The Expression of ILT4 in Myeloid Dendritic Cells in Patients with Hepatocellular Carcinoma

Tumor-Derived Immunoglobulin-Like Transcript 4 Promotes Postoperative Relapse via Inducing Vasculogenic Mimicry through MAPK/ERK Signaling in Hepatocellular Carcinoma

The efficacy of conventional anti-angiogenesis drugs is usually low in treating hepatocellular carcinoma (HCC). Therefore, there is an urgent need to find new precise therapeutic targets and to develop more effective drugs for the treatment of HCC. Vasculogenic mimicry (VM) is different from classic endothelium-dependent angiogenesis and is associated with a poor prognosis in patients with malignant tumor. However, the mechanism underlying VM is complex and not fully defined. Ig-like transcript (ILT)-4, as a negative regulator of immune response, is expressed in many solid tumors. However, whether and how ILT4 regulates VM remains unclear. This study found VM enriched in HCC tissues, especially in tissues from patients with relapse within 5 years after surgery. Similarly, ILT4 expression level was also higher in HCC tissues from patients with relapse within 5 years after surgery. Linear regression analysis revealed a positive correlation between the expression of ILT4 and VM density. Furthermore, overexpression/knockdown of ILT4 expression upregulated/down-regulated VM-related marker, three-dimensional tube formation, and migration and invasion in HCC cell lines in vitro. In mechanistic studies, ILT4 promoted VM formation via mitogen-activated protein kinase (MAPK)/ERK signaling. This study provides a rationale and mechanism for ILT4-mediated postoperative relapse via inducing VM in HCC. The related molecular pathways can be used as novel therapeutic targets for the inhibition of HCC angiogenesis and postoperative relapse.

Identifying CD1c as a potential biomarker by the comprehensive exploration of tumor mutational burden and immune infiltration in diffuse large B cell lymphoma

Background

Tumor mutational burden (TMB) is a valuable prognostic biomarker. This study explored the predictive value of TMB and the potential association between TMB and immune infiltration in diffuse large B-cell lymphoma (DLBCL).

Methods

We downloaded the gene expression profile, somatic mutation, and clinical data of DLBCL patients from The Cancer Genome Atlas (TCGA) database. We classified the samples into high-and low-TMB groups to identify differentially expressed genes (DEGs). Functional enrichment analyses were performed to determine the biological functions of the DEGs. We utilized the cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT) algorithm to estimate the abundance of 22 immune cells, and the significant difference was determined by the Wilcoxon rank-sum test between the high- and low-TMB group. Hub gene had been screened as the prognostic TMB-related immune biomarker by the combination of the Immunology Database and Analysis Portal (ImmPort) database and the univariate Cox analysis from the Gene Expression Omnibus (GEO) database including six DLBCL datasets. Various database applications such as Tumor Immune Estimation Resource (TIMER), CellMiner, konckTF, and Genotype-Tissue Expression (GTEx) verified the functions of the target gene. Wet assay confirmed the target gene expression at RNA and protein levels in DLBCL tissue and cell samples.

Results

Single nucleotide polymorphism (SNP) occurred more frequently than insertion and deletion, and C > T was the most common single nucleotide variant (SNV) in DLBCL. Survival analysis showed that the high-TMB group conferred poor survival outcomes. A total of 62 DEGs were obtained, and 13 TMB-related immune genes were identified. Univariate Cox analysis results illustrated that CD1c mutation was associated with lower TMB and manifested a satisfactory clinical prognosis by analysis of large samples from the GEO database. In addition, infiltration levels of immune cells in the high-TMB group were lower. Using the TIMER database, we systematically analyzed that the expression of CD1c was positively correlated with B cells, neutrophils, and dendritic cells and negatively correlated with CD8+ T cells, CD4+ T cells, and macrophages. Drug sensitivity showed a significant positive correlation between CD1c expression level and clinical drug sensitivity from the CellMiner database. CREB1, AHR, and TOX were used to comprehensively explore the regulation of CD1c-related transcription factors and signaling pathways by the KnockTF database. We searched the GETx database to compare the mRNA expression levels of CD1c between DLBCL and normal tissues, and the results suggested a significant difference between them. Moreover, wet experiments were conducted to verify the high expression of CD1c in DLBCL at the RNA and protein levels.

Conclusions

Higher TMB correlated with poor survival outcomes and inhibited the immune infiltrates in DLBCL. Our results suggest that CD1c is a TMB-related prognostic biomarker.

New and effective method to develop primary hepatocytes from liver cancer patients

Liver cancer (LC) is one of the most common malignant tumors worldwide. Since the mechanism of LC pathogenesis and metastasis cannot be carried out directly on the human body, it is particularly important to establish human liver cancer cell lines for research in vitro. In this study, tissue block adherence method combined with cell clumps digestion method was used to establish primary human hepatocytes (PHHs) with a successful rate of 60% (45/75). Short tandem repeat (STR) analysis proved the cells were derived from its paired tissues. These cells from hepatocellular carcinoma (HCC) expressed NTCP and secreted ALB and AAT as detected by western blot, and expressed hepatocyte-specific membrane protein ASGR1 as detected by flow cytometry. Liver cancer biomarkers like CK7 in ICC (intrahepatic cholangiocarcinoma), AFP, and GPC3 in HCC expressed of different degree as detected by immunohistochemical analysis. These cells displayed typical liver cancer cell morphological characteristics and can passage stably. In conclusion, we developed an effective method to establish PHHs. Further studies are necessary to study if these cells maintaining other liver function and reproduce the physiology of the tumors and how these cells behavior in the drug development.

Analysis of the expression and prognosis for leukocyte immunoglobulin-like receptor subfamily B in human liver cancer

Background

Leukocyte immunoglobulin-like receptor subfamily B (LILRB), including 5 subtypes, is a group of inhibitory receptors in the immune system. The LILRB family is known to be involved in the tumor progression of various cancer types, especially liver cancer. However, the expression patterns and prognostic values of LILRB family members in liver cancer tissues remain unclear.

Methods

We used the Oncomine database, GEPIA database, Kaplan–Meier Plotter, Timer, and TISIDB to assess the expression and prognostic value of the LILRB family in liver cancer patients. We also verified the expression of the LILRB family in tumor tissues and tumor-free liver tissues at the protein level by using immunohistochemistry. The STRING website was used to explore the interaction between the LILRB family and their related genes. The DAVID database was used to perform the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Flow cytometry was used to assess the infiltrated NK cells in liver cancer tissues.

Results

Our study revealed that the mRNA expression of LILRB1, LILRB2, LILRB3, and LILRB5 was downregulated, while compared with normal tissues, the mRNA expression of LILRB4 was upregulated in liver cancer tissues. Survival analysis revealed that LILRB2 and LILRB5 mRNA expression levels were significantly positively associated with overall survival (OS) and disease-free survival (DSS) and that the mRNA expression of all LILRB family members was significantly positively correlated with recurrence-free survival (RFS) and progression-free survival (PFS). Next, we further found that the mRNA expression of all LILRB family members was significantly associated with the infiltration of B cells, CD8⁺ T cells, CD4⁺ T cells, macrophages, neutrophils, and dendritic cells in liver cancer. Finally, GO and KEGG analyses found that the LILRB family and its related genes were involved in antigen processing and presentation and natural killer cell-mediated cytotoxicity pathways.

Conclusions

Our study suggested that LILRB family expression was associated with the prognosis of liver cancer patients and infiltrated immune cells. The LILRB family might be involved in antigen processing and presentation and natural killer cell-mediated cytotoxicity pathways.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02562-w.

The expression and function of immunoglobulin-like transcript 4 in dendritic cells from patients with hepatocellular carcinoma

Due to their easy availability and expansion in vitro, monocyte-derived dendritic cells (moDCs) are most frequently used for tumor vaccination. Immunoglobulin-like transcript 4 (ILT4), as inhibitory receptor, has been reported to be related to DC tolerance. However, the influence of ILT4 for DC tolerance in hepatocellular carcinoma (HCC) patients has not been illustrated. In this research, we explored the expression of ILT4 on moDCs from HCC patients and its effect on moDC function. We demonstrated that the expression of ILT4 on mature DCs (mDCs) was higher in the peripheral blood from HCC patients than in that from healthy donors. The levels of cytokines IL-1β and IL-6 secreted by mDCs from both HCC patients and healthy controls, stimulated by anti-ILT4 agonistic mAb, were decreased. In contrast, the levels of IL-10 and IL-23 were upregulated. In addition, ILT4, triggered by anti-ILT4 agonistic mAb, could reduce allogeneic T cell proliferation stimulated by the mDCs. Moreover, ILT4 triggered by anti-ILT4 agonistic mAb could also reduce the ability of the mDCs to stimulate tumor cell antigen-specific autologous CD4⁺ T cells (production of IFN-γ) and CD8⁺ T cells (production of IFN-γ and IL-2). Furthermore, ILT4 expression impaired the cytotoxicity of autologous T cells induced by the mDCs against the HCC tumor cell line SMMC-7721. Our data revealed that the high expression of ILT4 promoted the immune tolerance of DCs, resulting in an inefficiency of the T cell response, a process that is exacerbated in HCC patients.

Development of an In Vitro Assay to Assess Pharmacological Compounds and Reversion of Tumor-Derived Immunosuppression of Dendritic Cells

BACKGROUND

Cancer immunotherapies have achieved much success and have become the forefront treatment of cancers previously associated with poor prognosis. However, a major challenge in cancer immunotherapies remains the heterogeneity of the immunoregulatory capacities of cancers, and not all patients of a given cancer responds to current therapeutic strategies. To address this issue and to facilitate the development of new pharmacological compounds, we here describe an in vitro model of dendritic cell suppression by cancer cells.

METHODS

We treated monocyte-derived dendritic cells with conditioned medium from cancer cell lines and assessed their maturation using ELISA and flow cytometry. In addition, we assessed their ability to induce T cell activation and differentiation.

RESULTS

We found that both the phenotypic and functional maturation of dendritic cells was suppressed by the conditioned medium. The expression of IL-12p70, TNF-α, CD80, CD83, and CD86 was significantly reduced by conditioned medium from the 786-O and HeLa cell lines, and CD4⁺ T cells had a weaker T_H1 phenotype with significantly decreased expression of IFN-γ and T-bet following co-culturing. Furthermore, we use our model to characterize the differential immunoregulatory capacities of primary cancers by using conditioned medium of cultured primary cancer cells.

CONCLUSION

This model can be used to screen pharmacological compounds seeking to alleviate the immunosuppression of the tumor microenvironment and can furthermore be used to investigate the immunoregulatory capacities of primary cancer cells, which could be a helpful prognostic tool following tumor resection.

Trial watch: dendritic cell vaccination for cancer immunotherapy

Dendritic- cells (DCs) have received considerable attention as potential targets for the development of anticancer vaccines. DC-based anticancer vaccination relies on patient-derived DCs pulsed with a source of tumor-associated antigens (TAAs) in the context of standardized maturation-cocktails, followed by their reinfusion. Extensive evidence has confirmed that DC-based vaccines can generate TAA-specific, cytotoxic T cells. Nonetheless, clinical efficacy of DC-based vaccines remains suboptimal, reflecting the widespread immunosuppression within tumors. Thus, clinical interest is being refocused on DC-based vaccines as combinatorial partners for T cell-targeting immunotherapies. Here, we summarize the most recent preclinical/clinical development of anticancer DC vaccination and discuss future perspectives for DC-based vaccines in immuno-oncology.