Soluble Programmed Cell Death Protein Research Articles

Checkpoint inhibitor-expressing lentiviral vaccine suppresses tumor growth in preclinical cancer models

BackgroundWhile immunotherapy has been highly successful for the treatment of some cancers, for others, the immune response to tumor antigens is weak leading to treatment failure. The resistance of tumors...

The Influence of Drug-Eluting Beads Transarterial Chemoembolization on Serum Levels of Soluble Programmed Cell Death Protein-1 in Advanced Hepatocellular Carcinoma Patients.

This study aims to explore the role of soluble programmed cell death protein 1 (sPD-1) in individuals with hepatocellular carcinoma (HCC) undergoing treatment with drug-eluting beads transarterial chemoembolization (D-TACE). Additionally, we aim to assess the potential utility of sPD-1 for determining the optimal timing for combining D-TACE with immune checkpoint inhibitors (ICIs). A total of 44 HCC patients eligible for D-TACE and 55 healthy volunteers were enrolled in this study. Three milliliters of peripheral venous blood from the patients were collected on the day before D-TACE and 3, 7, and 30 days after D-TACE, respectively, for the assay of sPD-1. The relationships between sPD-1 levels, clinical features, outcomes, and the fluctuation of sPD-1 during treatment were analyzed. The initial sPD-1 levels in patients were found to be significantly higher than those in the control group. Although the initial sPD-1 levels displayed a decreasing trend with an increase in BCLC stage, no significant differences were observed among patients at different BCLC stages. The sPD-1 level on day 3 after D-TACE was similar to that on day 7 after D-TACE and significantly lower than the initial level. The sPD-1 level on day 30 after D-TACE was significantly higher than that on day 3 and day 7 after D-TACE and nearly returned to the initial level before D-TACE. The level of sPD-1 was found to be significantly elevated in patients with HCC. However, further research is deemed necessary to fully understand the role of sPD-1 as a potential biomarker in the initiation, progression, and prognosis of HCC. The decrease in sPD-1 following D-TACE suggests that immune effector cells might potentially be reduced, as well as immune function weakened, highlighting the need to avoid the prompt administration of ICIs after D-TACE.

Progression of type 1 diabetes is associated with high levels of soluble PD-1 in islet autoantibody-positive children

Aims/hypothesisType 1 diabetes is an autoimmune disorder that is characterised by destruction of pancreatic beta cells by autoreactive T lymphocytes. Although islet autoantibodies (AAb) are an indicator of disease progression, specific immune biomarkers that can be used as target molecules to halt development of type 1 diabetes have not been discovered. Soluble immune checkpoint molecules (sICM) play a pivotal role in counteracting excessive lymphocyte responses, but their role in type 1 diabetes is unexplored. In this longitudinal study, we measured sICM levels in AAb-positive (AAb+) children to identify molecules related to type 1 diabetes progression.MethodsWe measured the levels of 14 sICM in the sera of AAb+ children (n=57) compared to those with recent-onset type 1 diabetes (n=79) and healthy children (n=44), obtained from two cohorts. AAb+ children were followed up and divided based on their progression to type 1 diabetes (AAbP) or not (AAbNP) (if they lost islet autoimmunity and did not develop disease in subsequent years). sICM were also measured in the sample taken at the visit closest to disease onset in AAbP children.ResultsWe found that AAb+ children had a distinct sICM profile compared with healthy children and those with recent-onset type 1 diabetes. In addition, AAb+ children who progressed to type 1 diabetes (AAbP) had higher sICM concentrations than non-progressors (AAbNP). Further, sICM levels decreased in AAbP children close to disease onset. Application of Cox regression models highlighted that high concentrations of soluble programmed cell death protein 1 (sPD-1) are associated with type 1 diabetes progression (HR 1.71; 95% CI 1.16, 2.51; p=0.007).Conclusions/interpretationThis study reveals an sICM profile that is dysregulated during the preclinical stage of type 1 diabetes, and identifies sPD-1 as a pathophysiologically-relevant molecule that is associated with disease progression, offering a potential target for early interventions in autoimmune diabetes.Graphical

Lack of Association of Plasma Levels of Soluble Programmed Cell Death Protein 1, Programmed Death-Ligand 1, and CTLA-4 With Survival for Stage II to IIIA NSCLC After Complete Resection and Adjuvant Chemotherapy

IntroductionPerioperative treatment in NSCLC has gained marked attention with the introduction of immune checkpoint inhibitors. Such a paradigm shift has given us additional opportunities to evaluate potential biomarkers in patients with these curable disease stages. MethodsThis study (WJOG12319LTR) was designed as a biomarker study to evaluate whether soluble immune markers were prognostic or predictive on relapse-free survival in patients with stage II to IIIA NSCLC who underwent complete resection and adjuvant chemotherapy with cisplatin plus S-1, which is an oral fluoropyrimidine formulation that consists of tegafur, gimeracil, and oteracil, or S-1 alone in the previous WJOG4107 study. Archived plasma samples were assayed for soluble (s) forms of programmed cell death protein 1 (sPD-1), programmed death-ligand 1(sPD-L1), and CTLA-4 (sCTLA-4) with the highly sensitive HISCL system. Using time-dependent receiver operating characteristic curve analysis, the area under the curves were derived and optimal cutoff values were determined. Using the cutoff values, whether the marker was prognostic or predictive was assessed by survival analysis. ResultsA total of 150 patients were included in the study. The time-dependent receiver operating characteristics analysis revealed that the area under the curves for sPD-1, sPD-L1, and sCTLA-4 were 0.54, 0.51, and 0.58, respectively. The survival analysis did not reject that hazard ratios were 1 in terms of the soluble immune marker and the treatment-marker interaction for all three markers. ConclusionsThere was no proof that circulating concentrations of sPD-1, sPD-L1, and sCTLA-4 were prognostic or predictive factors of the outcome for adjuvant chemotherapy after complete resection in patients with NSCLC.

Regulation of the programmed cell death protein 1/programmed cell death ligand 1 axis in relapsing-remitting multiple sclerosis.

The programmed cell death protein 1/programmed cell death ligand 1 axis plays an important role in the adaptive immune system and has influence on neoplastic and inflammatory diseases, while its role in multiple sclerosis is unclear. Here, we aimed to analyse expression patterns of programmed cell death protein 1 and programmed cell death ligand 1 on peripheral blood mononuclear cells and their soluble variants in multiple sclerosis patients and controls, to determine their correlation with clinical disability and disease activity. In a cross-sectional study, we performed in-depth flow cytometric immunophenotyping of peripheral blood mononuclear cells and analysed soluble programmed cell death protein 1 and programmed cell death ligand 1 serum levels in patients with relapsing-remitting multiple sclerosis and controls. In comparison to control subjects, relapsing-remitting multiple sclerosis patients displayed distinct cellular programmed cell death protein 1/programmed cell death ligand 1 expression patterns in immune cell subsets and increased soluble programmed cell death ligand 1 levels, which correlated with clinical measures of disability and MRI activity over time. This study extends our knowledge of how programmed cell death protein 1 and programmed cell death ligand 1 are expressed in the membranes of patients with relapsing-remitting multiple sclerosis and describes for the first time the elevation of soluble programmed cell death ligand 1 in the blood of multiple sclerosis patients. The distinct expression pattern of membrane-bound programmed cell death protein 1 and programmed cell death ligand 1 and the correlation between soluble programmed cell death ligand 1, membrane-bound programmed cell death ligand 1, disease and clinical factors may offer therapeutic potential in the setting of multiple sclerosis and might improve future diagnosis and clinical decision-making.

Engineering a HER2-CAR-NK Cell Secreting Soluble Programmed Cell Death Protein with Superior Antitumor Efficacy

A new therapy strategy for relapsing patients who have received trastuzumab treatment urgently needs to be explored. HER2-specific chimeric antigen receptor (CAR)-expressing NK cells are being rapidly developed for solid tumor therapy, as they have many advantages over HER2-CAR-T cells. Endogenous soluble PD-1 (sPD-1) from the PD-1 extracellular domain blocks PD-1/PD-L1 interaction to promote cancer immunology. Herein, we engineered a new HER2-CAR-NK cell that co-expresses sPD-1 (designed as sPD-1-CAR-NK cells) and assessed its cytotoxic activities toward various cancer cells, activation of immunity and sPD-1 release in vitro and in mouse models bearing breast cancer cells with high HER2 expression, with or without trastuzumab resistance. We demonstrated that sPD-1-CAR-NK cells were able to release bioactive sPD-1, thereby enhancing the cytolytic activities of HER2-CAR-NK cells against HER2 and PD-L1 highly expressing target cells accompanied by increases in the secretion of perforin, granzyme B and IFN-γ. In vivo, sPD-1-CAR-NK cells had superior immunological anticancer efficacy compared to HER2-CAR-NK cells, and they had advantages over HER2-CAR-NK cells in the intraperitoneal injection of sPD-1. Moreover, the infiltration and activation of NK and T cells into tumor tissue were increased in mice with sPD-1-CAR-NK cells. There was no significant change in the body temperature, organ tissue and body weight in all groups except for the group with the PD-1 injection. Together, these data indicate that HER2-specific sPD-1-CAR-NK cells can transport sPD-1 into cancer tissues with high HER2 expression, further improving the efficacy of HER-CAR-NK cells without obvious side effects. sPD-1-CAR-NK is a promising cytotherapeutic agent for patients bearing HER2-positive breast cancer, including those with trastuzumab resistance.

Soluble immune checkpoints as correlates for HIV persistence and T cell function in people with HIV on antiretroviral therapy.

In people with HIV (PWH) both off and on antiretroviral therapy (ART), the expression of immune checkpoint (IC) proteins is elevated on the surface of total and HIV-specific T-cells, indicating T-cell exhaustion. Soluble IC proteins and their ligands can also be detected in plasma, but have not been systematically examined in PWH. Since T-cell exhaustion is associated with HIV persistence on ART, we aimed to determine if soluble IC proteins and their ligands also correlated with the size of the HIV reservoir and HIV-specific T-cell function. We used multiplex bead-based immunoassay to quantify soluble programmed cell death protein 1 (PD-1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), lymphocyte activation gene-3 (LAG-3), T cell immunoglobulin domain and mucin domain 3 (TIM-3), PD-1 Ligand 1 (PD-L1) and PD-1 Ligand 2 (PD-L2) in plasma from PWH off ART (n=20), on suppressive ART (n=75) and uninfected controls (n=20). We also quantified expression of membrane-bound IC and frequencies of functional T-cells to Gag and Nef peptide stimulation on CD4+ and CD8+ T-cells using flow cytometry. The HIV reservoir was quantified in circulating CD4+ T-cells using qPCR for total and integrated HIV DNA, cell-associated unspliced HIV RNA and 2LTR circles. Soluble (s) PD-L2 level was higher in PWH off and on ART compared to uninfected controls. Higher levels of sPD-L2 correlated with lower levels of HIV total DNA and higher frequencies of gag-specific CD8+ T-cells expressing CD107a, IFNγ or TNFα. In contrast, the concentration of sLAG-3 was similar in uninfected individuals and PWH on ART, but was significantly elevated in PWH off ART. Higher levels of sLAG-3 correlated with higher levels of HIV total and integrated DNA, and lower frequency of gag-specific CD4+ T cells expressing CD107a. Similar to sLAG-3, levels of sPD-1 were elevated in PWH off ART and normalized in PWH on ART. sPD-1 was positively correlated with the frequency of gag-specific CD4+ T cells expressing TNF-a and the expression of membrane-bound PD-1 on total CD8+ T-cells in PWH on ART. Plasma soluble IC proteins and their ligands correlate with markers of the HIV reservoir and HIV-specific T-cell function and should be investigated further in in large population-based studies of the HIV reservoir or cure interventions in PWH on ART.

Nanophotonic immunoarray with electrochemically roughened surfaces for handheld detection of secreted PD-L1 to predict immuno-oncology efficacy.

The analysis of secreted protein biomarkers can be a useful non-invasive method of predicting or monitoring cancer therapeutic response. The increased level of soluble programmed cell death protein ligand 1 (sPD-L1) is a promising predictive biomarker for selecting patients who are likely to respond to immune checkpoint immunotherapy. The current established immunoassay for secreted protein analysis is enzyme-linked immunosorbent assay (ELISA). Yet, ELISA is generally still liable to limited detection sensitivity and restricted to bulky chromogenic readout equipment. Herein, we present a designed nanophotonic immunoarray sensor which achieved sPD-L1 analysis at high-throughput, enhanced detection sensitivity and portability. The key benefits of our nanophotonic immunoarray sensor are (i) high-throughput surface-enhanced Raman scattering (SERS) analysis of multiple samples on a singular platform; (ii) improved sPD-L1 detection sensitivity at 1 pg mL-1 (by two orders of magnitude as compared to ELISA) via electrochemically roughened gold sensor surfaces; (iii) fit for handheld SERS detection with miniaturized equipment footprint. We evaluated the analytical performance of the nanophotonic immunoarray sensor and successfully demonstrated quantitative sPD-L1 detection in a cohort of contrived human plasma samples.

A LysLysLys-tag as trigger in polynorepinephrine epitope imprinting: The case study of soluble PD-L1 detection in serum by optical-based sensing

Polycatecholamines (pCAs)-based molecularly imprinted polymers (MIPs) represent the new performing generation of biocompatible ligand/receptor mimetics. In this context, dealing with MIPs synthesis for bio-macromolecules detection/extraction, one of the critical steps in ensuring effective binding affinity for the parent molecule is the selection of suitable epitopes for pCAs imprinting. To address this challenge, here we investigated the ability of lysine (K) residues to trigger the epitope imprinting process into a polynorepinephrine (PNE) matrix. To this aim, we first designed a set of model epitopes composed of three K and six alanine (A) residues to investigate the influence of each ‘KA’ combination on the imprinting process and the resulting binding performance by Surface Plasmon Resonance (SPR). Only the case of three flanking K residues in N-terminus arose as an excellent trigger for epitope imprinting. The efficacy of the 3K-tag strategy was then evaluated on two peptide templates belonging to soluble programmed cell death protein 1 ligand (PD-L1), which is of great interest as a cancer biomarker in liquid biopsies. These templates were selected due to their negligible natural ability to be imprinted into the PNE matrix and were modified with 3K-tags, in N-, C-, and N/C- positions, respectively. The SPR sensor developed by exploiting the N–3K tag strategy allowed us to achieve excellent sensitivity (0.31 ± 0.04 ng mL−1) and repeatability (avCV% = 4.5) in human serum samples. This strategy opens new insights both for epitopes' design for pCAs-based mimetics and as triggering tags when native epitopes display negligible imprinting capabilities.

Soluble Programmed Cell Death Protein 1 and Its Ligand: Potential Biomarkers to Predict Acute Kidney Injury After Surgery in Critically Ill Patients.

PurposeProgrammed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) have been detected in injury kidney. However, their expressions are unclear in mice kidneys under renal ischemia-reperfusion injury (IRI). In this study, we would observe the expressions of PD-1 and PD-L1 in kidney tissues and analyze the association between the concentrations of PD-1 and PD-L1 in mouse kidney homogenate and the corresponding concentrations of soluble PD-1 (sPD-1) and soluble PD-L1 (sPD-L1) in plasma after renal IRI. Further, we explored the predictive value of sPD-1 and sPD-L1 for acute kidney injury (AKI) in high-risk patients after surgery.MethodsThis study established an AKI model induced by IRI in mice. Plasma, kidney samples, and homogenate were collected 0h, 24h, and 48h after surgery for immunohistochemistry and enzyme-linked immunosorbent assay. Then, we continuously enrolled 88 AKI high-risk patients who underwent noncardiac surgery. The biomarkers, including sPD-1, sPD-L1, and urine neutrophil gelatinase-associated lipocalin (NGAL), tissue inhibitor of metalloproteinase-2 (TIMP-2), insulin-like growth factor-binding protein 7 (IGFBP7), were detected immediately after surgery.ResultsOur data revealed the concentrations of PD-1 and PD-L1 in kidney homogenate, and sPD-1 and sPD-L1 in plasma significantly increased at 0h, 24h, and 48h after IRI. A positive association was found between PD-1 and sPD-1 (r = 0.774, p < 0.001), and between PD-L1 and sPD-L1 (r = 0.881, p < 0.001). Compared to NGAL, [TIMP-2]*[IGFBP7], sPD-1 and sPD-L1 showed better predictive abilities for AKI with an area under the ROC curve of 0.856 (95% confidence interval [CI]: 0.825–0.958, p < 0.001) and 0.906 (95% CI: 0.764–0.921, p < 0.001).ConclusionThe increased expressions of PD-1 and PD-L1 in kidneys under IRI suggested they may play essential roles in AKI development. sPD-1 and sPD-L1 can indirectly reflect the expressions of PD-1 and PD-L1 in kidneys, respectively. sPD-1 and sPD-L1 showed excellent predictive ability for AKI in high-risk patients.

Mediastinal lymph node removal ameliorates cytotoxic T-lymphocyte functions in patients with non-small cell lung cancer.

Mediastinal lymph node (MLN) removal by video-assisted mediastinoscopic lymphadenectomy (VAMLA) for preoperative cancer staging was reported to be associated with increased survival. The aim of this study was to evaluate the immunologic effects of complete MLN removal by VAMLA on cytotoxic T lymphocyte (CTL) phenotype and function. Seventeen patients with non-small cell lung cancer (NSCLC) (stage cT1-4N0-3M0-1A) and 20 healthy participants were included in this study. Blood samples were collected before and 4 weeks after the procedure. Lymphocytes were isolated from the removed MLNs. CTL phenotypes and functions were evaluated by flow cytometry. Plasma levels of soluble programmed cell death protein 1 (sPD-1), soluble programmed cell death protein 1 ligand, and soluble CTL antigen 4 (sCTLA-4) were measured with enzyme-linked immunosorbent assay. The ratio of the immunosenescent CTLs (CD3+CD8+CD28-) was increased in peripheral blood and MLNs of the patients with NSCLC compared to controls (p = 0.037), and MLN removal did not change this ratio. PD-1 and CTL antigen 4 expressions were significantly reduced in peripheral blood CTLs after MLN removal by VAMLA (p = 0.01 and p = 0.01, respectively). Granzyme A expression was significantly reduced in the peripheral blood CTLs of the patients compared to controls (p = 0.006) and MLN removal by VAMLA significantly improved Granzyme A expression in CTLs (p = 0.003). Plasma concentrations of sPD-1 and sCTLA-4 remained unchanged after VAMLA. CTLs in the MLNs and peripheral blood of the patients with NSCLC had an immunosenescent phenotype, increased immune checkpoint receptor expression, and impaired cytotoxicity. MLN removal by VAMLA improved these phenotypic and functional characteristics of CTLs. These changes may explain the potential contribution of VAMLA to improved survival.

Overt Acute Hepatitis B Deteriorates in Females: Destructive Immunity With an Exaggerated Interleukin-17 Pathway.

Background and AimsWe previously showed that overt acute hepatitis B (AHB) was more severe in female patients. Using the same cohort and AHB mouse model, we examined the underlying mechanism.MethodsBaseline biochemistry, virological and cytokine assays, and T helper (Th)1 and Th2 immune markers of 118 consecutive patients were analyzed. The decompensated livers of AHB and chronic hepatitis B (CHB) patients who underwent liver transplantation were analyzed immunohistochemically. B6 mice were hydrodynamically injected with pHBV1.3 plasmids.ResultsDecompensated AHB patients (n=41) were older, more often female, and had higher alanine aminotransferase (ALT), soluble programmed cell death protein 1 (sPD-1) levels, and neutrophil-lymphocyte ratios but lower rates of HBeAg positivity and quantitative HBsAg, interferon (IFN)-γ-inducible protein 10 (IP-10), IFN-γ, and interleukin-4 (IL-4) levels than the compensated patients. Female sex (95% CI OR=1.07~54.9), age (1.06~1.40), and ALT levels (1.001~1.004) were associated with hepatic decompensation. Higher sPD-1 but lower IFN-γ and IL-4 levels were observed in female patients. Compared to CHB, decompensated AHB livers had more IL-17-positive cells but fewer HBsAg-positive cells and lower CD4/CD8 ratios. Higher serum IL-17 levels were noted in the female AHB mice than those in the males.ConclusionsFemales predominated in decompensated AHB, in which downregulated IFN-γ and IL-4 with augmented hepatic IL-17-positive cell development indicated accelerating destructive immunity to enhance viral clearance. The early surge of serum IL-17 was confirmed in the female AHB mice. Targeting the pathway involving IFN-γ, IL-4, and IL-17 might prevent liver transplantation or fatality in decompensated AHB.

Patients with Primary Central Nervous System Lymphoma Have High Levels of Soluble Programmed Cell Death Protein 1 in Their Pretherapeutic Cerebrospinal Fluid

§ s hared first authorship; §§ s hared last authorshipPrimary Central Nervous System Lymphoma (PCNSL) is a rare and aggressive non-Hodgkin lymphoma with limited treatment options and severe prognosis. It may display copy number abnormalities of the 9p24.1 locus harboring the programmed cell death protein ligand 1 (PD-L1) gene. Moreover, tumor lesions often overexpress programmed cell death protein 1 (PD-1) as well as its ligands (PD-L1/PD-L2). Soluble forms of these molecules have been demonstrated in serum and plasma, though the biological and clinical significance of these soluble checkpoint proteins is yet unclear. Furthermore, their presence in the cerebrospinal fluid (CSF), particularly in malignant diseases, is largely unexplored. Thus, the aim of our study was to measure the occurrence of soluble PD-1 (sPD-1) in the CSF of PCNSL patients.We measured sPD-1 levels in pretherapeutic plasma and CSF samples from 11 patients with histopathologically confirmed PCNSL of diffuse large B-cell type (DLBCL) and five patients in which the histopathological examination did not confirm the initial clinical and imaging-based suspicion of PCNSL diagnosis (non-PCNSL). All blood and CSF samples were obtained prior to neurosurgical biopsy. Of these five patients, four had reactive non-malignant lesions and one a glioblastoma. Six CSF samples routinely screened for non-malignant neurological disease (e.g. sclerosis) were included as an additional non-PCNSL control group (neuro-screen samples). All samples were handled identically prior to analysis. Soluble PD-1 was measured using an in-house time-resolved immunofluorometric assay (TRIFMA) as previously reported by our group (Mortensen JB et al. Eur J Haematol. 2021 Jul;107:81-91). All samples were analyzed in duplicates. The TRIFMA was validated for freeze/thaw interference and recovery.We found that pretherapeutic CSF sPD-1 levels in PCNSL patients were approximately 10 to 30-fold higher than those of non-PCNSL and neuro-screen patients (p<0,001). The median CSF sPD-1 level for PCNSL was 628 pg/mL, while the corresponding values for the non-PCNSL and neuro-screen subgroups were 48 pg/mL and 19 pg/mL, respectively. Fig. 1a shows the sPD-1 values measured in the three different subsets (PCNSL, non-PCNSL, neuro-screen) of the study cohort. Three PCSNL patients had particularly high sPD-1 values (range: 1642-2194 pg/mL) in their pretherapeutic CSF samples. Interestingly, these three patients all displayed ‘high-risk’ molecular features, i.e., one case of double-overexpression of bcl-6 and c-Myc and the only two cases of triple-overexpression of bcl-2, bcl-6 and c-Myc. In all 11 PCNSL patients, the DLBCL histology had an activated B-cell like (ABC)/non-germinal center B-cell like (non-GCB) signature. Plasma samples were only available for the PCNSL and non-PCNSL subsets. The median plasma sPD-1 value was 142 pg/mL and 124 pg/mL, respectively. As opposed to non-PCNSL, the CSF sPD-1 levels of PCNSL patients were higher than the paired plasma values (p<0.001; Fig.1b). TRIFMA based measurement of sPD-L1/2 in all available CSF samples and genomic analyses of pretherapeutic PCNSL tissue biopsies are ongoing.At the time of analysis, the median follow-up of the PCNSL cohort was 17 months (range: 1-47) with three deaths observed at 1, 2 and 4 months, respectively. Among the remaining eight patients, six are in continuous 1st complete remission (CR) and two in 2nd CR. Of the six patients in 1st CR, four underwent consolidation with upfront autologous transplant. So far, no significant correlation between CSF sPD-1 and survival has been observed.Despite the limited size of our cohort, we demonstrated that sPD-1 is present and measurable in the CSF of previously untreated PCNSL patients. Moreover, we observed that sPD-1 levels in the pretherapeutic CSF samples from PCNSL were significantly higher than those measured in the non-PCNSL and neuro-screen samples. The PCNSL patients with the most adverse histological features were also the ones with the highest sPD-1 levels in the pretherapeutic CSF. Confirmation of these findings in a larger independent cohort as well as sequential measurements obtained during the course of the disease are warranted. If confirmed, our observations may help to evaluate the usefulness of CSF sPD-1 measurements with regard to disease monitoring as well as checkpoint inhibition strategies in PCNSL. [Display omitted] DisclosuresPulczynski: Investigator of a clinical trial (Nordic Lymphoma Group NLG- LBC7(Polar Bear) EudraCT No 2018- 0038 funded by Roche: Research Funding.

Soluble type immune checkpoint regulators using multiplex luminex immunoassay in chronic hepatitis B patients

AimsSoluble immune checkpoint regulators (sICs) were reported to have clinical impact on the diagnosis and progress of various diseases. This study compared the serum levels of 16 sICs in patients...

Nanobubbles Containing sPD-1 and Ce6 Mediate Combination Immunotherapy and Suppress Hepatocellular Carcinoma in Mice.

PurposeImmune checkpoint inhibitors (ICIs) and sonodynamic therapy (SDT) are types of immunotherapy. In order to combine soluble programmed cell death protein 1 (sPD-1)-mediated immune checkpoint therapy and chlorin e6 (Ce6)-assisted SDT, nanobubbles (NBs) were generated to simultaneously load sPD-1 and Ce6.Materials and MethodsThe sPD-1/Ce6-NBs, which were prepared by thin-film hydration and mechanical oscillation, had a stable physical condition, and delivered sPD-1 and Ce6 in a targeted manner. NBs could strengthen tumor suppression by increasing tumor-targeting accumulation of Ce6 and sPD-1, and by inducing ultrasound-targeted NB destruction. A mouse H22 cell hepatoma xenograft model was used to evaluate the synergetic immunotherapeutic effect and mechanism of sPD-1/Ce6-NBs.ResultsBy observing the tumor inhibition rate, tissue and cell apoptosis, apoptosis-related genes and protein expression, the best immunotherapeutic effect was exhibited by the sPD-1/Ce6-NBs group. The immunotherapeutic mechanism initially demonstrated that when tumor cells were transfected by sPD-1 delivered by NBs, which downregulated the expression of programmed death-ligand 1 (PD-L1) in tumor cells, and blocked the PD-1/PD-L1 signaling pathway, which improved T-cell-mediated tumor inhibition. Furthermore, ICIs combined with SDT induced immunogenic cell death by translocating calreticulin to the cell surface and then synergistically enhancing antitumor immune responses.ConclusionIn conclusion, sPD-1/Ce6-NBs were successfully designed. Ultrasound-mediated sPD-1/Ce6-NBs are potentially effective delivery systems for combination immunotherapy of hepatocellular carcinoma.

Soluble programmed cell death protein 1 (sPD-1) and the soluble programmed cell death ligands 1 and 2 (sPD-L1 and sPD-L2) in lymphoid malignancies.

The programmed cell death protein 1 (PD-1) and its ligand 1 and 2 (PD-L1/PD-L2) regulate the immune system, and the checkpoint pathway can be exploited by malignant cells to evade anti-tumor immune response. Soluble forms (sPD-1/sPD-L1/sPD-L2) exist in the peripheral blood, but their biological and clinical significance is unclear. Time-resolved immunofluorometric assay (TRIFMA) and enzyme-linked immunosorbent assay (ELISA) were used to measure sPD-1, sPD-L1, and sPD-L2 levels in serum from 131 lymphoma patients and 22 healthy individuals. Patients had higher sPD-1 and sPD-L2 levels than healthy individuals. In diffuse large B-cell lymphoma, patients with high International Prognostic Index score had higher sPD-1 levels and sPD-L2 levels correlated with subtype according to cell of origin. Compared to other lymphoma types, follicular lymphoma displayed higher sPD-1 and lower sPD-L1 levels along with lower ligand/receptor ratios. This is the first study to simultaneously characterize pretherapeutic sPD-1, sPD-L1, and sPD-L2 in a variety of lymphoma subtypes. The relation between higher sPD-1 levels and adverse prognostic factors suggests a possible biological role and potential clinical usefulness of sPD-1. Moreover, the reverse expression pattern in follicular lymphoma and T-cell lymphoma/leukemia may reflect biological information relevant for immunotherapy targeting the PD-1 pathway.

Serum soluble PD-1 plays a role in predicting infection complications in patients with acute pancreatitis.

BackgroundMost of acute pancreatitis (AP) are mild and self‐limiting, however, 15%–20% of patients develop severe acute pancreatitis (SAP) or moderately acute pancreatitis (MSAP) with local or systemic complications. Infection complications (ICs) result in 40%–70% morbidity and high mortality rates among SAP and MSAP patients. It is more important to early recognize of ICs of MSAP or SAP. Several studies have indicated that serum soluble programmed cell death protein (sPD‐1) or programmed cell death 1 ligand (sPD‐L1) levels were higher in patients with severe sepsis than in healthy volunteers and have a predictive capacity for mortality. However, the role of serum sPD‐1/sPD‐L1 in AP remains unclear. This study aimed to investigate whether the ICs of AP patients is associated with their sPD‐1 and sPD‐L1 levels, which were determined via enzyme‐linked immunosorbent assay of peripheral blood samples from 63 MSAP and SAP patients and 30 healthy volunteers.ResultsThe serum sPD‐1 levels in AP patients on Days 1, 3, and 10 after onset were significantly increased in a time‐dependent manner compared with that in healthy volunteers. Moreover, the AP patients with ICs had significantly higher serum sPD‐1 levels than the AP without ICs. While serum sPD‐L1 levels in AP were similar to that in healthy volunteers. Besides, serum levels of sPD‐1/sPD‐L1 were negatively correlated with circulating lymphocytes. Univariate and multivariate regression analyses showed that the upregulated serum sPD‐1 level was an independent risk factor for ICs in AP. The area under the receiver operating characteristics curve indicated that combination with Acute Physiology and Chronic Health Evaluation II score and serum sPD‐1 level had a high accuracy in predicting ICs in AP.ConclusionSerum sPD‐1/sPD‐L1 may be involved in the immunosuppressive process in AP. Moreover, the serum sPD‐1 level may be an independent risk factor for predicting ICs in AP patients.

Avelumab for the treatment of relapsed or refractory extranodal NK/T-cell lymphoma: an open-label phase 2 study

AbstractThis study aimed to assess the efficacy and safety of treatment with avelumab, an anti–programmed death ligand 1 (PD-L1) antibody, in patients with relapsed or refractory extranodal natural killer/T-cell lymphoma (ENKTL). In this phase 2 trial, 21 patients with relapsed or refractory ENKTL were treated with 10 mg/kg of avelumab on days 1 and 15 of a 28-day cycle. The primary end point was the complete response (CR) rate based on the best response. Targeted sequencing and immunohistochemistry were performed using pretreatment tumor tissue, and blood samples were drawn before and after treatment for measurement of cytokines and soluble programmed cell death protein 1 (PD1), PD-L1, and PD-L2. The CR rate was 24% (5 of 21), and the overall response rate was 38% (8 of 21). Although nonresponders showed early progression, 5 responders currently continue to receive treatment and have maintained their response. Most treatment-related adverse events were grade 1 or 2; no grade 4 adverse events were observed. Treatment responses did not correlate with mutation profiles, tumor mutation burden, serum levels of cytokines, or soluble PD1/PD-L1 and PD-L2. However, the response to avelumab was significantly associated with the expression of PD-L1 by tumor tissue (P = .001). Therefore, all patients achieving CR showed high PD-L1 expression, and their tumor subtyping based on PD-L1 expression correlated with treatment response. In summary, avelumab showed single-agent activity in a subset of patients with relapsed or refractory ENKTL. The assessment of PD-L1 expression on tumor cells might be helpful for identifying responders to avelumab. This trial was registered at www.clinicaltrials.gov as #NCT03439501.

HGF-Induced PD-L1 Expression in Head and Neck Cancer: Preclinical and Clinical Findings.

Head and neck squamous cell carcinoma (HNSCC) is a widespread disease with a low survival rate and a high risk of recurrence. Nowadays, immune checkpoint inhibitor (ICI) treatment is approved for HNSCC as a first-line treatment in recurrent and metastatic disease. ICI treatment yields a clear survival benefit, but overall response rates are still unsatisfactory. As shown in different cancer models, hepatocyte growth factor/mesenchymal–epithelial transition (HGF/Met) signaling contributes to an immunosuppressive microenvironment. Therefore, we investigated the relationship between HGF and programmed cell death protein 1 (PD-L1) expression in HNSCC cell lines. The preclinical data show a robust PD-L1 induction upon HGF stimulation. Further analysis revealed that the HGF-mediated upregulation of PD-L1 is MAP kinase-dependent. We then hypothesized that serum levels of HGF and soluble programmed cell death protein 1 (sPD-L1) could be potential markers of ICI treatment failure. Thus, we determined serum levels of these proteins in 20 HNSCC patients before ICI treatment and correlated them with treatment outcomes. Importantly, the clinical data showed a positive correlation of both serum proteins (HGF and sPD-L1) in HNSCC patient’s sera. Moreover, the serum concentration of sPD-L1 was significantly higher in ICI non-responsive patients. Our findings indicate a potential role for sPD-L1 as a prognostic marker for ICI treatment in HNSCC.

Secretion of human soluble programmed cell death protein 1 by chimeric antigen receptor-modified T cells enhances anti-tumor efficacy

Background aimsChimeric antigen receptor (CAR) T cells have achieved favorable responses in patients with hematologic malignancies, but the outcome has been far from satisfactory in the treatment of tumors with high expression of immunosuppressive molecules. To overcome this limitation, we modified CAR T cells to secrete types of human soluble programmed cell death protein 1 (PD-1) called sPD-1 CAR T cells. MethodsTo compare the effector function between second (conventional second-generation CAR targeting CD19) and sPD-1 CAR T cells, we measured cytotoxicity, cytokine secretion and activation markers incubated with or without tumor cells expressing CD19 and/or programmed cell death ligand 1 (PD-L1). Furthermore, the anti-tumor efficacy of second and sPD-1 CAR T cells was determined using an NSG mouse model bearing NALM-6-PD-L1. Finally, the underlying mechanism was investigated by metabolic parameters and RNA sequencing analysis of different CAR T cells. ResultsCompared with second CAR T cells, sPD-1 CAR T cells enhanced killing efficiency toward CD19+PD-L1+ tumor cells in vitro. Furthermore, sPD-1 CAR T cells reduced the tumor burden and prolonged overall survival of the NSG (NOD-SCID-IL2rg) mice bearing NALM-6-PD-L1. To explore the effect of soluble PD-1 on CAR T cells, we found that sPD-1 CAR T cells exhibited higher levels of activation and ameliorative profiles of differentiation, exhaustion, glycolysis and apoptosis. ConclusionsWith constitutive soluble PD-1 secretion, sPD-1 CAR T cells have tended to eradicate tumors with a high expression of PD-L1 more effectively than second CAR T cells. This may be due to soluble PD-1 enhancing apoptosis resistance, aerobic metabolism and a more “stem” differentiation of CAR T cells. Overall, our study presents a feasible strategy to increase the efficacy of CAR T cells.