Study on Targeted Drugs for Non-Small Cell NSCLC with PD-1PD-L1 Signaling Pathway

OBJECTIVE

To study the biological function and clinical significance of PD-1/PD-L1 representation in non-small cell lung cancer (NSCLC), and the representation and correlation of PD-1/PD-L1 and epidermal growth factor receptor (EGFR) in NSCLC.

METHODS

The pathological specimens and clinical data of 108 patients with NSCLC were collected. The representation of PD-1/PD-L1 was detected by immunohistochemistry, and the representation of EGFR was detected by PCR. Logistic regression analysis was used to assess the correlation between PD-1/PD-L1 and EGFR.

RESULTS

The representations of PD-L1 and PD-1 in NSCLC tissues were higher than those in normal lung tissues (P<0.05), and the positive rates were 53.70% and 55.56% respectively, which were related to lymph node metastasis and TNM staging (P<0.05).

CONCLUSION

The risk of EGFR mutation in NSCLC patients is high, which is closely related to the positive of PD1/PD-L1. PD1/PD-L1 can be used as a predictor of EGFR mutation.

Expression of PD-1/PD-L1 axis in mediastinal lymph nodes and lung tissue of human and experimental lung fibrosis indicates a potential therapeutic target for idiopathic pulmonary fibrosis

BACKGROUND

Mediastinal lymph node enlargement is prevalent in patients with idiopathic pulmonary fibrosis (IPF). Studies investigating whether this phenomenon reflects specific immunologic activation are lacking.

METHODS

Programmed cell death-1 (PD-1)/ programmed cell death ligand-1 (PD-L1) expression in mediastinal lymph nodes and lung tissues was analyzed. PD-1, PD-L1 mRNA expression was measured in tracheobronchial lymph nodes of mice following bleomycin-induced injury on day 14. Finally, the effect of the PD-1 inhibitor, pembrolizumab, in bleomycin-induced pulmonary fibrosis was investigated.

RESULTS

We analyzed mediastinal lymph nodes of thirty-three patients (n = 33, IPF: n = 14, lung cancer: n = 10, concomitant IPF and lung cancer: n = 9) and lung tissues of two hundred nineteen patients (n = 219, IPF: 123, controls: 96). PD-1 expression was increased, while PD-L1 expression was decreased, in mediastinal lymph nodes of patients with IPF compared to lung cancer and in IPF lungs compared to control lungs. Tracheobronchial lymph nodes isolated on day 14 from bleomycin-treated mice exhibited increased size and higher PD-1, PD-L1 mRNA levels compared to saline-treated animals. Pembrolizumab blunted bleomycin-induced lung fibrosis, as indicated by reduction in Ashcroft score and improvement in respiratory mechanics.

CONCLUSIONS

Mediastinal lymph nodes of patients with IPF exhibit differential expression profiles than those of patients with lung cancer indicating distinct immune-mediated pathways regulating fibrogenesis and carcinogenesis. PD-1 expression in mediastinal lymph nodes is in line with lung tissue expression. Lower doses of pembrolizumab might exert antifibrotic effects. Clinical trials aiming to endotype patients based on mediastinal lymph node profiling and accordingly implement targeted therapies such as PD-1 inhibitors are greatly anticipated.

Site-Selective Functionalized PD-1 Mutant for a Modular Immunological Activity against Cancer Cells

Targeting immune checkpoints is a well-established strategy in cancer therapy, and antibodies blocking PD-1/PD-L1 interactions to restore the immunological activity against cancer cells have been clinically validated. High-affinity mutants of the PD-1 ectodomain have recently been proposed as an alternative to antibodies to target PD-L1 on cancer cells, shedding new light on this research area. In this dynamic scenario, the PD-1 mutant, here reported, largely expands the chemical space of nonantibody and nonsmall-molecule inhibitor therapeutics that can be used to target cancer cells overexpressing PD-L1 receptors. The polyethylene glycol moieties and the immune response-stimulating carbohydrates, used as site-selective tags, represent the proof of concept for future applications.

LAG3 and TIGIT Expression on Tumor-Infiltrating Lymphocytes in Cutaneous Melanoma

BACKGROUND

Melanoma is widely recognized to be an immunogenic tumor that often contains tumor-infiltrating lymphocytes (TILs) in the tumor microenvironment. During cancer progression, expression of ligands that bind immune checkpoint (IC) proteins, such as PD-1, expressed on the surface of TILs, hinder them from exerting their antitumor functions. TILs consist of a heterogenous group of immune cells and their presence is associated with an improved overall survival in melanoma patients. Introduction of IC inhibitors has revolutionized management and prognosis of advanced melanoma. Unfortunately, the response rates have continued to be limited, resulting in growing interest in characterizing novel IC proteins, and developing combination therapy that includes inhibitors against multiple IC proteins.

METHODS

In a regional cohort of 166 patients diagnosed with cutaneous superficial spreading melanoma with different degree of TILs, we investigated the tumor immune-associated gene expression profile using NanoString Technology. We used multiplex immunofluorescence (mIF) staining in a subset of tumors (N = 7), combining IC proteins T-cell immunoglobulin and ITIM domain (TIGIT) and LAG3 with a melanoma cell marker (SOX10) and immune cell markers (CD8 [cytotoxic T cells], CD4 [T helper cells], FOXP3 [regulatory T cells/Tregs], PAX5 [B cells], and CD56 [NK/NKT cells]) and IC protein PD-1.

RESULTS

We found upregulation of 91 differentially expressed genes, including IC proteins, LAG3 and TIGIT in melanomas with brisk TILs compared to tumors where TILs were absent. mIF staining revealed LAG3 and TIGIT expression in the majority of CD8+ T cells. Only few Tregs and CD4+ T cells expressed LAG3, whereas majority of them expressed TIGIT. LAG3 and TIGIT were expressed in a small fraction of the NK/NKT cells and lacked in the B cells. The majority of PD-1+ cells co-localized with LAG3 and TIGIT.

CONCLUSION

We report a variable expression of LAG3 and TIGIT on TILs subtypes and a coeval occurrence with PD-1. This knowledge places LAG3 and TIGIT in spatial and cellular context in melanoma. The data suggest that targeting multiple IC proteins might help overcome the current challenges with IC therapies.

Clinicopathological characteristics, molecular landscape, and biomarker landscape for predicting the efficacy of PD-1/PD-L1 inhibitors in Chinese population with mismatch repair deficient urothelial carcinoma: a real-world study

Urothelial carcinoma (UC) with deficient mismatch repair (dMMR) is a specific subtype of UC characterized by the loss of mismatch repair (MMR) proteins and its association with Lynch syndrome (LS). However, comprehensive real-world data on the incidence, clinicopathological characteristics, molecular landscape, and biomarker landscape for predicting the efficacy of PD-1/PD-L1 inhibitors in the Chinese patients with dMMR UC remains unknown. We analyzed 374 patients with bladder urothelial carcinoma (BUC) and 232 patients with upper tract urothelial carcinoma (UTUC) using tissue microarrays, immunohistochemistry, and targeted next-generation sequencing. Results showed the incidence of dMMR UC was higher in the upper urinary tract than in the bladder. Genomic analysis identified frequent mutations in KMT2D and KMT2C genes and LS was confirmed in 53.8% of dMMR UC cases. dMMR UC cases displayed microsatellite instability-high (MSI-H) (PCR method) in 91.7% and tumor mutational burden-high (TMB-H) in 40% of cases. The density of intratumoral CD8+ T cells correlated with better overall survival in dMMR UC patients. Positive PD-L1 expression was found in 20% cases, but some patients positively responded to immunotherapy despite negative PD-L1 expression. Our findings provide valuable insights into the characteristics of dMMR UC in the Chinese population and highlights the relevance of genetic testing and immunotherapy biomarkers for treatment decisions.

The prognostic value of a combined immune score in tumor and immune cells assessed by immunohistochemistry in triple-negative breast cancer

BACKGROUND

This study aimed to develop a novel combined immune score (CIS)-based model assessing prognosis in triple-negative breast cancer (TNBC).

METHODS

The expression of eight immune markers (PD-1, PD-L1, PD-L2, IDO, TIM3, OX40, OX40L, and H7-H2) was assessed with immunohistochemistry on the tumor cells (TCs) and immune cells (ICs) of 227 TNBC cases, respectively, and subsequently associated with selected clinicopathological parameters and survival. Data retrieved from The Cancer Genome Atlas (TCGA) were further examined to validate our findings.

RESULTS

All immune markers were often expressed in TCs and ICs, except for PD-1 which was not expressed in TCs. In ICs, the expression of all immune markers was positively correlated between one another, except between PD-L1 and OX40, also TIM3 and OX40. In ICs, PD-1, PD-L1, and OX40L positive expression was associated with a longer progression-free survival (PFS; p = 0.040, p = 0.020, and p = 0.020, respectively). In TCs, OX40 positive expression was associated with a shorter PFS (p = 0.025). Subsequently, the TNBC patients were classified into high and low combined immune score groups (CIS-H and CIS-L), based on the expression levels of a selection of biomarkers in TCs (TCIS-H or TCIS-L) and ICs (ICIS-H or ICIS-L). The TCIS-H group was significantly associated with a longer PFS (p < 0.001). Furthermore, the ICIS-H group was additionally associated with a longer PFS (p < 0.001) and overall survival (OS; p = 0.001), at significant levels. In the multivariate analysis, both TCIS-H and ICIS-H groups were identified as independent predictors of favorable PFS (p = 0.012 and p = 0.001, respectively). ICIS-H was also shown to be an independent predictor of favorable OS (p = 0.003). The analysis of the mRNA expression data from TCGA also validated our findings regarding TNBC.

CONCLUSION

Our novel TCIS and ICIS exhibited a significant prognostic value in TNBC. Additional research would be needed to strengthen our findings and identify the most efficient prognostic and predictive biomarkers for TNBC patients.

Targeting neuropilin-1 abolishes anti-PD-1-upregulated regulatory T cells and synergizes with 4-1BB agonist for liver cancer treatment

BACKGROUND AIMS

Regulatory T cells (Tregs) are an obstacle to PD-1 blockade-mediated antitumor efficacy. However, the behaviors of Tregs response to anti-PD-1 in HCC and the characteristics of Tregs tissue adaptation from peripheral lymphoid tissues to the tumor are still unclear.

APPROACH RESULTS

Here, we determine that PD-1 monotherapy potentially augments the accumulation of tumor CD4 + Tregs. Mechanistically, anti-PD-1 mediates Tregs proliferation in lymphoid tissues rather than in the tumor. Increased peripheral Tregs burden replenishes intratumoral Tregs, raising the ratio of intratumoral CD4 + Tregs to CD8 + T cells. Subsequently, single-cell transcriptomics revealed that neuropilin-1 (Nrp-1) supports Tregs migration behavior, and the genes of Crem and Tnfrsf9 regulate the behaviors of the terminal suppressive Tregs. Nrp-1 + 4-1BB - Tregs stepwise develop to the Nrp-1 - 4-1BB + Tregs from lymphoid tissues into the tumor. Moreover, Treg-restricted Nrp1 depletion abolishes anti-PD-1-upregulated intratumoral Tregs burden and synergizes with the 4-1BB agonist to enhance the antitumor response. Finally, a combination of the Nrp-1 inhibitor and the 4-1BB agonist in humanized HCC models showed a favorable and safe outcome and evoked the antitumor effect of the PD-1 blockade.

CONCLUSION

Our findings elucidate the potential mechanism of anti-PD-1-mediated intratumoral Tregs accumulation in HCC and uncover the tissue adaptation characteristics of Tregs and identify the therapeutic potential of targeting Nrp-1 and 4-1BB for reprogramming the HCC microenvironment.

Secretion of 4-1BB Ligand Crosslinked to PD-1 Checkpoint Inhibitor Potentiates Chimeric Antigen Receptor T Cell Solid Tumor Efficacy

Chimeric antigen receptor (CAR) T cell therapy has transformed the treatment of hematological malignancies but has yet to achieve similar success in solid tumors due to a lack of persistence and function in the tumor microenvironment. We previously reported the augmentation of CAR T cell therapy in an engineered solid tumor model through the secretion of anti-PD-1 single-chain fragment variable region (scFv), as shown by enhanced CAR T cell antitumor efficacy, expansion, and vitality. We have since improved the platform to create a superior cellular product-CAR T cells secreting single-chain trimeric 4-1BB ligand fused to anti-PD-1 scFv (αPD1-41BBL). 4-1BB signaling promotes cytotoxic T lymphocyte proliferation and survival but targeting 4-1BB with agonist antibodies in the clinic has been hindered by low antitumor activity and high toxicity. CAR T cells using 4-1BB endodomain for costimulatory signals have demonstrated milder antitumor response and longer persistence compared to CAR T cells costimulated by CD28 endodomain. We have, for the first time, engineered CD28-costimulated CAR T cells to secrete a fusion protein containing the soluble trimeric 4-1BB ligand. In vitro and in vivo, CAR19.αPD1-41BBL T cells exhibited reduced inhibitory receptor upregulation, enhanced persistence and proliferation, and a less differentiated memory status compared to CAR T cells without additional 4-1BB:4-1BBL costimulation. Accordingly, CAR19.αPD1-41BBL T cell-treated mice displayed significantly improved tumor growth control and overall survival. Spurred on by our preclinical success targeting CD19 as a model antigen, we produced mesothelin-targeting CAR T cells and confirmed the enhanced solid tumor efficacy of αPD1-41BBL-secreting CAR T cells.

Evaluation of the relationship between de-novo DSA development and CXCR5+PD-1+CD8+ T cells and PD-1/PD-L1 mRNA expression in kidney transplant recipients

BACKGROUND AND AIMS

The relationship between the Follicular Cytotoxic T cell subgroup and expression levels of PD1/PD-L1 genes and the development of donor specific antibody (DSA) is unknown. In this study, we aimed to examine CD8+CXCR5+PD-1+ follicular cytotoxic T cell levels and expression levels of PD1/PD-L1 genes in peripheral blood lymphocytes in de-novo DSA positive and negative kidney transplant recipients (KTR).

METHODS

In our study, expression of PD-1/ PD-L1 genes by Real-Time Quantitative PCR method and CD8+CXCR5+PD-1+ T cell expression levels by flow cytometric method were obtained from peripheral blood samples. 63 participants were included in the study (de-novo DSA positive recipients (n = 22, group 1), de-novo DSA negative recipients (n = 20, group 2) and healthy control (n = 21, group 3). All patients had negative PRA before kidney transplantation. Expression (%) levels of target cells were evaluated by flow cytometry method. IBM SPSS Statistics for Windows Version 22 and R.3.3.2 software were used to evaluate the data.

RESULTS

The demographic data of the groups were similar. PD-1 mRNA expression was higher in de-novo DSA positive KTR than negative (respectively, 1.03 ± .29/.82 ± .15, p: .001). CD8+CXCR5+PD-1+ T cell expression levels were found to be higher in the de-novo DSA positive group than in the negative group and similar to the healthy group (respectively, 3.06 ± 1.98/.52 ± .40, p:.001, 3.06 ± 1.98/2.78 ± .59, p:.62). The percentage of CD8+CXCR5+PD-1+ expressing T cells was significantly lower in the HLA-Class II+ group than other groups (HLA CI/II/ I+II, respectively, 3.63 ± 2.72/1.65 ± .50/3.68 ± 1.67, p: .04).

CONCLUSIONS

In our study, a significant relationship was found between DSA formation and PD-1 mRNA level and CD8+CXCR5+PD-1+ follicular cytotoxic T cell in KTR.

Increased co-expression of PD1 and TIM3 is associated with poor prognosis and immune microenvironment heterogeneity in gallbladder cancer

BACKGROUND

The effectiveness of immune checkpoint inhibitors in treating gallbladder cancer (GBC) remains unsatisfactory. Recently, several new immune checkpoints have been identified. However, investigations exploring these immune checkpoints in GBC are limited. In this study, we aim to investigate the expression patterns and clinical implications of various immune checkpoints, and further characterize the spatial and quantitative heterogeneity of immune components in GBC.

METHODS

We employed single and multiplex immunohistochemistry to evaluate the expression of five immune checkpoint markers and four immune cell markers in the primary tumor core, hepatic invasion margin, and liver metastasis. Subsequently, we analyzed their interrelationships and their prognostic significance.

RESULTS

We observed a robust positive correlation between PD1/TIM3 expression in GBC (R = 0.614, P < 0.001). The co-expression of PD1/TIM3 exhibited a synergistic effect in predicting poor prognosis among postoperative GBC patients. Further analysis revealed that the prognostic significance of PD1/TIM3 was prominent in the subgroup with high infiltration of CD8 + T cells (P < 0.001). Multiplex immunohistochemistry reveals that PD1 + TIM3 + FOXP3 + cells constitute a significant proportion of FOXP3 + TILs in GBC tissue. Moreover, the co-high expression of PD1 and TIM3 is positively correlated with the accumulation of CD8 + TILs at the hepatic invasion margin. Lastly, our findings indicated reduced expression levels of immune checkpoints and diminished immune cell infiltration in liver metastases compared to primary tumors.

CONCLUSIONS

Increased co-expression of PD1/TIM3 is associated with poor prognosis in GBC patients and is related to the heterogeneity of immune microenvironment between GBC primary tumor and its hepatic invasion margin or liver metastases, which may be a potential target for future immunotherapy of GBC.

Characteristics and anatomic location of PD-1+TCF1+ stem-like CD8 T cells in chronic viral infection and cancer

CD8 T cells play an essential role in antitumor immunity and chronic viral infections. Recent findings have delineated the differentiation pathway of CD8 T cells in accordance with the progenitor-progeny relationship of TCF1+ stem-like and Tim-3+TCF1- more differentiated T cells. Here, we investigated the characteristics of stem-like and differentiated CD8 T cells isolated from several murine tumor models and human lung cancer samples in terms of phenotypic and transcriptional features as well as their location compared to virus-specific CD8 T cells in the chronically lymphocytic choriomeningitis virus (LCMV)-infected mice. We found that CD8 tumor-infiltrating lymphocytes (TILs) in both murine and human tumors exhibited overall similar phenotypic and transcriptional characteristics compared to corresponding subsets in the spleen of chronically infected mice. Moreover, stem-like CD8 TILs exclusively responded and produced effector-like progeny CD8 T cells in vivo after antigenic restimulation, confirming their lineage relationship and the proliferative potential of stem-like CD8 TILs. Most importantly, similar to the preferential localization of PD-1+ stem-like CD8 T cells in T cell zones of the spleen during chronic LCMV infection, we found that the PD-1+ stem-like CD8 TILs in lung cancer samples are preferentially located not in the tumor parenchyma but in tertiary lymphoid structures (TLSs). The stem-like CD8 T cells are present in TLSs located within and at the periphery of the tumor, as well as in TLSs closely adjacent to the tumor parenchyma. These findings suggest that TLSs provide a protective niche to support the quiescence and maintenance of stem-like CD8 T cells in the tumor.

PD-1 instructs a tumor-suppressive metabolic program that restricts glycolysis and restrains AP-1 activity in T cell lymphoma

The PDCD1-encoded immune checkpoint receptor PD-1 is a key tumor suppressor in T cells that is recurrently inactivated in T cell non-Hodgkin lymphomas (T-NHLs). The highest frequencies of PDCD1 deletions are detected in advanced disease, predicting inferior prognosis. However, the tumor-suppressive mechanisms of PD-1 signaling remain unknown. Here, using tractable mouse models for T-NHL and primary patient samples, we demonstrate that PD-1 signaling suppresses T cell malignancy by restricting glycolytic energy and acetyl coenzyme A (CoA) production. In addition, PD-1 inactivation enforces ATP citrate lyase (ACLY) activity, which generates extramitochondrial acetyl-CoA for histone acetylation to enable hyperactivity of activating protein 1 (AP-1) transcription factors. Conversely, pharmacological ACLY inhibition impedes aberrant AP-1 signaling in PD-1-deficient T-NHLs and is toxic to these cancers. Our data uncover genotype-specific vulnerabilities in PDCD1-mutated T-NHL and identify PD-1 as regulator of AP-1 activity.

Activation of the transcription factor NFAT5 in the tumor microenvironment enforces CD8+ T cell exhaustion

Persistent exposure to antigen during chronic infection or cancer renders T cells dysfunctional. The molecular mechanisms regulating this state of exhaustion are thought to be common in infection and cancer, despite obvious differences in their microenvironments. Here we found that NFAT5, an NFAT family transcription factor that lacks an AP-1 docking site, was highly expressed in exhausted CD8+ T cells in the context of chronic infections and tumors but was selectively required in tumor-induced CD8+ T cell exhaustion. Overexpression of NFAT5 in CD8+ T cells reduced tumor control, while deletion of NFAT5 improved tumor control by promoting the accumulation of tumor-specific CD8+ T cells that had reduced expression of the exhaustion-associated proteins TOX and PD-1 and produced more cytokines, such as IFNɣ and TNF, than cells with wild-type levels of NFAT5, specifically in the precursor exhausted PD-1+TCF1+TIM-3-CD8+ T cell population. NFAT5 did not promote T cell exhaustion during chronic infection with clone 13 of lymphocytic choriomeningitis virus. Expression of NFAT5 was induced by TCR triggering, but its transcriptional activity was specific to the tumor microenvironment and required hyperosmolarity. Thus, NFAT5 promoted the exhaustion of CD8+ T cells in a tumor-selective fashion.

Lower PTEN may be associated with CD8+ T cell exhaustion in diffuse large B-cell lymphoma

Initially discovered in chronic viral infection and then extended to tumor, 'T-cell exhaustion' is a broad term describing the response of T cells to chronic antigen stimulation. By definition, whether T-cell exhaustion occurs in diffuse large B-cell lymphoma (DLBCL) remains largely unknown because little has been described. Here, the immune-suppressing checkpoint molecules involved in T-cell exhaustion, including PD-1, PD-L1, TIM-3 and TIGIT, whose expression levels were analyzed in DLBCL, were retrieved from the GEPIA database. Compared with the normal control, CD8A, TNFA, IFNG and GZMA were markedly elevated in DLBCL, indicating that infiltrated CD8+ T cells predominate in DLBCL. Meanwhile, inhibitory immune checkpoints, such as PD-1, PD-L1, TIGIT and TIM-3 were drastically higher in DLBCL. PTEN, WNT2 and DKK3 expression were also appraised. It was revealed that PTEN was lower in DLBCL, without being statistically significant. In contrast with PTEN, DKK3 and WNT2 were shown to be pronouncedly higher in DLBCL relative to the normal control. Prognostically, only TIGIT was found to be associated with overall survival in DLBCL. Collectively, all the data we curetted from the GEPIA and TIMER 2.0 databases explicitly indicate that CD8+ T cell exhaustion took place, which may be linked with lower PTEN in DLBCL. To the best of our knowledge, this is the first bioinformatic report explicitly proposing that CD8+ T cell exhaustion occurs in DLBCL, which may be associated with lower PTEN.

Immune micro-environment analysis and establishment of response prediction model for PD-1 blockade immunotherapy in glioblastoma based on transcriptome deconvolution

PURPOSE

Only a small proportion of patients obtain survival benefit from PD-1 blockade immunotherapy due to the highly heterogeneous and suppressed immune micro-environment of GBM. We aimed at revealing the characteristics of tumor micro-environment (TME) of GBM related to response to PD-1 inhibitors and constructing a response prediction model for screening patients possibly benefit from PD-1 inhibitors.

METHODS

Based on the composition and expression profiles of cell subpopulations calculated by deconvoluting the GBM bulk RNA-seq, differentially expressed gene analysis and gene set enrichment analysis (GSEA) were performed to explore genes and pathways related to response to PD-1 inhibitors. Further by combining least absolute shrinkage and selection operator (LASSO) regression and expression correlation with PD-L1, the response prediction genes of PD-1 inhibitors were identified and the response prediction model was constructed through binary logistic regression.

RESULTS

The comparison of abundances of tumor infiltrating immune cells showed that the abundance of M0 macrophages of responders was lower, while the abundance of activated dendritic cells (DCs) was higher before PD-1 inhibitors treatment; the abundances of plasma cells and M0 macrophages of responders were lower after PD-1 inhibitors treatment. In addition, GSEA showed that the main up-regulation pathways in the tumor micro-environment of responders before PD-1 inhibitors treatment included the regulation of T-helper 1 type immune response, the positive regulation of natural killer cell-mediated cytotoxicity, p53 signaling pathway, homotypic cell-cell adhesion, etc., the main down-regulation pathways included the activation of microglia and myeloid leukocytes, Ras signaling pathway, etc. Afterward, ITGAX, LRRFIP1 and FMN1 were identified as the key response prediction genes of PD-1 inhibitors and the response prediction model based on them showed good predictive performance with potential value of clinical application in its validation and verification.

CONCLUSIONS

ITGAX, LRRFIP1 and FMN1 were identified as the response prediction genes of PD-1 inhibitors and the response prediction model based on them was proved to have potential clinical value.

Tumor-specific cholinergic CD4+ T lymphocytes guide immunosurveillance of hepatocellular carcinoma

Cholinergic nerves are involved in tumor progression and dissemination. In contrast to other visceral tissues, cholinergic innervation in the hepatic parenchyma is poorly detected. It remains unclear whether there is any form of cholinergic regulation of liver cancer. Here, we show that cholinergic T cells curtail the development of liver cancer by supporting antitumor immune responses. In a mouse multihit model of hepatocellular carcinoma (HCC), we observed activation of the adaptive immune response and induction of two populations of CD4+ T cells expressing choline acetyltransferase (ChAT), including regulatory T cells and dysfunctional PD-1+ T cells. Tumor antigens drove the clonal expansion of these cholinergic T cells in HCC. Genetic ablation of Chat in T cells led to an increased prevalence of preneoplastic cells and exacerbated liver cancer due to compromised antitumor immunity. Mechanistically, the cholinergic activity intrinsic in T cells constrained Ca2+-NFAT signaling induced by T cell antigen receptor engagement. Without this cholinergic modulation, hyperactivated CD25+ T regulatory cells and dysregulated PD-1+ T cells impaired HCC immunosurveillance. Our results unveil a previously unappreciated role for cholinergic T cells in liver cancer immunobiology.

KSCBi005-A-8(hiPSC-PD-L1KO), a PD-L1 knockout human induced pluripotent stem cell line for demonstrating the role of the PD-1/PD-L1 axis

Programmed Cell Death Ligand 1 (PD-L1) is a trans-membrane protein that attenuates the host immune response to tumor cells. PD-L1 ligand on the surface of the cancer binds to PD-1 transmembrane receptors on T cells and exhausts T cells function. Using CRISPR-Cas9 genome editing, we generated biallelic PD-L1 mutants in human induced pluripotent stem cells (hiPSCs). The PD-L1 homozygous-knockout hiPSCs retained their normal morphology, gene expression, and in vivo differentiation potential.

Sub-lethal doses of chemotherapeutic agents induce senescence in T cells and upregulation of PD-1 expression

Cellular senescence is a stable cell cycle arrest, usually in response to internal and/or external stress, including telomere dysfunction, abnormal cellular growth, and DNA damage. Several chemotherapeutic drugs, such as melphalan (MEL) and doxorubicin (DXR), induce cellular senescence in cancer cells. However, it is not clear whether these drugs induce senescence in immune cells. We evaluated the induction of cellular senescence in T cells were derived from human peripheral blood mononuclear cells (PBMNCs) in healthy donors using sub-lethal doses of chemotherapeutic agents. The PBMNCs were kept overnight in RPMI 1640 medium with 2% phytohemagglutinin and 10% fetal bovine serum and then cultured in RPMI 1640 with 20 ng/mL IL-2 and sub-lethal doses of chemotherapeutic drugs (2 μM MEL and 50 nM DXR) for 48 h. Sub-lethal doses of chemotherapeutic agents induced phenotypes associated with senescence, such as the formation of γH2AX nuclear foci, cell proliferation arrest, and induction of senescence-associated beta-galactosidase (SA-β-Gal) activity, (control vs. MEL, DXR; median mean fluorescence intensity (MFI) 1883 (1130-2163) vs. 2233 (1385-2254), 2406.5 (1377-3119), respectively) in T cells. IL6 and SPP1 mRNA, which are senescence-associated secretory phenotype (SASP) factors, were significantly upregulated by sublethal doses of MEL and DXR compared to the control (P = 0.043 and 0.018, respectively). Moreover, sub-lethal doses of chemotherapeutic agents significantly enhanced the expression of programmed death 1 (PD-1) on CD3 + CD4 + and CD3 + CD8 + T cells compared to the control (CD4 + T cells; P = 0.043, 0.043, and 0.043, respectively, CD8 + T cells; P = 0.043, 0.043, and 0.043, respectively). Our results suggest that sub-lethal doses of chemotherapeutic agents induce senescence in T cells and tumor immunosuppression by upregulating PD-1 expression on T cells.

Clinical implications of aberrant PD-1 expression for acute leukemia prognosis

BACKGROUND

Acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) are the most common types of leukemia in adults with an overall poor prognosis. PD-1 alone or combined with other immune checkpoint blockade is a promising research direction for the treatment of acute leukemia (AL) patients. However, clinical Implications of aberrant PD-1 expression in peripheral CD4+ and CD8+ T lymphocytes of AML and ALL patients in assessing the prognosis of diseases, remains inconclusive.

METHODS

In the present study, we used flow cytometry to evaluate PD-1 expression on the surface of CD4+ and CD8+ T lymphocytes in the peripheral circulation of AML and ALL patients and its clinical significance. A total of 53 AML patients, 44 ALL patients and 28 healthy controls were enrolled in this study and peripheral blood specimens were detected by flow cytometry.

RESULTS

Our results indicated that percentages of CD4+ PD1+ and CD8+ PD1+ T lymphocytes in newly diagnosed and non-remission groups were significantly higher than healthy control both in AML and ALL patients. The high level of CD4+ PD1+ and CD8+ PD1+ T lymphocytes were respectively poor prognostic indicators of AML patients and ALL patients but had no significant correlation with most common clinical risks.

CONCLUSIONS

Our findings show that aberrant PD-1 expression correlates with the prognosis of AL patient and may thus serve as poor prognostic indicators. Immunotherapy using PD-1 inhibitors may be a promising strategy for AML and ALL patients with peripheral circulating CD4+ PD1+ and CD8+ PD1+ T lymphocytes positively expressed, respectively.

Large T cell clones expressing immune checkpoints increase during multiple myeloma evolution and predict treatment resistance

Tumor recognition by T cells is essential for antitumor immunity. A comprehensive characterization of T cell diversity may be key to understanding the success of immunomodulatory drugs and failure of PD-1 blockade in tumors such as multiple myeloma (MM). Here, we use single-cell RNA and T cell receptor sequencing to characterize bone marrow T cells from healthy adults (n = 4) and patients with precursor (n = 8) and full-blown MM (n = 10). Large T cell clones from patients with MM expressed multiple immune checkpoints, suggesting a potentially dysfunctional phenotype. Dual targeting of PD-1 + LAG3 or PD-1 + TIGIT partially restored their function in mice with MM. We identify phenotypic hallmarks of large intratumoral T cell clones, and demonstrate that the CD27- and CD27+ T cell ratio, measured by flow cytometry, may serve as a surrogate of clonal T cell expansions and an independent prognostic factor in 543 patients with MM treated with lenalidomide-based treatment combinations.

[Evaluation of Efficacy and Prognosis Analysis of Stage III-IV SMARCA4-deficient Non-small Cell Lung Cancer Treated by PD-1 Immune Checkpoint Inhibitors plus Chemotherapy and Chemotherapy]

BACKGROUND

The SMARCA4 mutation has been shown to account for at least 10% of non-small cell lung cancer (NSCLC). In the present, conventional radiotherapy and targeted therapy are difficult to improve outcomes due to the highly aggressive and refractory nature of SMARCA4-deficient NSCLC (SMARCA4-DNSCLC) and the absence of sensitive site mutations for targeted drug therapy, and chemotherapy combined with or without immunotherapy is the main treatment. Effective SMARCA4-DNSCLC therapeutic options, however, are still debatable. Our study aimed to investigate the efficacy and prognosis of programmed cell death 1 (PD-1) immune checkpoint inhibitors (ICIs) in combination with chemotherapy and chemotherapy in patients with stage III-IV SMARCA4-DNSCLC.

METHODS

46 patients with stage III-IV SMARCA4-DNSCLC were divided into two groups based on their treatment regimen: the chemotherapy group and the PD-1 ICIs plus chemotherapy group, and their clinical data were retrospectively analyzed. Efficacy assessment and survival analysis were performed in both groups, and the influencing factors for prognosis were explored for patients with SMARCA4-DNSCLC.

RESULTS

Male smokers are more likely to develop SMARCA4-DNSCLC. There was no significant difference in the objective response rate (76.5% vs 69.0%, P=0.836) between chemotherapy and the PD-1 ICIs plus chemotherapy or the disease control rate (100.0% vs 89.7%, P=0.286). The one-year overall survival rate in the group with PD-1 ICIs plus chemotherapy was 62.7%, and that of the chemotherapy group was 46.0%. The difference in median progression-free survival (PFS) between the PD-1 ICIs plus chemotherapy group and the chemotherapy group was statistically significant (9.3 mon vs 6.1 mon, P=0.048). The results of Cox regression analysis showed that treatment regimen and smoking history were independent influencing factors of PFS in patients with stage III-IV SMARCA4-DNSCLC, and family history was an individual influencing factor of overall survival in patients with stage III-IV SMARCA4-DNSCLC.

CONCLUSIONS

Treatment regimen may be a prognostic factor for patients with SMARCA4-DNSCLC, and patients with PD-1 ICIs plus chemotherapy may have a better prognosis.

PD-1 blockade and radiotherapy combination for advanced Epstein-Barr virus-associated intrahepatic cholangiocarcinoma: a case report and literature review

Advanced intrahepatic cholangiocarcinoma (ICC) is a rare malignant tumor of biliary epithelial cells, known for its extremely unfavorable prognosis. In the absence of intervention, patients typically survive for less than 5 months. Current guidelines from the Chinese Society of Clinical Oncology (CSCO), National Comprehensive Cancer Network (NCCN), and European Society for Medical Oncology (ESMO) recommend chemotherapy-based systemic therapy as the standard treatment for advanced ICC. However, the first-line regimen, consisting of gemcitabine in combination with cisplatin, generally results in a median survival of approximately one year, which is considered suboptimal. Significant progress has been made in radiotherapy techniques, molecular diagnostics, and tumor immune microenvironments. The integration of immune and radiation therapies has revolutionized treatment strategies for cholangiocarcinoma. Moreover, combined therapeutic regimens have shown promising results in improving survival rates among patients with advanced ICC. In this study, we present a case report of a 70-year-old male patient diagnosed with stage IV ICC, featuring metastases to the retroperitoneal, left adrenal, and left supraclavicular lymph nodes. The patient exhibited a high tumor mutational load, significant microsatellite instability, and hyper-expression of PD-L1 (90%), along with positive Epstein-Barr virus-encoded RNA (EBER). Pembrolizumab, a programmed cell death 1 (PD-1) inhibitor, was administered in conjunction with radiotherapy. As a result, considerable shrinkage and inactivation of the primary foci were observed, accompanied by the disappearance of metastases. Ultimately, the patient achieved complete remission and maintained progression-free survival for 41 months following the initial treatment. To the best of our knowledge, this represents the longest case of complete remission using a combination of immunotherapy and radiotherapy as a first-line regimen for the high tumor mutational load, microsatellite instability, and PD-L1 expression (90%) subtype of Epstein-Barr virus-associated ICC (EBVaICC). These findings suggest that the combination of PD-1 inhibitors with radiotherapy may serve as a promising therapeutic strategy for treating this particular cancer subtype.

PD-L1 positive astrocytes attenuate inflammatory functions of PD-1 positive microglia in models of autoimmune neuroinflammation

Multiple Sclerosis (MS) is a chronic autoimmune inflammatory disorder of the central nervous system (CNS). Current therapies mainly target inflammatory processes during acute stages, but effective treatments for progressive MS are limited. In this context, astrocytes have gained increasing attention as they have the capacity to drive, but also suppress tissue-degeneration. Here we show that astrocytes upregulate the immunomodulatory checkpoint molecule PD-L1 during acute autoimmune CNS inflammation in response to aryl hydrocarbon receptor and interferon signaling. Using CRISPR-Cas9 genetic perturbation in combination with small-molecule and antibody-mediated inhibition of PD-L1 and PD-1 both in vivo and in vitro, we demonstrate that astrocytic PD-L1 and its interaction with microglial PD-1 is required for the attenuation of autoimmune CNS inflammation in acute and progressive stages in a mouse model of MS. Our findings suggest the glial PD-L1/PD-1 axis as a potential therapeutic target for both acute and progressive MS stages.

Elevated programmed cell death-1 protein/ligand (PD-1/PD-L1) and variants are associated with susceptibility to multiple myeloma: a case-control study in the Chinese cohort

Multiple myeloma (MM) is a malignant disorder characterised by progressive immune dysregulation. The importance of programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) in MM has been documented in various populations, but studies have been limited to the Chinese cohort. In the present study, we examined the role of PD-1/PDL-1 in large cohorts of Chinese patients with MM and healthy controls to reveal a possible association with MM. Three hundred thirty-four MM patients and 202 healthy age-sex-matched subjects were enrolled in the present study. Serum levels of PD-1 and PD-L1 were quantified by ELISA. Percentages of T cells (CD4+ and CD8+ T cells) expressing PD-1 receptor were assessed by flow cytometry. Variants in PD-L1 (rs4143815) and PD-1 gene (rs2227981, rs2227982, rs7421861 and rs11568821) were genotyped by PCR-RFLP method. Patients with multiple myeloma had higher levels of PD-1 and PDL-1 than healthy controls, indicating an important role for programmed cell death protein-1 and its ligand in the pathogenesis of MM. T cells expressing PD-1 receptors were also significantly higher in MM patients than in controls. Mutants for PD-L1 (rs4143815) and PD-1 (rs2227982 and rs7421861) polymorphisms were significantly more common in MM than in HC. Interestingly, PD-L1 (rs4143815) and PD-1 (rs2227982 and rs7421861) variants were linked to higher sPD-L1 and sPD-1 levels, respectively. PD-1/PD-L1 levels are significantly higher in MM patients and could be a promising biomarker for the disease. Variants of PD-L1 and PD-1 are linked to serum-soluble proteins and are associated with the development of MM.

PD-L1/PD-1 checkpoint pathway regulates hippocampal neuronal excitability and learning and memory behavior

Programmed death protein 1 (PD-1) and its ligand PD-L1 constitute an immune checkpoint pathway. We report that neuronal PD-1 signaling regulates learning/memory in health and disease. Mice lacking PD-1 (encoded by Pdcd1) exhibit enhanced long-term potentiation (LTP) and memory. Intraventricular administration of anti-mouse PD-1 monoclonal antibody (RMP1-14) potentiated learning and memory. Selective deletion of PD-1 in excitatory neurons (but not microglia) also enhances LTP and memory. Traumatic brain injury (TBI) impairs learning and memory, which is rescued by Pdcd1 deletion or intraventricular PD-1 blockade. Conversely, re-expression of Pdcd1 in PD-1-deficient hippocampal neurons suppresses memory and LTP. Exogenous PD-L1 suppresses learning/memory in mice and the excitability of mouse and NHP hippocampal neurons through PD-1. Notably, neuronal activation suppresses PD-L1 secretion, and PD-L1/PD-1 signaling is distinctly regulated by learning and TBI. Thus, conditions that reduce PD-L1 levels or PD-1 signaling could promote memory in both physiological and pathological conditions.