Possible mechanisms associated with immune escape and apoptosis on anti-hepatocellular carcinoma effect of Mu Ji Fang granules

BACKGROUND Hepatocellular carcinoma(HCC)is one of the most common digestive system cancers with high mortality rates worldwide.The main ingredients in Mu Ji Fang Granules(MJF)are alkaloids,flavonoids,and polysaccharides.MJF has been used in the clinical treatment of hepatitis,cirrhosis and HCC for more than 30 years.Few previous studies have focused on the mechanism of MJF on tumor immunology in the treatment of HCC.AIM To explore the mechanism of action of MJF on tumor immunology in the treatment of HCC.METHODS The absorbable ingredients of MJF were identified using Molecule Network related to High Performance Liquid Chromatography-Electron Spray Ionization-Time of Flight-Mass Spectrometry,and hub potential anti-HCC targets were screened using network pharmacology and pathway enrichment analysis.Forty male mice were randomly divided into the Blank,Model,and MJF groups(1.8,5.4,and 10.8 g/kg/d)following 7 d of oral administration.Average body weight gain,spleen and thymus indices were calculated,tumor tissues were stained with hematoxylin and eosin,and Interferon gamma(IFN-γ),Tumor necrosis factorα(TNF-α),Interleukin-2,aspartate aminotransferase,alanine aminotransferase,alpha-fetoprotein(AFP),Fas,and FasL were measured by Enzyme-linked Immunosorbent Assay.Relevant mRNA expression of Bax and Bcl2 was evaluated by Real Time Quantitative PCR(RTqPCR)and protein expression of Transforming growth factorβ1(TGF-β1)and Mothers against decapentaplegic homolog(SMAD)4 was assessed by Western blotting.The HepG2 cell line was treated with 10 mg/mL,20 mg/mL,30 mg/mL,40 mg/mL of MJF,and another 3 groups were treated with TGF-β1 inhibitor(LY364947)and different doses of MJF.Relevant mRNA expression of TNF-α,IFN-γ,Bax and Bcl2 was evaluated by RT-qPCR and protein expression of TGF-β1,SMAD2,p-SMAD2,SMAD4,and SMAD7 was assessed by Western blotting.RESULTS It was shown that MJF improved body weight gain and tumor inhibition rate in H22 tumorbearing mice,protected immune organs and liver function,reduced the HCC indicator AFP,affected immunity and apoptosis,and up-regulated the TGF-β1/SMAD signaling pathway,by increasing the relative expression of TGF-β1,SMAD2,p-SMAD2 and SMAD4 and decreasing SMAD7,reducing immune factors TNF-αand IFN-γ,decreasing apoptosis cytokines Fas,FasL and Bcl2/Bax,and inhibiting the effect of LY364947 in HepG2 cells.CONCLUSION MJF inhibits HCC by activating the TGF-β1/SMAD signaling pathway,and affecting immune and apoptotic cytokines,which may be due to MJF adjusting immune escape and apoptosis.

Initial Study on Immune Escape Mechanism of Mouse Acute Myelomonocytic Leukemic Cell Line WEHI-3

Objective： To investigate the expression of Fas, Fas ligand （FasL） and CD80 on the cell surface of mouse acute myelomonocytic leukemia cell line WEHI-3 and the function of FasL. Methods： The expression of Fas, FasL and CD80 was detected on WEHI-3 cell surface by flow cytometry. Simultaneously the function of FasL was determined by Thymidine （^3H-TdR） Incorporation. Results： The expression of CD80 and Fas on WEHI-3 cell surface was 5.06%±0.41% and 6.75%±2.31% （n=5） respectively, and the expression of FasL was up to 63.73%±5.23% （n=5）. The apoptotic rate of YAC-1 cells was 26%±4.5%, 35%±3.2% and 43%±2.7% （n=5） respectively when WEHI-3 （effector cell, E） and Fas^＋ YAC-1 cells （target cell, T） were cultured in the ratio of 3：1, 10：1 and 30：1. Conclusion： WEHI-3 cells express high FasL, low Fas and CD80, and can induce apoptosis of Fas^＋ YAC-1 cells.

Single-cell RNA-seq reveals the immune escape and drug resistance mechanisms of mantle cell lymphoma

Objective:Mantle cell lymphoma(MCL)is a rare subtype of non-Hodgkin lymphoma(NHL)with high heterogeneity and a high recurrence rate.How heterogenous cell populations contribute to relapse remains to be elucidated.Methods:We performed single cell RNA sequencing(scRNA-seq)on approximately 4,000 bone marrow cells sampled from one patient with multidrug resistant MCL.We identified 10 subpopulations comprising 4 malignant B cell subtypes,3 T cell subtypes,2 dendritic cell subtypes and 1 natural killer(NK)cell subtype.Subsequently,we identified cell markers,including a series of genes associated with immune escape and drug resistance.In addition,we explored the roles of these genes in the mechanism of immune escape and drug resistance,and we verified the expression imbalance and clinical prognostic potential by using GEO datasets including 211 MCL samples.Results:The major immune escape mechanisms of MCL included anti-perforin activity,decreased immunogenicity and direct inhibition of apoptosis and cell killing,as mediated by type I and II B cells.The drug resistance mechanisms of different cell clusters included drug metabolism,DNA damage repair,apoptosis and survival promotion.Type III B cells closely communicate with other cells.The key genes involved in the resistance mechanisms showed dysregulated expression and may have significant clinical prognostic value.Conclusion:This study investigated potential immune escape and drug resistance mechanisms in MCL.The results may guide individualized treatment and promote the development of therapeutic drugs.

Action and mechanism of Fas and Fas ligand in immune escape of gallbladder carcinoma

AIM: To study the role of Fas and Fas ligand (FasL) in biological behaviors of gallbladder carcinoma, and their correlated action and mechanism in tumor escape.METHODS: Streptavidin-biotin-peroxidase immunohistochemistry technique was used to study the expression of Fas and FasL protein in 26 gallbladder carcinoma tissues,18 gallbladder adenoma tissues, 3 gallbladder dysplasia tissues and 20 chronic cholecystitis tissues. Apoptosis of the infiltrating lymphocytes in these tissues was studied by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) method. Expression of both proteins and apoptosis of the tumor infiltrating lymphocytes in cancer tissues of primary foci was compared with clinicopathological features of gallbladder carcinoma.RESULTS: The positive rates of Fas were not significantly different among carcinoma, adenoma, dysplasia and chronic cholecystitis. The positive rate of FasL in carcinoma was significantly higher than that in chronic cholecystitis (x2 = 4.89, P＜0.05). The apoptotic index (AI) in carcinoma was significantly higher than that in adenoma (t'= 4.19, P＜0.01) and chronic cholecystitis (t'= 8.06, P＜0.01). The AI was significantly lower in well-differentiated carcinoma and Nevin Ⅰ-Ⅲ carcinoma than that in poorly-differentiated carcinoma (t'= 2.63, P＜0.05) and Nevin Ⅳ-Ⅴ carcinoma(t'= 3.33, P＜0.01). The confidence interval (CI) ofinfiltrating lymphocytes in adenoma, chronic cholecystitis, well-differentiated carcinoma and Nevin Ⅰ-Ⅲ carcinoma wasvery significantly lower than that in carcinoma (t' = 6.99,P＜0.01), adenoma (t' = 3.66, P＜0.01), poorly-differentiated carcinoma (t' = 5.31, P＜0.01) and Nevin Ⅳ-Ⅴ carcinoma(t' = 3.76, P＜0.01), respectively. The CI of apoptosis of infiltrating lymphocytes in well-differentiated carcinoma was significantly lower than that in poorly-differentiated carcinoma (t = 2.52, P＜0.05), and was not significantly lower in Nevin Ⅰ-Ⅲ carcinoma than in Nevin Ⅳ-Ⅴ carcinoma (t = 1.42, P＞0.05). Apoptosis of infiltrating lymphocytes was not discovered in adenoma and chronic cholecystitis. CONCLUSION: FasL expressed in gallbladder carcinoma cells permits tumor cells to escape from immune surveillance of organism by inducing apoptosis in infiltrating lymphocytes of carcinoma tissues. Up-regulation of FasL expression plays an important role in invasive depth, histological classification and metastasis of gallbladder carcinoma.

Costimulatory Molecule B7-H1 on the Immune Escape of Bladder Cancer and Its Clinical Significance

B7-H1, a recently described member of the B7 family of costimulatory molecules, is thought to be involved in tumor immune escape by inducing T-cell apoptosis. In order to investigate the relationship between B7-H1 and immune escape of bladder cancer, B7-H1 expression in 50 cases of bladder cancer was detected by using immunohistochemical method. Survival curves were con- structed using the Kaplan-Meier method and independent prognostic factors were evaluated using the Cox regression model. Our results showed that the positive rate of B7-H1 immunostaining in normal bladder tissue and bladder cancer was 0 and 72% respectively. The expression of B7-H1 was strongly associated with the pathological grade, clinical stage and recurrence （P〈0.05）. The survival rate was significantly lower in patients with B7-H1 positive group than in those with B7-H1 negative group and multi-variable analysis revealed that B7-H1 could be regarded as an independent factor in evaluating the prognosis of bladder cancer. It is concluded that the expression of B7-H1 is strongly associated with neoplastic progression and prognosis of bladder cancer. The manipulation of B7-H1 may become a beneficial target for immunotherapy in human bladder cancer.

Shuyu pills inhibit immune escape and enhance chemosensitization in hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma(HCC)is characterized by dysregulation of the immune microenvironment and the development of chemoresistance.Specifically,expression of the programmed cell death protein 1(PD-1)/programmed cell death 1 ligand 1(PD-L1)axis,an immune checkpoint,may lead to tumour immune escape,resulting in disease progression.The latest research shows that tumour immune escape may be caused by the upregulation of PD-L1 mediated by hypoxia-inducible factor-1 alpha(HIF-1α),and simultaneous inhibition of HIF-1αand PD-L1 has the potential to enhance the host’s antitumour immunity.Moreover,inhibition of the PD-1/PD-L1 axis may mitigate tumour chemoresistance.Shuyu pills(SYPs)contain immunity-enhancing and antitumour components,making them a potential HCC treatment.AIM To investigate the efficacy of SYPs for HCC treatment via simultaneous HIF-1α and PD-L1 inhibition and the mechanism involved.METHODS A subcutaneous xenograft tumour model was first established in BALB/c nude mice by the subcutaneous injection of 1×107 SMMC-7721 cells.Male mice(male,5 weeks old;n=24)were then randomly divided into the following four groups(n=6):Control(0.9%normal saline),SYP(200 mg/kg),SYP+cisplatin(DDP)(200 mg/kg+5 mg/kg DDP weekly via intraperitoneal injection),and DDP(5 mg/kg cisplatin weekly via intraperitoneal injection).The dose of saline or SYPs for the indicated mouse groups was 0.2 mL/d via intragastric administration.The tumour volumes and body weights of the mice were measured every 2 d.The mice were euthanized by cervical dislocation after 14 d of continuous treatment,and the xenograft tissues were excised and weighed.Western blot assays were used to measure the protein expression of HIF-1α,PD1,PD-L1,CD4+T cells,and CD8+T cells in HCC tumours from mice.Quantitative reverse transcription polymerase chain reaction was used for real-time quantitative detection of PD-1,PD-L1,and HIF-1α mRNA expression.An immunofluorescence assay was conducted to examine the expression of CD4+T cells and CD8+T cells.RESULTS Compared to mice in the control group,those in the SYP and SYP+DDP groups exhibited reduced tumour volumes and tumour weights.Moreover,the protein and mRNA expression levels of the oncogene HIF1α and that of the negative immunomodulatory factors PD-1 and PD-L1 were decreased in both the SYP and SYP+DDP groups,with the decrease effects being more prominent in the SYP+DDP group than in the SYP group(HIF-1α protein:Control vs SYP,P=0.0129;control vs SYP+DDP,P=0.0004;control vs DDP,P=0.0152,SYP+DDP vs DDP,P=0.0448;HIF-1αmRNA:control vs SYP,P=0.0009;control vs SYP+DDP,P<0.0001;control vs DDP,P=0.0003,SYP vs SYP+DDP,P=0.0192.PD-1 protein:Control vs SYP,P=0.0099;control vs SYP+DDP,P<0.0001,SPY vs SYP+DDP,P=0.0009;SYP+DDP vs DDP,P<0.0001;PD-1 mRNA:control vs SYP,P=0.0002;control vs SYP+DDP,P<0.0001;control vs DDP,P=0.0003,SPY vs SYP+DDP,P=0.0003;SYP+DDP vs DDP,P=0.0002.PD-L1 protein:control vs SYP,P<0.0001;control vs SYP+DDP,P<0.0001;control vs DDP,P<0.0001,SPY vs SYP+DDP,P=0.0040;SYP+DDP vs DDP,P=0.0010;PD-L1 mRNA:Control vs SYP,P<0.0001;control vs SYP+DDP,P<0.0001;control vs DDP,P<0.0001,SPY vs SYP+DDP,P<0.0001;SYP+DDP vs DDP,P=0.0014).Additionally,the quantitative and protein expression levels of CD4+T cells and CD8+T cells were simultaneously upregulated in the SYP+DDP group,whereas only the expression of CD4+T cells was upregulated in the SYP group.(CD4+T cell quantitative:Control vs SYP+DDP,P<0.0001,SYP vs SYP+DDP,P=0.0005;SYP+DDP vs DDP,P=0.0002.CD4+T cell protein:Control vs SYP,P=0.0033;Control vs SYP+DDP,P<0.0001;Control vs DDP,P=0.0021,SYP vs SYP+DDP,P=0.0004;SYP+DDP vs DDP,P=0.0006.Quantitative CD8+T cells:Control vs SYP+DDP,P=0.0013;SYP vs SYP+DDP,P=0.0347;SYP+DDP vs DDP,P=0.0043.CD8+T cell protein:Control vs SYP+DDP,P<0.0001;SYP vs SYP+DDP,P<0.0001;SYP+DDP vs DDP,P<0.0001).Finally,expression of HIF-1αwas positively correlated with that of PD-1/PD-L1 and negatively correlated with the expression of CD4+T cells and CD8+T cells.CONCLUSION SYPs inhibit immune escape and enhance chemosensitization in HCC via simultaneous inhibition of HIF-1α and PD-L1,thus inhibiting the growth of subcutaneous xenograft HCC tumours.

Morphine-3-glucuronide upregulates PD-L1 expression via TLR4 and promotes the immune escape of non-small cell lung cancer

Objective:Patients with cancer pain are highly dependent on morphine analgesia,but studies have shown a negative correlation between morphine demand and patient outcomes.The long-term use of morphine may result in abnormally elevated serum morphine-3-glucuronide(M3G)levels.Hence,the effects of M3G on tumor progression are worth studying.Methods:The effects of M3G on PD-L1 expressions in human non-small cell lung cancer(NSCLC)cell lines were first evaluated.Activation of TLR4 downstream pathways after M3G treatment was then determined by Western blot.The effects of M3G on human cytotoxic T lymphocytes(CTL)cytotoxicity and INF-γrelease was also detected.Finally,the LLC murine lung adenocarcinoma cell line were used to establish a murine lung cancer model,and the effects of M3G on tumor growth and metastasis were determined.Results:M3G promoted the expressions of PD-L1 in the A549 and H1299 cell lines in a TLR4-dependent manner(P<0.05).M3G activated the PI3 K and the NFκB signaling pathways,and this effect was antagonized by a TLR4 pathway inhibitor.A PI3 K pathway inhibitor reversed the M3G-mediated PD-L1 upregulation.M3G inhibited the cytotoxicity of CTL on A549 cells and decreased the level of INF-γ.Repeated M3G intraperitoneal injections promoted LLC tumor growth and lung metastasis through the upregulation of tumor expressed PD-L1 and the reduction of CTL in the tumor microenvironment.Conclusions:M3G specifically activated TLR4 in NSCLC cells and upregulated PD-L1 expression through the PI3 K signaling pathway,thereby inhibiting CTL cytotoxicity and finally promoting tumor immune escape.

Role of cytokines in promoting immune escape of FasL-expressing human colon cancer cells

AIM: To investigate the potential role of cytokines in promoting Fas ligand (FasL)-expressing colon cancer cells. METHODS: Immunohistochemical SABC method was used to observe the expression of Fas receptor and ligand in SW620 colon cancer cell line and Jurkat T cells in order to provide the morphological evidence for the functions of Fas receptor and ligand. To examine the cytotoxicity of effector cells, CytoTox96 non-radioactive cytotoxicity assay was adopted to measure the lactate dehydrogenase-releasing value after SW620 cells were co-cultured with Jurkat T lymphocytes. RESULTS: The FasL of colon cancer SW620 cells was positive. The positive substances were distributed in the cell membrane and cytoplasm. The Fas receptor of colon cancer SW620 cells was negative. The Fas receptor and ligand of Jurkat T lymphocytes turned out to be positive. The positive substances were distributed in the cell membrane. After phytohemagglutinin (PHA)-stimulated Jurkat T lymphocytes were co-cultured with phorbol 12-myristate 13-acetate (PMA)-plus-ionomycin-stimulated (for 48 h) SW620 cells or tumor necrosis factor-alpha (TNF-α)-stimulated (for 48 h) SW620 cells or unstimulated SW620 cells for 4 h, the cytotoxicity of SW620 cells to PHA-stimulated Jurkat cells at effector-to-target ratios of 10:1, 5:1, 2.5:1, and 1.25:1 was 74.6%, 40.8%, 32.4%, and 10.9% (F= 8.19, P<0.05); or 54.9%, 35.3%, 22.0%, and 10.3% (F= 11.12, P<0.05); or 14.9%, 10.5%, 6.9%, and 5.8% (F = 3.45, P<0.05). After PHA-stimulated Jurkat T lymphocytes were co-cultured with unstimulated SW620 cells for 8 h, the cytotoxicity of SW620 cells to PHA-stimulated Jurkat cells at effector-to-target ratios of 5:1, 2.5:1, and 1.25:1 from the experiment was 83.9%, 74.1%, and 28.5% (F=137.04, P<0.05) respectively. Non-radioactive cytotoxicity assay showed that the apoptotic rate of Jurkat cells remarkably increased with the increase of planting concentration of SW620 cells and co-culture time after the SW620 cells were co-cultured with the Jurkat T lymphocytes. The cytotoxicity was significantly enhanced by PMA+ionomycin or TNF-α. CONCLUSION: The FasL expressed in human colon cancer cells may be regulated by endogenous factors in the microenvironment of the host and facilitate the escape of tumor cells from the host immune system.

Role of immune escape in different digestive tumours

A counterbalance between immune cells and tumour cells is key to fighting tumours,and immune escape is an important mechanism for the survival of tumour cells in the body.Tumor cells and their cytokines impair the activity of T cells,NK cells,macrophages and other immune cells through various ways,and change the expression of their own surface antigens so as to avoid the clearance of the immune system.Changes in major histocompatibility complex molecules,high expression of programmed death-ligand 1,and the presence of immunosuppressive cells in the tumor microenvironment(TME)are main means by which tumors impair the function of immune cells.During the development of tumours of the digestive system,different mechanisms acting on tumour cells,the TME,and immune cells lead to immune escape and promote tumour progression.In this paper,the mechanisms of immune escape in tumour cells of the digestive system are reviewed to provide a theoretical basis for the immunotherapy of gastrointestinal tumours.

The interaction between end-metabolites and immune escape

Emerging data from metabolites-relating trails in cancers demonstrate that a common mechanism of resistance to many novel classes of immune therapeutics is the emergence of immune escape due to the reprogramming of cellular metabolism.Among them,current work about end-metabolites mostly focuses on the intersection between lactate acid,adenosine,reactive oxygen species(ROS),and tumour immune escape.In this article,we aim to review the evidence to date for the dynamic interplay between the three end-metabolites and tumour immune escape for potential approaches to overcome obstacles in the efficacy and durability of immune cancer therapies.We have organized known end-metabolites-associated immune escape mechanisms into three hallmarks:(1)decreased immunogenicity of cancer cells which constitutes defective antigen presentation and the attenuated expression of costimulatory molecules on tumour cells,(2)immunosuppressive microenvironment with aberrant angiogenesis inhibits the differentiation,maturation,and immune deviation of immune cells while drives the activation of immunosuppressive cells by immune-suppressive mediators(cytokines and other factors),(3)immune tolerance retained by inhibitory molecules and depletion of immune cells.

Advances in research on relationship between tumor immune escape and tumor microenvironment

Tumor immune escape is an important way for tumor cells to evade surveillance and attack by host immune system and promote tumor survival and proliferation.Immunotherapy for immune escape has made significant progress in recent years.Immunotherapy involves multiple factors and pathways,and is associated with changes in tumor cells themselves and tumor microenvironments,and the mechanisms are complex.At present,there are still many challenges in the clinical practice process.Starting from the tumor microenvironment,the article describes the role of various cells in the tumor microenvironment on tumor cell immune escape.

ROS-sensitive PD-L1 siRNA cationic selenide nanogels for self-inhibition of autophagy and prevention of immune escape

In the field of cancer therapy,inhibiting autophagy has emerged as a promising strategy.However,pharmacological disruption of autophagy can lead to the upregulation of programmed death-ligand 1(PD-L1),enabling tumor immune evasion.To address this issue,we developed innovative ROS-responsive cationic poly(ethylene imine)(PEI)nanogels using selenol chemistry-mediated multicomponent reaction(MCR)technology.This procedure involved simple mixing of low-molecular-weight PEI(LMW PEI),γ-selenobutylacetone(γ-SBL),and poly(ethylene glycol)methacrylate(PEGMA).Through high-throughput screening,we constructed a library of AxSeyOz nanogels and identified the optimized A1.8Se3O0.5/siPD-L1 nanogels,which exhibited a size of approximately 200 nm,excellent colloidal stability,and the most effective PD-L1 silencing efficacy.These nanogels demonstrated enhanced uptake by tumor cells,excellent oxidative degradation ability,and inhibited autophagy by alkalinizing lysosomes.The A1.8Se3O0.5/siPD-L1 nanogels significantly downregulated PD-L1 expression and increased the expression of major histocompatibility complex class I(MHC-I),resulting in robust proliferation of specific CD8+T cells and a decrease in MC38 tumor growth.As a result,the A1.8Se3O0.5/siPD-L1 nanogels inhibited tumor growth through self-inhibition of autophagy,upregulation of MHC-I,and downregulation of PD-L1.Designed with dynamic diselenide bonds,the A1.8Se3O0.5/siPD-L1 nanogels showed synergistic antitumor efficacy through self-inhibition of autophagy and prevention of immune escape.

Distinct immune escape and microenvironment between RG-like and pri-OPC-like glioma revealed by single-cell RNA-seq analysis

The association of neurogenesis and gliogenesis with glioma remains unclear.By conducting single-cell RNA-seq analyses on 26 gliomas,we reported their classification into primitive oligodendrocyte precursor cell(pri-OPC)-like and radial glia(RG)-like tumors and validated it in a public cohort and TCGA glioma.The RG-like tumors exhibited wild-type isocitrate dehydrogenase and tended to carry EGFR mutations,and the pri-OPC-like ones were prone to carrying TP53 mutations.Tumor subclones only in pri-OPC-like tumors showed substantially down-regulated MHC-I genes,suggesting their distinct immune evasion programs.Furthermore,the two subgroups appeared to extensively modulate glioma-infiltrating lymphocytes in distinct manners.Some specific genes not expressed in normal immune cells were found in glioma-infiltrating lymphocytes.For example,glial/glioma stem cell markers OLIG1/PTPRZ1 and B cell-specific receptors IGLC2/IGKC were expressed in pri-OPC-like and RG-like glioma-infiltrating lymphocytes,respectively.Their expression was positively correlated with those of immune checkpoint genes(e.g.,LGALS33)and poor survivals as validated by the increased expression of LGALS3 upon IGKC overexpression in Jurkat cells.This finding indicated a potential inhibitory role in tumor-infiltrating lymphocytes and could provide a new way of cancer immune evasion.

Aryl hydrocarbon receptor dynamics in esophageal squamous cell carcinoma:From immune modulation to therapeutic opportunities

Esophageal squamous cell carcinoma(ESCC)is a substantial global health burden.Immune escape mechanisms are important in ESCC progression,enabling cancer cells to escape the surveillance of the host immune system.One key player in this process is the Aryl Hydrocarbon Receptor(AhR),which influences multiple cellular processes,including proliferation,differentiation,metabolism,and immune regulation.Dysregulated AhR signaling participates in ESCC development by stimulating carcinogenesis,epithelial-mesenchymal transition,and immune escape.Targeting AhR signaling is a potential therapeutic approach for ESCC,with AhR ligands showing efficacy in preclinical studies.Additionally,modification of AhR ligands and combination therapies present new opportunities for therapeutic intervention.This review aims to address the knowledge gap related to the role of AhR signaling in ESCC pathogenesis and immune escape.

HLA class Ⅰ loss in colorectal cancer:implications for immune escape and immunotherapy

T cell-mediated immune therapies have emerged as a promising treatment modality in different malignancies including colorectal cancer(CRC).However,only a fraction of patients currently respond to treatment.Understanding the lack of responses and finding biomarkers with predictive value is of great importance.There is evidence that CRC is a heterogeneous disease and several classification systems have been proposed that are based on genomic instability,immune cell infiltration,stromal content and molecular subtypes of gene expression.Human leukocyte antigen class Ⅰ(HLA-Ⅰ)plays a pivotal role in presenting processed antigens to T lymphocytes,including tumour antigens.These molecules are frequently lost in different types of cancers,including CRC resulting in tumour immune escape from cytotoxic T lymphocytes during the natural history of cancer development.The aim of this review is to(i)summarize the prevalence and molecular mechanisms behind HLA-Ⅰ loss in CRC,(ii)discuss HLA-Ⅰ expression/loss in the context of the newly identified CRC molecular subtypes,(iii)analyze the HLA-Ⅰ phenotypes of CRC metastases disseminated via blood or the lymphatic system,(iv)discuss strategies to recover/circumvent HLA-I expression/loss and finally(v)review the role of HLA class Ⅱ(HLA-Ⅱ)in CRC prognosis.

SARS-CoV-2 variants,immune escape,and countermeasures

Coronavirus disease 2019(COVID-19)has become a global pandemic disease.SARS-CoV-2 variants have aroused great concern and are expected to continue spreading.Although many countries have promoted rollout vaccination,the immune barrier has not yet been fully established,indicating that populations remain susceptible to infection.In this review,we summarize the literature on variants of concern and focus on the changes in their transmissibility,pathogenicity,and resistance to the immunity constructed by current vaccines.Furthermore,we analyzed relationships between variants and breakthrough infections,as well as the paradigm of new variants in countries with high vaccination rates.Terminating transmission,continuing to strengthen variant surveillance,and combining nonpharmaceutical intervention measures and vaccines are necessary to control these variants.

Multi-target combinatory strategy to overcome tumor immune escape

Immune therapy has become the fourth approach after surgery,chemotherapy,and radiotherapy in cancer treatment.Many immune checkpoints were identified in the last decade since ipilimumab,which is the first immune checkpoint inhibitor to cytotoxic T-lymphocyte associated protein 4,had been approved by the US Food and Drug Administration(FDA)for the treatment of unresectable or metastatic melanoma in 2011.The use of several antibody drugs that target PD1/PD-L1 for various cancer treatments has been approved by the FDA.However,fewer people are benefitting from immune checkpoint inhibitor treatment in solid cancers.Approximately 80%of patients do not respond appropriately because of primary or acquired therapeutic resistance.Along with the characterization of more immune checkpoints,the combinatory treatment of multi-immune checkpoint inhibitors becomes a new option when monotherapy could not receive a good response.In this work,the author focuses on the combination therapy of multiple immune checkpoints(does not include targeted therapy of oncogenes or chemotherapy),introduces the current progression of multiple immune checkpoints and their related inhibitors,and discusses the advantages of combination therapy,as well as the risk of immune-related adverse events.

Study on blocking the leukemia immune escape after BMT by Fas-Fas ligand pathway

Background To investigate if bone marrow transplantation (BMT) with bone marrow mononuclear cells (BMMCs) transducted with murine soluble Fas gene (sFas) using adenovirus vector could block the immune escape of leukemia cells eliminate the residual leukemia cells and reduce their relapse.Methods The recombinant adenovirus vector with murine sFas, adsFas, and the control vector adEGFP were constructed using homologous recombination between two plasmids in Escherichia coli. BMT was carried out after the BMMCs were infected with Adenoviruses. The mice models of leukemia/lymphoma were constructed by inoculating female C57BL/6 mice (H-2 b) with 10 5 EL4 cells/mouse through caudal vein. Donors of bone marrow grafts were syngeneic male mice. BMMCs were infected with AdsFas or AdEGFP 24 hours before (Group D or E). The following three groups were simultaneously used: Group A, no BMMCs transplanted; Group B, transplanted with BMMCs not infected with adenoviruses; Group C, only transfusing EL4 cells, neither irradiation nor BMT. The hematopoietic reconstitution, generation of leukemia/lymphoma and the survival rate were observed in all groups after BMT. Results The adenovirus vectors were successfully constructed. The titre of virus after purification was up to 2.5×10 11 pfu/ml. Spleen indices examined 11 days after BMT were not obviously different among Group B, D and E (P>0.05), but indices in Group A were significantly lower than those in the latter three groups (P<0.01). Counts of leukocytes and platelets on +30 day showed mice were reconstituted satisfactorily in Group B and D, but very low in Group C and E. The Y-chromosomes existed 2 months after BMT and examination of bone marrow cytology showed that Group B and D were almost normal, but Group C and E had plenty of lymphoblast-like tumor cells. Tumors were obviously observed in the mice of Group C and E by histopathological examination, but the mice in Group B and D were normal. The survival rates were 0 (0/4) in Group A, 100% in Group B (6 /6) and D (16/16), 12.5% (2/16) in Group C and 6.25% (1/16) in Group E respectively. It is demonstrated that, in contrast with the control (Group EGFP), surviv al rate was significantly increased in the sFas Group (P<0.01). Conclusions The transfer of sFas gene by adenovirus changed the prognosis state of leukemia/lymphoma mice after auto-BMT. The transduction of sFas might block the effect of the immune escape of EL4 cells through FasL. These results could thus provide a new direction to find a way to treat the leukemia and its recurrence after BMT.

Preparation, identification, and clinical application ofanti-HBs monoclonal antibody that binds both wild-typeand immune escape mutant HBsAgs

Using a standard cellular fusion technique and indirect enzyme-linked immunosorbent assay(ELISA),a hybridoma cell line strain secreting anti-HBs monoclonal antibody(mAb)(defined G6 mAb)was obtained.The cells grew and secreted mAb stably.Antibody titers in the culture supernatant and ascites were 2.048�106 and 4.096�106,respectively.By applying the anti-HBs G6 mAb and horseradish peroxidase(HRP)-labeled goat anti-HBs antibody,we developed a sandwich ELISA(defined G6m ELISA)for detecting both wild-type and immune escape mutant HBsAgs(IEM HBsAg).The assay was performed to detect 17 species of genome recombinant expression HBsAg,including two wild-type species and 15 IEM HBsAg species,which varied in the“a”determinant,in a group of patients infected with hepatitis B virus(HBV).The patients previously had a lower ELISA detection signal[(absorbance of patients/absorbance of normal people(P/N):1.0–4.5)].The results demonstrated that the sensitivity of this assay to wild-type HBsAg was no less than 0.125μg/L;12 of 15 IEM HBsAg species(P/N≥2.5)were positive for G6 mAb.Of the positive IEM HBsAg species,two had a low absorbance value at 450 nm(A450),one had an intermediate A450 value and nine had a high A450 value,which was 7.55%(mean),59.4%and 92.1%–109.4%of the wild-type A450 value,respectively.The two species with low A450 value and the three negative species mutated at the bases 120–124 in thefirst loop of the HBV“a”determinant.Using the G6 ELISA and two commercial ELISA kits(A and B),177 patients were tested.The G6 ELISA had a significantly higher detection rate than either commercial ELISAs(19.21%vs 14.89%and 6.21%,respectively;P<0.01,P<0.05,respectively).

Exosomes as mediators of tumor immune escape and immunotherapy in hepatocellular carcinoma

Hepatocellular carcinoma(HCC),a typical inflammatory-related cancer,mainly occurs in patients with chronic liver diseases.Moreover,the liver is an immunologically privileged apparatus with multiple immunosuppressive cell groups.The long process of inflammation-mediated carcinogenesis turns the HCC tumor microenvironment(TME)into one with strong immunosuppression,facilitating the immune escape of HCC cells.Accumulated data have manifested that tumor-associated cell-derived exosomes carry diverse molecular cargoes(e.g.,proteins and nucleic acids)for mediating cell-to-cell communication and are implicated in TME remodeling to promote tumor-infiltrating immune cell reprogramming,ultimately creating a tumor-friendly microenvironment.Characterized by several intrinsic attributes,such as good stability(bilayer-like structure)and high biocompatibility(cell secretion),exosomes can be modified or engineered as nanocarriers to deliver tumor-specific antigens or antitumor drugs to targeted cells or organs,thus effectively triggering the HCC cell elimination by the immune system.This review aimed to highlight the pivotal role of exosomes in regulating immune escape mechanisms in HCC and recent advances in exosome-mediated immunotherapy for HCC.