Expression and Significance of PD-1, PD-L1 and PD-L2 in T Cell Subsets and Myeloma Cells in Newly Diagnosed Multiple Myeloma Patients / 肿瘤防治研究

Objective To investigate the expression of PD-1 and PD-L1/2 in T cell subsets and myeloma cells in the bone marrow from newly diagnosed multiple myeloma (NDMM) patients and their relation with clinical features. Methods We collected the bone marrow and clinical data of 22 NDMM patients and 18 cases of healthy controls. We sorted CD4+T cells, CD8+T cells and myeloma cells by flow cytometry, and observed the expression of PD-1 and PD-L1/2. Results Compared with the control group, the proportion of CD8+T cells in the NDMM group was significantly higher, while the ratio of CD4+/CD8+ was significantly lower (both P < 0.05). The expression levels of PD-1 and PD-L2 in CD4+T cells in the NDMM group were significantly higher than those in the control group (both P < 0.05). The expression levels of PD-1, PD-L1 and PD-L2 in T cell subsets and myeloma cells of NDMM patients were not correlated with the gender, age, immune typing, Durie-Salmon stage and subtypes, ISS stage or mSMART3.0 stratification (both P > 0.05). Conclusion Most of MM patients suffering immune abnormality, which may be associated with the mutual immunosuppressive effects between T lymphocytes and plasma cells which expressing PD-1 and PD-L1/2.

Progress of programmed death ligand 2 in immunotherapy of solid tumors / 肿瘤研究与临床

With the breakthrough of immune checkpoint blocking therapy in the clinical treatment of a variety of malignant solid tumors, tumor immunotherapy has opened a new era. However, clinical practice has proved that the response rate of this therapy is low. Seeking for the key factors limiting its response rate has become a research hotspot in this field. Programmed death ligand 2 (PD-L2) is the second important ligand binding to programmed death 1 (PD-1) after programmed death ligand 1 (PD-L1). The encoded protein can bind to PD-1 and then inhibit immune cells. This paper reviews the biological characteristics of PD-L2, its mechanism in immune regulation and its research progress in solid tumor immunotherapy to provide more theoretical support for solid tumor immunotherapy.

Expressions of programmed death-ligand 1 and 2 and phosphorylated protein kinase B in diffuse large B-cell lymphoma and their clinical significances / 白血病·淋巴瘤

Objective To investigate the expressions of programmed death-ligand 1 (PD-L1) and PD-L2 and phosphorylated protein kinase B (p-AKT) in diffuse large B-cell lymphoma (DLBCL) patients and their correlations with clinicopathological features and prognosis. Methods A total of 68 paraffin-embedded specimens of DLBCL patients diagnosed in Shanxi Provincial Cancer Hospital with detailed follow-up record from January 2010 to December 2012 were included in the study. The expressions of PD-L1, PD-L2 and p-AKT proteins in DLBCL were detected by using immunohistochemistry (IHC). Results The positive rate of PD-L1 protein in DLBCL patients was 22.1％ (15/68), which was related to germinal center B-cell (GCB) subtype or not (χ2= 5.591, P= 0.018), clinical stage (χ2= 3.969, P= 0.046), international prognostic index (IPI) grades (χ2=4.178, P=0.041) and treatment remission rate (χ2=6.587, P=0.010). The positive rate of PD-L2 protein in DLBCL patients was 14.7％ (10/68), which was related to extranodal metastasis or not (χ2=6.772, P= 0.009). The positive rate of p-AKT for DLBCL patients was 61.8％ (42/68), which was correlated with age (≥60 years old) or not (χ2=6.227, P=0.013), Eastern Cooperative Oncology Group (ECOG) grades (χ2=4.005, P=0.045), B symptoms (χ2=10.187, P=0.001) and treatment remission rate (χ2=4.096, P=0.043). Univariate survival analysis showed that the overall survival (OS) rate and progression free survival (PFS) rate of PD-L1 protein positive expression group were lower than those of PD-L1 protein negative expression group (both P< 0.05). In the patients with non-GCB subtype, OS rate and PFS rate of PD-L1 protein positive expression group were lower than those of PD-L1 protein negative expression group (both P<0.05). p-AKT protein positive expression group had poorer OS rate and PFS rate compared to p-AKT negative expression group (both P< 0.05). Correlation analysis showed that PD-L1 protein expression was correlated with PD-L2 and p-AKT proteins expressions (r= 0.380, P= 0.001;r= 0.273, P= 0.025). The prognosis was worse when p-AKT and PD-L1 proteins was co-expressed (P< 0.05). Multivariate analysis suggested high expressions of PD-L1 and p-AKT proteins were independent prognosis risk factors in DLBCL (both P<0.05). Conclusions The expressions of PD-L1 and p-AKT proteins may be involved in the occurrence and development of DLBCL. Blocking PD-1 and PD-L1 access or combined blocking could provide a promising future for the clinical therapy.

Expression and clinical significance of PD-1/PD-Ls in EBV-positive T/NK lymphoprolif-erative disorders / 中国肿瘤临床

Objective: To investigate the expression and clinical significance of programmed death-ligand 1 (PD-L1), programmed death-ligand 2 (PD-L2), and their receptor programmed cell death protein 1 (PD-1) in EBV-positive T/NK lymphoproliferative disease [Epstein-Barr virus-positive T/natural killer (NK)-cell lymphoproliferative disease, EBV(+)-T/NK-LPD]. Methods: The pathological paraffin-embedded tissues of 17 patients with EBV(+)-T/NK-LPD from the First Affiliated Hospital of Zhengzhou University from January 2013 to December 2017 were collected. These patients include 12 males and 5 females, aged 10-82 years old, the average age being 29 years, 4 people in gradeⅠ, 7 in gradeⅡ, 3 in gradeⅢ, and 3 people with hydroa vacciniforme-like lymphoproliferative disorders. Immunohistochemical SP method was used to detect the expression of PD-1, PD-L1, and PD-L2 in human EBV(+)-T/NK-LPD tissues. The relationship between PD-1, PD-L1, PD-L2 expression, and clinicopathological parameters, pathological grades and prognosis were analyzed by Fisher's exact probabilities and Spearman rank correlation. Result: After statistical analysis, the results showed that in 17 cases of tissue samples, there were 12 cases with positive PD-1 expression, 6 cases with positive PD-L1 expression and 5 cases with positive PD-L2 expression. There was no significant correlation between PD-1 and PD-L2 expression and prognosis (P>0.05). PD-L1 expression showed a positive correlation with prognosis (P<0.05). There was no significant correlation between the expression of PD-L1 and PD-L2 with age, sex, as well as LDH and Ki-67 levels (P>0.05). Moreover, there was no significant correlation of PD-1 and PD-L2 expression with pathological grade (r=0.141, r=-0.149, both P>0.05). However, there was a negative correlation between the PD-L1 expression and pathological grade (r=-0.563), and the correlation between the PD-L1 ex-pression and pathological grade was statistically significant (P<0.05). Conclusions: PD-1, PD-L1, and PD-L2 are abnormally expressed in the pathological tissues of EBV(+)-T/NK-LPD. Although there was no significant correlation between the expression of PD-1 and prognosis or pathological grade, it was significantly higher in EBV+T/NK-LPD. PD-1/PD-Ls associated signaling pathway is expected to be a potential new target for EBV(+)-T/NK-LPD immunotherapy.

GLUT1 as a Prognostic Factor for Classical Hodgkin's Lymphoma: Correlation with PD-L1 and PD-L2 Expression

BACKGROUND: Glucose transporter type 1 (GLUT1) expression is linked to glucose metabolism and tissue hypoxia. A recent study reported that GLUT1 was significantly associated with programmed death ligand 1 (PD-L1) as a therapeutic target in relapsed or refractory classical Hodgkin's lymphoma (cHL). The purpose of this study was to measure the expression of GLUT1 and assess its prognostic significance and potential relationships with PD-L1, programmed death ligand 2 (PD-L2), and programmed death-1 (PD-1) expressions in cHL. METHODS: Diagnostic tissues from 125 patients with cHL treated with doxorubicin, bleomycin, vinblastine, and dacarbazine were evaluated retrospectively via immunohistochemical analysis of GLUT1, PD-L1, PD-L2, and PD-1 expression. RESULTS: The median follow-up time was 4.83 years (range, 0.08 to 17.33 years). GLUT1, PD-L1, PD-L2, and PD-1 were expressed in 44.8%, 63.2%, 9.6%, and 13.6% of the specimens, respectively. Positive correlations were found between GLUT1 and PD-L1 expression (p = .004) and between GLUT1 and PD-L2 expression (p = .031). GLUT1 expression in Hodgkin/Reed-Sternberg (HRS) cells was not associated with overall survival or event-free survival (EFS) in the entire cohort (p = .299 and p = .143, respectively). A subgroup analysis according to the Ann Arbor stage illustrated that GLUT1 expression in HRS cells was associated with better EFS in advanced-stage disease (p = .029). A multivariate analysis identified GLUT1 as a marginally significant prognostic factor for EFS (p = .068). CONCLUSIONS: This study suggests that GLUT1 expression is associated with better clinical outcomes in advanced-stage cHL and is significantly associated with PD-L1 and PD-L2 expressions.

The role of PDL2 in human placenta mesenchymal stem cell-mediated inhibition of peripheral blood T cells / 中华微生物学和免疫学杂志

Objective To investigate the effect of programmed death ligand 2 (PDL2) in human placenta derived mesenchymal stem cells(hPMSCs) mediated immunoregulation on peripheral blood T cells activation,proliferation and cell cycle.Methods The expression of the PDL2 on hPMSCs was detected by RT-PCR,LSCM and FCM,respectively.Specific PDL2 siRNAs were transfected into hPMSCs via cathodolyte liposome transfection method.T cells were sorted from healthy peripheral blood by gradient centrifugation.The expression of early activation phenotype,proliferation and cell cycle of T cells were analyzed by FCM.Results PDL2 siRNA could effectively block the expression of PDL2 which was highly expressed on hPMSCs.The expression of CD69 on T cells had no significantly difference in blocking groups compared with unblocking groups.hPMSCs could inhibit the proliferation of T cells induced by PMA,compared with that of unblocking groups,the number of the T cells in G0/G1 phase was decreased while the number of the T cells in S phase was increased in the blocking groups.Conclusion PDL2 expressed on hPMSCs could promote the inhibitory effect of hPMSCs on T cell cycle and proliferation.