Sequential delivery of PD-1/PD-L1 blockade peptide and IDO inhibitor for immunosuppressive microenvironment remodeling via an MMP-2 responsive dual-targeting liposome

Intelligent responsive drug delivery system opens up new avenues for realizing safer and more effective combination immunotherapy. Herein, a kind of tumor cascade-targeted responsive liposome (NLG919@Lip-pep1) is developed by conjugating polypeptide inhibitor of PD-1 signal pathway (AUNP-12), which is also a targeted peptide that conjugated with liposome carrier through matrix metalloproteinase-2 (MMP-2) cleavable peptide (GPLGVRGD). This targeted liposome is prepared through a mature preparation process, and indoleamine-2,3-dioxygenase (IDO) inhibitor NLG919 was encapsulated into it. Moreover, mediated by the enhanced permeability and retention effect (EPR effect) and AUNP-12, NLG919@Lip-pep1 first targets the cells that highly express PD-L1 in tumor tissues. At the same time, the over-expressed MMP-2 in the tumor site triggers the dissociation of AUNP-12, thus realizing the precise block of PD-1 signal pathway, and restoring the activity of T cells. The exposure of secondary targeting module II VRGDC-NLG919@Lip mediated tumor cells targeting, and further relieved the immunosuppressive microenvironment. Overall, this study offers a potentially appealing paradigm of a high efficiency, low toxicity, and simple intelligent responsive drug delivery system for targeted drug delivery in breast cancer, which can effectively rescue and activate the body's anti-tumor immune response and furthermore achieve effective treatment of metastatic breast cancer.

Panax notoginseng saponins prevent colitis-associated colorectal cancer via inhibition IDO1 mediated immune regulation / 中国天然药物

Colorectal cancer (CRC) is the third most lethal cancer and leading cause of cancer mortality worldwide. A key driver of CRC development is colon inflammatory responses especially in patients with inflammatory bowl disease (IBD). It has been proved that Panax notoginseng saponins (PNS) have anti-inflammatory, anti-oxidant and anti-tumor effects. The chemopreventive and immunomodulatory functions of PNS on colitis-associated colorectal cancer (CAC) have not been evaluated.This present study was designed to study the potential protective effects of PNS on AOM/DSS-induced CAC mice to explore the possible mechanism of PNS against CAC. Our study showed that PNS significantly alleviated colitis severity and prevented the occurrence of CAC. Functional assays revealed that PNS relieved immunosuppression of Treg cells in the CAC microenvironment by inhibiting the expression of IDO1 mediated directly by signal transducer and activator of transcription 1 (STAT1) rather than phosphorylated STAT1. Ultimately, Rh1, one of the PNS metabolites, exhibited the best inhibitory effect on IDO1 enzyme activity. Our study showed that PNS exerted significant chemopreventive function and immunomodulatory properties on CAC. It could reduce macrophages accumulation and Treg cells differentiation to reshape the immune microenvironment of CAC. These findings provided a promising approach for CAC intervention.

Tryptophan and tumor immunity / 药学学报

As an essential amino acid, tryptophan (Trp) has various physiological functions and is of great significance in the metabolic process of tumors. In the human body, tryptophan is mainly transformed through kynurenine metabolic pathway, which not only promotes the inherent malignant properties of tumor cells, but also leads to immune-suppressive tumor microenvironment. Changes in tryptophan metabolism often occur in tumors, accompanied by abnormal gene expression of tryptophan-related enzymes, among which indoleamine 2,3-bioxygenase (IDO)-related gene expression and tryptophan 2,3-dioxygenase (TDO)-related gene changes are the most significant. A large number of clinical trials on IDO inhibitors, TDO inhibitors and combination therapy have been carried out. This paper reviewed the tryptophan metabolic pathway, regulation of IDO (TDO), kynurenine (KYN) and other related genes in tumor cells, and outlined the development of therapeutic schedule targeting tryptophan-related genes. The new progress provides new ideas for the further exploration of tumor treatment options.

Research progress on indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors / 药学学报

Indoleamine 2,3-dioxygenase 1 (IDO1) is the rate-limiting enzyme in the degradation of tryptophan to kynurenine. IDO1 is highly expressed in some tumor tissues. IDO1 can deplete tryptophan in tumor microenvironment, inhibit T cell function, and mediate the immune escape of tumor cells. Thus, IDO1 is considered a potential target of tumor immunotherapy. Currently, there are several IDO1 inhibitors in clinical research studies. The mechanism of IDO1-mediated tumor immune escape and the structure of IDO1 inhibitors are summarized in this review.

Isolation and purification of indoleamine 2,3-dioxygenase (IDO) inhibitory constituents from Rabdosia japonica / 中草药

Objective: To isolate indoleamine 2,3-dioxygenase (IDO) inhibitory constituents from Rabdosia japonica based on bioactivity tracking separation. Methods: The overground part of R. japonica was extracted with boiling water and precipitated by ethanol, the precipitation was collected and lyophilized to obtain XPS, then successively separated by DEAE Sepharose Fast Flow anion-exchange and Superdex-75 gel permeation chromatographic steps to give XPS10-1. A combination of HPGPC, monosaccharide and amino acid composition analysis and IDO inhibitory studies was performed to investigate the structure and bioactivity of XPS10-1. Results: A IDO inhibitory glycoprotein, XPS10-1, was obtained from R. japonica based on activity tracking, its average molecular weight was estimated to 8 852, monosaccharide composition analysis showed the glycosyl part of XPS10-1 was mainly composed of rhamnose and glucose with the ratio of 10.0:2.2, and the protein part was mainly composed of glutamic acid, serine and glycine with mass ratio of 37.3:16.9:45.8. XPS10-1 showed potent IDO inhibitory effect with IC50 of (46.6 ± 3.4) μg/mL, and IC50 of IDO inhibitory effect of XPS10-1 on HeLa cells was (139.0 ± 8.7) μg/mL. Conclusion: In this study, a glycoprotein with IDO inhibitory effect was isolated from R. japonica, which could lay the foundation for the substance basis study of R. japonica.

Identification of an IDO1 inhibitor prodrug that specifically targets tumor tissue / 药学学报

Hypoxia-activated prodrugs that specifically target tumor tissues were designed by attaching the nitro-aromatic ring carrier molecules that can be degraded in the hypoxic microenvironment of the tumor to the hydroxyamidine group of IDO1 inhibitor compound B and epacadostat. Eleven prodrug compounds were synthesized and their structures were confirmed by 1H NMR and HR-MS. Compounds F-1 and F-6, which had a higher stability and drug release rate, were identified by an in vitro stability assay, nitroreductase reduction assay, MTT assay, and an in vivo tumor tissue hypoxia degradation assay, and then evaluated for anti-tumor efficacy in vivo. The results showed that prodrug F-1 inhibited tumor growth by 67.41%, which was significantly higher than 42.31% for the starting drug group. It appeared that the inhibition of IDO1 in the tumor tissue was different from the overall inhibition of IDO1 in vivo. Animal treatment procedures were carried out with the approval of the Animal Care and Use Committee of the Chinese Academy of Medical Sciences and Peking Union Medical College.

Design, synthesis and inhibitory activity of indoleamine 2,3-dioxygenase 1 inhibitors / 药学学报

Indoleamine 2,3-dioxygenase 1 (IDO1) is a key enzyme in the human tryptophan metabolism pathway, which can mediate tumor immune response. An IDO1 inhibitor would be a potential cancer immunotherapy drug. Based on the recently reported crystal of an IDO1 protein-inhibitor complex (PDBID: 6AZV), the structure of reported inhibitor, and by analyzing the interaction mode between the inhibitor and IDO1, new inhibitor molecules were designed and synthesized. All structures were confirmed by spectral data. Preliminary activity studies showed that compounds containing an azabiphenyl tetrazole structure (B1 and B2) and biphenyl compounds containing a sulfonamide structure (D1, D2 and D3) had excellent inhibitory activity of IDO1 at the enzyme and cell level, and were comparable or even better than the control drug INCB24360.

Indolamina 2, 3-dioxigenase (IDO) em melanoma: regulação frente ao inibidor de BRAF e sua expressão na progressão da doença / Indoleamine 2, 3-dioxygenase (IDO) in melanoma: regulation against BRAF inhibitor and its expression in disease progression

Os inibidores de BRAF (iBRAFs) e de MEK (iMEK), inauguraram uma nova classe de medicamentos, a terapia direcionada, no combate ao melanoma metastático. Entretanto, os pacientes adquirem resistência ao tratamento em poucos meses. Além disso, a imunoterapia vem ganhando espaço no tratamento do câncer, incluindo o melanoma, porém, com alguns aspectos inexplorados. Dentro deste tema, a enzima IDO vem despertando um grande interesse pela participação nos mecanismos de imunotolerância, imunoescape e progressão tumoral. A IDO é responsável pelo consumo e depleção do triptofano, produzindo a quinurenina. Ela está presente em diversos tipos celulares, incluindo células do sistema imune e células tumorais. Este trabalho objetivou avaliar a expressão de IDO durante a progressão da doença - desde do nevo até o melanoma metastático e também avaliar a regulação de IDO induzido por IFN-γ após tratamento com iBRAF em linhagens parentais e resistentes ao iBRAF, buscando-se os mecanismos moleculares. Por fim, objetivou-se entender os efeitos do 1-metil-triptofano (1-MT), um inibidor de IDO, tanto na sua capacidade de inibir a atividade de IDO quanto na sua influência na capacidade clonogênica. O estudo de bioinformática sobre o repositório público GSE12391 mostrou que o nível de expressão gênica de IDO foi superior nos estágios mais avançado da doença. Além disso, todas amostras de melanoma primário de pacientes apresentaram a imunomarcação de IDO, enquanto que nenhuma amostra de nevo apresentou tal marcação. Adicionalmente, a ocorrência de IDO se deu nos infiltrados linfoides, em células mononucleares do sistema imune. Duas análises de bioinformática de expressão gênica demonstraram que a IDO estava expressa positivamente na fase de resistência ao iBRAF. Ademais, os resultados de expressão proteica mostraram que a inibição de via MAPK (tanto por iBRAF quanto por iMEK) conseguiu modular a expressão de IDO, sendo que a maioria das linhagens apresentou uma diminuição de IDO. A atividade de IDO, medida através da produção de quinurenina, por HPLC se mostrou em consonância com os resultados de expressão proteica, exceto pela linhagem WM164 que não apresentou atividade enzimática, embora a proteína estivesse presente. Por fim, o 1-MT conseguiu inibir de maneira eficiente a enzima IDO, bloqueando a produção de quinurenina. Além de que, o 1-MT reduziu a capacidade clonogênica de maneira dose-dependente. Portanto, conclui-se que a expressão de IDO é crescente conforme a progressão do melanoma, que a inibição da via MAPK regulou a expressão de IDO e que o 1-MT reduz a capacidade clonogênica, além da sua função primária de inibir IDO

BRAF and MEK inhibitors (BRAFi and MEKi) has launched a new class of medication, the target therapy, to combat metastatic melanoma. Nevertheless, patients acquired resistance to the treatment in few months. Additionally, immunotherapy has been gaining space in cancer treatment, including melanoma, but some aspects need to be explored. Inside this theme, IDO enzyme has called the attention due to its participation in the mechanisms of immune tolerance, scape and tumor progression. IDO is responsible for tryptophan consume e depletion, producing kynurenine. It is present in different cells, including cells from immune system and tumor cells. This work purposed evaluate IDO expression during disease progression - since nevus until metastatic melanoma and also, evaluate IFN-γ-induced IDO regulation after BRAFi treatment in parental and resistant melanoma cell lines, seeking the molecular mechanisms. Lastly, it was evaluated the effects of 1-methyltryptopahn (1-MT), an IDO inhibitor, by its ability to inhibit IDO and also by its influency on the clonogenic capability. Bioinformatic study performed on GSE12391 showed that gene expression level of IDO was superior in the most advanced stages of the disease. Additionally, all sample of patient's primary melanoma presented IDO immunostaining, whereas, no nevus samples presented such staining. Besides, IDO occurrence was in the lymphoid infiltrates, in mononuclear cells from immune system. Two bioinformatic analysis of gene expression demonstrated that IDO was differentially overexpressed during BRAFi resistance stage. Moreover, protein expression results presented that MAPK pathway inhibition (both by BRAFi and by MEKy) was able to modulate IDO expression, and most of the cell lines presented an IDO downregulation. IDO activity, measured through kynurenine production, by HPLC was consonant with protein expression results, except by WM164 cell line, which did not present enzymatic activity, albeit the protein was present. By the end, 1-MT could inhibit efficiently IDO enzyme, blocking kynurenine production. Furthermore, 1-MT reduced clonogenic capability in a dosedependent manner. Therefore, it was concluded that IDO expression increases along with melanoma progression, MAPK pathway inhibition regulated IDO expression and 1-MT reduced clonogenic capability, besides its primary function of IDO inhibitor

The research progress of indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors / 药学学报

Indoleamine 2,3-dioxygenase 1 (IDO1) is a key enzyme of L-tryptophan metabolic oxidation pathway, in which the L-tryptophan is transformed into N-formyl kynurenine by oxidative cleavage. IDO1 is considered as a potential target for the development of cancer immunotherapeutic molecules. Up to now, at least 10 drug candidates have been advanced into clinical research. In this review, the binding mode and structure-activity relationships of the representative IDO1 small molecule inhibitors were summarized according the characteristics of chemical structures. Hopefully, this review could provide some insights for further development of novel IDO1 inhibitors.

Overexpression of indoleamine 2,3-dioxygenase correlates with regulatory T cell phenotype in acute myeloid leukemia patients with normal karyotype

BACKGROUND: Production of immunosuppressive enzymes such as indoleamine 2,3-dioxygenase (IDO) is one of the strategies employed by hematologic malignancies, including acute myeloid leukemia (AML), to circumvent immune surveillance. Moreover, IDO has the ability to convert CD4+CD25− conventional T cells into regulatory T cells (Tregs). In this study, we evaluated the expression of IDO in cytogenetically normal acute myeloid leukemia (CN-AML) patients and its correlation with the Treg marker, FOXP3, as well as clinical and laboratory parameters. METHODS: Thirty-seven newly diagnosed CN-AML patients were enrolled in our study along with 22 healthy individuals. The expression of the IDO and FOXP3 genes was analyzed by SYBR Green real-time PCR. RESULTS: Both IDO and FOXP3 were highly upregulated in CN-AML patients compared to control groups (P=0.004 and P=0.031, respectively). A positive correlation was observed between IDO and FOXP3 expression among AML patients (r=0.512, P=0.001). Expression of IDO and FOXP3 showed no significant correlation with laboratory parameters such as white blood cell and platelet counts, hemoglobin levels, bone marrow blast percentage, gender, and FLT3 mutation status (P>0.05). CONCLUSION: Higher IDO expression in CN-AML patients may be associated with an increased Treg phenotype which may promote disease progression and lead to poor prognosis of CN-AML patients.

Therapeutic and prognostic significance of indoleamine 2, 3-dioxygenase (IDO) in he-matologic malignancy / 中国肿瘤临床

The defense mechanism of tumor immune response is triggered spontaneously with the onset of oncogenesis in hemato-logical malignancy. However, the presence of activated immune cells and effector cytokines activates multiple immunosuppressive pathways prior to clinical diagnosis of tumors,which synergize with each other and cause dysfunction of tumor antigen-specific T cells, ultimately leading to a state of immune tolerance in hematological malignancies.Indoleamine-2,3-dioxygenase(IDO)is an important member of these immunosuppressive pathways,which induces counter-regulation to limit the inflammatory response and triggers T cell-acquired tolerance,eventually inhibiting the tumor immune response.Considering the role of IDO in immunosuppression,IDO in-hibitors constitute an important part of the immunotherapeutic arsenal against various tumors,especially hematological malignancies, and have been studied extensively in recent years.This review discusses the significance of IDO and its inhibitors in the treatment and prognosis of hematological malignancies.

Design,synthesis and biological evaluation of phenylsulfonamide-based IDO1 inhibitors / 中国药科大学学报

Based on the reported IDO1 inhibitor U-3i,11 phenylsulfonamide derivatives were designed and syn-thesized by adopting bioisosterism and molecular docking technology.The inhibitory activities of the target compounds against IDO1 were determined by the HeLa cell-based kynurenine assay.The results demonstrated that most compounds showed different degrees of inhibitory effects on IDO1.Among them,compounds 3b and 3e displayed the most potent activity and could reverse IDO1-mediated immune suppression,which might be worth of further investigation.

Kidney-replenishing herb modulates phenotype of NK cells at fetal-maternal interface by up-regulating IDO expression of trophoblasts / 中国免疫学杂志

Objective:To study the mechanism of kidney-replenishing herb in regulating the tolerance of fetal-maternal interface and the effect of IDO on modulating the phenotype of decidual NK cells. Methods: Indoleamine-2,3-dioxygenase ( IDO) expression in villus tissues from normal pregnancies and recurrent spontaneous abortion (RSA) patients was monitored by immunohisto-chemistry (IHC). IDO expression in HTR-8/Svneo cells treated with control or herb serum medium was detected by flow cytometry (FCM). The influence of kidney-replenishing herb on modulating the phenotype of NK cells,CD16 and CD56 expression in peripheral NK cells co-cultured with control or herb serum medium in the presence or absence of 1-methyltryptophan (1-MT) treated HTR-8/Svneo cells were measured by FCM. Results: IDO expression was decreased in villus tissue of RSA patients compared to normal preg-nancies. Herb medium could increase the IDO expression of HTR-8/Svneo. Kidney-replenishing herb could enhance the regulatory function of trophoblasts on NK cells and further induce the immune tolerance at fetal-maternal interface in IDO dependent and independent manners. Conclusion: Kidney-replenishing herb can modulate the phenotype of peripheral NK cell by up-regulating IDO expression in trophoblasts and play a role in the treatment of RSA patients.

Correlation of tyrosine phosphatase-1/2 (SHP-1,SHP-2) with indoleamine 2,3-dioxygenase (IDO) in villi and decidua of early pregnancy / 中国免疫学杂志

Objective:To explore the correlation of tyrosine phosphatase-1/2 (SHP-1,SHP-2) with indoleamine 2,3-dioxygenase(IDO) in maternal fetal interface.Methods: The expression of SHP-1,SHP-2 and IDO were detected by Western blot method and the relationship of the proteins was analysed,in human chorionic villi and decidua tissues of 30 cases of artificial abortion patients.Results:The expression of SHP-1,SHP-2 were positively correlated withthe expression of IDO in human chorionic villi and de-cidua;the expression of SHP-1,SHP-2 and IDO in decidual tissues were higher than those in the villi.Conclusion: Normal physiological state of pregnancy,SHP-1 and SHP-2 may be involved in the regulation of immune tolerance by positive regulation of IDO expression at maternal fetal interface.

Effect and mechanism of mesenchymal stem cell derived from different sources on inhibiting follicular helper T cells / 器官移植

Objective To investigate the inhibitory effect and underlying mechanism of mesenchymal stem cell (MSC) derived from different sources on follicular helper T cell (Tfh cell). Methods Umbilical cord-derived MSC (UC MSC), bone marrow-derived MSC (BM MSC) and fat-derived MSC (Fat MSC) were co-cultured with peripheral blood mononuclear cell (PBMC) for 48 h. A control group was established. Flow cytometry was adopted to calculate the proportion of Tfh cells among the lymphocytes in four groups. The content of interleukin (IL)-21 in the supernatant was detected by enzyme-linked immune absorbent assay (ELISA) in four groups. BM MSC was co-cultured with PBMC, and supplemented with indoleamine 2,3-dioxygenase (IDO) inhibitor 1-methyl tryptophan (1-MT), IL-10 antibody, human leukocyte antigen (HLA)-G antibody in the 1-MT group, IL-10 inhibition group, HLA-G inhibition group and BM MSC group without addition of other substances. After 48 h culture, flow cytometry was used to detect the percentage of Tfh cells among lymphocytes. Results Flow cytometry demonstrated that compared with the control group, the proportion of Tfh cells in the BM MSC group was significantly decreased (P<0.05). Compared with the BM MSC group, the percentage of Tfh cells in the UC MSC and Fat MSC groups was significantly higher (both P<0.05). ELISA revealed that compared with the control group, the IL-21 content in the BM MSC group was significantly decreased (P<0.05). Compared with the BM MSC group, the IL-21 contents were considerably higher in the UC MSC and Fat MSC groups (both P<0.05). The analysis of underlying mechanism revealed that the proportions of Tfh cells in the 1-MT, IL-10 inhibition and the HLA-G inhibition groups were (1.75±0.07)%, (1.31±0.09)% and (1.50±0.03)%, respectively, which were significantly higher than (1.03±0.43)% in the BM MSC group (all P<0.05). Conclusions BM MSC exerts the highest inhibitory effect upon the differentiation of Tfh cell and IL-21. The mechanism underlying suppressing the differentiation of Tfh cells differentiation is probably correlated to promoting the secretion of IDO.

Antidepressant effect and mechanism of Gross saponins of Tribulus terrestris / 中国药理学通报

Aim Tostudytheantidepressanteffectand mechanism of Gross saponins of Tribulus terrestris. Methods Themodelofdepressionwasestablishedby unpredictable chronic mild stress(UCMS),then open filed test (OFT)and tail suspension test (TST)were used to evaluate the behavioral changes.LC-MS/MS method was employed to measure blood neurotransmit-ters.mRNA expressions of IDO,IL-10 and IL-1βwere detected by quantitative PCR method.Hippocampus protein expression was detected by Western blot.Re-sults Comparedwithcontrolgroup,modelgroup's total distance,number of standing and tail suspension fixed time increased significantly (P <0. 05 ),Neuro-transmitter level of 5-HT in the blood was significantly decreased(P<0. 05 ).mRNA expression of IDO and IL-1βwas increased in hippocampus.Protein expres-sion of IDO was significantly increased in hippocampus (P <0. 05 ).Compared with model group,the treat-ment group was significantly decreased in total distance,number of standing and tail suspension fixedtime(P<0. 05).Neurotransmitter level of 5-HT in the blood and mRNA expression of IL-10 in hippocampus were significantly increased after treatment (P <0. 05 ).mRNA and protein expression of IDO were ob-viously down-regulated in hippocampus (P <0. 05 ). Conclusions GrosssaponinsofTribulusterrestriscan obviously improve rat behavior and show antidepressanteffect,which can increase neurotransmitter level of 5-HT in the blood,down-regulate mRNA expression of IDO and IL-1β,and obviously increase protein expres-sion levels of IDO in hippocampus(P<0. 05 ).

Research progress on the mechanism and clinical data of IDO inhibitor in reversing the resistance of malignancies to PD-1 antibody by regulating MDSCs / 中国肿瘤临床

PD-1 antibody immunotherapy has been used as a first-line treatment against various malignancies,but resistance to this treatment limits its efficacy.For instance,myeloid derived suppressor cells,myeloid derived suppressor cells induce resistance to PD-1 antibody in a tumor microenvironment.A few combination regimens of an IDO inhibitor plus PD-1 antibody are currently subjected to ongoing clinical trials in the US,and preliminary results have shown that this inhibitor can reverse the resistance of malignancies to PD-1 antibody.This study reviewed the research progress on the resistance mechanism of malignancies to PD-1 antibody and revealed that IDO inhibitor regulates MDSCs to reverse the resistance to PD-1 antibody.This study also described the clinical efficacy of this in-hibitor plus PD-1 antibody.

Improved survival of heterotopic heart transplant overexpressing IDO rat bone mesenchymal stem cells / 中国免疫学杂志

Objective:To explores the improvement in survival mechanism of a rat model of enterocoelia heterotopic heart transplant with rat bone marrow mesenchymal stem cells( BMSCs) IDO-overexpressing. Methods:IDO-overexpressing rat BMSCs were produced through transfection of rat BMSCs with IDO gene carried by the lentiviral vector GV308. A rat model of enterocoelia heterotopic heart transplantation was established. This rat model received a cell treatment via its tail veins, as follows: ①Echocardiography was employed to detect the functional changes in the transplanted heart.②The fluorescence intensity of the different parts of the transplanted heart was evaluated using a body imaging system for small living animals.③Receptors rat spleens cells were obtained and used for a flow cytometric detection of the expression levels of CD40,CD86,CD80,MHCⅡ,CD274,CD45RA,CD45RA+CD45RB,and Treg cells. ④A transplanted heart was obtained after injection to evaluate inflammatory cell infiltration through HE staining.⑤Liquid phase chips were used to detect changes in the serum factors IL-1ɑ,IL-4,IL-1β,IL-2,IL-10,IFN-γ,IL-18,TGFβ1, TGFβ2 and TGFβ3 in after injection cells. Results:①After the rat heterotopic heart transplantation model and the corresponding cell treatment were established,after over-expressed IDO-BMSCs treatment 2 days the EF and FS were higher in the transplanted heart than other groups.②The fluorescence intensity of the parts of the transplanted heart was highest in the IDO-BMSC overexpression group as revealed by small animal living body evaluation. ③Two days after the interventions, spleen cells in the over-expressed IDO-BMSCs group showed reduced expression levels of CD40,CD86,CD80,MHCⅡ,CD45RA,CD45RA+CD45RB and increased expression levels of CD274 and Treg cells as revealed by flow cytometry.④Liquid phase chips were used to examine the serum obtained from each group 2 days after the intervention,and the results showed that the expression levels of IL-1α,IL-4,IL-1β,IL-2,IFN-γand IL-18 in the IDO-BMSC overexpression group decrease. By contrast,the expression levels of IL-10,TGFβ1,TGFβ2 and TGFβ3 increase. HE staining results demonstrate that inflammatory cell infiltration was lower in IDO-BMSC overexpression group than in other groups. Conclusion:IDO-overexpressing BMSCs improve the survival of a transplanted heart through effective adjustment of immune DC and T cells,as well as cell factors.

Research progress on the mechanism and clinical data of IDO inhibitor in reversing the resistance of malignancies to PD-1 antibody by regulating MDSCs / 中国肿瘤临床

PD-1 antibody immunotherapy has been used as a first-line treatment against various malignancies,but resistance to this treatment limits its efficacy.For instance,myeloid derived suppressor cells,myeloid derived suppressor cells induce resistance to PD-1 antibody in a tumor microenvironment.A few combination regimens of an IDO inhibitor plus PD-1 antibody are currently subjected to ongoing clinical trials in the US,and preliminary results have shown that this inhibitor can reverse the resistance of malignancies to PD-1 antibody.This study reviewed the research progress on the resistance mechanism of malignancies to PD-1 antibody and revealed that IDO inhibitor regulates MDSCs to reverse the resistance to PD-1 antibody.This study also described the clinical efficacy of this in-hibitor plus PD-1 antibody.

Improved survival of heterotopic heart transplant overexpressing IDO rat bone mesenchymal stem cells / 中国免疫学杂志

Objective:To explores the improvement in survival mechanism of a rat model of enterocoelia heterotopic heart transplant with rat bone marrow mesenchymal stem cells( BMSCs) IDO-overexpressing. Methods:IDO-overexpressing rat BMSCs were produced through transfection of rat BMSCs with IDO gene carried by the lentiviral vector GV308. A rat model of enterocoelia heterotopic heart transplantation was established. This rat model received a cell treatment via its tail veins, as follows: ①Echocardiography was employed to detect the functional changes in the transplanted heart.②The fluorescence intensity of the different parts of the transplanted heart was evaluated using a body imaging system for small living animals.③Receptors rat spleens cells were obtained and used for a flow cytometric detection of the expression levels of CD40,CD86,CD80,MHCⅡ,CD274,CD45RA,CD45RA+CD45RB,and Treg cells. ④A transplanted heart was obtained after injection to evaluate inflammatory cell infiltration through HE staining.⑤Liquid phase chips were used to detect changes in the serum factors IL-1ɑ,IL-4,IL-1β,IL-2,IL-10,IFN-γ,IL-18,TGFβ1, TGFβ2 and TGFβ3 in after injection cells. Results:①After the rat heterotopic heart transplantation model and the corresponding cell treatment were established,after over-expressed IDO-BMSCs treatment 2 days the EF and FS were higher in the transplanted heart than other groups.②The fluorescence intensity of the parts of the transplanted heart was highest in the IDO-BMSC overexpression group as revealed by small animal living body evaluation. ③Two days after the interventions, spleen cells in the over-expressed IDO-BMSCs group showed reduced expression levels of CD40,CD86,CD80,MHCⅡ,CD45RA,CD45RA+CD45RB and increased expression levels of CD274 and Treg cells as revealed by flow cytometry.④Liquid phase chips were used to examine the serum obtained from each group 2 days after the intervention,and the results showed that the expression levels of IL-1α,IL-4,IL-1β,IL-2,IFN-γand IL-18 in the IDO-BMSC overexpression group decrease. By contrast,the expression levels of IL-10,TGFβ1,TGFβ2 and TGFβ3 increase. HE staining results demonstrate that inflammatory cell infiltration was lower in IDO-BMSC overexpression group than in other groups. Conclusion:IDO-overexpressing BMSCs improve the survival of a transplanted heart through effective adjustment of immune DC and T cells,as well as cell factors.