Expression of Immune Checkpoint Regulators IDO, VISTA, LAG3, and TIM3 in Resected Pancreatic Ductal Adenocarcinoma

Pancreatic cancer features elaborate mechanisms of immune evasion. The potential of new immune molecules was explored to restore the antitumor immune response. If these immune molecules are associated with poor survival, specific drugs could take effect. Here, we analyze the expression of VISTA, LAG3, IDO, and TIM3 on tumor-infiltrating lymphocytes (TILs) and its impact on patient survival. We analyzed 153 pancreatic cancer patients from the prospectively managed database of the multicentered PANCALYZE study. Immunohistochemistry on a tissue microarray assessed VISTA, LAG3, IDO, and TIM3 expression of TILs from the patients undergoing primary resection. Complementarily, we analyzed publicly available transcriptomic data (n = 903). Successful completion of chemotherapy, and lymph node status were independent predictors of survival in the multivariate analysis of the clinicopathologic parameters. Fifteen tumors were exclusively VISTA-positive, thirteen tumors expressed VISTA together with TIM3, and ten tumors expressed VISTA together with IDO. Patients featuring tumors with high numbers of IDO-positive TILs had better patient survival (p = 0.037). VISTA, LAG3, and TIM3 expression did not correlate with survival. The analysis of publicly available data did not show survival differences. Tumors rarely co-express more than two immune molecules at the same time, and VISTA is most frequently co-expressed. Although IDO generally inhibits T-cell proliferation, a high expression of IDO was associated with improved survival. We expect immune checkpoint inhibitors against VISTA, LAG3, and TIM3 to be inefficient in a clinical application.

Oridonin Could Inhibit Inflammation and T-cell Immunoglobulin and Mucin-3/Galectin-9 (TIM-3/Gal-9) Autocrine Loop in the Acute Myeloid Leukemia Cell Line (U937) as Compared to Doxorubicin

The T-cell immunoglobulin and mucin-3 (TIM-3)/galectin-9 (Gal-9) autocrine loop is an indispensable signaling in acute myeloid leukemia (AML) cells, which induces their self-renewal through activation of nuclear factor-kappa b (NF-kB) and β-catenin pathways. In this study, we evaluated the effects of oridonin and doxorubicin on the TIM-3/Gal-9 autocrine loop. We also evaluated oridonin anti-inflammatory and anti-cancer properties on U937 cells, as an AML cell line in comparison to doxorubicin as a common anthracycline drug for AML treatment. Cell counting kit-8 (CCK-8) was applied to evaluate the cytotoxicity of oridonin and doxorubicin on U937 cells and also to determine the impact of galectin-9 (Gal-9) on their proliferation. The effects of oridonin and doxorubicin on Gal-9, TIM-3, and interleukin-1β (IL-1β) gene expression were determined by real-time polymerase chain reaction (RT-PCR). The Gal-9 secretion level was measured by enzyme-linked immunosorbent assay (ELISA) and activation of NF-kB pathway was assessed by western blotting. In a dose-dependent manner, oridonin and doxorubicin were capable to eradicate U937 cells while Gal-9 expanded them. Following the treatment of U937 cells with oridonin, the expression of Gal-9, TIM-3, and IL-1β genes was down-regulated, and the Gal-9 secretion and NF-kB phosphorylation were diminished, whereas doxorubicin increased all of these factors. Doxorubicin is a common treatment agent in AML, but it may induce inflammation and up-regulate the TIM3/Gal-9 autocrine loop, consequently can enhance the possibility of disease relapse. Meanwhile, oridonin is capable to inhibit the essential signaling pathways in AML cells and reduce the inflammation and expansion of tumor cells and postpone AML recurrence.

IFNγ and TNFα synergistically promote galectin 9 secretion by human osteosarcoma cells MG-63 to prevent T cell killing

OBJECTIVES

Osteosarcoma is the most common bone tumor usually distributed in adolescence and the elderly. IFNγ and TNFα play double-sided roles in tumor immunity. The fundamental mechanism of IFNγ and TNFα in osteosarcoma remains elusive. We speculated that TNFα and IFNγ serve a role in regulating immune checkpoint molecule, Galectin 9, expression of MG-63 osteosarcoma cells.

METHODS

The human osteosarcoma cell line, MG-63, was stimulated with recombinant human IFNγ and TNFα. Cytokine stimulated MG-63 cells were cocultured with human peripheral T cells. Real-time PCR, flow cytometry and ELISA were used to detect related molecule expression.

RESULTS

IFNγ and TNFα up-regulate Galectin 9 expression of MG-63 cells synergistically. IFNγ and TNFα stimulated MG-63 cells induce CD4 and CD8 T cell apoptosis and inhibit cytokine production through the Tim-3/Galectin 9 pathway. A High level of serum Galectin 9 and highly expressed Tim-3 of peripheral T cells were detected in osteosarcoma patients.

CONCLUSION

We found that Galectin-9 is induced by IFNγ and TNFα stimuli in osteosarcoma cells. Furthermore, Tim-3/Galectin-9 pathway contributes to the inducible immunomodulatory functions of osteosarcoma cells, which may provide a new clue to novel strategies for the osteosarcoma therapy.

[Prediction of acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation by the level of galectin-9 in peripheral blood]

Objective: To evaluate possible effects of Gelctin-9 on acute graft versus host disease (aGVHD) development and clinical outcomes in patients before and afer allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: Peripheral blood samples were obtained from 29 patients and 15 healthy volunteers with heparin anticoagulant tubes. Samples were analyzed using ELISA kits to measure the serum concentrations of Galectin-9. Results: Patients developing aGVHD had significantly lower level of Galectin-9 [ (7.96±1.18) μg/L] before allo-HSCT compared with those not developing aGVHD [ (12.37±0.97) μg/L, P<0.001]. And after allo-HSCT, the consentration of Galectin-9 increased markedly in patients developing aGVHD [ (17.78±1.78) μg/L] compared with those not developing aGVHD [ (9.45±0.80) μg/L, P<0.001]. Patients developing 3-4 grade aGVHD had significantly higher level of Galectin-9 [ (23.25±2.59) μg/L] compared with those developing 1-2 grade aGVHD [ (14.37±1.45) μg/L, P=0.008] and those without aGVHD [ (9.45±0.80) μg/L, P<0.001]. The patients with lower level of Galectin-9 after allo-HSCT (<13.61 μg/L) showed more favorable clinical outcomes compared with those with higher level of Galectin-9 (≥13.61 μg/L) . The 3-year overall survival rates were (100.00±6.05) % and (69.23±12.80) %, respectively (P=0.009) . The cumulative incidence of non-relapse mortality was significantly higher in high Galectin-9 group [ (23.08±11.69) %] in comparison with low Gaelctin-9 group [ (0.00±7.39) %] (P=0.023) . There was no significant difference between the two groups in terms of the cumulative incidence of relapse. The cumulative incidence of relapse at 3 years were (8.33±7.98) % and (12.50±8.27) % in high and low Galectin-9 groups, respectively (P=0.708) . Conclusions: The serum concentration of Galectin-9 at the time of engraftment after allo-HSCT may be used as a predictor for the development and severity of aGVHD. Galectin-9 might be considered as a potential new approach to regulate transplant rejection to achieve desirable survival.

Molecular and immune correlates of TIM-3 (HAVCR2) and galectin 9 (LGALS9) mRNA expression and DNA methylation in melanoma

BACKGROUND

The T cell immunoglobulin and mucin-domain containing-3 receptor TIM-3 (also known as hepatitis A virus cellular receptor 2, encoded by HAVCR2) and its ligand galectin 9 (LGALS9) are promising targets for immune checkpoint inhibition immunotherapies. However, little is known about epigenetic regulation of the encoding genes. This study aimed to investigate the association of TIM-3 and LGALS9 DNA methylation with gene expression, patients' survival, as well as molecular and immune correlates in malignant melanoma.

RESULTS

Methylation of all six TIM-3 CpGs correlated significantly with TIM-3 mRNA levels (P ≤ 0.05). A strong inverse correlation (Spearman's ρ = - 0.49) was found in promoter regions, while a strong positive correlation (ρ = 0.63) was present in the gene body of TIM-3. High TIM-3 mRNA expression (hazard ratio (HR) = 0.88, 95% confidence interval (CI) [0.81-0.97], P = 0.007) was significantly associated with better overall survival. Seven of the eight LGALS9 CpG sites correlated significantly with LGALS9 mRNA levels (P ≤ 0.003). Methylation at five CpG sites showed a strong inverse correlation (Spearman's ρ = - 0.67) and at two sites a weak positive correlation (Spearman's ρ = 0.15). High LGALS9 mRNA expression was significantly associated with increased overall survival (HR = 0.83, 95%CI [0.75-0.93], P = 0.001). In addition, we found significant correlations between TIM-3 and LGALS9 methylation and mRNA expression with immune cell infiltrates and significant differences among distinct immune cell subsets.

CONCLUSIONS

Our study points toward an epigenetic regulation of TIM-3 and LGALS9 via DNA methylation and might provide an avenue for the development of a predictive biomarker for response to immune checkpoint blockade.

Antibodies Against Immune Checkpoint Molecules Restore Functions of Tumor-Infiltrating T Cells in Hepatocellular Carcinomas

BACKGROUND & AIMS

Ligand binding to inhibitory receptors on immune cells, such as programmed cell death 1 (PD-1) and cytotoxic T-lymphocyte associated protein 4 (CTLA4), down-regulates the T-cell-mediated immune response (called immune checkpoints). Antibodies that block these receptors increase antitumor immunity in patients with melanoma, non-small-cell lung cancer, and renal cell cancer. Tumor-infiltrating CD4⁺ and CD8⁺ T cells in patients with hepatocellular carcinoma (HCC) have been found to be functionally compromised. We analyzed HCC samples from patients to determine if these inhibitory pathways prevent T-cell responses in HCCs and to find ways to restore their antitumor functions.

METHODS

We collected HCC samples from 59 patients who underwent surgical resection from November 2013 through May 2017, along with tumor-free liver tissues (control tissues) and peripheral blood samples. We isolated tumor-infiltrating lymphocytes (TIL) and intra-hepatic lymphocytes. We used flow cytometry to quantify expression of the inhibitory receptors PD-1, hepatitis A virus cellular receptor 2 (TIM3), lymphocyte activating 3 (LAG3), and CTLA4 on CD8⁺ and CD4⁺ T cells from tumor, control tissue, and blood; we studied the effects of antibodies that block these pathways in T-cell activation assays.

RESULTS

Expression of PD-1, TIM3, LAG3, and CTLA4 was significantly higher on CD8⁺ and CD4⁺ T cells isolated from HCC tissue than control tissue or blood. Dendritic cells, monocytes, and B cells in HCC tumors expressed ligands for these receptors. Expression of PD-1, TIM3, and LAG3 was higher on tumor-associated antigen (TAA)-specific CD8⁺ TIL, compared with other CD8⁺ TIL. Compared with TIL that did not express these inhibitory receptors, CD8⁺ and CD4⁺ TIL that did express these receptors had higher levels of markers of activation, but similar or decreased levels of granzyme B and effector cytokines. Antibodies against CD274 (PD-ligand1 [PD-L1]), TIM3, or LAG3 increased proliferation of CD8⁺ and CD4⁺ TIL and cytokine production in response to stimulation with polyclonal antigens or TAA. Importantly, combining antibody against PD-L1 with antibodies against TIM3, LAG3, or CTLA4 further increased TIL functions.

CONCLUSIONS

The immune checkpoint inhibitory molecules PD-1, TIM3, and LAG3 are up-regulated on TAA-specific T cells isolated from human HCC tissues, compared with T cells from tumor-free liver tissues or blood. Antibodies against PD-L1, TIM3, or LAG3 restore responses of HCC-derived T cells to tumor antigens, and combinations of the antibodies have additive effects. Strategies to block PD-L1, TIM3, and LAG3 might be developed for treatment of primary liver cancer.