[The effect of semimature dendritic cell and the levels of Treg on transplantation tolerance of hepatocytes differentiated from mouse embryonic stem cell]

Immunosuppressive properties of human PD-1 + , PDL-1 + and CD80 + dendritic cells from lymph nodes aspirates of lung cancer patients

Dendritic cells (DCs) play a pivotal role in the homeostasis of the immune system. The tumor microenvironment impairs the proper function of DCs. The immunomodulatory properties of DCs in lung cancer are of interest. In the present study, we analysed DCs subsets and immune cells with the expression of immunomodulatory molecules: PD-1 and PD-L1 and co-stimulatory molecule CD80 in metastatic, non-metastatic lymph nodes (LNs) and peripheral blood (PB). LNs aspirates were obtained during the EBUS/TBNA procedure of 29 patients with primary lung cancer. The cells were analyzed by flow cytometry. We reported a higher percentage of DCs in the metastatic than in the non-metastatic LNs and the PB (0.709% vs. 0.166% vs. 0.043%, p < 0.0001). The proportions of PD-1 + , PD-L1 + and CD80 + DCs were higher in the metastatic LNs than in the non-metastatic ones. A higher proportion of regulatory DCs (DCregs) was found in the metastatic ones than in the non-metastatic LNs (22.5% vs. 3.1%, p = 0.0189). We report that DCs cells show increased expression of PD-1, PD-L1 and CD80 molecules that can interact with T lymphocytes. It can be assumed that mature DCs infiltrating metastatic LNs can develop into DCregs, which are involved in the suppression of anti-tumor response.

Impaired dendritic cell functions in lung cancer: a review of recent advances and future perspectives

Lung cancer is the leading cause of cancer mortality worldwide. Dendritic cells (DCs) are the key factors providing protective immunity against lung tumors and clinical trials have proven that DC function is reduced in lung cancer patients. It is evident that the immunoregulatory network may play a key role in the failure of the immune response to terminate tumors. Lung tumors likely employ numerous strategies to suppress DC-based anti-tumor immunity. Here, we summarize the recent advances in our understanding on lung tumor-induced immunosuppression in DCs, which affects the initiation and development of T-cell responses. We also describe which existing measures to restore DC function may be useful for clinical treatment of lung tumors. Furthering our knowledge of how lung cancer cells alter DC function to generate a tumor-supportive environment will be essential in order to guide the design of new immunotherapy strategies for clinical use.

The similarities between smDCs and regDCs in alleviating the immune injury caused by transplantation of hepatocytes differentiated from ESCs

Background

This study aimed to investigate the tolerogenic mechanisms induced by semimature dendritic cells (smDCs) and regulatory dendritic cells (regDCs) after transplantation of hepatocytes differentiated from mouse embryonic stem cells (ESCs) and to confirm the low immunogenicity of hepatocytes differentiated from ESCs.

Methods

Green fluorescent protein-labeled ESCs collected from 129 mice were cultured to differentiate into hepatocytes. smDCs and regDCs were cultured in vitro. The hepatocytes were cultured after being extracted from the livers of 129 mice. After injecting smDCs or regDCs 3 days in advance, these differentiated hepatocytes and normal hepatocytes were transplanted into the livers of BALB/c mice separately. Subsequently, the histopathological features and cytokines in transplant tissues as well as the Foxp3 expression in peripheral blood CD4⁺ T cells of the recipients were examined.

Results

The morphological phenotypes of smDCs and regDCs were similar. They both expressed medium levels of MHC-II, CD40, CD80, and CD86, high levels of TGF-β and IL-10, and low levels of IL-2. The survival of differentiated hepatocytes was prolonged and inflammatory infiltration in transplant tissues was reduced in both the smDC and regDC groups. Foxp3 expression in peripheral blood CD4⁺ T cells of the smDC group increased to 5.38% and that of the regDC group also rose to 3.87%. Moreover, the inflammatory infiltration in the tissues receiving transplanted hepatocytes was more obvious.

Conclusions

smDCs and regDCs were similar tolerogenic dendritic cells. They both could alleviate the immune injury by inducing CD4⁺CD25⁺Foxp3⁺ regulatory T cells through the medium expression of MHC-II, CD40, CD80, and CD86 and the appropriate secretion of cytokines. Hepatocytes differentiated from ESCs displayed low immunogenicity.