BACKGROUND: The application of programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) antibodies has greatly improved the clinical outcomes of lung cancer patients. Here, we retrospectively analyzed the efficacy of PD-1 antibody therapy in locally advanced non-surgical or metastatic lung cancer patients, and preliminarily explored the correlation between peripheral blood biomarkers and clinical responses. METHODS: We conducted a single center study that included 61 IIIA-IV lung cancer patients who received PD-1 antibody treatment from March 2020 to December 2021, and collected the medical record data on PD-1 antibody first-line or second-line treatment. The levels of multiple Th1 and Th2 cytokines in the patient's peripheral blood serum, as well as the phenotype of peripheral blood T cells, were detected and analyzed. RESULTS: All the patients completed at least 2 cycles of PD-1 monoclonal antibody treatment. Among them, 42 patients (68.9%) achieved partial response (PR); 7 patients (11.5%) had stable disease (SD); and 12 patients (19.7%) had progressive disease (PD). The levels of peripheral blood interferon gamma (IFN-γ) (P=0.023), tumor necrosis factor α (TNF-α) (P=0.007) and interleukin 5 (IL-5) (P=0.002) before treatment were higher in patients of the disease control rate (DCR) (PR+SD) group than in the PD group. In addition, the decrease in absolute peripheral blood lymphocyte count after PD-1 antibody treatment was associated with disease progression (P=0.023). Moreover, the levels of IL-5 (P=0.0027) and IL-10 (P=0.0208) in the blood serum after immunotherapy were significantly increased compared to baseline. CONCLUSIONS Peripheral blood serum IFN-γ, TNF-α and IL-5 in lung cancer patients have certain roles in predicting the clinical efficacy of anti-PD-1 therapy. The decrease in absolute peripheral blood lymphocyte count in lung cancer patients is related to disease progression, but large-scale prospective studies are needed to further elucidate the value of these biomarkers.
Humans ; Lung Neoplasms/metabolism* ; Interleukin-5/therapeutic use* ; Tumor Necrosis Factor-alpha/therapeutic use* ; Retrospective Studies ; Programmed Cell Death 1 Receptor ; Biomarkers ; Immunotherapy ; Disease Progression ; B7-H1 Antigen

OBJECTIVE: To investigate the effect of circulating exosomes (EXO) on T cell function in patients with sepsis. METHODS: Plasma EXO were obtained by ultracentrifugation from 10 patients with sepsis admitted to the emergency intensive care unit of Guangdong Provincial People's Hospital Affiliated to Southern Medical University. Transmission electron microscopy observation, nanoparticle tracking analysis (NTA), and Western blotting were used to detect EXO markers to identify their characteristics. Furthermore, peripheral blood mononuclear cells (PBMC) were isolated from the peripheral blood of 5 healthy volunteers, primary T cells were sorted by magnetic beads and expanded in vitro. After 24 hours of intervention with different doses (0, 1, 2.5, 5, 10 mg/L) of circulating EXO in patients with sepsis, T-cell activity was assessed using a cell counting kit-8 (CCK-8). The expression of T cell activation indicators CD69 and CD25 were observed using flow cytometry. Additional evaluations were performed on immunosuppressive indicators including the expression of programmed cell death 1 (PD-1) in CD4⁺ T cells and the proportion of regulatory T cell (Treg). RESULTS: The identification results confirmed that the successful isolation of EXO from the plasma of sepsis patients. The expression level of circulating EXO in sepsis patients was higher than that in healthy control group (mg/L: 48.78±5.14 vs. 22.18±2.25, P < 0.01). After 24 hours of intervention with 5 mg/L of plasma EXO from sepsis patients, T cells activity began to show suppression [(85.84±0.56)% vs. (100.00±0.00)%, P < 0.05]. As the dosage increased, after 24 hours of intervention with 10 mg/L of EXO, T cells activity was significantly suppressed [(72.44±2.36)% vs. (100.00±0.00)%, P < 0.01]. Compared with the healthy control group, after T cells intervention with plasma EXO from sepsis patients, the expression of early activation marker CD69 was significantly reduced [(52.87±1.29)% vs. (67.13±3.56)%, P < 0.05]. Meanwhile, there was an upregulation of PD-1 expression in T cells [(57.73±3.06)% vs. (32.07±0.22)%, P < 0.01] and an increase in the proportion of Treg [(54.67±1.19)% vs. (24.60±3.51)%, P < 0.01]. However, the expression of the late activation marker CD25 remained stable [(84.77±3.44)% vs. (85.93±2.32)%, P > 0.05]. CONCLUSIONS Circulating EXO in sepsis patients induce T cell dysfunction, which may be a novel mechanism lead to immunosuppression in sepsis.
Humans ; Leukocytes, Mononuclear ; Exosomes/metabolism* ; Programmed Cell Death 1 Receptor/metabolism* ; T-Lymphocytes, Regulatory/metabolism* ; Sepsis/metabolism*

OBJECTIVE: To explore the effect of microRNA-424-5p (miR-424-5p) on the drug resistance of diffuse large B-cell lymphoma (DLBCL) cells by regulating the programmed death receptor-1 (PD-1)/programmed death ligand-1 (PD-L1) signaling pathway. METHODS: Human DLBCL cell line CRL2631 cells were induced to construct CRL2631-CHOP resistant cell line. RT-qPCR and Western blot were used to detect the expression levels of MiR-424-5p, PD-L1 mRNA and protein, and multidrug resistance gene-1 (MDR-1) protein in CRL2631 cells and CRL2631-CHOP cells, respectively. The target genes of MiR-424-5p was verified by dual luciferase reporter assay. The miRNA simulation/interference technology and thiazole blue (MTT) method were used to detect the resistance of CRL2631 cells and CRL2631-CHOP cells to CHOP. RESULTS: Compared with CRL2631 cells, the drug resistance of CRL2631-CHOP cells to CHOP and the levels of MDR-1 protein (P<0.05), PD-L1 mRNA and protein in the cells were significantly increased (both P<0.001), while the relative level of MiR-424-5p was significantly reduced (P<0.001). The result of the dual luciferase reporter assay showed that PD-L1 was the direct downstream target gene of MiR-424-5p (P<0.001). After transfection of MiR-424-5p inhibitor, the resistance of CRL2631 cells to CHOP drugs increased, and the expression level of MDR-1 protein (P<0.01), PD-L1 mRNA and protein also increased significantly (both P<0.01). After transfection of MiR-424-5p mimics, the resistance of CRL2631-CHOP cells to CHOP drugs decreased, and the expression level of MDR-1 protein (P<0.001), PD-L1 mRNA and protein also decreased significantly (both P<0.001). Overexpression of PD-L1 could reverse the inhibitory effect of upregulating MiR-424-5p on PD-L1 (P<0.001). CONCLUSION Down-regulation of MiR-424-5p enhances the drug resistance of DLBCL cells by regulating the PD-1/PD-L1 signaling pathway.
Humans ; B7-H1 Antigen/metabolism* ; Cell Line, Tumor ; Drug Resistance ; Luciferases ; Lymphoma, Large B-Cell, Diffuse/pathology* ; MicroRNAs/metabolism* ; Programmed Cell Death 1 Receptor ; RNA, Messenger ; Signal Transduction

Objective To investigate the effect of T cell immunoreceptor with Ig and ITIM domains (TIGIT) on the function of CD8⁺ T cells in the lungs of Plasmodium infected mice. Methods The lungs of the mice infected with Plasmodium yoelii were isolated, weighed and photographed after 12 days' infection. After dissolution, lung lymphocytes were isolated, counted and stained, and then the contents of CD8⁺ and TIGIT⁺CD8⁺ T cells were detected by flow cytometry. The expressions of L selectin (CD62L), CD69, programmed death 1 (PD-1), CD25, and C-X3-C motif chemokine receptor 1 (CX3CR1) on TIGIT⁺CD8⁺ T cells were detected by flow cytometry. After stimulation with phorbol 12-myristate 13-acetate (PMA) and ionomycin, the ability of TIGIT⁺CD8⁺T cells to secrete interferon γ(IFN-γ), interleukin 21 (IL-21), IL-4, IL-17, and IL-10 was detected. Results The body mass of mice with Plasmodium infection was reduced. The lungs became darker, and the ratio of the lung mass to body mass was significantly increased. Compared with the normal mice, the percentages and absolute quantity of CD8⁺ and TIGIT⁺CD8⁺ T cells in the lungs of the infected mice were significantly increased. The percentage of TIGIT⁺CD8⁺ T cells expressing CD62L in the infected group was significantly lower, while the percentage of the CD69, PD-1, and CX3CR1 cells were significantly higher than that of TIGIT⁺CD8⁺ T cells from the normal mice. The percentages of TIGIT⁺CD8⁺ T cells secreting IL-21, IL-4, IL-17 and IL-10 cells in the infected group were significantly lower. Conclusion The lung lesions from mice with Plasmodium infection are obvious, the numbers of TIGIT⁺CD8⁺ T cells increase, and these cells express a variety of activation-related molecules, but the ability to secrete cytokines is reduced.
Animals ; Mice ; CD8-Positive T-Lymphocytes ; Cytokines/metabolism* ; Interferon-gamma/metabolism* ; Interleukin-10/metabolism* ; Interleukin-17/metabolism* ; Interleukin-4/metabolism* ; Lung/metabolism* ; Malaria/metabolism* ; Plasmodium yoelii/metabolism* ; Programmed Cell Death 1 Receptor/metabolism*

Objective To explore the effect of formononetin on immunity of mice with transplanted H22 hepatocarcinoma. Methods Male C57BL/6 mice were subcutaneously inoculated with H22 cells (4×10⁵) to establish a tumor-bearing mouse model. The mice were treated with formononetin [10 mg/(kg.d)] or [50 mg/(kg.d)] for 28 days, and then the tumor inhibition rate was calculated. Carrilizumab was used as a positive control drug. The expressions of CD8, granzyme B and forkbox transcription factor 3 (FOXP3) in HCC tissues were analyzed by immunohistochemical staining. The mRNA and protein expression of programmed cell death protein 1 (PD-1) and its ligand 1 (PD-L1) in HCC tissues were detected by real-time PCR or Western blot analysis, respectively. The serum levels of interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) were detected by ELISA. Results Formononetin increased the tumor inhibition rate and the positive rate of CD8 and granzyme B staining in tumor-bearing mice. There was no significant difference in the positive rate of FOXP3 staining in tumor tissues of mice in each group. Formononetin decreased the levels of IL-10 and TGF-β in serum of tumor-bearing mice, and decreased the relative expression of mRNA and protein of PD-1 and PD-L1 in tumor tissue of tumor-bearing mice. Conclusion Formononetin can activate CD8⁺ T cells and reduce the release of immunosuppressive factors in regulatory T cells by blocking PD-1/PD-L1 pathway and play an antitumor role.
Male ; Animals ; Mice ; Carcinoma, Hepatocellular/pathology* ; Liver Neoplasms/genetics* ; Interleukin-10/genetics* ; B7-H1 Antigen ; Granzymes/genetics* ; Programmed Cell Death 1 Receptor/metabolism* ; CD8-Positive T-Lymphocytes/metabolism* ; Mice, Inbred C57BL ; Transforming Growth Factor beta/genetics* ; RNA, Messenger/metabolism* ; Forkhead Transcription Factors/genetics* ; Cell Line, Tumor

Objective: To investigate the role of CXCL5 in tumor immune of lung cancer and to explore the potential molecular mechanisms. Methods: A total of 62 cases of patients with lung cancer admitted in the First Affiliated Hospital of Henan University from May 2018 to December 2019 were recruited as study object. Another 20 cases of patients with pulmonary infectious diseases and 20 cases of healthy control were selected as control. Enzyme-linked immunosorbent assay (ELISA) was used to determine serum levels of CXCL5 in patients with lung cancer, pulmonary infectious diseases and healthy control. Immunohistochemical staining (IHC) was used to detect the expressions of CXCL5 and PD-1/PD-L1 in tumor and paracarcinoma tissues of patients with lung cancer. Pearson correlation analysis was used to evaluate the correlation between CXCL5 and PD-1 in tumor and paracarcinoma tissues of patients with lung cancer. Lewis cells either expressing CXCL5 or vector plasmids were used to establish C57BL/6J mice model of lung cancer, and all mice were then divided into vehicle and PD-1 antibody treatment groups, 10 mice for each group. The mice survival and tumor growth curves were recorded. IHC was used to evaluate the expressions of CXCL5, PD-1 as well as the proportions of CD8(+) T and Treg cells in xenograft tumor tissues. Results: In patients with lung cancer, the serum level of CXCL5 [(351.7±51.5) ng/L] was significant higher than that in patients with pulmonary infectious diseases and healthy control [(124.7±23.4) ng/L, P<0.001]. The expression levels of CXCL5 (0.136±0.034), CXCR2 (0.255±0.050), PD-1 (0.054±0.012) and PD-L1 (0.350±0.084) in tumor were significant higher than those in paracarcinoma normal tissues [(0.074±0.022), (0.112±0.023), (0.041±0.007) and (0.270±0.043) respectively, P<0.001]. CXCL5 was significant positively correlated with PD-1 in tumor tissues of lung cancer (r=0.643, P<0.001), but not correlated with PD-1 in paracarcinoma tissues(r=0.088, P=0.496). The vector control group, CXCL5 overexpression group, vector control + anti-PD-1 antibody treatment group and CXCL5 overexpression + anti-PD-1 antibody treatment group all successfully formed tumors in mice, while CXCL5 overexpression increased the tumor growth significantly (P<0.01), which was abrogated by the treatment of anti-PD-1 antibody. CXCL5 overexpression decreased the mice survival time significantly (P<0.01), this effect was also abrogated by the treatment of anti-PD-1 antibody. The proportion of CD8(+) T cells in CXCL5 overexpression group [(10.40±2.00)%] was significant lower than that in vector control group [(21.20±3.30)%, P=0.002]. The proportion of CD4(+) Foxp3(+) Treg cells in CXCL5 overexpression group [(38.40±3.70)%] was significant higher than that in vector control group [(23.30±2.25)%, P<0.001]. After the treatment of anti-PD-1 antibody, no significant difference were observed for the proportion of CD8(+) T cells [(34.10±5.00)% and (33.40±4.00)% respectively] and Treg cells [(14.70±3.50)% and (14.50±3.30)% respectively] in xenograft tumor tissues between CXCL5 overexpression+ anti-PD-1 antibody treatment group and vector control + anti-PD-1 antibody treatment group (P>0.05). Conclusion: The expressions of CXCL5 and PD-1/PD-L1 are all increased significantly in the tumor tissues of patients with lung cancer, CXCL5 may inhibit tumor immune of lung cancer via modulating PD-1/PD-L1 signaling.
Animals ; B7-H1 Antigen/metabolism* ; CD8-Positive T-Lymphocytes ; Chemokine CXCL5/metabolism* ; Humans ; Lung Neoplasms/pathology* ; Mice ; Mice, Inbred C57BL ; Programmed Cell Death 1 Receptor/metabolism*

Objective: To describe the actual efficacy of programmed death-1 (PD-1)/ programmed-death ligand 1 (PD-L1) inhibitors in patients with metastatic non-small cell lung cancer (NSCLC) and explore potential prognostic predictive biomarkers. Methods: Patients with metastatic NSCLC who were treated with PD-1/PD-L1 inhibitors at Cancer Hospital, Chinese Academy of Medical Sciences from January 2016 to December 2019, either as monotherapy or in combination with other agents, were consecutively enrolled into this study. We retrospectively collected the data of demographics, clinical information and pathologic assessment to evaluate the therapeutic efficacy and conduct the survival analysis. Major endpoint of our study is progression-free survival (PFS). Secondary endpoints include objective response rate (ORR), disease control rate (DCR) and overall survival (OS). Results: The ORR of 174 patients who underwent PD-1/PD-L1 inhibitor was 28.7%, and the DCR was 79.3%. Immune-related adverse events (irAEs) occurred in 23 patients (13.2%). Brain metastasis, line of treatment, and treatment patterns were associated with the ORR of metastatic NSCLC patients who underwent immunotherapy (P<0.05). After a median follow-up duration of 18.8 months, the median PFS was 10.5 months (ranged from 1.5 to 40.8 months) while the median OS was not reached. The 2-year survival rate was estimated to be 63.0%. The pathologic type was related with the PFS of metastatic NSCLC patients who underwent immunotherapy (P=0.028). Sex, age, brain metastasis and autoimmune diseases were associated with OS (P<0.05). Analysis of the receptor characteristic curve (ROC) of neutrophil/lymphocyte ratio (NLR) predicting ORR of immunotherapy in metastatic NSCLC showed that the areas under the curve of NLR before immunotherapy (NLR(C0)), NLR after one cycle of immunotherapy (NLR(C1)) and ΔNLR were 0.600, 0.706 and 0.628, respectively. Multivariate logistic regression analysis showed that NLR(C1) was an independent factor of the ORR of metastatic NSCLC patients who underwent immunotherapy (OR=0.161, 95% CI: 0.062-0.422), and the efficacy of combination therapy was better than that of single agent (OR=0.395, 95% CI: 0.174-0.896). The immunotherapy efficacy in patients without brain metastasis was better than those with metastasis (OR=0.291, 95% CI: 0.095-0.887). Multivariate Cox regression analysis showed that NLR(C1) was an independent influencing factor of PFS of metastatic NSCLC patients after immunotherapy (HR=0.480, 95% CI: 0.303-0.759). Sex (HR=0.399, 95% CI: 0.161-0.991, P=0.048), age (HR=0.356, 95% CI: 0.170-0.745, P=0.006) were independent influencing factors of OS of metastatic NSCLC patients after immunotherapy. Conclusions: PD-1/PD-L1 inhibitors are proved to be efficacious and have tolerable toxicities for patients with metastatic NSCLC. Patients at advanced age could still benefit from immunotherapy. Brain metastasis is related to compromised response. Earlier application of immunotherapy in combination with other modalities enhances the efficacy without elevating risk of irAEs. NLR(C1) is an early predictor of clinical outcome. The OS of patients younger than 75 years may be improved when treated with immunotherapy.
B7-H1 Antigen/metabolism* ; Brain Neoplasms/drug therapy* ; Carcinoma, Non-Small-Cell Lung/pathology* ; Humans ; Immune Checkpoint Inhibitors ; Lung Neoplasms/pathology* ; Prognosis ; Programmed Cell Death 1 Receptor ; Retrospective Studies

The programmed cell death ligand 1 (PD-L1) and its receptor programmed cell death 1 (PD-1) deliver inhibitory signals to regulate immunological tolerance during immune-mediated diseases. However, the role of PD-1 signaling and its blockade effect on human dental pulp stem cells (hDPSCs) differentiation into the osteo-/odontogenic lineage remain unknown. We show here that PD-L1 expression, but not PD-1, is downregulated during osteo-/odontogenic differentiation of hDPSCs. Importantly, PD-L1/PD-1 signaling has been shown to negatively regulate the osteo-/odontogenic differentiation of hDPSCs. Mechanistically, depletion of either PD-L1 or PD-1 expression increased ERK and AKT phosphorylation levels through the upregulation of Ras enzyme activity, which plays a pivotal role during hDPSCs osteo-/odontogenic differentiation. Treatment with nivolumab (a human anti-PD-1 monoclonal antibody), which targets PD-1 to prevent PD-L1 binding, successfully enhanced osteo-/odontogenic differentiation of hDPSCs through enhanced Ras activity-mediated phosphorylation of ERK and AKT. Our findings underscore that downregulation of PD-L1 expression accompanies during osteo-/odontogenic differentiation, and hDPSCs-intrinsic PD-1 signaling inhibits osteo-/odontogenic differentiation. These findings provide a significant basis that PD-1 blockade could be effective immunotherapeutic strategies in hDPSCs-mediated dental pulp regeneration.
B7-H1 Antigen/metabolism* ; Dental Pulp/metabolism* ; Humans ; Programmed Cell Death 1 Receptor/metabolism* ; Regeneration ; Stem Cells

OBJECTIVE: To investigate the expression of PD-L1 and PD-1 in pathological tissue of patients newly diagnosed with diffuse large B-cell lymphoma (DLBCL). METHODS: Data of DLBCL patients who visited the Department of Hematology, Peking University Third Hospital from May 2014 to March 2017 were collected, and a total of 21 patients with pathological tissue sections which were still available at the initial treatment were selected. The patients were divided into complete remission (CR) group and refractory relapse (RR) group according to clinical outcome. The expression and proportion of PD-1 and PD-L1 in pathological tissue sections were detected by multiplex fluorescence immunohistochemical staining, and the differences in the expression of different molecular markers in different clinical characteristics and different prognosis were compared using non-parametric test. RESULTS: The ratio of PD-L1⁺ cells to PD-1⁺ cells (PD-L1⁺ : PD-1⁺) was 5.14±3.825 in increased lactate dehydrogenase (LDH) group, which was significantly higher than 0.76±0.563 in non-increased LDH group (P=0.001). The ratio of PD-L1⁺ : PD-1⁺ in increased Treg cells group was 1.41±1.454, which was lower than 6.42±4.426 in decreased Treg cells group (P=0.023). CONCLUSION The increased expression ratio of PD-L1 to PD-1 in pathological tissue sections of newly diagnosed DLBCL patients is associated with poor prognostic clinical characteristics.
B7-H1 Antigen/metabolism* ; Biomarkers, Tumor/metabolism* ; Humans ; Lymphoma, Large B-Cell, Diffuse/pathology* ; Neoplasm Recurrence, Local ; Prognosis ; Programmed Cell Death 1 Receptor/metabolism*

Interferon-γ (IFN-γ), a key effector molecule in anti-tumor immune response, has been well documented to correlate with the intratumoral infiltration of immune cells. Of interest, however, a high level of IFN-γ has been reported in salivary adenoid cystic carcinoma (SACC), which is actually a type of immunologically cold cancer with few infiltrated immune cells. Investigating the functional significance of IFN-γ in SACC would help to explain such a paradoxical phenomenon. In the present study, we revealed that, compared to oral squamous cell carcinoma cells (a type of immunologically hot cancer), SACC cells were less sensitive to the growth-inhibition effect of IFN-γ. Moreover, the migration and invasion abilities of SACC cells were obviously enhanced upon IFN-γ treatment. In addition, our results revealed that exposure to IFN-γ significantly up-regulated the level of programmed death ligand 1 (PD-L1) on SACC cell-derived small extracellular vesicles (sEVs), which subsequently induced the apoptosis of CD8⁺ T cells through antagonizing PD-1. Importantly, it was also found that SACC patients with higher levels of plasma IFN-γ also had higher levels of circulating sEVs that carried PD-L1 on their surface. Our study unveils a mechanism that IFN-γ induces immunosuppression in SACC via sEV PD-L1, which would account for the scarce immune cell infiltration and insensitivity to immunotherapy.
B7-H1 Antigen/metabolism* ; CD8-Positive T-Lymphocytes/pathology* ; Carcinoma, Adenoid Cystic/pathology* ; Carcinoma, Squamous Cell/pathology* ; Cell Line, Tumor ; Humans ; Immunosuppression Therapy ; Interferon-gamma/pharmacology* ; Mouth Neoplasms/metabolism* ; Programmed Cell Death 1 Receptor/metabolism* ; Salivary Gland Neoplasms/pathology*