Efficacy of chemotherapy containing bevacizumab in patients with metastatic colorectal cancer according to programmed cell death ligand 1

BACKGROUND Bevacizumab,an anti-vascular endothelial growth factor(VEGF)monoclonal antibody,inhibits angiogenesis and reduces tumor growth.Serum VEGF-C,lactate dehydrogenase,and inflammatory markers have been reported as predictive markers related to bevacizumab treatment.Programmed cell death ligand 1(PD-L1)could act upon VEGF receptor 2 to induce cancer cell angiogenesis and metastasis.AIM To investigate the efficacy of bevacizumab-containing chemotherapy in patients with metastatic colorectal cancer(CRC)according to the expression of PD-L1.METHODS This analysis included CRC patients who received bevacizumab plus FOLFOX or FOLFIRI as first-line therapy between June 24,2014 and February 28,2022,at Samsung Medical Center(Seoul,South Korea).Analysis of patient data included evaluation of PD-L1 expression by the combined positive score(CPS).We analyzed the efficacy of bevacizumab according to PD-L1 expression status in patients with CRC.RESULTS A total of 124 patients was included in this analysis.Almost all patients were treated with bevacizumab plus FOLFIRI or FOLFOX as the first-line chemotherapy.While 77%of patients received FOLFOX,23%received FOLFIRI as backbone first-line chemotherapy.The numbers of patients with a PD-L1 CPS of 1 or more,5 or more,or 10 or more were 105(85%),64(52%),and 32(26%),respectively.The results showed no significant difference in progression-free survival(PFS)and overall survival(OS)with bevacizumab treatment between patients with PDL1 CPS less than 1 and those with PD-L1 CPS of 1 or more(PD-L1<1%vs PD-L1≥1%;PFS:P=0.93,OS:P=0.33),between patients with PD-L1 CPS less than 5 and of 5 or more(PD-L1<5%vs PD-L1≥5%;PFS:P=0.409,OS:P=0.746),and between patients with PD-L1 CPS less than 10 and of 10 or more(PD-L1<10%vs PD-L1≥10%;PFS:P=0.529,OS:P=0.568).CONCLUSION Chemotherapy containing bevacizumab can be considered as first-line therapy in metastatic CRC irrespective of PD-L1 expression.

C-reactive protein to albumin ratio predict responses to programmed cell death-1 inhibitors in hepatocellular carcinoma patients

BACKGROUND Over the years,programmed cell death-1(PD-1)inhibitors have been routinely used for hepatocellular carcinoma(HCC)treatment and yielded improved survival outcomes.Nonetheless,significant heterogeneity surrounds the outcomes of most studies.Therefore,it is critical to search for biomarkers that predict the efficacy of PD-1 inhibitors in patients with HCC.AIM To investigate the role of the C-reactive protein to albumin ratio(CAR)in evaluating the efficacy of PD-1 inhibitors for HCC.METHODS The clinical data of 160 patients with HCC treated with PD-1 inhibitors from January 2018 to November 2022 at the First Affiliated Hospital of Guangxi Medical University were retrospectively analyzed.RESULTS The optimal cut-off value for CAR based on progression-free survival(PFS)was determined to be 1.20 using x-tile software.Cox proportional risk model was used to determine the factors affecting prognosis.Eastern Cooperative Oncology Group performance status[hazard ratio(HR)=1.754,95%confidence interval(95%CI)=1.045-2.944,P=0.033],CAR(HR=2.118,95%CI=1.057-4.243,P=0.034)and tumor number(HR=2.932,95%CI=1.246-6.897,P=0.014)were independent prognostic factors for overall survival.CAR(HR=2.730,95%CI=1.502-4.961,P=0.001),tumor number(HR=1.584,95%CI=1.003-2.500,P=0.048)and neutrophil to lymphocyte ratio(HR=1.120,95%CI=1.022-1.228,P=0.015)were independent prognostic factors for PFS.Two nomograms were constructed based on independent prognostic factors.The C-index index and calibration plots confirmed that the nomogram is a reliable risk prediction tool.The ROC curve and decision curve analysis confirmed that the nomogram has a good predictive effect as well as a net clinical benefit.CONCLUSION Overall,we reveal that the CAR is a potential predictor of short-and long-term prognosis in patients with HCC treated with PD-1 inhibitors.If further verified,CAR-based nomogram may increase the number of markers that predict individualized prognosis.

Over-expression of programmed death-ligand 1 and programmed death-1 on antigen-presenting cells as a predictor of organ dysfunction and mortality during early sepsis: a prospective cohort study

BACKGROUND:This study aimed to explore the changes of programmed death-ligand 1(PDL1)and programmed death-1(PD-1)expression on antigen-presenting cells(APCs)and evaluate their association with organ failure and mortality during early sepsis.METHODS:In total,40 healthy controls and 198 patients with sepsis were included in this study.Peripheral blood was collected within the first 24 h after the diagnosis of sepsis.The expression of PDL1 and PD-1 was determined on APCs,such as B cells,monocytes,and dendritic cells(DCs),by flow cytometry.Cytokines in plasma,such as interferon-γ(IFN-γ),tumor necrosis factor-α(TNF-α),interleukin-4(IL-4),IL-6,IL-10,and IL-17A were determined by Luminex assay.RESULTS:PD-1 expression decreased significantly on B cells,monocytes,myeloid DCs(mDCs),and plasmacytoid DCs(pDCs)as the severity of sepsis increased.PD-1 expression was also markedly decreased in non-survivors compared with survivors.In contrast,PD-L1 expression was markedly higher on mDCs,pDCs,and monocytes in patients with sepsis than in healthy controls and in non-survivors than in survivors.The PD-L1 expression on APCs(monocytes and DCs)was weakly related to organ dysfunction and infl ammation.The area under the receiver operating characteristic curve(AUC)of the PD-1 percentage of monocytes(monocyte PD-1%)+APACHE II model(0.823)and monocyte PD-1%+SOFA model(0.816)had higher prognostic value than other parameters alone.Monocyte PD-1%was an independent risk factor for 28-day mortality.CONCLUSION:The severity of sepsis was correlated with PD-L1 or PD-1 over-expression on APCs.PD-L1 in monocytes and DCs was weakly correlated with infl ammation and organ dysfunction during early sepsis.The combination of SOFA or APACHE II scores with monocyte PD-1%could improve the prediction ability for mortality.

Advances on biological evaluation methods of programmed cell death protein-1/ligand-1 inhibitors

Immuno-oncology represents a groundbreaking and well-established field within cancer treatment.Among the various immuno-oncology targets,the exploration of programmed cell death-1/ligand-1 for drug discovery has proven to be one of the most successful endeavors.Remarkably,it took nearly 30 years from the initial target identification to the clinical approval of monoclonal antibodies.Providing suitable and reliable bioassays for drug candidate evaluation is of paramount importance throughout the early stages of drug discovery,from lead compound identification to in vivo efficacy testing.This assay review aims to shed light on diverse assays reported in the literature for testing antagonism activity and efficacy of programmed cell death-1/ligand-1 inhibitors.Each of these assays possesses inherent advantages and can be applied in different research scenarios.The insights presented in this summary can serve as a valuable resource for scientists in this field,aiding in the selection of appropriate assays for their specific investigations.

Prognostic value of programmed death.1, programmed death-ligand 1, programmed death-ligand 2 expression, and CD8(+) T cell density in primary tumors and metastatic lymph nodes from patients with stage T1.4N+M0 gastric adenocarcinoma

Background: Anti-programmed death-1/programmed death-ligand 1(PD-1/PD-L1) immunotherapy has been proved to be effective on gastric cancer in ongoing clinical trials. However, the value of PD-L1 in predicting responses of patients with gastric cancer to anti-PD-1/PD-L1 immunotherapy is controversial. Some studies suggested that intra-and inter-tumoral heterogeneity of PD-L1 expression might explain the controversy.This study aimed to analyze the expression of PD-L1, PD-L2, and PD-1 as well as CD8(+) T-cell density in primary tumors and lymph nodes from patients with stage T1-4 N+M0 gastric adenocarcinoma to explore the heterogeneity of PD-1 signaling pathway molecules.Methods: In primary tumors and metastatic as well as non-metastatic lymph nodes from patients with stage T1-4 N+M0 gastric adenocarcinoma, we detected PD-L1 and PD-L2 expression with immunohistochemistry. CD8(+)T-cell density in primary tumors and PD-1 expression on CD8(+)T cells were detected with immunofluorescence. Univariate analysis was used to determine the prognostic values of them. Cox proportional hazard regression model was used to identify independent risk factors that affect patients' overall survival and disease-free survival.Results: Among 119 eligible patients who had undergone surgical resection, the positive rate of PD-L1 was higher in metastatic lymph nodes than in primary tumors(45.4% vs. 38.7%, P = 0.005); the positive rate of PD-1 on CD8(+)T cells was significantly higher in primary tumors and metastatic lymph nodes than in tumor-free lymph nodes(both P < 0.001). The intensity of PD-1 expression on CD8(+) T cells in primary tumors and in metastatic lymph nodes were stronger than that in tumor-free lymph nodes from the same patient. Beside, the positive rate of PD-L2 did not show any differences between primary tumors and metastatic lymph nodes. In multivariate analysis, PD-L1 expression,PD-L2 expression, a low density of CD8(+) T cells in primary tumors, and PD-1 expression on CD8(+) T cells in primary tumors were associated with poor prognosis.Conclusion: The expression of PD-L1 is heterogeneous in primary tumors and in metastatic lymph nodes from patients with stageT1-4 N+M0 gastric adenocarcinoma, which might explain the inconsistent results in assessing the prognostic value of PD-L1 expression in previous studies.

Comprehensive insights into the effects and regulatory mechanisms of immune cells expressing programmed death-1/programmed death ligand 1 in solid tumors

The programmed cell death-1(PD-1)/programmed cell death ligand 1(PD-L1)signaling pathway is an important mechanism in tumor immune escape,and expression of PD-L1 on tumor cells has been reported more frequently.However,accumulating evidence suggests that PD-1/PD-L1 is also widely expressed on immune cells,and that regulation is also critical for tumor immune responses.In this review,we emphasized that under solid tumor conditions,the immunoregulatory effects of immune cells expressing PD-1 or PD-L1,affected the prognoses of cancer patients.Therefore,a better understanding of the mechanisms that regulate PD-1 or PD-L1 expression on immune cells would provide clear insights into the increased efficacy of anti-PD antibodies and the development of novel tumor immunotherapy strategies.

Expression and clinical value of programmed cell death-ligand 1(PD-L1)in diffuse large B cell lymphoma:a retrospective study

Background: The programmed cell death-1(PD-1)/programmed cell death-ligand 1(PD-L1) pathway inhibits the activation of T cells and plays a crucial role in the negative regulation of cellular and humoral immune responses.Diffuse large B-cell lymphoma(DLBCL) is the most common lymphoid malignancy in adults. In the present study, we aimed to detect the expression of PD-L1 in DLBCL and to analyze its relationship with prognosis.Methods: We reviewed medical records of 204 newly diagnosed DLBCL patients in Sun Yat-sen University Cancer Center between October 2005 and August 2012. The expression of PD-L1 in tumor tissues from these 204 patients was detected using immunohistochemical(IHC) assay. The expression of anaplastic lymphoma kinase(ALK), CD5,CD30, and C-Myc in tumor specimens from 109 patients was detected using IHC, and Epstein-Barr virus(EBV)-encoded RNAs(EBERs) were detected using fluorescence in situ hybridization. The Spearman method was used for correlation analysis. The Kaplan-Meier method with log-rank test was used for univariate analysis. Cox proportional hazards model was used for multivariate analysis.Results: Of the 204 patients, 100(49.0%) were PD-L1-positive in tumor cells and 44(21.6%) were PD-L1-positive in tumor microenvironment. PD-L1 expression in tumor cells and tumor microenvironment were more common in the non-germinal center B-cell-like(GCB) subtype than in the GCB subtype(P = 0.02 and P= 0.04). Patients with PD-L1 expression in tumor microenvironment were more likely to be resistant to first-line chemotherapy when compared with the patients without PD-L1 expression in tumor microenvironment(P = 0.03). PD-L1 expression in tumor microenvironment was negatively correlated with C-Myc expression(r =-0.20, P = 0.04). No correlations were detected between PD-L1 expression and the expression of ALK, CD5, and CD30 as well as EBERs. The 5-year overall survival(OS)rates were 50.0% and 67.3% in patients with and without PD-L1 expression in tumor cells(P = 0.02). PD-L1 expression in tumor cells was an independent risk predictor for OS(P < 0.01).Conclusions: PD-L1 expression is more common in the non-GCB subtype than in the GCB subtype. PD-L1 expression in tumor microenvironment has a negative correlation with C-Myc. PD-L1 positivity predicts short survival in DLBCL patients. For patients with PD-L1 expression, more strategy such as anti-PD-L1 antibody treatment should be recommended.

Immunotherapy against programmed death-1/programmed death ligand 1 in hepatocellular carcinoma: Importance of molecular variations, cellular heterogeneity, and cancer stem cells

Hepatocellular carcinoma(HCC)is a heterogeneous malignancy related to diverse etiological factors.Different oncogenic mechanisms and genetic variations lead to multiple HCC molecular classifications.Recently,an immune-based strategy using immune checkpoint inhibitors(ICIs)was presented in HCC therapy,especially with ICIs against the programmed death-1(PD-1)and its ligand PD-L1.However,despite the success of anti-PD-1/PD-L1 in other cancers,a substantial proportion of HCC patients fail to respond.In this review,we gather current information on biomarkers of anti-PD-1/PD-L1 treatment and the contribution of HCC heterogeneity and hepatic cancer stem cells(CSCs).Genetic variations of PD-1 and PD-L1 are associated with chronic liver disease and progression to cancer.PD-L1 expression in tumoral tissues is differentially expressed in CSCs,particularly in those with a close association with the tumor microenvironment.This information will be beneficial for the selection of patients and the management of the ICIs against PD-1/PD-L1.

Use of programmed cell death protein ligand 1 assay to predict the outcomes of non-small cell lung cancer patients treated with immune checkpoint inhibitors

The recent discovery of immune checkpoints inhibitors, especially anti-programmed cell death protein 1(PD-1)and anti-programmed cell death protein ligand 1(PD-L1) monoclonal antibodies, has opened new scenarios in the management of non-small cell lung cancer(NSCLC) and this new class of drugs has achieved a rapid development in the treatment of this disease. However, considering the costs of these drugs and the fact that only a subset of patients experience long-term disease control, the identification of predictive biomarkers for the selection of candidates suitable for treatment has become a priority. The research focused mainly on the expression of the PD-L1 receptor on both tumor cells and/or immune infiltrates determined by immunohistochemistry(IHC). However, different checkpoint inhibitors were tested, different IHC assays were used, different targets were considered(tumor cells, immune infiltrates or both) and different expression thresholds were employed in clinical trials. In some trials the assay was used prospectively to select the patients, while in other trials it was evaluated retrospectively. Some confusion emerges, which makes it difficult to easily compare the literature data and to translate them in practice management. This mini-review shows the possibilities and pitfalls of the PD-L1 expression to predict the activity and efficacy of anti PD1/PD-L1 monoclonal antibodies in the treatment of NSCLC.

Programmed cell death-1 inhibitor-related sclerosing cholangitis:A systematic review

BACKGROUND Programmed cell death-1(PD-1)inhibitor has been indicated for many types of malignancies.However,these inhibitors also cause immune-related adverse events.Hepatobiliary disorder is a phenotype of immune-related adverse event affecting 0%–4.5%of patients treated with PD-1 inhibitors.Recent studies have reported PD-1 inhibitor-related sclerosing cholangitis(SC);however,the associated clinical and pathological features are unclear.AIM To evaluate the clinical and pathological features of PD-1 inhibitor-related SC through a systematic review of the literature.METHODS The review,conducted using electronic databases in PubMed,was restricted to the period from January 2014 to September 2019 and focused on case reports/series on PD-1 inhibitor-related SC published in English.We scanned the references of the selected literature to identify any further relevant studies.Six cases previously studied by us,including three that have not yet been published,were included in this review.RESULTS Thirty-one PD-1 inhibitor-related SC cases were evaluated.Median age of patients was 67 years(range,43–89),with a male to female ratio of 21:10.The main disease requiring PD-1 inhibitor treatment was non-small cell lung cancer.Agents that caused PD-1 inhibitor-related SC were nivolumab(19 cases),pembrolizumab(10 cases),avelumab(1 case),and durvalumab(1 case).The median number of cycles until PD-1 inhibitor-related SC onset was 5.5(range,1–27).Abdominal pain or discomfort(35.5%,11/31)was the most frequent symptom.Blood serum tests identified liver dysfunction with a notable increase in biliary tract enzymes relative to hepatic enzymes,and a normal level of serum immunoglobulin G4.Biliary dilation without obstruction(76.9%,20/26),diffuse hypertrophy of the extrahepatic biliary tract(90.5%,19/21),and multiple strictures of the intrahepatic biliary tract(30.4%,7/23)were noted.In 11/23(47.8%)cases,pathological examination indicated that CD8+T cells were the dominant inflammatory cells in the bile duct or peribiliary tract.Although corticosteroids were mainly used for PD inhibitor-related SC treatment,the response rate was 11.5%(3/26).CONCLUSION Some clinical and pathological features of PD-1 inhibitor-related SC were revealed.To establish diagnostic criteria for PD-1 inhibitor-related SC,more cases need to be evaluated.

The prognostic value of programmed cell death ligand 1expression in non-Hodgkin lymphoma:a meta-analysis

Objective: Although the prognostic value of programmed cell death-ligand 1(PD-L1) expression in non-Hodgkin lymphoma(NHL) has been evaluated in many studies, the results remain controversial. To investigate the prognostic role of PD-L1 expression and the association between PD-L1 expression and clinicopathological features of NHL, we performed a meta-analysis.Methods: The Pub Med, EMBASE, and Cochrane Library databases were searched up to November 30, 2017. The hazard ratio(HR), 95% confidence interval(CI), and odds ratios(OR) with 95% CIs were combined to evaluate the association of PD-L1 expression with overall survival(OS) and clinicopathological features. Review manager 5.3 and STATA 12.0 were used in this meta-analysis.Results: A total of 2,005 patients across nine studies were enrolled in our meta-analysis, and the pooled results showed that high PD-L1 expression was associated with a poor prognosis(HR=2.04, 95% CI: 1.18–3.54, P=0.01). In the subgroup analysis according to histology types, pooled results demonstrated that an increased PD-L1 expression was an unfavorable prognostic factor for diffuse large B-cell lymphoma(HR=1.92, 95% CI: 1.06–3.48, P=0.03) but not for natural killer/T-cell lymphoma(HR=2.41, 95%CI: 0.47–12.22, P=0.29). Pooled ORs indicated that PD-L1 expression was higher in NHL with international prognostic indices of≥3. However, PD-L1 expression had no correlation with gender, age, disease stage, lactate dehydrogenase level, B symptoms, and germinal center B-cell-like lymphoma.Conclusions: High PD-L1 expression was a poor prognostic biomarker in patients with NHL. Because of our limited sample size,high-quality studies with larger sample sizes are needed to validate our results.

Research progress regarding programmed cell death 1/programmed cell death ligand 1 inhibitors combined with targeted therapy for treating hepatocellular carcinoma

In recent years,a number of targeted therapeutic agents have achieved success in phase III trials in patients with advanced hepatocellular carcinoma(HCC),including sorafenib,lenvatinib,and regorafenib.Immunotherapy is considered to be an effective treatment for advanced HCC.Immune checkpoint inhibitors targeting programmed cell death 1(PD-1)/programmed cell death ligand 1(PDL1)are important antitumor immunotherapy agents that represent breakthroughs in the treatment of advanced HCC.However,treating advanced HCC is still a great challenge,and the need for new treatments remains urgent.This review briefly summarizes the research progress in the use of PD-1/PD-L1 inhibitors combined with targeted therapy for treating HCC.

Regorafenib combined with programmed cell death-1 inhibitor against refractory colorectal cancer and the platelet-to-lymphocyte ratio’s prediction on effectiveness

BACKGROUND The effectiveness of regorafenib plus programmed cell death-1(PD-1)inhibitor in treating microsatellite stable(MSS)metastatic colorectal cancer(mCRC)remains controversial.AIM To investigate the benefits of regorafenib combined with PD-1 inhibitor in treating MSS mCRC and explore indicators predicting response.METHODS This retrospective study included a total of 30 patients with microsatellite stable metastatic colorectal cancer treated with regorafenib combined with programmed cell death-1 inhibitor at Henan Provincial People’s Hospital between December 2018 and December 2020.During a 4-wk treatment cycle,regorafenib was performed for 3 continuous weeks.PD-1 inhibitor was intravenously injected starting on the first day of the oral intake of regorafenib.We reviewed tumor response,progression-free survival(PFS),overall survival,and treatment-related adverse events(TRAEs)and evaluated association between platelet-tolymphocyte ratio(PLR)and outcomes in this retrospective study.RESULTS Stable disease and progressive disease were found in 18(60.0%)and 12(40.0%)patients,respectively.The disease control rate was 60.0%.The median follow-up time was 12.0 mo,and median PFS was 3.4 mo[95%confidence interval(CI):2.2-4.6 mo].Of the 12 patients with progressive disease,10(83.3%)had liver metastasis before starting the combined treatment.Among the 18 patients with SD,10(55.6%)did not have liver metastases.One patient without liver metastases at baseline was found with a substantially prolonged PFS of 11.2 mo.The liver metastasis,the choice of programmed cell death-1 inhibitor other than nivolumab or pembrolizumab and previous exposure to regorafenib was’t associated with treatment outcome.The median PFS in the low-PLR group was 4.2 mo(95%CI:3.5-4.9 mo),compared with 2.8 mo(95%CI:1.4-4.2 mo)in the high-PLR group(P=0.005).The major TRAEs included hand-foot syndrome(33.3%),hypertension(23.3%),malaise(20.0%),and gastrointestinal reaction(16.7%).The incidence of grade 3 TRAEs was 13.3%(4/30),which comprised abnormal capillary proliferation(n=1),transaminase elevation(n=1),and hand-foot syndrome(n=2).No grade 4 or higher toxicity was observed.CONCLUSION Regorafenib combined with PD-1 inhibitor could lead to a longer PFS in some patients with MSS mCRC.The PLR might be a prediction of the patient response to this therapy.

Anti-programmed cell death ligand 1-based immunotherapy in recurrent hepatocellular carcinoma with inferior vena cava tumor thrombus and metastasis:Three case reports

BACKGROUND Recurrent hepatocellular carcinoma(HCC)with inferior vena cava tumor thrombus is a great challenge for oncologists and has a poor prognosis.To date,the safety and efficacy of programmed cell death ligand 1(PD-L1)inhibitors are still unknown.CASE SUMMARY A 59-year-old male was identified as having a tumor thrombus in the inferior vena cava 3 years after surgery.The patient underwent a second surgery and adjuvant chemotherapy.However,the level of alpha-fetoprotein was elevated after 2 mo,and lung metastases and mediastinal lymph node metastases were identified.The expression of PD-L1 in HCC and inferior vena cava tumor thrombus tissues was analyzed by immunohistochemistry.Then,the patient received atezolizumab immunotherapy.The level of alpha-fetoprotein dropped to normal,the mediastinal lymph node metastases decreased in size and the lung metastases disappeared after 3 mo of immunotherapy.The patient had no signs of recurrence at 21 mo of follow-up.A 60-year-old male underwent left hepatic tumor resection,inferior vena cava incision and thrombus removal,followed by regular chemotherapy.The patient developed lung and splenic metastases after surgery.Pembrolizumab was used for six courses,and the splenic metastasis shrank,after which splenectomy was performed.The patient continued to receive pembrolizumab for thirteen courses,and the lung metastases showed no progression.A 34-year-old male was diagnosed with liver cancer with inferior vena cava tumor thrombus.The patient underwent right hepatectomy and received tislelizumab for three courses.He is still receiving immunotherapy and in good condition.CONCLUSION Anti-PD-L1 therapy in HCC patients with inferior vena cava tumor thrombus and metastasis is associated with relatively good patient outcomes.

Natural course of chronic hepatitis B is characterized by changing patterns of programmed death type-1 of CD8-positive T cells

AIM:To investigate if and how programmed death type-1(PD-1)expression affects the natural course of hepatitis B virus(HBV)infection. METHODS:Sixty-four patients in different natural stages of chronic HBV infection were enrolled in this study.PD-1 expression in total T cells was detected by flow cytometry.Levels of total CD8+T cell responses and proliferation in relation to PD-1 expression levels were analyzed with intracellular staining and PD-1/ PD-L1 blockage. RESULTS:The PD-1 expression in T cells was dynamically changed during the natural course of chronic HBV infection,did not significantly increase in the immune tolerance phase,and returned to normal in the inactive virus carrier stage.Blockage of the PD-1/PD-L1 pathway could not affect the T-cell response in the immune tolerance and inactive virus carrier stages of chronic HBV infection.However,it could significantly restore the T-cell response in the immune clearance stage of chronic HBV infection.Furthermore,the PD-1 expression level in T cells was associated with the alanine aminotransferase level during the immune clearance stage of chronic HBV infection. CONCLUSION:The PD-l/PD-L1 pathway plays a different role in T-cell response during the natural course of chronic HBV infection.

Advances in immuno-oncology biomarkers for gastroesophageal cancer:programmed death ligand 1,microsatellite instability,and beyond

Blockade of the programmed death ligand 1(PD-L1) and programmed cell death 1(PD-1) receptor axis represents an effective form of cancer immunotherapy. Preclinical evidence initially suggested that gastric and gastroesophageal junction(GEJ) cancers are potentially immunotherapy-sensitive tumors. Early phase clinical trials have demonstrated promising antitumor activity with PD-1/PD-L1 blockade in advanced or metastatic gastric/GEJ cancer. Microsatellite instability(MSI) and PD-L1 expression have been shown to predict higher response to PD-1 inhibitors as highlighted by the recent approvals of pembrolizumab in treatmentrefractory solid tumors with MSI status and the thirdline or greater treatment of PD-L1 positive advanced gastric/GEJ cancers. However, predictive and prognostic biomarkers remain an ongoing need. In this review, we detail the preclinical evidence and early tissue biomarker analyses illustrating potential predictive biomarkers to PD-1/PD-L1 blockade in gastric/GEJ cancer. We also review the clinical development of PD-1/PD-L1 inhibitors in gastric/GEJ cancer and highlight several areas in need of future investigation in order to optimize the efficacy of PD-1/PD-L1 blockade in gastric/GEJ cancer.

Costimulatory molecule programmed death-1 in the cytotoxic response during chronic hepatitis C

Hepatitis C virus（HCV）-specific CD8^＋ T cells play an important role in the resolution of HCV infection. Nevertheless, during chronic hepatitis C these cells lack their effector functions and fail to control the virus. HCV has developed several mechanisms to escape immune control. One of these strategies is the upregulation of negative co-stimulatory molecules such us programmed death-1 （PD-1）. This molecule is upregulated on intrahepatic and peripheral HCV-specific cytotoxic T cells during acute and chronic phases of the disease, whereas PD-1 expression is low in resolved infection. PD-1 expressing HCV-specific CD8^＋ T cells are exhausted with impairment of several effector mechanisms, such as： type-1 cytokine production, expansion ability after antigen encounter and cytotoxic ability. However, PD-1 associated exhaustion can be restored by blocking the interaction between PD-1 and its ligand （PD-L1）. After this blockade, HCV-specific CD8^＋ T cells reacquire their functionality. Nevertheless, functional restoration depends on PD-1 expression level. High PD-l-expressing intrahepatic HCV-specific CD8^＋ T cells do not restore their effector abilities after PD-1/ PD-L1 blockade. The mechanisms by which HCV is able to induce PD-1 up-regulation to escape immune control are unknown. Persistent TCR stimulation by a high level of HCV antigens could favour early PD-1 induction, but the interaction between HCV core protein and gClq receptor could also participate in this process. The PD-1/PD-L1 pathway modulation could be a therapeutic strategy, in conjunction with the regulation of others co-stimulatory pathways, in order to restore immune response aclainst HCV to succeed in clearing the infection.

Pathological significance of abnormal recepteur d'origine nantais and programmed death ligand 1 expression in colorectal cancer

BACKGROUND Programmed death ligand 1(PD-L1) immunotherapy remains poorly efficacious in colorectal cancer(CRC). The recepteur d'origine nantais(RON) receptor tyrosine kinase plays an important role in regulating tumor immunity.AIM To identify the patterns of RON and PD-L1 expression and explore their clinical significance in CRC.METHODS Gene expression data from the Gene Expression Omnibus database(GEO;n = 290) and patients at the First Affiliated Hospital, Zhejiang University School of Medicine(FAHZUSM;n = 381) were analyzed to determine the prognostic value of RON and PD-L1 expression within the tumor microenvironment of CRC. HT29 cell line was treated with BMS-777607 to explore the relationship between RON activity and PD-L1 expression. Signaling pathways and protein expression perturbed by RON inhibition were evaluated by cellular immunofluorescence and Western blot.RESULTS In the GEO patient cohort, cut-off values for RON and PD-L1 expression were determined to be 7.70 and 4.3, respectively. Stratification of patients based on these cutoffs demonstrated that high expression of RON and PD-L1 was associated with a poor prognosis. In the FAHZUSM cohort, rates of high expression of RON in tumor cells, high PD-L1 expression in tumor cells and tumor infiltrating monocytes, and both high RON and high PD-L1 expression in the tumor microenvironment were 121(32%), 43(11%), 91(24%), and 51(13.4%), respectively. High expression of RON was significantly correlated with high expression of PD-L1 in the tumor cell compartment(P < 0.001). High expression of RON and that of PD-L1 were independent prognostic factors for poorer overall survival. Concurrent high expression of both RON and PD-L1 in the tumor microenvironment was significantly associated with a poor prognosis. In vitro, BMS-777607 inhibited the phosphorylation of RON, inhibited PD-L1 expression, and attenuated activation of the ERK1/2 and AKT signaling pathways in CRC cells.CONCLUSION RON, PD-L1, and their crosstalk are significant in predicting the prognostic value of CRC. Moreover, phosphorylation of RON upregulates PD-L1 expression, which provides a novel approach to immunotherapy in CRC.

Risk of interstitial lung disease with the use of programmed cell death 1 (PD-1) inhibitor compared with programmed cell death ligand 1 (PD-L1) inhibitor in patients with breast cancer: A systematic review and meta-analysis

Background:Programmed cell death 1(PD-1)and programmed cell death ligand 1(PD-L1)inhibitors have become integral elements within the current landscape of breast cancer treatment modalities;however,they are associ-ated with interstitial lung disease(ILD),which is rare but potentially fatal.Notably,only a few studies have compared the difference in ILD incidence between PD-1 and PD-L1 inhibitors.Therefore,this study aimed to assess the discrepancies regarding ILD risk between the two immune checkpoint inhibitors.We also reported three cases of ILD after PD-1 inhibitor treatment.Methods:We comprehensively searched PubMed,EMBASE,and the Cochrane Library to identify clinical trials that investigated PD-1/PD-L1 inhibitor treatment for patients with breast cancer.Pooled overall estimates of incidence and risk ratio(RR)were calculated with a 95%confidence interval(CI),and a mirror group analysis was per-formed using eligible studies.Results:This meta-analysis included 29 studies with 4639 patients who received PD-1/PD-L1 inhibitor treatment.A higher ILD incidence was observed among 2508 patients treated with PD-1 inhibitors than among 2131 patients treated with PD-L1 inhibitors(0.05 vs.0.02).The mirror group analysis further revealed a higher ILD event risk in patients treated with PD-1 inhibitors than in those treated with PD-L1 inhibitors(RR=2.34,95%CI,1.13-4.82,P=0.02).Conclusion:Our findings suggest a greater risk of ILD with PD-1 inhibitors than with PD-L1 inhibitors.These findings are instrumental for clinicians in treatment deliberations,and the adoption of more structured diagnostic approaches and management protocols is necessary to mitigate the risk of ILD.

ITP患者PD-1/PD-L1表达特点及其在Treg与Breg细胞之间的相互作用机制分析

目的探讨原发免疫性血小板减少症(ITP)患者细胞程序性死亡受体-1(PD-1)/细胞程序性死亡配体1(PD-L1)表达特点及其在调节性T细胞(Treg)、调节性B细胞(Breg)间的相互作用。方法选取2018年12月—2022年1月在我院治疗的ITP患者106例作为观察组,其中轻度患者32例,中度患者44例,重度患者30例。同时选取同期健康志愿者100例作为对照组。检测两组Treg细胞百分比、Breg细胞百分比、Treg细胞表面PD-1阳性率、Breg细胞表面PD-L1阳性率等,同时分析观察组不同病情程度患者各指标差异。结果观察组Breg细胞百分比、Treg细胞百分比、TGF-β、IL-10和IL-4水平均明显低于对照组(P<0.05);观察组Treg细胞表面PD-1阳性率、Breg细胞表面PD-L1阳性率、可溶性程序性细胞死亡蛋白-1(sPD-1)和IL-17水平均明显高于对照组(均P<0.05);两组可溶性程序性细胞死亡蛋白配体-1(sPD-L1)水平比较差异无统计学意义(P>0.05)。观察组重度患者Breg细胞百分比、Treg细胞百分比均明显低于轻度和中度患者(均P<0.05),而Treg细胞表面PD-1阳性率、Breg细胞表面PD-L1阳性率均明显高于轻度和中度患者(均P<0.05)。Treg细胞表面PD-1阳性率与Breg细胞表面PD-L1阳性率呈正相关(r=0.446,P<0.05)。观察组治疗后Breg细胞百分比、Treg细胞百分比、TGF-β、IL-10和IL-4水平有所升高(P<0.05),而Treg细胞表面PD-1阳性率、Breg细胞表面PD-L1阳性率、sPD-1和IL-17水平有所降低(P<0.05),治疗前后sPD-L1水平比较差异无统计学意义(P>0.05)。结论ITP患者Treg细胞表面PD-1和Breg细胞表面PD-L1阳性率明显升高,与患者病情严重程度呈正相关,同时Treg细胞表面PD-1和Breg细胞表面PD-L1表达之间存在相关性。