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We investigate the impact of differential vaccine effectiveness, waning immunity, and natural cross-immunity on the capacity for vaccine-induced strain replacement in two-strain models of infectious disease spread. We focus specifically on the case where the first strain is more transmissible but the second strain is more immune-resistant. We consider two cases on vaccine-induced immunity: (1) a monovalent model where the second strain has immune escape with respect to vaccination; and (2) a bivalent model where the vaccine remains equally effective against both strains. Our analysis reaffirms the capacity for vaccine-induced strain replacement under a variety of circumstances; surprisingly, however, we find that which strain is preferred depends sensitively on the degree of differential vaccine effectiveness. In general, the monovalent model favors the more immune-resistant strain at high vaccination levels while the bivalent model favors the more transmissible strain at high vaccination levels. To further investigate this phenomenon, we parametrize the bifurcation space between the monovalent and bivalent model. [ABSTRACT FROM AUTHOR]

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer, originating from the malignant proliferation of squamous epithelial cells. However, its pathogenesis remains unclear. To further explore the mechanisms underlying cSCC, we analyzed the data from one single-cell RNA sequencing study and discovered a significant upregulation of tryptophan 2,3-dioxygenase (TDO2) in the cancer-associated fibroblasts (CAFs). Nonetheless, the specific expression and potential biological significance of TDO2 in cSCC have not yet been reported. In this study, we confirmed that TDO2 is highly expressed in CAFs of cSCC. Clinical correlation analysis indicated that high TDO2 expression was significantly associated with poor tumor differentiation. Furthermore, increased TDO2 expression in cSCC correlated with reduced CD8 + T cell infiltration, suggesting its role in modulating immune responses. TDO2 inhibitors significantly reduced the size and number of tumors in mice and effectively increased CD8 + T cell infiltration. RNA sequencing analysis revealed that TDO2 inhibitors modulate immune cell activity and downregulate the PI3K-Akt signaling pathway. In summary, our study demonstrates that TDO2 + CAFs induce immune evasion by inhibiting CD8 + T cell infiltration in cSCC. Inhibiting TDO2 could enhance antitumor immune responses, providing a promising strategy to improve treatment outcomes in cSCC. [ABSTRACT FROM AUTHOR]

The three-year COVID-19 pandemic 'has' caused a wide range of medical, social, political, and financial implications. Since the end of 2020, various mutations and variations in SARS-CoV-2 strains, along with the immune escape phenomenon, have emerged. There is an urgent need to identify a relatively stable target for the development of universal vaccines and drugs that can effectively combat both SARS-CoV-2 strains and their mutants. Currently, the main focus in treating SARS-CoV-2 lies in disrupting the virus's life cycle. The main protease (Mpro) is closely associated with virus replication and maturation and plays a crucial role in the early stages of infection. Consequently, it has become an important target for the development of SARS-CoV-2-specific drugs. This review summarizes the recent research progress on the novel coronavirus's main proteases, including the pivotal role of Mpro in the virus's life cycle, the structure and catalytic mechanism of Mpro, the self-maturation mechanism of Mpro, the role of Mpro in virus immune escape, the current methods of developing antiviral drugs targeting Mpro, and the key drugs that have successfully entered clinical trials. The aim is to provide researchers involved in the development of antiviral drugs targeting Mpro with systematic and comprehensive information. [ABSTRACT FROM AUTHOR]

Background: Intratumor-resident bacteria represent an integral component of the tumor microenvironment (TME). Microbial dysbiosis, which refers to an imbalance in the bacterial composition and bacterial metabolic activities, plays an important role in regulating breast cancer development and progression. However, the impact of specific intratumor-resident bacteria on tumor progression and their underlying mechanisms remain elusive. Methods: 16S rDNA gene sequencing was used to analyze the cancerous and paracancerous tissues from breast cancer patients. The mouse models of bearing 4T1 cell tumors were employed to assess the influence of bacterial colonization on tumor growth. Tissue infiltration of regulatory T (Treg) cells and CD8+ T cells was evaluated through immunohistochemistry and flow cytometric analysis. Comparative metabolite profiling in mice tumors was conducted using targeted metabolomics. Differential genes of tumor cells stimulated by bacteria were analyzed by transcriptomics and validated by qPCR assay. Results: We found that Sphingobacterium displayed high abundance in cancerous tissues. Intra-tumoral colonization of Sphingobacterium multivorum (S. multivorum) promoted tumor progression in 4T1 tumor-bearing mice. Moreover, S. multivorum diminished the therapeutic efficacy of αPD-1 mAb, which was associated with the increase of regulatory T cell (Treg) infiltration, and decrese of the CD8+ T cell infiltration. Targeted metabolomics revealed a conspicuous reduction of propionylcarnitine in tumors colonized by S. multivorum Furthermore, the combination of metabolite propionylcarnitine and S. multivorum shown to suppress tumor growth compared that in S. multivorum alone in vivo. Mechanistically, S. multivorum promoted the secretion of chemokines CCL20 and CXCL8 from tumor cells. CCL20 secreted into the TME facilitated the recruitment of Treg cells and reduced CD8+ T cell infiltration, thus promoting tumor immune escape. Conclusions: This study reveals S. multivorum suppresses immune surveillance within the TME, thereby promoting breast cancer progression. [ABSTRACT FROM AUTHOR]

This study explores the prognostic value of immune escape-related genes in acute myeloid leukemia (AML) patients. Using TARGET_AML and GSE37642 datasets, we identified CEP55, DNAJC13, and EMC2 as significant prognostic indicators, with high transcript abundance correlating with poor outcomes. Consensus clustering divided patients into two groups, with Cluster 1 showing worse prognosis. A prognostic signature based on these genes stratified patients into high- and low-risk groups, with the high-risk group experiencing worse outcomes. The risk score was an independent prognostic factor. Functional analysis revealed that high-risk genes could promote cell cycle progression. The selected genes were strongly associated with immune cells, particularly mast cells and CD8+ T cells. This study enriches the prognostic evaluation system for AML and suggests a new therapeutic direction. [ABSTRACT FROM AUTHOR]

The TIMO meeting XVIII 2024 covered both basic and translational tumor immunological topics, which were presented by national and international scientists and clinicians. [ABSTRACT FROM AUTHOR]

ABSTRACT: The most common STD that triggers cervical cancer is the human papillomavirus. More than 20 types of human papillomavirus (HPV) can induce uterine cervical cancer. Almost all women acquire genital HPV infection soon after their first intercourse, with most of them clearing the virus within 3 years. An immune response is necessary to clear. The first responders to HPV infection are the innate immune system elements composed of macrophages, keratinocytes, natural killer cells, and natural killer T-lymphocytic (NKT) cells. Cytotoxic T lymphocytes (CTLs) comprise the second line of defense and kill HPV16-infected cells expressing various peptides derived from their transforming early viral oncoproteins, mainly E2•E6. Even though HPV can manage to trick away our immune systems, first of all, it is important to emphasize that HPV replication does not kill the host cells. It does not replicate viral antigens or cause inflammation. The HPV16 E6 and E7 genes suppress host cell type 1 interferons (IFNs), which are detectable after infection. The patient may have immunological tolerance; hence, there are no costimulatory signals from inflammatory cytokines like IFNs during antigen recognition. Evidence shows that HlA class I generations have been inhibited by HPV16 E5, which could protect this tumor cell from CTL attack. HPV16 E7 is responsible for initiating immunotolerance and increasing regulatory T cells (Treg) to repress immunological regression. Evasion from immune system protection plays a critical role in the outcome of persistent HPV infection and the development of cervical cancer. Vaccination against HPV16 and 18 during adolescence is the most effective method for preventing cervical cancer in women, considering the immunological processes involved. [ABSTRACT FROM AUTHOR]

Background/Aim: The Kaplan-Meier curves for patients treated with immune checkpoint inhibitors (ICIs) display a small group of potentially-cured patients with longterm survival, creating a 'kangaroo-tail' shape of the survival curve. However, the mechanistic basis of this phenomenon and what occurs in patients whose cancer is resistant to ICIs remain unclear. The present study aimed to answer these questions. Materials and Methods: We analyzed mutations in mouse 4T1 mammary-gland-derived cancer cells expressing the hemagglutinin antigen (4T1-HA), which were grown in either wild-type mice or cytotoxic T-lymphocyte (CTL)-loaded immunocompromised mice (RAG-/- + ACT) under immune stress. These mutations were compared to those in 4T1-HA cells grown in RAG-/- mice without immune stress as a control. Results: The number of gene mutations, the tumor mutation burden (TMB) and microsatellite instability (MSI) scores were increased in the cancer cells under immune stress. The mutations in the antigen protein were such that the protein retained its immunogenicity and could still function as a neoantigen. Repeated immune recognition of additional neoantigens may lead to the kangaroo-tail survival phenomenon. The common genetic mutations of the analyzed 4T1-HA cells under immune stress included genes related to immune response. Analysis of alternative splicing of genes showed that are accumulated gene alterations under immune stress related to cancer-cell proliferation. Copy-number variation (CNV) analysis indicated that normal-antigen presentation and immune responses may be impaired under immune stress. Conclusion: Cancer cells, under immune stress, may acquire both immune escape capabilities and increased immunogenicity. This dual effect could lead to either resistance or response to ICIs, respectively. [ABSTRACT FROM AUTHOR]

Objective: Small cell lung cancer (SCLC) is commonly recognized as the most fatal lung cancer type. Despite substantial advances in immune checkpoint blockade therapies for treating solid cancers, their benefits are limited to a minority of patients with SCLC. In the present study, novel indicators for predicting the outcomes and molecular targets for SCLC treatment were elucidated. Methods: We conducted bioinformatics analysis to identify the key genes associated with tumor-infiltrating lymphocytes in SCLC. The functional role of the key gene identified in SCLC was determined both in vitro and in vivo. Results: A significant correlation was observed between patient survival and CD56dim natural killer (NK) cell proportion. Furthermore, we noted that the hub gene ubiquitin-specific protease 1 (USP1) is closely correlated with both CD56dim NK cells and overall survival in SCLC. Bioinformatics analysis revealed that USP1 is upregulated in SCLC. In addition, gene set enrichment analysis revealed that USP1 overexpression hinders NK cell-mediated immune responses. By co-cultivating NK-92 cells with SCLC cells, we demonstrated that NK cell cytotoxicity against SCLC could be improved either via USP1 knock-down or pharmacological inhibition. Furthermore, using a nude-mice xenograft tumor model, we noted that USP1 inhibition effectively suppressed tumor proliferation and increased the expression of NK cell-associated markers. Conclusions: Our study findings highlight the importance of NK cells in regulating SCLC. USP1 overexpression can inhibit NK cell-mediated immunity; therefore, USP1 may serve not only as a prognostic biomarker but also as a potential molecular target of SCLC therapy. [ABSTRACT FROM AUTHOR]

Background: Conventional treatments, including surgery, radiotherapy and chemotherapy, have many limitations in the prognosis of glioma patients. Atorvastatin (ATOR) has a significant inhibitory effect on glioma malignancy. Thus, ATOR may play a key role in the search for new drugs for the effective treatment of gliomas. Methods: U87 cells were treated with different doses of ATOR and transfected. Viability was assessed using MTT, proliferative ability was determined using the colony formation test, Bax and Bcl-2 were identified using Western blot, apoptosis was identified using flow cytometry, and U87 cell migration and invasion were detected using the Transwell assay. Glucose uptake, lactate secretion, and ATP production in U87 cell culture medium were quantified. The positive rates of IFN-γ and TNF-α in CD8T were measured through flow cytometry. Subcutaneous injection of U87 cells was carried out to construct an in vivo mouse model of gliom, followed by HE staining to assess the effects of ATOR and miR-125a-5p on tumor development. Results: ATOR blocked the viability, proliferation, migration, and invasion of U87 cells through the miR-125a-5p/TXLNA axis, and suppressed glycolysis and immune escape of glioma cells. Furthermore, overexpressing miR-125a-5p enhanced the anti-tumor effect of ATOR in vivo. Conclusion: ATOR blocks glioma progression by modulating the miR-125a-5p/TXLNA axis, further demonstrating that ATOR provides an effective therapeutic target for the treatment of glioma. [ABSTRACT FROM AUTHOR]

Background: Acute myeloid leukemia (AML) is a hematologic tumor with poor prognosis and significant clinical heterogeneity. By integrating transcriptomic data, single-cell RNA sequencing data and independently collected RNA sequencing data this study aims to identify key genes in AML and establish a prognostic assessment model to improve the accuracy of prognostic prediction. Materials and methods: We analyzed RNA-seq data from AML patients and combined it with single-cell RNA sequencing data to identify genes associated with AML prognosis. Key genes were screened by bioinformatics methods, and a prognostic assessment model was established based on these genes to validate their accuracy. Results: The study identified eight key genes significantly associated with AML prognosis: SPATS2L, SPINK2, AREG, CLEC11A, HGF, IRF8, ARHGAP5, and CD34. The prognostic model constructed on the basis of these genes effectively differentiated between high-risk and low-risk patients and revealed differences in immune function and metabolic pathways of AML cells. Conclusion: This study provides a new approach to AML prognostic assessment and reveals the role of key genes in AML. These genes may become new biomarkers and therapeutic targets that can help improve prognostic prediction and personalized treatment of AML. [ABSTRACT FROM AUTHOR]

ABSTRACT This study attempted to identify the relevant pathways involved in autophagy activation of pancreatic cancer and explore the mechanisms underlying immune evasion. Western blot (WB) was used to detect the expression of ITGB4, BNIP3, autophagy‐related proteins and MHC‐I. Co‐immunoprecipitation (Co‐IP) was used to verify the binding mode of ITGB4 and BNIP3. Flow cytometry was used to detect the expression of MHC‐I on the cell membrane. Transmission electron microscope (TEM) was used to observe cell autophagy. Confocal microscopy was used to observe the co‐localisation relationship between MHC‐I and autophagosomes in cells. ELISA was used to detect the level of lactate dehydrogenase and granzyme B in a tumour cell‐CD8+ T‐cell co‐culture system. Mouse syngeneic transplant tumour model and orthotopic tumour model were constructed and treated with PD‐1 monoclonal antibody to observe tumour growth. Quantitative reverse transcription polymerase chain reaction (qRT‐PCR) was used to detect the mRNA expression of ITGB4 and BNIP3 in tumour tissues. WB was used to determine the expression of autophagy‐related proteins. Flow cytometry was used to detect the expression of MHC‐I on cell membranes and the proportion of CD3+ and CD8+ cells. The results of Co‐IP experiments showed that ITGB4 could bind to BNIP3. It was observed under confocal microscopy that activating ITGB4/BNIP3 could promote the phagocytosis of MHC‐I by autophagosomes. Finally, the subcutaneous tumour transplantation and orthotopic tumour experiments in mice demonstrated the downregulation of ITGB4 significantly improved the therapeutic effect of PD‐1 antibodies on pancreatic cancer. In pancreatic cancer cells, autophagy is positively correlated with the ITGB4‐BNIP3 complex protein expression level. Autophagy diminishes the protein expression of MHC‐I, thereby promoting immune escape in pancreatic cancer cells. [ABSTRACT FROM AUTHOR]

Environmental pollution poses a significant risk to public health, as demonstrated by the bioaccumulation of aluminum (Al) in colorectal cancer (CRC). This study aimed to investigate the potential mutagenic effect of Al bioaccumulation in CRC samples, linking it to the alteration of key mediators of cancer progression, including immune response biomarkers. Aluminum levels in 20 CRC biopsy samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The results indicated that Al bioaccumulation occurred in 100% of the cases. A correlation between Al levels and tumor mutation burden was observed. Furthermore, RNA sequencing revealed a significant association between Al concentration and the expression of the immune checkpoint molecule CTLA-4. Although correlations with PD-1 and PD-L1 were not statistically significant, a trend was observed. Additionally, a correlation between Al levels and both the presence of myeloid cells and IFNγ expression was detected, linking Al exposure to inflammatory responses within the tumor microenvironment. These findings suggested that Al can play a role in CRC progression by promoting both genetic mutations and immune evasion. Given the ubiquitous presence of Al in industrial and consumer products, dietary sources, and environmental pollutants, these results underscored the need for stricter regulatory measures to control Al exposure. [ABSTRACT FROM AUTHOR]

Currently, risk stratification for pediatric Hodgkin lymphoma is based on clinical factors such as stage, bulk, and systemic symptoms. Novel minimally invasive biomarkers could enhance both prognosis and treatment strategies. Therefore, the plasma extracellular vesicles' microRNA profile was characterized by small RNA sequencing in 36 classical Hodgkin lymphoma cases and these findings were confirmed in an extended cohort of 86 patients by RT-qPCR. It was found that the levels of miR-122-5p at diagnosis were significantly higher (p-value: 0.0002) in patients who relapsed compared to patients in remission. The 5-year event-free survival of cases with high and low levels of miR-122-5p was 65 ± 7% and 93 ± 4%, respectively. MiR-122-5p levels were significantly associated with clinical events in both univariate (p-value: 0.0009) and multivariate (p-value: 0.0037) analysis (hazard ratio 5.8). Target prediction analysis suggests an involvement in the polarization of immune cells. The phenotypic characterization of peripheral blood mononuclear cells in 12 patients showed significantly increased levels of CD4+ T-cells in cases with high miR-122-5p levels as compared to low levels (p-value: 0.048). Moreover, CCL17 (TARC) and IL-6 plasma levels at diagnosis were significantly higher as compared to healthy donors (p-value: ≤0.0001). MiR-122-5p could complement current prognostic assays to identify patients at high risk of relapse. [ABSTRACT FROM AUTHOR]

Angiotensensin-converting enzyme-2 (ACE2) is a receptor for SARS-CoV-2, allowing the virus to enter cells. Although tumor patients infected by SARS-CoV-2 often have a worse outcome, the expression, function and clinical relevance of ACE2 in tumors has not yet been thoroughly analyzed. In this study, RNA sequencing (RNA-seq) data from tumors, adjacent tissues and whole blood samples of COVID-19 patients from genome databases and from tumor cell lines and endothelial cells infected with different SARS-CoV-2 variants or transfected with an ACE2 expression vector (ACE2high) or mock (ACE2low) were analyzed for the expression of ACE2 and immune response relevant molecules in silico or by qPCR, flow cytometry, Western blot and/or RNA-seq. The differential expression profiles in ACE2high vs. ACE2low cells correlated with available SARS-CoV-2 RNA-seq datasets. ACE2high cells demonstrated upregulated mRNA and/or protein levels of HLA class I, programmed death ligand 1 (PD-L1), components of the antigen processing machinery (APM) and the interferon (IFN) signaling pathway compared to ACE2low cells. Co-cultures of ACE2high cells with peripheral blood mononuclear cells increased immune cell migration and infiltration towards ACE2high cells, apoptosis of ACE2high cells, release of innate immunity-related cytokines and altered NK cell-mediated cytotoxicity. Thus, ACE2 expression was associated in different model systems and upon SARS-CoV-2 infection with an altered host immunogenicity, which might influence the efficacy of immune checkpoint inhibitors. These results provide novel insights into the (patho)physiological role of ACE2 on immune response-relevant mechanisms and suggest an alternative strategy to reduce COVID-19 severity in infected tumor patients targeting the ACE2-induced IFN-PD-L1 axis. [ABSTRACT FROM AUTHOR]

Acute myeloid leukemia (AML) is a clonal and invasive haematological malignancy originating from primitive myeloid cells of the haematopoietic system. Its incidence is the highest in leukemia, accounting for 58. 7% of all cases. The prognosis of relapsed and refractory AML is poor, with a 5-year survival rate of approximately 10%. Immunotherapy is considered an effective method for the clinical treatment of AML; however, immune escape during treatment affects the therapeutic effect. Therefore, solving this immune escape problem is necessary to improve clinical efficacy. Myeloid-derived suppressor cells(MDSCs) play an important role in the regulation of immune escape, which can damage anti-tumor therapy by mediating the immune escape of AML cells. This article reviews the activation mechanism and immune regulation mechanism of MDSCs, and the MDSC-targeting immunotherapy in AML. [ABSTRACT FROM AUTHOR]

The aberrant expression of CMTM4 protein has been implicated in tumorigenesis, development, and prognosis; however, its precise role and underlying mechanism in cervical cancer remain elusive. We aimed to investigate the expression level of CMTM4 in cervical cancer and its regulatory effect and molecular mechanism on MDSCs differentiation and immune cell function. Firstly, immunohistochemical (IHC) staining and Western blot analysis were employed to assess the expression level of CMTM4 in cervical cancer tumors and adjacent tissues. The results revealed a significant decrease in the expression level of CMTM4 in cervical cancer tissues compared to adjacent tissues (P<0.01). Differentiation of MDSCs in tumor samples from cervical cancer patients was assessed using flow cytometry, with CD45, CD11b, and Ly6G used as markers for M-MDSCs, and CD45, CD11b, and Ly6C used as markers for G-MDSCs. The percentage of M-MDSCs and G-MDSCs in the blood of cervical cancer patients was significantly higher than that observed in healthy volunteers (P<0.01). Furthermore, flow cytometry analysis demonstrated that high expression of CMTM4 increased the proportion of CD3+CD4+ T cells and CD3+CD8+ T cells in the blood of cervical cancer patients (P<0.01), while also promoting the activation ratio of Th1 and Th17 cells (P<0.05). Conversely, it inhibited the activation ratio of Th2 and Treg cells (P<0.05 or P<0.01). The percentage of CD8+PD-1+ T cells and CD8+PD-L1+ T cells within tumor tissues was determined by flow cytometry analysis which showed that high expression levels of CMTM4 suppressed their presence within tumor tissues (P <0.05). The in vitro studies demonstrated that overexpression of CMTM4 in HeLa cells significantly suppressed the generation of MDSCs (P <0.01), while overexpression of PD-1 in HeLa cells further enhanced the generation of MDSCs (P <0.05). Additionally, ELISA was employed to measure the levels of Th1, Th2, Th17, and Treg cytokines. It was observed that CMTM4 overexpression in HeLa cells reduced IL-10 secretion by T cells (P<0.01), but increased IFN-γ and TNF-α secretion (P<0.01), both of which were reversed by PD-1 overexpression (P<0.05 or P<0.01). In conclusion, low expression of CMTM4 in cervical cancer leads to abnormal differentiation of MDSCs and immune escape of tumors. CMTM4 influences the activation of tumor T cells by regulating the PD-1/PD-L1 pathway. Thus, CMTM4 may be a potential target for the treatment of cervical cancer. [ABSTRACT FROM AUTHOR]

Breast cancer (BC) is a leading cause of death worldwide, particularly also among African woman. In order to better stratify patients for the most effective (immuno-) therapy, an in depth characterization of the immune status of BC patients is required. In this study, a cohort of 65 Ethiopian patients with primary BC underwent immune profiling by multicolor flow cytometry on peripheral blood samples collected prior to surgery and to any other therapy. Comparison with peripheral blood samples from healthy donors highlighted a general activation of the immune system, accompanied by the presence of exhausted CD4+ T cells and senescent CD8+ T cells with an inverted CD4/CD8 ratio in approximately 50% of BC cases. Enhanced frequencies of γδ T cells, myeloid-derived suppressor cells and regulatory T cells were also found. Correlation with clinical parameters demonstrated a progressive reduction in T cell frequencies with increasing histopathological grading of the tumor. Differences in CD8+ T cells and B cells were also noted among luminal and non-luminal BC subtypes. In conclusion, Ethiopian BC patients showed several alterations in the composition and activation status of the blood immune cell repertoire, which were phenotypically associated with immune suppression. The role of these immunological changes in the clinical outcome of patients with BC will have to be determined in follow-up studies and confirmed in additional patients' cohorts. [ABSTRACT FROM AUTHOR]

Genetic aberrations and immune escape are fundamental in MDS and CMML initiation and progression to sAML. Therefore, quantitative and spatial immune cell organization, expression of immune checkpoints (ICP), classical human leukocyte antigen class I (HLA-I) and the non-classical HLA-Ib antigens were analyzed in 274 neoplastic and 50 non-neoplastic bone marrow (BM) biopsies using conventional and multiplex immunohistochemistry and correlated to publicly available dataset. Higher numbers of tissue infiltrating lymphocytes (TILs) were found in MDS/CMML (8.8%) compared to sAML (7.5%) and non-neoplastic BM (5.3%). Higher T cell abundance, including the CD8+ T cell subset, inversely correlated with the number of pathogenic mutations and was associated with blast BM counts, ICP expression, spatial T cell distribution and improved patients' survival in MDS and CMML. In MDS/CMML, higher PD-1/PD-L1/PD-L2 and HLA-I, but lower HLA-G expression correlated with a significantly better patients' outcome. Moreover, a closer spatial proximity of T cell subpopulations and their proximity to myeloid blasts showed a stronger prognostic impact when compared to TIL numbers. In sAML – the continuum of MDS and CMML – the number of TILs had no impact on prognosis, but higher CD28 and HLA-I expression correlated with a better outcome of sAML patients. This study underlines the independent prognostic value of the tumor microenvironment in MDS/CMML progression to sAML, which shows the most pronounced immune escape. Moreover, new prognostic markers, like HLA-G expression and spatial T cell distribution, were described for the first time, which might also serve as therapeutic targets. [ABSTRACT FROM AUTHOR]

Cancer immunotherapies have greatly changed the prospects for the therapy of many malignancies, including colon cancer. Macrophages as the effectors of cancer immunotherapy provide considerable promise for cancer treatment. Prolyl 4-hydroxylase subunit alpha 3 (P4HA3) plays a cancer-promoting role in a variety of cancers, including colon cancer. In the present work, we provided evidence for the first time that P4HA3 promoted colon cancer cell escape from macrophage phagocytosis, and preliminarily explored its possible molecular mechanism. Immunohistochemistry was used to detect the expression of P4HA3 in tissues. Bioinformatics methods were used to analyze the tumor public databases (including TCGA database and GEO database). Macrophage phagocytosis assay and flow cytometric analysis were used to detect the phagocytic capacity of macrophages. Western blot and qRT-PCR were used to detect the expression of related markers (such as P4HA3, CD47, CD24, IL-34, and M-CSF). First, we found that P4HA3 was significantly and highly expressed in both colon cancer tissues and cells, and that P4HA3 had a positive correlation with lymph node metastasis, Dukes stage and also strongly correlated with poorer survival. Subsequently, we found that P4HA3 was strongly associated with the macrophage infiltration level in colon cancer. Immediately we also found that decreasing P4HA3 expression promoted macrophage phagocytosis in colon cancer cells, whereas P4HA3 overexpression produced the opposite effect. Finally, we demonstrated that P4HA3 promoted the expression of cluster of differentiation 47 (CD47) in colon cancer cells. Moreover, P4HA3 caused colon cancer cells to secrete Interleukin 34 (IL34) and Macrophage colony stimulating factor (M-CSF), which further induced macrophages to differentiate to M2 type and thereby contributed to the progression of colon cancer. We have demonstrated that P4HA3-driven CD47 overexpression may act as an escape mechanism, causing colon cancer cells to evade phagocytosis from macrophages. [ABSTRACT FROM AUTHOR]

Abstract Background Triple-negative breast cancer (TNBC) is characterized by high invasiveness and metastasis potential. Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) is strongly associated with breast cancer progression, although the underlying mechanisms are largely unknown. Methods The gene expression profiles of TNBC samples were downloaded from the TCGA database, and ubiquitination enzymes related to immune regulation were screened. UCHL1 expression in the TNBC tissues and in adipose-derived mesenchymal stem cells (ADSCs) stimulated in vitro with pro-inflammatory cytokines were analyzed. Exosomes were isolated from these stimulated ADSCs and transfected with scrambled (si-NC) or UCHL1-specific (si-UCHL1) siRNA constructs. TNBC cells were treated with the ADSCs-derived exosomes (ADSCs-Exos) and then co-cultured with macrophages or T cells. Finally, the tumorigenic potential of the ADSCs-Exos was evaluated by injecting the exosomes into mice bearing TNBC xenografts. Results UCHL1 was highly expressed in TNBC tissues and the stimulated ADSCs. The exosomes derived from stimulated ADSCs increased the viability and migration capacity of TNBC cells in vitro, and significantly increased Ki-67 expression through UCHL1. Furthermore, ADSCs-Exos induced M2 polarization of THP-1 monocytes by upregulating CD206 and Arg-1, and downregulating TNF-α and iNOS, and also decreased the proportion of CD3+CD8+ T cells. Mechanistically, UCHL1 regulated the STAT3 and PD-L1 signaling pathways through HDAC6. Exosomes derived from the control and cytokine-stimulated ADSCs also promoted tumor growth in vivo, and increased the expression of UCHL1, CD206, HDAC6, STAT3, and PD-L1. However, UCHL1 knockdown reversed the pro-tumorigenic effects of the ADSCs-derived exosomes in vivo and in vitro. Conclusion Pro-inflammatory factors (IFN-γ + TNF-α) stimulating ADSCs-Exos enhance immune evasion in triple-negative breast cancer by regulating the HDAC6/STAT3/PD-L1 pathway via UCHL1 transporter. Thus, UCHL1 inhibition may enhance the response of TNBC to immunotherapy. Graphical Abstract

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.

Abstract Pseudorabies virus (PRV) can establish lifelong latent infection in peripheral nervous ganglion, and persistent infections in peripheral blood lymphocytes. Establishing an infection in the lymphocytes does not only enable the PRV to escape host immune surveillance but pass through the placental barrier, leading to fetal death and abortion. Due to the pathogenicity of the PRV, it poses a huge challenge in its prevention and control. The PRV escapes host immunity through downregulation of swine leukocyte antigen class I (SLA I) molecules on infected cells. However, data on the molecular mechanisms of the SLA I suppression remains scant. Here, in order to verify the effect of candidate proteins PRV pUL44 and pUS6 on PRV immune escape related molecules SLA I and peptide loading complex (PLC), we detected the expression of SLA I and PLC components after expressing PRV pUL44 and pUS6. The effects of pUS6 and pUL44 on SLA I and PLC were analyzed by qRT-PCR and Western blot at mRNA and protein level, respectively. Cells expressing pUS6 or pUL44 genes showed a significantly suppressed expression of surface and total SLA I molecules. In addition, unlike UL44, the US6 gene was shown to downregulate the transporter associated with antigen processing 1 (TAP1), TAP2 and Tapasin molecules. The results show that PRV pUS6 may participate in virus immune escape by directly regulating the SLA I, TAP dimer and Tapasin molecules, thus blocking the transportation of TAP-bound peptides to the ER to bind SLA I molecules. We provide a theoretical basis on the mechanism of TAP mediated immune escape by the PRV.

Recent studies have identified that metabolic reprogramming in lung adenocarcinoma cells, particularly lactate metabolism disorders, plays a crucial role in tumor development and immune therapy response. The accumulation of lactic acid not only provides energy support for the proliferation of tumor cells but also affects the function of immune cells by changing the tumor microenvironment, thereby promoting immune escape. Immunotherapy, especially the application of immune checkpoint inhibitors, has become an important strategy for treating lung adenocarcinoma. However, lactate metabolism disorders might affect the efficacy of immunotherapy, leading to resistance in some patients. Therefore, a thorough understanding of the mechanisms of lactic acid metabolism in lung adenocarcinoma and its impact on the response to immunotherapy is essential for developing new therapeutic strategies and improving the efficacy of immunotherapy. This review summarizes the role of lactate metabolism disorders in the development and immunotherapy of lung adenocarcinoma, discusses the potential role of lactic acid metabolism-related genes and pathways in lung adenocarcinoma, and explores the progress in therapeutic strategies targeting lactic acid metabolism regulation. This work aims to provide new insights for the treatment of lung adenocarcinoma.

Abstract Immune cell therapy based on chimeric antigen receptor (CAR) technology platform has been greatly developed. The types of CAR immune cell therapy have expanded from T cells to innate immune cells such as NK cells and macrophages, and the diseases treated have expanded from hematological malignancies to non-tumor fields such as infectious diseases and autoimmune diseases. Among them, CAR-T and CAR-NK therapy have observed examples of rapid remission in approved clinical trials, but the efficacy is unstable and plagued by tumor resistance. Trogocytosis is a special phenomenon of intercellular molecular transfer that is common in the immune system and is achieved by recipient cells through acquisition and internalization of donor cell-derived molecules and mediates immune effects. Recently, a novel short-term drug resistance mechanism based on trogocytosis has been proposed, and the bidirectional molecular exchange between CAR immune cells and tumor cells triggered by trogocytosis partially explains the long-term relapse phenomenon after treatment with CAR immune cells. In this review, we summarize the research progress of trogocytosis in CAR immunotherapy, discuss the influencing factors of trogocytosis and its direct and indirect interference with CAR immune cells and emphasize that the interference of trogocytosis can further release the potential of CAR immune cell therapy.

Abstract Background Cluster of differentiation 24 (CD24) is a highly glycosylated glycosylphosphatidylinositol (GPI)-anchored surface protein, expressed in various tumor cells, as a "don't eat me" signaling molecule in tumor immune. This study aimed to investigate the potential features of CD24 in pan-cancer. Methods The correlations between 22 immune cells and CD24 expression were using TIMER analysis. R package “ESTIMATE” was used to predict the proportion of immune and stromal cells in pan-cancer. Spearman's correlation analysis was performed to evaluate the relationships between CD24 expression and immune checkpoints, chemokines, mismatch repair, tumor mutation burden and microsatellite instability, and qPCR and western blot were conducted to assess CD24 expression levels in liver hepatocellular carcinoma (LIHC). In addition, loss of function was performed for the biological evaluation of CD24 in LIHC. Results CD24 expression was positively correlated with myeloid cells, including neutrophils and myeloid-derived suppressor cells, in various tumors, such as BLCA, HNSC-HPV, HNSC, KICH, KIRC, KIRP, TGCT, THCA, THYM, and UCEC. In contrast, anti-tumor NK cells and NKT cells showed a negative association with CD24 expression in BRCA-Her2, ESCA, HNSC-HPV, KIRC, THCA, and THYM. The top three tumors with the highest correlation between CD24 and ImmuneScore were TGCT, THCA, and SKCM. Functional enrichment analysis revealed CD24 expression was negatively associated with various immune-related pathways. Immune checkpoints and chemokines also exhibited inverse correlations with CD24 in CESC, CHOL, COAD, ESCA, READ, TGCT, and THCA. Additionally, CD24 was overexpressed in most tumors, with high CD24 expression in BRCA, LIHC, and CESC correlating with poor prognosis. The TIDE database indicated tumors with high CD24 expression, particularly melanoma, were less responsive to PD1/PD-L1 immunotherapy. Finally, CD24 knockdown resulted in impaired proliferation and cell cycle progression in LIHC. Conclusion CD24 participates in regulation of immune infiltration, influences patient prognosis and serves as a potential tumor marker.

Abstract Hematological malignancies (HM) are common malignant tumors with high morbidity and mortality rates, and are malignant diseases that seriously affect human health, with chemotherapy prone to recurrence and toxic side effects. Therefore, the development of precise, effective, and safe targeted therapeutic agents has become a hotspot in the current research of antitumor technology. More and more studies have shown that the interaction of C–C chemokine ligand 17 (CCL17) and C–C chemokine ligand 22 (CCL22) with the receptor C–C chemokine receptor type 4 (CCR4) promotes the immune escape of tumors and is closely related to the occurrence, development, and prognosis of hematological tumors. In this regard, we present a review on the expression and role of the CCL17/CCL22-CCR4 axis in HM, including lymphoma, leukemia, and multiple myeloma, with the aim of providing latest ideas and directions for the diagnosis and treatment of HM. In addition, we discuss the role and related mechanisms of HM therapeutic agents targeting the CCL17/CCL22-CCR4 axis and the potential of humanized anti-CCR4 antibodies for the treatment of HM.

Abstract Prostate cancer (PCa) is one of the most common male genitourinary system malignancies. Despite the significant benefits of anti-PD-L1 immune checkpoint inhibitor therapy in other cancers, the reasons for its poor therapeutic efficacy in prostate cancer (PCa) remain unclear.NDR1 plays an important role in innate immunity, but its role in tumor immunity and immunotherapy has not been investigated. The role of NDR1 in the immune microenvironment of PCa and the related mechanisms are unknown. Here, we found a positive correlation between NDR1 and PD-L1 expression in PCa. NDR1 significantly inhibits CD8 + T cell infiltration and function, thereby promoting immune escape in prostate cancer.More importantly, NDR1 inhibition significantly enhanced CD8 + T cell activation, which enhanced the therapeutic effect of anti-PD-L1. Mechanistic studies revealed that NDR1 inhibits ubiquitination-mediated PD-L1 degradation via the deubiquitinase USP10, upregulates PD-L1, and promotes PCa immune escape. Thus, our study suggests a unique PD-L1 regulatory mechanism underlying PCa immunotherapy failure. The significance of NDR1 in PCa immune escape and its mechanism of action were clarified, and combined NDR1/PD-L1 inhibition was suggested as an approach to boost PCa immunotherapy effectiveness. Graphical Abstract