ABSTRACT
Objective To investigate the effects of leptin on Treg cells and the possible mecha-nism. Methods Leptin-deficient ( ob/ob) mice and homologous wild-type mice were used in this study. The percentages of Treg cells in spleen tissues and peripheral blood samples were measured by flow cytometry ( FCM) . Differences in Treg cell functionality were compared between the two groups. Splenic CD4+T cells, separated from the ob/ob mice and the wild-type mice by magnetic beads, were respectively cultured with leptin and anti-leptin neutralization antibody to evaluate the effects of leptin on Treg cells. Quantitative real-time PCR was performed to analyze the expression of Treg cell-related cytokines at transcriptional level. The levels of IL-10 and TGF-β in the supernatants of CD4+T cell culture were measured with Luminex technolo-gy. Results Compared with the wild-type mice, the ob/ob mice showed higher percentages of Treg cells in both peripheral blood samples and spleen tissues [(11. 56 ± 0. 72)％ vs (5. 47 ± 0. 81)％, (10. 16 ± 0.93)％ vs (6.29±0. 69)％]. Treg cells isolated from the ob/ob mice had stronger immunosuppressive effects on the proliferation of effector T ( Teff) cells and the secretion of TNF-α and IFN-γ than those from the wild-type mice [TNF-α:(1. 6±0. 2)％ vs (2. 4±0. 5)％, IFN-γ:(4. 3±0. 3)％ vs (7. 2±1. 2)％]. The percentages of Treg cells were decreased from (12. 2±1. 8)％ to (7. 6±0. 9)％ upon the in vitro treat-ment of CD4+ T cells from the ob/ob mice with leptin and the immunosuppressive effects of Treg cells were also weakened. However, the percentages of Treg cells were increased from (7. 8±0. 85)％ to (13. 1± 1. 5)％ upon the in vitro treatment of CD4+T cells from the wild-type mice with anti-leptin antibody and the immunosuppressive effects of Treg cells were improved as well. Moreover, the expression of Foxp3, IL-10 and TGF-β at transcriptional level and the levels of IL-10 and TGF-β in the ob/ob group were higher than those in the wild-type group. Conclusions Leptin deficiency significantly promoted the generation of Treg cells in mice and resulted in an increased expression of Foxp3, IL-10 and TGF-βat mRNA level and elevat-ed levels of IL-10 and TGF-β. The treatment of CD4+T cells with leptin might inhibit the generation of Treg cells through down-regulating the transcription of Foxp3, IL-10 and TGF-β.
ABSTRACT
Objective To investigate the effects of leptin on Th17 cells and the possible mechanism. Methods The leptin-deficient ( ob/ob) mice and their homologous wild-type mice were used in the study.The percentages of Th17 cells in peripheral blood samples, spleen tissues and lymph nodes were measured by flow cytometry ( FCM) analysis.The splenic CD4+T cells, separated from the ob/ob mice and the wild-type mice by using magnetic beads,were respectively cultured with leptin at various concentrations and with anti-leptin neu-tralization antibody to evaluate the effects of leptin on Th17 cells.The quantitative real-time PCR was performed to analyze Th17 cell-related cytokines at transcriptional levels.The levels of IL-6 and IL-17A in the supernatants of CD4+T cell culture were measured with Luminex technology.Results Compared with the wild-type mice, the ob/ob mice showed lower percentages of Th17 cells in both peripheral blood samples and spleen tissues (0.49%±0.03%vs 1.29%±0.1%, 1.56%±0.22%vs 2.47%±0.11%).There was a decrease in the percentages of Th17 cells upon the in vitro treatment of CD4+T cells from wild-type mice with anti-leptin antibody.The per-centages of Th17 cells were increased in a dose-dependent manner upon the in vitro treatment of CD4+T cells from ob/ob mice with leptin.Moreover, the levels of IL-17A and IL-6 and the transcriptional levels of RORγt, IL-17A and IL-6 in leptin deficiency group were lower than those of wild-type group, but were increased upon the treatment with leptin.No significant difference with the transcriptional levels of TGF-βand IL-23 was ob-served between the two groups with and without intervention.Conclusion Leptin deficiency seriously hampered the generation of Th17 cells in mice and resulted in a decreased expression of RORγt, IL-17A and IL-6 at mRNA level.The treatment of CD4 T cells with leptin might promote the generation of Th17 cells through up-regulating the transcription of RORγt and IL-6.
ABSTRACT
<p><b>OBJECTIVE</b>To detect the expression levels of co-inhibitory molecules, including CTLA-4, LAG-3, PD-1 and CD39, on CD4⁺ T cells in peripheral blood or tumor tissues from NSCLC patients and to investigate their potential internal relationships with the progression of NSCLC.</p><p><b>METHODS</b>Eighty-eight patients including 53 NSCLC, 17 disease control cases and 18 healthy controls were studied. All the peripheral blood and 13 cases of tumor and tumor-adjacent tissues from surgically treated NSCLC patients were obtained. The expression levels of co-inhibitory molecules CTLA-4, LAG-3, PD-1 and CD39 were assayed by flow cytometry (FCM).</p><p><b>RESULTS</b>The ratios of CD4⁺ CTLA-4⁺ T cells, CD4⁺ LAG-3⁺ T cells, CD4⁺ PD-1⁺ T cells and CD4⁺ CD39⁺ T cells in the peripheral blood of NSCLC patients were (2.49 ± 2.43)%, (2.47 ± 3.50)%, (12.94 ± 5.96)% and (6.78 ± 5.21)%, respectively, the ratio of CD4⁺ CTLA-4⁺ T cells was significantly higher in the peripheral blood of NSCLC patients than that in the disease controls and healthy controls (P < 0.05) . The ratio of CD4(+)PD-1⁺ T cells was also highly raised in the peripheral blood of NSCLC patients than that in the healthy controls (P < 0.05). Further stratified analysis indicated that the ratio of CD4⁺ PD-1⁺ T cells was (13.21 ± 5.96)% in NSCLC patients entering stages III and IV, also significantly increased as compared with that of (11.06 ± 3.42)% in the patients undergoing stages I and II (P < 0.05). More CD4⁺ CTLA-4⁺ T cells, CD4⁺ LAG-3⁺ T cells and CD4⁺ PD-1⁺ T cells were verified in the cancer tissues (5.07 ± 2.11)%, (7.86 ± 3.24)% and (40.20 ± 18.84)%, respectively, than those in their matched peripheral blood (3.13 ± 1.01)%, (2.65 ± 1.48)% and (15.79 ± 5.69)%, (P < 0.05 for all), and especially, CD4⁺ CTLA-4⁺ T cells and CD4⁺ PD-1⁺ T cells were also highly increased than those in matched cancer-adjacent tissues (P < 0.05 for all).</p><p><b>CONCLUSIONS</b>The increased expression levels of co-inhibitory molecules CTLA-4, LAG-3 and PD-1 on CD4⁺ T cells in peripheral blood and tumor tissues may be one of the mechanisms related to immune escape of tumor cells, acceleration of disease progression and poor prognosis in NSCLC patients.</p>