using log-rank statistics. Results: In our study, a significant correlation was found between PD-L1 expression and female sex and tumors with medullary morphology. No expression of PD-L2 was observed in tumors containing medullary morphology, and a statistically inverse relationship was observed between PD-L2 and the medullary component. PD-L1 positive tumor-infiltrating lymphocytes were determined to be an important predictor for recurrence-free survival. Conclusions: We believe that the evaluation of these parameters may be useful in the selection of patients who will benefit from immunotherapy in CRC cases.

Development and validation of a risk-prediction model for immune-related adverse events in patients with non-small-cell lung cancer receiving PD-1/PD-L1 inhibitors / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Lung cancer remains the leading cause of cancer deaths worldwide and is the most common cancer in males. Immune-checkpoint inhibitors (ICIs) that target programmed cell death protein-1 (PD-1) or programmed cell death-ligand 1 (PD-L1) have achieved impressive efficacy in the treatment of non-small-cell lung cancer (NSCLC) (Pardoll, 2012; Champiat et al., 2016; Gao et al., 2022). Although ICIs are usually well tolerated, they are often accompanied by immune-related adverse events (irAEs) (Doroshow et al., 2019). Non-specific activation of the immune system produces off-target immune and inflammatory responses that can affect virtually any organ or system (O'Kane et al., 2017; Puzanov et al., 2017). Compared with adverse events caused by chemotherapy, irAEs are often characterized by delayed onset and prolonged duration and can occur in any organ at any stage of treatment, including after cessation of treatment (Puzanov et al., 2017; von Itzstein et al., 2020). They range from rash, pneumonitis, hypothyroidism, enterocolitis, and autoimmune hepatitis to cardiovascular, hematological, renal, neurological, and ophthalmic irAEs (Nishino et al., 2016; Kumar et al., 2017; Song et al., 2020). Hence, we conducted a retrospective study to identify validated factors that could predict the magnitude of the risk of irAEs in patients receiving PD-1/PD-L1 inhibitors; our approach was to analyze the correlation between the clinical characteristics of patients at the start of treatment and relevant indicators such as hematological indices and the risk of developing irAEs. Then, we developed an economical, practical, rapid, and simple model to assess the risk of irAEs in patients receiving ICI treatment, as early as possible.

Metabolic interventions combined with CTLA-4 and PD-1/PD-L1 blockade for the treatment of tumors: mechanisms and strategies / 医学前沿

Immunotherapies based on immune checkpoint blockade (ICB) have significantly improved patient outcomes and offered new approaches to cancer therapy over the past decade. To date, immune checkpoint inhibitors (ICIs) of CTLA-4 and PD-1/PD-L1 represent the main class of immunotherapy. Blockade of CTLA-4 and PD-1/PD-L1 has shown remarkable efficacy in several specific types of cancers, however, a large subset of refractory patients presents poor responsiveness to ICB therapy; and the underlying mechanism remains elusive. Recently, numerous studies have revealed that metabolic reprogramming of tumor cells restrains immune responses by remodeling the tumor microenvironment (TME) with various products of metabolism, and combination therapies involving metabolic inhibitors and ICIs provide new approaches to cancer therapy. Nevertheless, a systematic summary is lacking regarding the manner by which different targetable metabolic pathways regulate immune checkpoints to overcome ICI resistance. Here, we demonstrate the generalized mechanism of targeting cancer metabolism at three crucial immune checkpoints (CTLA-4, PD-1, and PD-L1) to influence ICB therapy and propose potential combined immunotherapeutic strategies co-targeting tumor metabolic pathways and immune checkpoints.

PBRM1 loss promotes PD-L1 secretion in renal cell carcinoma cells through TNF-α/exosome signaling axis / 现代泌尿外科杂志

【Objective】 To explore the expressions of PBRM1 and PD-L1 in renal cell carcinoma (RCC), and the molecular mechanism of PBRM1 regulating PD-L1, in order to provide experimental results for clinical immunotherapy. 【Methods】 The protein expressions of PBRM1 and PD-L1 were detected with immunohistochemistry, and their mRNA expressions were determined by analyzing TCGA database. Meanwhile, the relationship between overall survival and mRNA expressions of PBRM1 and PD-L1 were analyzed in TCGA database. The exosomes were extracted with exoEasy Maxi Kit. Expressions of exosomal biomarkers CD63 and CD9 were detected with Western blotting, and their morphology was observed with transmission electron microscope. PD-L1 expression after IFN-γ, IL-6 and TNF-α treatment was detected with Western blotting. 【Results】 The expression of PBRM1 was significantly lower in canver tissue than in paracancerous tissue (P<0.001). The loss rate of PBRM1 was up to 76.4%. PBRM1 expression was not correlated with PD-L1 expression. PBRM1 deletion activated TNF-α/exosome signaling pathway, leading to increase of PD-L1 secretion in exosomes, which was then transported to the outside of cells. 【Conclusion】 There is no relationship between PBRM1 and PD-L1 protein expressions in RCC. However, PBRM1 mutation can lead to inflammatory signaling pathway activation, inducing PD-L1 secretion, which is encapsulated in exosomes and transported to the outside of cells, and affects the response of immunotherapy.

Application of StrucGP in medical immunology: site-specific N-glycoproteomic analysis of macrophages / 医学前沿

The structure of N-glycans on specific proteins can regulate innate and adaptive immunity via sensing environmental signals. Meanwhile, the structural diversity of N-glycans poses analytical challenges that limit the exploration of specific glycosylation functions. In this work, we used THP-1-derived macrophages as examples to show the vast potential of a N-glycan structural interpretation tool StrucGP in N-glycoproteomic analysis. The intact glycopeptides of macrophages were enriched and analyzed using mass spectrometry (MS)-based glycoproteomic approaches, followed by the large-scale mapping of site-specific glycan structures via StrucGP. Results revealed that bisected GlcNAc, core fucosylated, and sialylated glycans (e.g., HexNAc4Hex5Fuc1Neu5Ac1, N4H5F1S1) were increased in M1 and M2 macrophages, especially in the latter. The findings indicated that these structures may be closely related to macrophage polarization. In addition, a high level of glycosylated PD-L1 was observed in M1 macrophages, and the LacNAc moiety was detected at Asn-192 and Asn-200 of PD-L1, and Asn-200 contained Lewis epitopes. The precision structural interpretation of site-specific glycans and subsequent intervention of target glycoproteins and related glycosyltransferases are of great value for the development of new diagnostic and therapeutic approaches for different diseases.

Mevalonate improves anti-PD-1/PD-L1 efficacy by stabilizing CD274 mRNA

Mevalonate metabolism plays an important role in regulating tumor growth and progression; however, its role in immune evasion and immune checkpoint modulation remains unclear. Here, we found that non-small cell lung cancer (NSCLC) patients with higher plasma mevalonate response better to anti-PD-(L)1 therapy, as indicated by prolonged progression-free survival and overall survival. Plasma mevalonate levels were positively correlated with programmed death ligand-1 (PD-L1) expression in tumor tissues. In NSCLC cell lines and patient-derived cells, supplementation of mevalonate significantly up-regulated the expression of PD-L1, whereas deprivation of mevalonate reduced PD-L1 expression. Mevalonate increased CD274 mRNA level but did not affect CD274 transcription. Further, we confirmed that mevalonate improved CD274 mRNA stability. Mevalonate promoted the affinity of the AU-rich element-binding protein HuR to the 3'-UTR regions of CD274 mRNA and thereby stabilized CD274 mRNA. By in vivo study, we further confirmed that mevalonate addition enhanced the anti-tumor effect of anti-PD-L1, increased the infiltration of CD8+ T cells, and improved cytotoxic function of T cells. Collectively, our findings discovered plasma mevalonate levels positively correlated with the therapeutic efficacy of anti-PD-(L)1 antibody, and provided the evidence that mevalonate supplementation could be an immunosensitizer in NSCLC.

Activation of insulin-like growth factor-1 receptor (IGF-1R) promotes growth of colorectal cancer through triggering the MEX3A-mediated degradation of RIG-I

Insulin-like growth factor-1 receptor (IGF-1R) has been made an attractive anticancer target due to its overexpression in cancers. However, targeting it has often produced the disappointing results as the role played by cross talk with numerous downstream signalings. Here, we report a disobliging IGF-1R signaling which promotes growth of cancer through triggering the E3 ubiquitin ligase MEX3A-mediated degradation of RIG-I. The active β-arrestin-2 scaffolds this disobliging signaling to talk with MEX3A. In response to ligands, IGF-1Rβ activated the basal βarr2 into its active state by phosphorylating the interdomain domain on Tyr64 and Tyr250, opening the middle loop (Leu130‒Cys141) to the RING domain of MEX3A through the conformational changes of βarr2. The models of βarr2/IGF-1Rβ and βarr2/MEX3A could interpret the mechanism of the activated-IGF-1R in triggering degradation of RIG-I. The assay of the mutants βarr2Y64A and βarr2Y250A further confirmed the role of these two Tyr residues of the interlobe in mediating the talk between IGF-1Rβ and the RING domain of MEX3A. The truncated-βarr2 and the peptide ATQAIRIF, which mimicked the RING domain of MEX3A could prevent the formation of βarr2/IGF-1Rβ and βarr2/MEX3A complexes, thus blocking the IGF-1R-triggered RIG-I degradation. Degradation of RIG-I resulted in the suppression of the IFN-I-associated immune cells in the TME due to the blockade of the RIG-I-MAVS-IFN-I pathway. Poly(I:C) could reverse anti-PD-L1 insensitivity by recovery of RIG-I. In summary, we revealed a disobliging IGF-1R signaling by which IGF-1Rβ promoted cancer growth through triggering the MEX3A-mediated degradation of RIG-I.