Programmed Death Receptor-1 Expression Research Articles

Evaluation of Immune Exhaustion and Co-Inhibitory Receptor Expression in Mycobacterium avium Subspecies paratuberculosis (MAP) Seropositive Diarrhoeic Bovines.

Mycobacterium avium subspecies paratuberculosis (MAP) infection leads to chronic, persistent granulomatous enteritis, causing prolonged diarrhoea and emaciation. The disease is managed using medications such as antibiotics, live vaccines, mycobacteriophage therapies and other treatments; however, a notable proportion of affected animals do not show improvement with this approach. We hypothesise that immunoinhibitory receptors TIM-3 (T cell immunoglobulin mucin protein-3) and PD-1 (Programmed death receptor 1) may be upregulated on Peripheral blood mononuclear cells (PBMCs) of MAP-seropositive bovines, potentially contributing to immune exhaustion. Samples (blood and faeces) were collected from 32 diarrhoeic bovines suspected of MAP infection; eight apparently healthy buffaloes from the dairy farm at Hisar, Haryana and from 14 cows (suffering from chronic diarrhoea, weakness and emaciation) housed in stray cattle shed. MAP infection was estimated using indigenous ELISA (i-ELISA), faecal IS900 PCR, culture and acid-fast staining. TIM-3 and PD-1 gene expression on PBMCs were determined using qRT-PCR. TIM3 expression was relatively higher (~400-fold, 330-fold, 112-fold, 65-fold and 16-fold) in 5 chronically diarrhoeic PBMCs samples (MAP-seropositive), and higher PD-1 expression (around ~7-fold, 1.75-fold, 2.5-fold, 7.6-fold) was recorded in 4 diarrhoeic MAP-seropositive animals, compared to apparently healthy and other MAP-seronegative diarrhoeic animals. High co-expression of TIM-3 and PD-1 levels was also recorded in chronically diarrhoeic, emaciated stray cattle. Understanding immune responses in field conditions might aid in the therapeutic management of paratuberculosis.

Periostin deficiency reduces PD-1+ tumor-associated macrophage infiltration and enhances anti-PD-1 efficacy in colorectal cancer.

Periostin, a multifunctional extracellular protein, plays an important role in inflammatory disorders and tumorigenesis. Our previous work has demonstrated that periostin deficiency inhibits colorectal cancer (CRC) progression. Here, we aim to clarify the role of periostin in the immune microenvironment of CRC. We find that periostin deficiency significantly decreases the infiltration of programmed death receptor 1 (PD-1)+ tumor-associated macrophages (TAMs) in CRC tissues. Periostin promotes the expression of PD-1 on TAMs by integrin-ILK-nuclear factor κB (NF-κB) signaling, and PD-1+ TAMs produce interleukin-6 (IL-6) and interferon γ (IFN-γ) to induce the expression of PD-L1 on colorectal tumor cells. Moreover, combined inhibition of periostin and PD-1 significantly suppresses CRC progression compared with the inhibition of periostin or PD-1 alone. In summary, our results suggest that periostin deficiency reduces the infiltration of PD-1+ TAMs and enhances the efficacy of anti-PD-1 treatment in CRC.

PD-1 combined with TRBC1 and pan-T cell antibodies for robustly monitoring angioimmunoblastic T-cell lymphoma.

BackgroundThe diagnosis of AITL is challenging. It may be delayed or even missed due to critical clinical conditions and its histologic and immunophenotypic overlap with other neoplastic and reactive lymphoid proliferations.ObjectiveThe key objective is to obtain an efficient diagnosis, sensitive disease monitoring and treatment efficacy assessment of AITL using multiparameter flow cytometry (MFC).MethodsIn total, 167 de novo AITL patients were immunophenotypically profiled using sensitive MFC. We precisely identified the aberrant T-cell populations of AITL and performed an in-depth description of their phenotypic characteristics in comparison with their residual normal CD4+ T cells. A comparison of Programmed death receptor-1 (PD-1) expression was performed among AITL and other T-cell lymphomas.ResultsMFC detected a neoplastic T-cell population in 94.1% (80/85) of tissue, 71.5% (108/151) of bone marrow (BM), 100% (8/8) of peripheral blood (PB) and 78.6% (11/14) of body fluid samples. The most frequent immunophenotypic aberrations included the absence and diminished expression of CD3 (71.25% in tissues, 71.3% in BM, 75% in PB, 81.8% in hydrothorax and ascites specimens), followed by the loss or partial loss of CD7 (71.25% in LN, 67.6% in BM, 50% in PB, 81.8% in hydrothorax and ascites specimens). The immunophenotyping of neoplastic T-cell populations showed a high degree of similarity among different sites of the same patient and they might change over time but were relatively stable. Bright PD-1 expression showed high sensitivity and specificity in differentiating AITL from other T-cell lymphomas. In 14 AITL patients, neoplastic T-cell populations were initially missed by T-cell screening tube but were successfully discovered by bright PD-1 expression.ConclusionT-cell screening tube can reliably screen neoplastic T-cell populations in AITL patients with typical immunophenotyping, such as loss of surface CD3 and loss of CD7 with a relatively high ratio. Bright PD-1 expression is essential for identifying aberrant T cells in almost all AITLs. The clonality assessment antibody TRBC1 is efficient for robustly and cheaply assessing T-cell clonality. Using PD-1 and TRBC1 combined with pan-T cell antibodies can make a precise diagnosis of AITL and also sensitively monitor minimal residual disease regardless of the antigenic drift of the neoplastic T cells.

Analysis of combination therapy of immune checkpoint inhibitors in osteosarcoma.

One of the most common primary bone malignant tumors is osteosarcoma (OS), possessing a high tendency of local invasion and distant metastasis. Although surgery combined with chemotherapy can extend the patients’ survival time, the prognosis for most patients with metastases or relapses is poor. Immunotherapy has been proved to be a promising treatment alternative for malignant tumors. Although there is a significant amount of animal- and cell-based evidence supporting the relationship between immune checkpoint inhibitors (anti-PD-1, anti-PD-L1, anti-CTLA-4) and cancers, no pan-cancer analysis is available. Simultaneously, immune checkpoint inhibitors have demonstrated satisfactory clinical results in some tumors; however, only a small fraction of patients with certain cancer types have been benefitted. Therefore, based on the TCGA dataset, we first explored the potential roles of immune checkpoints in 33 tumors. Programmed death receptor 1 (PD-1), programmed cell death ligand 1 (PD-L1), and cytotoxic T lymphocyte antigen 4 (CTLA-4) were not consistently expressed in the same direction in all tumors; however, the direction of expression change was the same in most immune cells. Although there is no well-established relationship between the expression of PD-1/PD-L1/CTLA-4 genes and the prognosis of patients with sarcomas, their interaction and extent of immune cell infiltration into sarcomas are probably the key determinants of therapeutic response. Our first pan-cancer study provides a relatively comprehensive understanding of immune checkpoint inhibitors in different sarcomas.

Analysis of the Relationship between Scleritis and T Cell Activation in Patients with Hepatocellular Carcinoma Treated with PD-1 Carrelizumab.

In order to explore the function of inhibiting the immune effect, the relationship between programmed death receptor 1 (PD-1) carrelizumab in the treatment of hepatocellular carcinoma-induced scleritis and T cell activation is investigated. A total of 120 patients with primary liver cancer treated in the department of oncology of our hospital from July 2020 to January 2022 are selected and treated with carrelizumab. According to the occurrence of PD-1 carrelizumab treatment, the patients are divided into the scleritis group and nonscleritis group. The levels of T cells, PD-1, PD-L1 proteins, and serum inflammatory factors at different time points are compared. The experimental results show that the occurrence of scleritis after liver cancer treatment with PD-1 carrelizumab is closely associated with Treg cells, the percentage of Th17 cells, the expression of PD-1, PD-L1 proteins, and inflammatory factors. It is clearly evident that PD-1 carrelizumab can increase the risk of scleritis by affecting T cell activation.

Expression of PD-L1 and PD-1 in stage T4 rectal cancer tissues and surrounding metastatic lymph nodes and correlation with prognosis.

The expressions of programmed death ligand 1 (PD-L1) and programmed death receptor 1 (PD-1) in T4 rectal cancer tissues and surrounding metastatic lymph nodes were analyzed and correlated with prognosis. For this purpose, ninety-eight patients with T4 rectal cancer treated in our hospital from July 2021 to July 2022 were selected, and surgically resected rectal cancer tissues as well as para carcinoma tissue samples, and surrounding metastatic lymph node tissues were obtained from all patients. Analysis of PD-L1 and PD-1 expression in rectal cancer tissues as well as in adjacent tissue specimens and surrounding metastatic lymph node tissues were performed using immunohistochemical staining. PD-L1 and PD-1 expression were analyzed in relation to lymph node metastasis, maximum tumor diameter, as well as histological analysis, and the relationship between the two and prognosis was analyzed. Immunohistochemistry for PD-L1, PD-1 revealed that both proteins were expressed in association with the target cytoplasm as well as within the cell membrane; The number of cases with positive expression of PD-L1 and PD-1 in cancer tissues was significantly higher than the number of cases with expression in adjacent tissues, which was statistically significant (P < 0.05); The expression rates of PD-L1, PD-1 in poor expression in progression-free survival as well as in progression survival were significantly higher than those in medium and high expression with statistical significance (P < 0.05); Compared with patients without lymph node metastasis, patients with T4 rectal cancer with lymph node metastasis had a higher number of cases with high expression levels of PD-L1 and PD-1 proteins, and the difference was statistically significant (P < 0.05); PD-L1 and PD-1 in T4 stage rectal cancer prognosis is closely related, distant metastasis as well as lymph node metastasis has a greater effect on PD-L1 and PD-1. PD-L1 and PD-1 showed abnormal expression in T4 rectal cancer tissues as well as in surrounding metastatic lymph nodes, and PD-L1 and PD-1 were closely related to prognosis in T4 rectal cancer, distant metastasis, as well as lymph node metastasis had a greater effect on PD-L1 and PD-1. Its detection is able to provide a certain data reference for the prognosis of T4 rectal cancer.

Expression and Significance of PD-1 and ICOS in Patients with Primary Immune Thrombocytopenia

To investigate the expression of programmed death receptor-1 (PD-1) and inducible costimulator (ICOS) on the surface of CD8+ T cells in peripheral blood of patients with primary immune thrombocytopenia (ITP), and explore the roles of PD-1 and ICOS in the occurrence and development of ITP. A total of 28 ITP patients treated in Tianjin Medical University General Hospital from September to December 2020 were selected, including 13 patients with newly diagnosed ITP, 15 patients with chronic ITP, and 22 healthy volunteers were recruited as control group. Flow cytometry was used to detect the expression levels of PD-1 and ICOS, and evaluate their correlation with clinical indicators. The percentage of CD8 + T cells in ITP patients of chronic group was higher than that of the newly diagnosed group and the control group (P<0.05). The expression level of PD-1 on CD8+ T cells in ITP patients of newly diagnosed group and chronic group were significantly lower than that of the control group (P<0.05), while the expression level of ICOS were significantly higher (P<0.05). In ITP patients, PD-1 was negatively correlated with platelet count (r=-0.4942, P<0.01), but positively with ICOS (r=0.4342). PD-1 and ICOS were both negatively correlated with lymphocyte count (rPD-1=-0.4374; rICOS=-0.4492). In ITP patients, the unbalanced expression of PD-1 and ICOS may interfere with the immune homeostasis of the body, which can be used as a therapeutic target for ITP patients.

Implications of PD-1, Tim-3, and TIGIT Expression for Cancer Immunity and Pancreatic Cancer Prognosis

The development and application of cancer immunotherapy to pancreatic cancer has not progressed because its efficacy has not been proven in clinical trials. In this study, we aimed to explore potential targets of immune checkpoint inhibitor therapy for pancreatic cancer treatment. We collected resected specimens from 40 patients with pancreatic cancer who underwent resection at our Institution without any preoperative treatment. We evaluated the expression of molecules in the programmed death receptor-1 (PD-1), T cell immunoglobulin mucin-3 (Tim-3)/Galectin-9, and CD155/T cell immunoreceptor with Ig and ITIM domains (TIGIT) pathways using immunohistochemical staining. The correlation between the expression pattern of these molecules and patient prognosis were assessed using Kaplan-Meier analysis. An increased number of CD8+ T cells in pancreatic cancer tissue was significantly associated with a better patient prognosis. Additionally, patients with a higher ratio of PD-1 expression to CD8+ T cells had a worse prognosis. We observed no correlation between the Tim-3/Galectin-9 and CD155/TIGIT pathways and patient prognosis. Modifications in the immune environment to increase T cell infiltration into tumors could result in the PD-1 pathway becoming a potential target to treat pancreatic cancer using immune checkpoint inhibition.

Changes in the expression of T-cell factor-1 in follicular helper T cells reflect the condition of systemic lupus erythematosus patients

ObjectiveThis study aimed to identify changes in T-cell factor-1 (TCF1) in circulating T-cell subsets of systemic lupus erythematosus (SLE) patients and to explore their significance in SLE. MethodsPeripheral blood was collected from 41 SLE patients and 45 healthy controls (HCs). TCF1 in follicular helper T (TFH), follicular regulatory T (TFR) and regulatory T (Treg) cells was analyzed by flow cytometry. Interleukin-21 (IL-21), programmed death receptor 1 (PD-1) and killer cell lectin-like receptor G1 (KLRG1) were detected and compared among TFH subsets sorted according to TCF1 and CD62L expression. Correlation analyses were conducted between TCF1-related TFH cell subsets and autoantibody levels, systemic lupus erythematosus disease activity index (SLEDAI), and plasmablast levels of SLE patients. ResultsAbsolute numbers of TCF1- TFH and TCF1+ Treg cells were increased in SLE patients. According to TCF1 and CD62L expression, circulating TFH cells and Tregs were sorted into four subsets. CD62L+TCF1+ TFH cell percentages were decreased, and CD62L-TCF1- TFH cells were increased. CD62L+TCF1+ Treg cell percentages were increased, and CD62L-TCF1- Treg cell percentages were decreased. KLRG1+ percentages in CD62L-TCF1-TFH were higher in SLE patients than in HCs. Functionally, CD62L+TCF1+ TFH cells had stronger IL-21 secretion, while CD62L-TCF1-TFH cells had weaker IL-21 secretion and lower PD-1 expression. TCF1- and CD62L-TCF1- TFH numbers were positively correlated with anti-ribosomal P, anti-dsDNA and SLEDAI. ConclusionThe increased TFH cells in SLE patients were mostly TCF1-negative subsets with weakened function. Changes in TCF1-related subsets can reflect the condition and abnormal humoral immunity of SLE patients.

Burgeoning Exploration of the Role of Natural Killer Cells in Anti-PD-1/PD-L1 Therapy

Antibodies targeting programmed death receptor-1 (PD-1)/programmed death ligand-1 (PD-L1) have been considered breakthrough therapies for a variety of solid and hematological malignancies. Although cytotoxic T cells play an important antitumor role during checkpoint blockade, they still show a potential killing effect on tumor types showing loss of/low major histocompatibility complex (MHC) expression and/or low neoantigen load; this knowledge has shifted the focus of researchers toward mechanisms of action other than T cell-driven immune responses. Evidence suggests that the blockade of the PD-1/PD-L1 axis may also improve natural killer (NK)-cell function and activity through direct or indirect mechanisms, which enhances antitumor cytotoxic effects; although important, this topic has been neglected in previous studies. Recently, some studies have reported evidence of PD-1 and PD-L1 expression in human NK cells, performed exploration of the intrinsic mechanism by which PD-1/PD-L1 blockade enhances NK-cell responses, and made some progress. This article summarizes the recent advances regarding the expression of PD-1 and PD-L1 molecules on the surface of NK cells as well as the interaction between anti-PD-1/PD-L1 drugs and NK cells and associated molecular mechanisms in the tumor microenvironment.

VISTA in Soft Tissue Sarcomas: A Perspective for Immunotherapy?

Simple SummaryV domain immunoglobulin suppressor of T cell activation (VISTA) has recently been described as a protein expressed on immune cells and tumour cells and a possible target for immunotherapy. We show for the first time that VISTA is broadly expressed across subtypes of soft tissue sarcoma. We found VISTA related to other immunopathological parameters such as tumour-infiltrating lymphocytes and observed improved survival in patients with non-T-cell-inflamed tumours expressing VISTA. Our research supports the notion of VISTA as a potential target for immunotherapy in soft tissue sarcoma.(1) Background: V domain immunoglobulin suppressor of T cell activation (VISTA) plays a critical role in antitumor immunity and may be a valuable target in cancer immunotherapy. To date, it has never been studied in a large and well-characterised cohort of soft tissue sarcomas (STS). (2) Methods: Using immunohistochemistry, we examined VISTA expression in tumour tissues of 213 high-risk STS. We then analysed whether VISTA was associated with other clinicopathological parameters, including tumour-infiltrating lymphocyte (TIL) counts, programmed death receptor-1 (PD1), programmed death ligand-1 (PDL1), CD3, grading, and long-term survival. (3) Results: We observed VISTA expression in 96 (45%) of 213 specimens with distinct patterns ranging from 26 to 63% for histological subtypes. VISTA was associated with higher grade (G3 vs. G2, p = 0.019), higher TIL counts (p = 0.033), expression of PD1 (p = 0.046), PDL1 (p = 0.031), and CD3+ (p = 0.023). In patients without CD3+ TILs, 10-year survival was higher when VISTA was expressed compared to when there was no VISTA expression (p = 0.013). In a multivariate analysis, VISTA expression was independently associated with prolonged survival (p = 0.043). (4) Conclusions: VISTA is expressed in different STS subtypes and is associated with increased TILs, PD-1, PD-L1, and CD3 expression. Patients with VISTA+ tumours show improved survival. These results may help define future immunotherapeutic approaches in STS.

Programmed death receptor-1 expression in neonatal sepsis as a diagnostic and prognostic marker

Programmed death receptor-1 expression in neonatal sepsis as a diagnostic and prognostic marker

PD-1 is associated with CD8(+)T lymphocyte dysfunction in patients with acute and chronic liver failure

Objective: To explore whether peripheral blood CD8(+)T lymphocyte dysfunction is correlated with the programmed death receptor-1 (PD-1) expression in patients with acute-on-chronic liver failure (HBV-ACLF). Methods: Peripheral blood mononuclear cells (PBMC) were collected from patients with HBV-ACLF and healthy controls. CD8(+)T lymphocytes number and PD-1 expression condition in CD8(+)T lymphocytes were detected by flow cytometry. CD8(+)T lymphocytes isolated from peripheral blood of HBV-ACLF patients were further cultured in vitro. One group was added with PD-L1-IgG fusion protein (ACLF+PD-1 group), and the other group was added with IgG fusion protein (ACLF group). Proliferation ability (ki67), cell viability (CD69), and secretion ability of effector cytokines (IL-2, IFN-γ, TNF-α) were analyzed. Results: 30 cases with HBV-ACLF and healthy controls were enrolled. CD8(+)T lymphocytes absolute number was significantly lower in the peripheral blood of patients with ACLF group (333.88 ± 147.74)/μl than healthy controls (872.50 ± 206.64)/μl (P < 0.001). PD-1 expression in peripheral blood CD8(+)T lymphocytes were significantly increased in ACLF group (13.33% ± 2.52%), (P = 0.027) than healthy controls (7.02% ± 2.12%). In in vitro culture, compared with healthy controls, the peripheral blood CD8(+)T lymphocytes cell viability (CD69), proliferation ability (ki67) (all P ​​< 0.001), and the level of cytokine production (IL-2, IFN-γ, TNF-α) (all P < 0.05) were equally weakened in patients with ACLF group. Compared with ACLF group, CD8(+)T cell viability (CD69), proliferation ability (KI67) (all P < 0.05), and the level of cytokine production were weakened in ACLF+PD-1 group (all P < 0.05). Conclusion: HBV-ACLF patients have CD8(+)T lymphocyte dysfunction. Therefore, PD-1 may have correlation in the regulation of CD8(+)T lymphocyte dysfunction in ACLF patients.

Correlation Study on Expression of PD-1 and PD-L1 in Non-small Cell Lung Cancer and Epidermal Growth Factor Receptor Mutations

背景与目的肺癌的治疗模式以表皮生长因子受体酪氨酸激酶抑制剂（epidermal growth factor receptor-tyrosine kinase inhibitors, EGFR-TKIs）作为EGFR突变的非小细胞肺癌（non-small cell lung cancer, NSCLC）患者一线治疗；同时以程序性死亡受体1（programmed death receptor 1, PD-1）及其配体（programmed death receptor ligand 1, PD-L1）抑制剂为代表的免疫检查点抑制剂（immune checkpoint inhibitors, ICIs）的免疫治疗在肺癌治疗中疗效显著。本研究旨在探讨PD-1和PD-L1在NSCLC中的表达及其与临床病理特征、EGFR突变之间的关系。方法采用免疫组化方法检测127例NSCLC PD-1和PD-L1蛋白表达，同时用定量聚合酶链反应（quantitative polymerase chain reaction, qPCR）检测EGFR基因突变，分析其与临床病理特征之间的关系，研究PD-1、PD-L1表达之间以及其与EGFR突变的关系。结果NSCLC肿瘤细胞及肿瘤浸润免疫细胞PD-1阳性表达53.5%（68/127），肿瘤细胞PD-L1表达57.5%（73/127），PD-1和PD-L1的表达在低分化癌、临床分期Ⅰ期+Ⅱ期明显高于高中分化癌、Ⅲ期+Ⅳ期（均P < 0.05）；EGFR突变率为46.5%（59/127），EGFR突变的患者中女性、无吸烟史、腺癌、高中分化组分别高于男性、吸烟史、鳞癌、低分化组患者（均P < 0.05）；NSCLC患者PD-L1与PD-1蛋白表达存在一致性（kappa=0.107, 5, P=0.487），EGFR突变与PD-1、PD-L1表达存在负相关关系（Φ=-0.209，Φ=-0.221，均P < 0.05）；对NSCLC患者随访，在 < 65岁、腺癌、高中分化癌、PD-L1表达的患者中位总生存期分别高于≥65岁、鳞癌、低分化癌、PD-L1不表达患者（均P < 0.05）。PD-L1低表达患者中位生存期明显高于高表达患者（P=0.04）。结论参照《非小细胞肺癌PD-L1免疫组织化学检测规范中国专家共识》检测非小细胞肺癌PD-L1表达，筛选出抗PD-1/PD-L1治疗的优势人群；同时检测出EGFR突变的患者，并且EGFR突变与PD-1、PD-L1表达存在负相关关系，依据PD-L1表达和EGFR突变状态，可能使NSCLC患者在的个体化治疗中获益，同时65岁以下、腺癌、高中分化、PD-L1低表达的患者有相对好的预后，为NSCLC预后评估提供参考。

Early loss of T lymphocyte 4-1BB receptor expression is associated with higher short-term mortality in alcoholic hepatitis.

ObjectivesIn alcoholic hepatitis (AH), dysfunctional T lymphocytes may contribute to the high mortality from infections. T lymphocyte activation is governed by the expression of co-stimulatory receptors such as 4-1BB balanced by inhibitory receptors such as Programmed Death receptor 1 (PD-1). 4-1BB expression is unaccounted for in AH, while PD-1 is elevated. We characterized expression of 4-1BB and PD-1 and the associated T lymphocyte functional status in AH and investigated whether these were associated with short-term mortality.MethodsThirty-five patients with AH (at diagnosis and days 7 and 90) were compared with healthy controls (HC). Spontaneous and in vitro stimulated receptor expression were quantified by flow cytometry, and plasma proteins by ELISA.ResultsAt diagnosis, the patients showed increased stimulated 4-1BB responses of CD4+ T lymphocytes. Also, the frequencies of PD-1+ T lymphocytes both with and without co-expressed 4-1BB were increased. Further, interferon-gamma was predominantly produced in T lymphocytes co-expressing 4-1BB. A decrease in the frequency of spontaneous 4-1BB+ T lymphocytes and an increase in soluble 4-1BB during the first week after diagnosis were associated with higher mortality at day 90 in AH. PD-1 expression showed no systematic dynamics related to mortality.ConclusionsWe found an increased stimulated 4-1BB response of T lymphocytes in AH and early loss of these lymphocytes was associated with a higher short-term mortality. This suggests a role of T lymphocyte 4-1BB expression in the progression of AH.

Predictive biomarkers of inhibitors immune checkpoints therapy in malignant tumors

Immune checkpoint inhibitors (ICT) therapy is a successful immunotherapy (IT) strategy that is quite effective in a number of patients with non-small cell lung cancer, melanoma, bladder cancer, breast cancer and others. Nevertheless, there is a need in predictive markers for ICT therapy for personalized IT as far as there is a large group of patients, the proportion of which varies depending on the tumor, who do not have a clinical response to such therapy. The review summarizes the theoretical aspects and results of clinical trials dedicated to various clinical efficiency predictor using modern databases. As a result of the analysis it is established that the main candidates for the role of such markers are tumor infiltrating lymphocytes and their subpopulations, peripheral blood lymphocytes (PBL) and their subpopulations. PD1 (programmed death receptor 1) and PDL1 (programmed death receptor ligand 1) expression in tumor tissue can also be important for predicting IT efficiency. The most promising predictive biomarker meaning the most clinically relevant is a combination of the PBL subpopulations study and PD1 and PDL1 expression on the tumor cells.PubMed, Scopus, Web of Science, eLibrary, Russian Science Citation Index databases were searched for the available appropriate literature reports. The authors included 82 in the given review.

Abstract 1671: Evaluation of total PD-1 expression using multi-color flow cytometry in metastatic non-small Cell lung cancer patients treated with multi-neoantigen vector (ADXS-503) alone and in combination of pembrolizumab to assess T-cell &amp; T-cell memory subsets

Abstract Precision for Medicine (Precision) developed and qualified two 17 color flow immunophenotyping assays to be used as pharmacodynamic biomarkers for Advaxis clinical studies in patients with Metastatic Non-Small Cell Lung Cancer treated with ADXS-503 alone and in combination with Pembrolizumab (Pembro). ADXS-503 (A503) is an off-the-shelf, attenuated Listeria monocytogenes (Lm)-based immunotherapy bioengineered to elicit potent T-cell responses against 22 tumor antigens commonly found in NSCLC. Pembrolizumab (Pembro) is a programmed death receptor-1 (PD-1)-blocking antibody approved for the treatment of advanced lung cancer. A503 and Pembro have complementary mechanisms of immune activation and reversal of immune tolerance. Here, we qualified two multi-color flow cytometry assays to quantify total PD-1 expression in cryopreserved peripheral blood mononuclear cells (PBMCs) from individuals that were treated either with A503 only or with A503 in combination with Pembro. The detection of free PD-1 and Pembro-bound PD-1 was achieved by co-staining a partially competing αPD-1 antibody (clone PD1.3.1.3) with a biotinylated αHu-IgG4 antibody. The robustness of the assay was demonstrated using a nine-point half-log serial dilution of Pembro, where the highest concentration was 10µg/mL and the lowest concentration was 0.001µg/mL, including a no drug control. The assay conditions were optimized for sensitivity, optimal signal:noise ratio, detection of free and drug bound receptor by titrating and testing various commercial αPD-1 antibody clones and tertiary reagents to detect biotinylated αHu-IgG4. The Pembro bound receptor was detected using a biotinylated αHu-IgG4 antibody, while the free receptors were quantified using a commercial αPD-1 antibody. The assay was able to quantify free and drug bound PD-1 in the intended immune cell types without compromising the staining of other cell surface and intra-nuclear markers. Majority of the evaluable patients, 6 out of 8, had increased counts of NK, CD4+ and CD8+ T-cells, including TCM, TEM and memory stem cells after the administration of ADXS-503 ± Pembro. PD1 expression on circulating CD4+, CD8+ and NK T-cells was also increased while PD-L1 expression was elevated in on-therapy tumor biopsies in some of these patients. Measuring total PD-1 in T-cells can be more challenging in patients on Pembrolizumab therapy as no known commercial non-competing αPD-1 antibody clones are available. This novel assay will facilitate the evaluation of total PD-1 expression as a pharmacodynamic biomarker in T-cells when PD-1 blockade is being used. These results also support that combination of ADXS-503 with PD-1 blockade could lead to enhancement of efficacy of anti-tumor immunotherapy. Citation Format: Venkat Mohanram, Natalya Belkina, Angelina R. Bisconte, Jonathan W. Goldman, Gregory J. Gerstner, Missak Haigentz, Thomas Stinchcombe, Balazs Halmos, Surya Vangala, Victor Kabala, Dinesh Simkhada, Cristiane Metran, Darren Davis, Megan Parsi, Andres A. Gutierrez, Deborah Phippard, Suresh S. Ramalingam. Evaluation of total PD-1 expression using multi-color flow cytometry in metastatic non-small Cell lung cancer patients treated with multi-neoantigen vector (ADXS-503) alone and in combination of pembrolizumab to assess T-cell &amp; T-cell memory subsets [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1671.

Pilot Study of Pembrolizumab for Immunoprevention in Smoldering Multiple Myeloma

Background: The current management of patients with smoldering multiple myeloma (SMM) is watchful waiting. However, a fraction of these patients are at significant risk of progression to symptomatic multiple myeloma (MM). In a recent study, expression of PD-L1 on tumor cells correlated with increased risk of progression from SMM to MM (Dhodapkar et al Blood. 2015; 126(22): 2475-2478) suggesting a role for immune checkpoint blockade for immunoprevention of MM. Pembrolizumab is a humanized monoclonal antibody against programmed death receptor-1 (PD-1) and blocks the interaction between PD-1 and PD-L1. Here, we report the results of a pilot study evaluating the safety and efficacy of pembrolizumab in intermediate- and high-risk SMM patients (I-HR-SMM). Methods: Patients with I-HR-SMM by PETHEMA, Mayo or SWOG criteria were eligible. Permbrolizumab was administered at a dose of 200 mg IV every 21 days for up to 8 cycles. Patients were eligible to continue treatment for up to 24 cycles if they achieved ≥ minor response after 8 cycles. The primary objective was the overall response rate (ORR) after 8 cycles. The target ORR was 25%. The trial was conducted by the Simon's Minimax design and the ORR was estimated accordingly (Simon, 1989). Twelve patients were planned for the first stage. If at least one patient had ≥ partial response, 4 more patients could enroll for a total of 16 patients. Serial peripheral blood mononuclear cells and bone marrow samples were collected for comprehensive immunophenotyping using multiparametric flow cytometry, and molecular profiling with gene expression profiling (GEP) and exome sequencing. Results: Twelve patients with I-HR-SMM were dosed on the first stage between 08/2016 and 06/2017 (Table 1a/b). Median age was 67.5 years (range 49-74). Median number of cycles received was 8 (range 3-8) and all 12 were evaluable for safety and efficacy. Median follow up was 8.54 months (4.7 to 9.6 months). One patient achieved a stringent complete remission (sCR) (8%), ten patients had stable disease (83%), and one patient had progressive disease (8%). The patient with sCR had HR-SMM by GEP70 and FISH (deletion 17p and amplification of CKS1B) and 50% plasma cells infiltration in the bone marrow at study entry. The sCR with negative flow cytometry on bone marrow was noted in this patient after only 3 cycles of therapy and response is ongoing 8 months after the end of treatment. Five patients discontinued therapy due to related adverse events: grade 2 elevation in LFT (n=2), grade 3 myalgia (n=1), and grade 3 acute kidney injury (AKI) due to tubulo-interstitial nephritis (n=2) [all resolved with discontinuation of treatment or prednisone administration]. There were no grade 4/5 adverse events. Enrollment on second stage is ongoing. Imunophenotyping of paired baseline and end of treatment bone marrow samples showed that the patient who achieved sCR had high levels of PD-1 expression on CD4+ and CD8+ T cells at baseline and showed evidence of CD8+ T-cell activation after therapy with greater upregulation of CD69, CTLA-4, PD-1, TIM-3, 4-1BB, and ICOS relative to non-responders. In contrast, expression of other immune checkpoint molecules such as TIM-3, LAG-3, and CD244 were greater on T cells in non-responders at baseline relative to the responder suggesting greater exhaustion of T cells in non-responders. Molecular profiling including GEP, exome sequencing, and neoantigens analysis is ongoing and will be presented at the meeting. Conclusions: This pilot study of pembrolizumab monotherapy showed that it is tolerable and can induce sCR in patients with SMM. More importantly, it suggested that immunoprevention to prevent progression of SMM to MM is possible. Additional biomarker studies are needed to identify patients that are most likely to respond to this approach. Our correlative studies also provide insights into potential future combination approaches to further improve efficacy of immunoprevention strategies in SMM. [Display omitted] DisclosuresManasanch:takeda: Consultancy; celgene: Consultancy; sanofi: Research Funding; quest diagnostics: Research Funding; merck: Research Funding; adaptive biotechnologies: Consultancy. Lee:Eutropics Pharmaceuticals: Research Funding; Adaptive: Membership on an entity's Board of Directors or advisory committees; Pimera Inc: Consultancy; Celgene: Consultancy; Daiichi Sankyo: Research Funding; Takeda: Consultancy. Patel:Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Juno: Consultancy; Celgene: Consultancy. Thomas:Celgene: Research Funding; Bristol Myers Squibb: Research Funding. Neelapu:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Karus: Research Funding; Cellectis Inc.: Research Funding; Poseida Therapeutics, Inc: Research Funding; Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding. Orlowski:BioTheryX: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Association between immunotherapy biomarkers and glucose metabolism from F-18 FDG PET.

To assess associations between parameters derived from F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and mRNA expression levels of immune checkpoint biomarkers such as programmed death receptor 1 (PD-1), programmed death-ligand 1 (PD-L1), cytotoxic T-lymphocyte antigen 4 (CTLA-4) as well as tumor mutation burden (TMB) in non-small cell lung cancer (NSCLC) patients. Integrated data were downloaded from Genomic Data Common Data Portal. Clinical, mRNA-seq, and whole exome-seq data of lung adenocarcinoma and squamous cell carcinoma from The Cancer Genome Atlas (TCGA) database were analyzed. TMB was defined as the total number of somatic missense mutations per megabase of the genome examined. Expression levels of PD-1, PD-L1, CTLA4 mRNA and TMB were collected. Correlations between imaging parameters of glucose metabolism and the expression levels of genomic biomarkers from cancers were evaluated. Bonferroni correction (adjusted p<0.0027) was applied to reduce type 1 error. Of 31 NSCLC cases, 11 cases were adenocarcinoma (LUAD) and 20 were squamous cell carcinoma (LUSC). In linear regression analysis, texture parameters such as low gray-level run emphasis (LGRE, R2=0.48, p<0.0001), short run low gray-level emphasis (SRLGE, R2=0.45, p<0.0001) and long run low gray-level emphasis (LRLGE, R2=0.41, p=0.0001) derived from gray-level run length matrix (GLRLM) showed remarkable correlation with PD-L1 mRNA expression. Expression of PD-1, CTLA-4, and TMB failed to show any significant correlation with parameters of the F-18 FDG PET/CT. Texture parameters derived from PET, known to indicate glucose uptake distribution, were correlated with expression of PD-L1 mRNA but not with expression of PD-1, CTLA-4 and TMB. Thus, tumoral heterogeneity could be a surrogate marker for the identification of PD-L1 level in NSCLC.

Development of programmed death receptor-1 and programmed death receptor-1 ligand in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a common malignant tumor in the oral and maxillofacial region. At present, the treatment of OSCC is mainly based on surgical oriented comprehensive sequence therapy, especially the triple therapy of surgery, radiotherapy, and chemotherapy. However, the overall five-year survival rate is relatively low. Therefore, researching the pathogenesis and treatment methods of OSCC is important. The immune checkpoint of programmed death receptor-1 (PD-1) and programmed death receptor-1 ligand (PD-L1) have been the focus of research in recent years. Several studies have shown that the high expression of PD-1/PD-L1 in most OSCC microenvironments may contribute to the immune escape of tumors. In this study, the research status of immune checkpoint of PD-1/PD-L1 and its relevant inhibitors in OSCC were reviewed.