Cooperation between Constitutive and Inducible Chemokines Enables T Cell Engraftment and Immune Attack in Solid Tumors

Altered epitopes enhance macrophage-mediated anti-tumour immunity to low-immunogenic tumour mutations

Personalized neoantigen therapy has shown long-term and stable efficacy in specific patient populations. However, not all patients have sufficient levels of neoantigens for treatment. Although somatic mutations are commonly found in tumours, a significant portion of these mutations do not trigger an immune response. Patients with low mutation burdens continue to exhibit unresponsiveness to this treatment. We propose a design paradigm for neoantigen vaccines by utilizing the highly immunogenic unnatural amino acid p-nitrophenylalanine (pNO2Phe) for sequence alteration of somatic mutations that failed to generate neoepitopes. This enhances the immunogenicity of the mutations and transforms it into a suitable candidate for immunotherapy. The nitrated altered epitope vaccines designed according to this paradigm is capable of activating circulating CD8+ T cells and inducing immune cross-reactivity against autologous mutated epitopes in different MHC backgrounds (H-2Kb, H-2Kd, and human HLA-A02:01), leading to the elimination of tumour cells carrying the mutation. After immunization with the altered epitopes, tumour growth was significantly inhibited. It is noteworthy that nitrated epitopes induce tumour-infiltrating macrophages to differentiate into the M1 phenotype, surprisingly enhancing the MHC II molecule presenting pathway of macrophages. Nitrated epitope-treated macrophages have the potential to cross-activate CD4+ and CD8+ T cells, which may explain why pNO2Phe can enhance the immunogenicity of epitopes. Meanwhile, the immunosuppressive microenvironment of the tumour is altered due to the activation of macrophages. The nitrated neoantigen vaccine strategy enables the design of vaccines targeting non-immunogenic tumour mutations, expanding the pool of potential peptides for personalized and shared novel antigen therapy. This approach provides treatment opportunities for patients previously ineligible for new antigen vaccine therapy.

Mechanisms by which obesity regulates inflammation and anti-tumor immunity in cancer

Obesity is associated with an increased risk for 13 different cancers. The increased risk for cancer in obesity is mediated by obesity-associated changes in the immune system. Obesity has distinct effects on different types of inflammation that are tied to tumorigenesis. For example, obesity promotes chronic inflammation in adipose tissue that is tumor-promoting in peripheral tissues. Conversely, obesity inhibits acute inflammation that rejects tumors. Obesity therefore promotes cancer by differentially regulating chronic versus acute inflammation. Given that obesity is chronic, the initial inflammation in adipose tissue will lead to systemic inflammation that could induce compensatory anti-inflammatory reactions in peripheral tissues to suppress chronic inflammation. The overall effect of obesity in peripheral tissues is therefore dependent on the duration and severity of obesity. Adipose tissue is a complex tissue that is composed of many cell types in addition to adipocytes. Further, adipose tissue cellularity is different at different anatomical sites throughout the body. Consequently, the sensitivity of adipose tissue to obesity is dependent on the anatomical location of the adipose depot. For example, obesity induces more inflammation in visceral than subcutaneous adipose tissue. Based on these studies, the mechanisms by which obesity promotes tumorigenesis are multifactorial and immune cell type-specific. The objective of our paper is to discuss the cellular mechanisms by which obesity promotes tumorigenesis by regulating distinct types of inflammation in adipose tissue and the tumor microenvironment.

Immunotherapy for ovarian cancer: towards a tailored immunophenotype-based approach

Despite documented evidence that ovarian cancer cells express immune-checkpoint molecules, such as PD-1 and PD-L1, and of a positive correlation between the presence of tumour-infiltrating lymphocytes and favourable overall survival outcomes in patients with this tumour type, the results of trials testing immune-checkpoint inhibitors (ICIs) in these patients thus far have been disappointing. The lack of response to ICIs can be attributed to tumour heterogeneity as well as inherent or acquired resistance associated with the tumour microenvironment (TME). Understanding tumour immunobiology, discovering biomarkers for patient selection and establishing optimal treatment combinations remains the hope but also a key challenge for the future application of immunotherapy in ovarian cancer. In this Review, we summarize results from trials testing ICIs in patients with ovarian cancer. We propose the implementation of a systematic CD8+ T cell-based immunophenotypic classification of this malignancy, followed by discussions of the preclinical data providing the basis to treat such immunophenotypes with combination immunotherapies. We posit that the integration of an accurate TME immunophenotype characterization with genetic data can enable the design of tailored therapeutic approaches and improve patient recruitment in clinical trials. Lastly, we propose a roadmap incorporating tissue-based profiling to guide future trials testing adoptive cell therapy approaches and assess novel immunotherapy combinations while promoting collaborative research.

Cold and hot tumors: from molecular mechanisms to targeted therapy

Immunotherapy has made significant strides in cancer treatment, particularly through immune checkpoint blockade (ICB), which has shown notable clinical benefits across various tumor types. Despite the transformative impact of ICB treatment in cancer therapy, only a minority of patients exhibit a positive response to it. In patients with solid tumors, those who respond well to ICB treatment typically demonstrate an active immune profile referred to as the "hot" (immune-inflamed) phenotype. On the other hand, non-responsive patients may exhibit a distinct "cold" (immune-desert) phenotype, differing from the features of "hot" tumors. Additionally, there is a more nuanced "excluded" immune phenotype, positioned between the "cold" and "hot" categories, known as the immune "excluded" type. Effective differentiation between "cold" and "hot" tumors, and understanding tumor intrinsic factors, immune characteristics, TME, and external factors are critical for predicting tumor response and treatment results. It is widely accepted that ICB therapy exerts a more profound effect on "hot" tumors, with limited efficacy against "cold" or "altered" tumors, necessitating combinations with other therapeutic modalities to enhance immune cell infiltration into tumor tissue and convert "cold" or "altered" tumors into "hot" ones. Therefore, aligning with the traits of "cold" and "hot" tumors, this review systematically delineates the respective immune characteristics, influencing factors, and extensively discusses varied treatment approaches and drug targets based on "cold" and "hot" tumors to assess clinical efficacy.

SET facilitates immune escape of microsatellite stability colorectal cancer by inhibiting c-Myc degradation

Microsatellite stability (MSS) colorectal cancer (CRC) exhibits a low mutation load and poor immunogenicity, contributing to immune escape of tumor cells and less benefit from immune checkpoint blockade (ICB) treatment. The mechanisms underlying immunotherapeutic resistance in MSS CRC remain to be elucidated. Here, we identified that nuclear proto-oncogene SET is significantly higher expressed in MSS CRC compared to microsatellite instability (MSI) CRC and facilitates immune escape of MSS CRC. Mechanistically, SET represses the expression of C-C motif chemokine ligand 5 (CCL5) and upregulates mismatch repair (MMR) proteins expression in a c-Myc-dependent manner, which inhibits infiltration and migration of CD8+ T cells to tumor tissues and results in low immunogenicity in MSS CRC. In addition, we found that SET impairs ubiquitination and proteasomal degradation of c-Myc by disrupting the interaction between E3 ligase FBXW7 and c-Myc. Moreover, SET inhibition enhances the response to immunotherapy in MSS CRC in vivo. Overall, this study reveals the critical roles and posttranslational regulatory mechanism of SET in immune escape and highlights the SET/c-Myc axis as a potential target for immunotherapy of MSS CRC that have implications for targeting a unique aspect of this disease.

Transcriptional repression by HDAC3 mediates T cell exclusion from Kras mutant lung tumors

Histone Deacetylase 3 (HDAC3) function in vivo is nuanced and directed in a tissue-specific fashion. The importance of HDAC3 in Kras mutant lung tumors has recently been identified, but HDAC3 function in this context remains to be fully elucidated. Here, we identified HDAC3 as a lung tumor cell-intrinsic transcriptional regulator of the tumor immune microenvironment. In Kras mutant lung cancer cells, we found that HDAC3 is a direct transcriptional repressor of a cassette of secreted chemokines, including Cxcl10. Genetic and pharmacological inhibition of HDAC3 robustly up-regulated this gene set in human and mouse Kras, LKB1 (KL) and Kras, p53 (KP) mutant lung cancer cells through an NF-κB/p65-dependent mechanism. Using genetically engineered mouse models, we found that HDAC3 inactivation in vivo induced expression of this gene set selectively in lung tumors and resulted in enhanced T cell recruitment at least in part via Cxcl10. Furthermore, we found that inhibition of HDAC3 in the presence of Kras pathway inhibitors dissociated Cxcl10 expression from that of immunosuppressive chemokines and that combination treatment of entinostat with trametinib enhanced T cell recruitment into lung tumors in vivo. Finally, we showed that T cells contribute to in vivo tumor growth control in the presence of entinostat and trametinib combination treatment. Together, our findings reveal that HDAC3 is a druggable endogenous repressor of T cell recruitment into Kras mutant lung tumors.

CD8+ T cells infiltrating into tumors were controlled by immune status of pulmonary lymph nodes and correlated with non-small cell lung cancer (NSCLC) patients' prognosis treated with chemoimmunotherapy

PURPOSE

Neoadjuvant chemoimmunotherapy has the potential to reduce tumor burden, improve the pathological complete response (pCR) rate, and significantly prolong patients' disease-free survival (DFS). However, the treatment's effectiveness varies among NSCLC patients. The immunological mechanisms contributing to tumor regression still require further exploration and elucidation.

METHODS

The immune status of patients' local tumor microenvironment (TME) before and after neoadjuvant chemoimmunotherapy, their paired pulmonary lymph nodes (11th LNs) after therapy, including infiltrating immune cell densities and their correlations, were analyzed using multiplex immunofluorescence.

RESULTS

Fifty-six NSCLC patients undergoing neoadjuvant chemoimmunotherapy were enrolled and subsequently underwent surgical resection and pathological evaluation. Among these, 19 patients achieved a pCR, 6 patients exhibited a major pathological response (MPR), and 31 patients did not achieve MPR. There were no significant difference in the densities of CD8+ T cell, Treg and Dendritic cell (DC) in patients' TME before neoadjuvant therapy (n = 26, P = 0.091, P = 0.753, P = 0.905, respectively), but after treament, these immune cells' dynamics were significantly different between different response group. CD8+ T cell densities were increased in pCR gourp (P = 0.006), but not in non-pCR group (P = 0.389); the densities of Treg were increased in non-pCR gourp (P = 0.0004), but DC were significantly decreased in non-pCR gourp (P = 0.005). After surgery, the TME were also significantly different: patients achieving pCR typically demonstrated high densities of CD8+ T cell, DC and low densities of Tregs (P = 0.0001, P < 0.0001 and P = 0.0004). The immune status of 11th LNs also exhibited significant differences. DC densities were much higher in pCR patients, whereas Treg in the pCR group were significantly lower than those in the non-pCR group (P = 0.0008 and P = 0.003). Furthermore, the densities of DC in the TME showed a moderate positive correlation with DC in 11th LNs (P = 0.0002), while the densities of Tregs in the TME exhibited a moderate negative correlation with DC densities in 11th LNs (P = 0.03). Patients who had high densities of CD8+ T cell in the resection tissues and DC in the LNs, experienced longer DFS (P = 0.048 and P = 0.024).

CONCLUSION

Immune cells in both pulmonary LNs and the TME collectively influence the remodeling of the NSCLC patient's TME, thus impacting treatment response and prognosis.

Nuclear translocation of plasma membrane protein ADCY7 potentiates T cell-mediated antitumour immunity in HCC

BACKGROUND

The potency of T cell-mediated responses is a determinant of immunotherapy effectiveness in treating malignancies; however, the clinical efficacy of T-cell therapies has been limited in hepatocellular carcinoma (HCC) owing to the extensive immunosuppressive microenvironment.

OBJECTIVE

Here, we aimed to investigate the key genes contributing to immune escape in HCC and raise a new therapeutic strategy for remoulding the HCC microenvironment.

DESIGN

The genome-wide in vivo clustered regularly interspaced short palindromic repeats (CRISPR) screen library was conducted to identify the key genes associated with immune tolerance. Single-cell RNA-seq (scRNA-seq), flow cytometry, HCC mouse models, chromatin immunoprecipitation and coimmunoprecipitation were used to explore the function and mechanism of adenylate cyclase 7 (ADCY7) in HCC immune surveillance.

RESULTS

Here, a genome-wide in vivo CRISPR screen identified a novel immune modulator-ADCY7. The transmembrane protein ADCY7 undergoes subcellular translocation via caveolae-mediated endocytosis and then translocates to the nucleus with the help of leucine-rich repeat-containing protein 59 (LRRC59) and karyopherin subunit beta 1 (KPNB1). In the nucleus, it functions as a transcription cofactor of CCAAT/enhancer binding protein alpha (CEBPA) to induce CCL5 transcription, thereby increasing CD8+ T cell infiltration to restrain HCC progression. Furthermore, ADCY7 can be secreted as exosomes and enter neighbouring tumour cells to promote CCL5 induction. Exosomes with high ADCY7 levels promote intratumoural infiltration of CD8+ T cells and suppress HCC tumour growth.

CONCLUSION

We delineate the unconventional function and subcellular location of ADCY7, highlighting its pivotal role in T cell-mediated immunity in HCC and its potential as a promising treatment target.

CD74 is a potential biomarker predicting the response to immune checkpoint blockade

BACKGROUND

Immune checkpoint blockade (ICB) has been improving the patient outcome in multiple cancer types. However, not all patients respond to ICB. Biomarkers are needed for selecting appropriate patients to receive ICB. CD74 is an important chaperone that regulates antigen presentation for immune response. However, the relationship between CD74 expression and ICB response remains elusive.

METHODS

The unified normalized pan-cancer dataset was downloaded from the UCSC database. Wilcoxon Rank Sum Rank Tests were used to analyze the expression differences between normal and tumor samples in each tumor type. Then, the prognostic value of CD74 was determined using univariable Cox proportional hazards regression analysis. The STRING database was utilized to construct the protein-protein interaction (PPI) network of CD74 and the signal pathways were analyzed as well. The correlation of CD74 expression with immune cells and immune regulating genes was investigated in the TIMER database. The TIDE framework was utilized to evaluate the relationship between CD74 expression and the response to immunotherapy. Moreover, the localization of CD74 in the tumor immune microenvironment was verified using multiplex immunohistochemistry. Clinically annotated samples from 38 patients with esophageal cancer treated with neoadjuvant chemotherapy combined with ICB were analyzed for CD74 expression using immunohistochemistry.

RESULTS

In this study, we investigated the prognostic and predictive value of CD74 in different types of cancer. Compared with normal tissue, the expression of CD74 was higher in tumor tissue in various cancers. High expression of CD74 was associated with improved patient prognosis in the majority of cancers. CD74 and its interacting proteins were mainly enriched in the immune-related pathways. The expression of CD74 was significantly positively correlated with B cells, CD4 T-cells, CD8 T-cells, neutrophils, macrophages and dendritic cells. TIDE analysis showed that tumors with high CD74 expression may have better responses to immunotherapy and improved patient survival. In patients with esophageal cancer who had received ICB, higher intratumoral CD74 expression was associated with improved response to ICB.

CONCLUSIONS

The findings of this study suggest that the high expression of CD74 may be a potential predictive biomarker of response to ICB.

Immunologically effective biomaterials enhance immunotherapy of prostate cancer

Prostate cancer (PCa) is one of the most common malignant neoplasms affecting the male population. The onset of the disease is insidious and often associated with severe consequences, such as bone metastases at the time of initial diagnosis. Once it advances to metastatic castration-resistant PCa (mCRPC), conventional treatment methods become ineffective. As research on the mechanism of tumor therapy advances, immunotherapy has been evolving rapidly. However, PCa is a solid tumor type that primarily faces the challenges of poor immunogenicity and inhibitory tumor microenvironment (TME). Fortunately, the extensive use of biomaterials has led to continuous advancement in PCa immunotherapy. These innovative materials aim to address intractable issues, such as immune escape and immune desert, to inhibit tumor progression and metastasis. This detailed review focuses on the regulation of different aspects of tumor immunity by immunologically effective biomaterials, including modulating adaptive immunity, innate immunity, and the immune microenvironment, to enhance the efficacy of PCa immunotherapy. In addition, this review provides a perspective on the future prospects of immunotherapeutic nanoplatforms based on biomaterials in the treatment of PCa.

Tumor-reactive T cell clonotype dynamics underlying clinical response to TIL therapy in melanoma

Adoptive cell therapy (ACT) using in vitro expanded tumor-infiltrating lymphocytes (TILs) has inconsistent clinical responses. To better understand determinants of therapeutic success, we tracked TIL clonotypes from baseline tumors to ACT products and post-ACT blood and tumor samples in melanoma patients using single-cell RNA and T cell receptor (TCR) sequencing. Patients with clinical responses had baseline tumors enriched in tumor-reactive TILs, and these were more effectively mobilized upon in vitro expansion, yielding products enriched in tumor-specific CD8+ cells that preferentially infiltrated tumors post-ACT. Conversely, lack of clinical responses was associated with tumors devoid of tumor-reactive resident clonotypes and with cell products mostly composed of blood-borne clonotypes that persisted in blood but not in tumors post-ACT. Upon expansion, tumor-specific TILs lost tumor-associated transcriptional signatures, including exhaustion, and responders exhibited an intermediate exhausted effector state after TIL engraftment in the tumor, suggesting functional reinvigoration. Our findings provide insight into the nature and dynamics of tumor-specific clonotypes associated with clinical response to TIL-ACT, with implications for treatment optimization.

NME4 suppresses NFκB2-CCL5 axis, restricting CD8+ T cell tumour infiltration in oesophageal squamous cell carcinoma

Thought of as a metastasis-associated gene, however, NME/NM23 nucleoside diphosphate kinase 4 (NME4) has rarely been described in the context of the tumour microenvironment. To understand the immunological implications of NME4 in oesophageal squamous cell carcinoma (ESCC), we used multiplex immunohistochemistry to analyse the clinicopathological and prognostic importance of NME4 expression. Then, after establishing a syngeneic tumour model with a C57BL/6 mouse strain that can recapitulate the tumour microenvironment of humans, we examined the immunological involvement of NME4 expression. To explore the underlying molecular mechanism, via quantitative proteomics and protein microarray screening, we investigated the potential signalling pathways involved. The clinicopathological and prognostic importance of NME4 expression is limited in ESCC patients. In vivo, single-cell RNA sequencing showed that NME4 strikingly prevented CD8+ T cells from infiltrating the tumour microenvironment in murine ESCC. Mechanistically, we mapped out the NFκB2-CCL5 axis that was negatively controlled by NME4 in the murine ESCC cell line AKR. Collectively, these data demonstrated that regulation of NFκB2-CCL5 axis by NME4 prevents CD8+ T cells infiltration in ESCC.

CD4+ T cells in antitumor immunity

Advances in cancer immunotherapy have transformed cancer care and realized unprecedented responses in many patients. The growing arsenal of novel therapeutics - including immune checkpoint inhibition (ICI), adoptive T cell therapies (ACTs), and cancer vaccines - reflects the success of cancer immunotherapy. The therapeutic benefits of these treatment modalities are generally attributed to the enhanced quantity and quality of antitumor CD8+ T cell responses. Nevertheless, CD4+ T cells are now recognized to play key roles in both the priming and effector phases of the antitumor immune response. In addition to providing T cell help through co-stimulation and cytokine production, CD4+ T cells can also possess cytotoxicity either directly on MHC class II-expressing tumor cells or to other cells within the tumor microenvironment (TME). The presence of specific populations of CD4+ T cells, and their intrinsic plasticity, within the TME can represent an important determinant of clinical response to immune checkpoint inhibitors, vaccines, and chimeric antigen receptor (CAR) T cell therapies. Understanding how the antitumor functions of specific CD4+ T cell types are induced while limiting their protumorigenic attributes will enable more successful immunotherapies.

Integrated immuno-transcriptomic analysis of ovarian cancer identifies a four-chemokine-dominated subtype with antitumor immune-active phenotype and favorable prognosis

BACKGROUND

Ovarian cancer (OV) is a heterogeneous disease but has traditionally been treated as an immunologically cold malignancy. The relationship between the immune-active cancer phenotype typified by a T helper 1 (Th-1) immune response and clinical outcome in OV remains uncertain.

METHODS

A cohort-scale compendium of transcriptomic data from 2850 OV samples from 19 individual datasets was compiled for integrative immuno-transcriptomic analysis. The immunological constant of rejection was used as a metric to assess the Th-1/cytotoxic response orientation and investigate the clinical-biological significance of immune polarization towards a Th-1 immune response. Single-cell RNA sequencing data from 39 OV samples were analyzed to elucidate the variability of the immune microenvironment, and immunohistochemical validation was performed on 39 samples from the Harbin Medical University Cancer Hospital.

RESULTS

Our results demonstrated the prognostic significance of a Th-1/cytotoxic immune profile within the tumor microenvironment (TME) using the immunological constant of rejection classification to OV samples. Specifically, patients with tumors expressing high levels of ICR markers showed significantly improved survival. A gene panel consisting of four chemokines (CXCL9, CXCL10, CXCL11 and CXCL13) was identified as critical players in mediating the establishment of an active T-cell-inflamed antitumor phenotype. This 4-chemokine signature, which was extensively validated in external multicenter cohorts through transcriptomic profiling and in an independent in-house cohort through immunohistochemistry, introduced a novel immune classification in OV and identified a chemokine-dominated subtype associated with an active antitumor immune phenotype and favorable prognosis. Single-cell transcriptomic analysis revealed that chemokine-dominated tumors increase CXCR3 + NK and T cell recruitment to the TME primarily through the overexpression of macrophage-derived CXCL9/10/11.

CONCLUSIONS

This study provides new insights into understanding immune heterogeneity within the TME and paves the way for tailoring appropriate therapeutic interventions for patients with differing immune profiles.

IDO1 inhibitors are synergistic with CXCL10 agonists in inhibiting colon cancer growth

Indoleamine 2,3-dioxygenase 1 (IDO1) is an immune checkpoint that degrades L-tryptophan to kynurenine (Kyn) and enhance immunosuppression, which can be an attractive target for treating colon cancer. IDO1 inhibitors have limited efficacy when used as monotherapies, and their combination approach has been shown to provide synergistic benefits. Many studies have shown that targeting chemokines can promote the efficacy of immune checkpoint inhibitors. Therefore, this study explored the use of IDO1 inhibitors with multiple chemokines to develop a new combination regimen for IDO1 inhibitors. We found that IDO1 inhibitors reduce the secretion of C-X-C motif ligand 10(CXCL10) in cancer cells, and CXCL10 supplementation significantly improved the anticancer effect of IDO1 inhibitors. The combination of the IDO1 inhibitor with CXCL10 or its agonist axitinib had a synergistic inhibitory effect on the growth of colon cancer cells and transplanted CT26 tumors. This synergistic effect may be achieved by inhibiting cancer cell proliferation, promoting cancer cell apoptosis, promoting CD8+T cell differentiation and decreasing Tregs. Two downstream pathways of IDO1 affect CXCL10 secretion. One being the Kyn-aryl hydrocarbon receptor (AHR) pathway, the other is the general control nonderepressible 2(GCN2). Our study provides a new reference for combination regimens of IDO1 inhibitors.

Novel insights into immune cells modulation of tumor resistance

Tumor resistance poses a significant challenge to effective cancer treatment, making it imperative to explore new therapeutic strategies. Recent studies have highlighted the profound involvement of immune cells in the development of tumor resistance. Within the tumor microenvironment, macrophages undergo polarization into the M2 phenotype, thus promoting the emergence of drug-resistant tumors. Neutrophils contribute to tumor resistance by forming extracellular traps. While T cells and natural killer (NK) cells exert their impact through direct cytotoxicity against tumor cells. Additionally, dendritic cells (DCs) have been implicated in preventing tumor drug resistance by stimulating T cell activation. In this review, we provide a comprehensive summary of the current knowledge regarding immune cell-mediated modulation of tumor resistance at the molecular level, with a particular focus on macrophages, neutrophils, DCs, T cells, and NK cells. The targeting of immune cell modulation exhibits considerable potential for addressing drug resistance, and an in-depth understanding of the molecular interactions between immune cells and tumor cells holds promise for the development of innovative therapies. Furthermore, we explore the clinical implications of these immune cells in the treatment of drug-resistant tumors. This review emphasizes the exploration of novel approaches that harness the functional capabilities of immune cells to effectively overcome drug-resistant tumors.

Advances in Immune Checkpoint Therapy in Hepatocellular Carcinoma

The incidence and lethality of hepatocellular carcinoma (HCC) are increasing annually, and traditional treatments have been proven to be ineffective for patients with advanced stages of the disease. In recent years, immune checkpoint therapy has rapidly evolved, demonstrating promising results across a wide range of cancers and offering new hope for cancer treatment. However, the efficacy of immune checkpoint therapy in HCC varies greatly among individuals, with only a small proportion of HCC patients responding positively. A major cause of immune resistance and poor efficacy in HCC patients is immune evasion, which is often due to insufficient infiltration of immune cells. Understanding the mechanisms underlying immune evasion is crucial for enhancing the efficacy of immune therapies. In this review, we aim to summarize the mechanisms of immune evasion observed during immune checkpoint therapy and discuss future directions for this therapeutic approach. Our goal is to provide insights that could help overcome immune evasion, thereby improving the efficacy of immune therapies and extending patient survival time.

Crosstalk of T cells within the ovarian cancer microenvironment

Ovarian cancer (OC) represents ecosystems of highly diverse tumor microenvironments (TMEs). The presence of tumor-infiltrating lymphocytes (TILs) is linked to enhanced immune responses and long-term survival. In this review we present emerging evidence suggesting that cellular crosstalk tightly regulates the distribution of TILs within the TME, underscoring the need to better understand key cellular networks that promote or impede T cell infiltration in OC. We also capture the emergent methodologies and computational techniques that enable the dissection of cell-cell crosstalk. Finally, we present innovative ex vivo TME models that can be leveraged to map and perturb cellular communications to enhance T cell infiltration and immune reactivity.

Enhancing T-cell recruitment in renal cell carcinoma with cytokine-armed adenoviruses

Immunotherapy has emerged as a promising approach for cancer treatment, with oncolytic adenoviruses showing power as immunotherapeutic agents. In this study, we investigated the immunotherapeutic potential of an adenovirus construct expressing CXCL9, CXCL10, or IL-15 in clear cell renal cell carcinoma (ccRCC) tumor models. Our results demonstrated robust cytokine secretion upon viral treatment, suggesting effective transgene expression. Subsequent analysis using resistance-based transwell migration and microfluidic chip assays demonstrated increased T-cell migration in response to chemokine secretion by infected cells in both 2D and 3D cell models. Flow cytometry analysis revealed CXCR3 receptor expression across T-cell subsets, with the highest percentage found on CD8+ T-cells, underscoring their key role in immune cell migration. Alongside T-cells, we also detected NK-cells in the tumors of immunocompromised mice treated with cytokine-encoding adenoviruses. Furthermore, we identified potential immunogenic antigens that may enhance the efficacy and specificity of our armed oncolytic adenoviruses in ccRCC. Overall, our findings using ccRCC cell line, in vivo humanized mice, physiologically relevant PDCs in 2D and patient-derived organoids (PDOs) in 3D suggest that chemokine-armed adenoviruses hold promise for enhancing T-cell migration and improving immunotherapy outcomes in ccRCC. Our study contributes to the development of more effective ccRCC treatment strategies by elucidating immune cell infiltration and activation mechanisms within the tumor microenvironment (TME) and highlights the usefulness of PDOs for predicting clinical relevance and validating novel immunotherapeutic approaches. Overall, our research offers insights into the rational design and optimization of viral-based immunotherapies for ccRCC.

Involvement of ICAM5 in Carcinostasis Effects on LUAD Based on the ROS1-Related Prognostic Model

Background

Lung cancer is the most common type of cancer in the world. In lung adenocarcinoma (LUAD), studies on receptor tyrosine kinase ROS proto-oncogene 1 (ROS1) have mainly focused on the oncogenic effects of its fusion mutations, whereas ROS1 has been reported to be aberrantly expressed in a variety of cancers and can extensively regulate the growth, survival, and proliferation of tumor cells through multiple signaling pathways. The comprehensive analysis of ROS1 expression has not been fully investigated regarding its predictive value for LUAD patients.

Methods

Gene expression profiles collected from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases were used to build and validate prognostic risk models. The association of ROS1 with overall survival and the immune landscape was obtained from the Tumor Immune Estimation Resource (TIMER) database. The following analyses were performed using the R package to determine the model's validity: pathway dysregulation analysis, gene set enrichment analysis, Gene Oncology analysis, immune invasion analysis, chemotherapy, radiotherapy, and immunotherapy sensitivity analysis. Finally, we conducted a pan-cancer analysis and performed in vitro experiments to explore the regulatory role of intercellular adhesion molecule 5 (ICAM5) in the progression of LUAD.

Results

We constructed a 17-gene model that categorized patients into two risk groups. The model had predictive accuracy for tumor prognosis and was specific for patients with high ROS1 expression. Comprehensive analysis showed that patients in the high-risk group were characterized by marked dysregulation of multiple pathways (eg, unfolded protein response), immune suppression of the tumor microenvironment, and poor benefit from immunotherapy and radiotherapy compared with patients in the low-risk group. PLX4720 may be a suitable treatment for the high-risk patient population. The ICAM5 gene has been demonstrated to inhibit the proliferation, cell cycle, invasion, and migration of LUAD cells.

Conclusion

We constructed a 17-gene prognostic risk model and found differences in immune-related cells, biological processes, and prognosis among patients in different risk groups based on the correlation between ROS1 and immunity. Personalized therapy may play an essential role in treatment. We further investigated the role of ICAM5 in inhibiting the malignant bioactivity of LUAD cells.

Longitudinal Intravascular Antibody Labeling Identified Regulatory T Cell Recruitment as a Therapeutic Target in a Mouse Model of Lung Cancer

Anticancer immunity is predicated on leukocyte migration into tumors. Once recruited, leukocytes undergo substantial reprogramming to adapt to the tumor microenvironment. A major challenge in the field is distinguishing recently recruited from resident leukocytes in tumors. In this study, we developed an intravascular Ab technique to label circulating mouse leukocytes before they migrate to tissues, providing unprecedented insight into the kinetics of recruitment. This approach unveiled the substantial role of leukocyte migration in tumor progression using a preclinical mouse model of lung adenocarcinoma. Regulatory T cells (Tregs), critical mediators of immunosuppression, were continuously and rapidly recruited into tumors throughout cancer progression. Moreover, leukocyte trafficking depended on the integrins CD11a/CD49d, and CD11a/CD49d blockade led to significant tumor burden reduction in mice. Importantly, preventing circulating Treg recruitment through depletion or sequestration in lymph nodes was sufficient to decrease tumor burden, indicating that Treg migration was crucial for suppressing antitumor immunity. These findings underscore the dynamic nature of the immune compartment within mouse lung tumors and demonstrate the relevance of a temporal map of leukocyte recruitment into tumors, thereby advancing our understanding of leukocyte migration in the context of tumor development.

Eravacycline improves the efficacy of anti-PD1 immunotherapy via AP1/CCL5 mediated M1 macrophage polarization in melanoma

Screening approved library is a promising and safe strategy to overcome the limitation of low response rate and drug resistance in immunotherapy. Accumulating evidence showed that the application of antibiotics has been considered to reduce the effectiveness of anti-PD1 immunotherapy in tumor treatment, however, in this study, an antibiotic drug (Eravacycline, ERV) was identified to improve the efficacy of anti-PD1 immunotherapy in melanoma through screening approved library. Administration of ERV significantly attenuated melanoma cells growth as well as directly or indirectly benefited M1 macrophage polarization. Meanwhile, ERV treatment significantly induced cellular autophagy via damage of mitochondria, leading to up-regulation of ROS production, subsequently, raised CCL5 secretion through elevation AP1 binding to CCL5 promoter via p38 or JNK1/2 activation. Knockdown of Ccl5 expression attenuated ERV triggered M1 macrophage polarization in melanoma cells. Clinical analysis revealed a positive association between high expression of CCL5 and improved prognosis as well as a favorable anti-PD1 therapy in melanoma patients. As expected, application of ERV improved the efficacy of anti-PD1. Overall, our results approved that ERV enhances the efficacy of anti-PD1 immunotherapy in melanoma by promoting the polarization of M1 macrophages, which provided novel therapeutic strategy for improving the effectiveness of melanoma anti-PD1 immunotherapy.

Endosialin-positive CAFs promote hepatocellular carcinoma progression by suppressing CD8+ T cell infiltration

BACKGROUND AND AIMS

Endosialin, also known as tumor endothelial marker1 or CD248, is a transmembrane glycoprotein that is mainly expressed in cancer-associated fibroblasts (CAFs) in hepatocellular carcinoma (HCC). Our previous study has found that endosialin-positive CAFs could recruit and induce the M2 polarization of macrophages in HCC. However, whether they may regulate other types of immune cells to promoting HCC progression is not known.

APPROACH AND RESULTS

The growth of both subcutaneous and orthotopic HCC tumors was significantly inhibited in endosialin knockout (ENKO) mice. Single-cell sequencing and flow cytometry analysis showed that tumor tissues from ENKO mice had increased CD8+ T cell infiltration. Mixed HCC tumor with Hepa1-6 cells and endosialin knockdown fibroblasts also showed inhibited growth and increased CD8+ T cell infiltration. Data from in vitro co-culture assay, chemokine array and antibody blocking assay, RNA-seq and validation experiments showed that endosialin inhibits the phosphorylation and nuclear translocation of STAT1 in CAFs. This inhibition leads to a decrease in CXCL9/10 expression and secretion, resulting in the suppression of CD8+ T cell infiltration. High level of endosialin protein expression was correlated with low CD8+ T infiltration in the tumor tissue of HCC patients. The combination therapy of endosialin antibody and PD-1 antibody showed synergistic antitumor effect compared with either antibody used individually.

CONCLUSIONS

Endosialin could inhibit CD8+ T cell infiltration by inhibiting the expression and secretion of CXCL9/10 in CAFs, thus promote HCC progression. Combination therapy with endosialin antibody could increase the antitumor effect of PD-1 antibody in HCC, which may overcome the resistance to PD-1 blockade.

Phenotypic and spatial heterogeneity of CD8+ tumour infiltrating lymphocytes

CD8+ T cells are the workhorses executing adaptive anti-tumour response, and targets of various cancer immunotherapies. Latest advances have unearthed the sheer heterogeneity of CD8+ tumour infiltrating lymphocytes, and made it increasingly clear that the bulk of the endogenous and therapeutically induced tumour-suppressive momentum hinges on a particular selection of CD8+ T cells with advantageous attributes, namely the memory and stem-like exhausted subsets. A scrutiny of the contemporary perception of CD8+ T cells in cancer and the subgroups of interest along with the factors arbitrating their infiltration contextures, presented herein, may serve as the groundwork for future endeavours to probe further into the regulatory networks underlying their differentiation and migration, and optimise T cell-based immunotherapies accordingly.

Infiltrating treg reprogramming in the tumor immune microenvironment and its optimization for immunotherapy

Immunotherapy has shown promising anti-tumor effects across various tumors, yet it encounters challenges from the inhibitory tumor immune microenvironment (TIME). Infiltrating regulatory T cells (Tregs) are important contributors to immunosuppressive TIME, limiting tumor immunosurveillance and blocking effective anti-tumor immune responses. Although depletion or inhibition of systemic Tregs enhances the anti-tumor immunity, autoimmune sequelae have diminished expectations for the approach. Herein, we summarize emerging strategies, specifically targeting tumor-infiltrating (TI)-Tregs, that elevate the capacity of organisms to resist tumors by reprogramming their phenotype. The regulatory mechanisms of Treg reprogramming are also discussed as well as how this knowledge could be utilized to develop novel and effective cancer immunotherapies.

PTPRT loss enhances anti-PD-1 therapy efficacy by regulation of STING pathway in non-small cell lung cancer

With the revolutionary progress of immune checkpoint inhibitors (ICIs) in non-small cell lung cancer, identifying patients with cancer who would benefit from ICIs has become critical and urgent. Here, we report protein tyrosine phosphatase receptor type T (PTPRT) loss as a precise and convenient predictive marker independent of PD-L1 expression for anti-PD-1/PD-L1 axis therapy. Anti-PD-1/PD-L1 axis treatment markedly increased progression-free survival in patients with PTPRT-deficient tumors. PTPRT-deficient tumors displayed cumulative DNA damage, increased cytosolic DNA release, and higher tumor mutation burden. Moreover, the tyrosine residue 240 of STING was identified as a direct substrate of PTPRT. PTPRT loss elevated phosphorylation of STING at Y240 and thus inhibited its proteasome-mediated degradation. PTPRT-deficient tumors released more IFN-β, CCL5, and CXCL10 by activation of STING pathway and increased immune cell infiltration, especially of CD8 T cells and natural killer cells, ultimately enhancing the efficacy of anti-PD-1 therapy in multiple subcutaneous and orthotopic tumor mouse models. The response of PTPRT-deficient tumors to anti-PD-1 therapy depends on the tumor-intrinsic STING pathway. In summary, our findings reveal the mechanism of how PTPRT-deficient tumors become sensitive to anti-PD-1 therapy and highlight the biological function of PTPRT in innate immunity. Considering the prevalence of PTPRT mutations and negative expression, this study has great value for patient stratification and clinical decision-making.

CD24 affects the immunosuppressive effect of tumor-infiltrating cells and tumor resistance in a variety of cancers

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.

A hot and cold tumor‑related prognostic signature for stage II colorectal cancer

Globally, colorectal cancer (CRC) is one of the most lethal and prevalent malignancies. Based on the presence of immune cell infiltration in the tumor microenvironment, CRC can be divided into immunologically 'hot' or 'cold' tumors, which in turn leads to the differential efficacy of immunotherapy. However, the immune characteristics of hot and cold CRC tumors remain largely elusive, prompting further investigation of their properties regarding the tumor microenvironment. In the present study, a predictive model was developed based on the differential expression of proteins between cold and hot CRC tumors. First, the differentially expressed proteins (DEPs) were identified using digital spatial profiling and mass spectrometry-based proteomics analysis, and the pathway features of the DEPs were analyzed using functional enrichment analysis. A novel eight-gene signature prognostic risk model was developed (IDO1, MAT1A, NPEPL1, NT5C, PTGR2, RPL29, TMEM126A and TUBB4B), which was validated using data obtained from The Cancer Genome Atlas. The results revealed that the risk score of the eight-gene signature acted as an independent prognostic indicator in patients with stage II CRC (T3-4N0M0). It was also found that a high-risk score in the eight-gene signature was associated with high immune cell infiltration in patients with CRC. Taken together, these findings revealed some of the differential immune characteristics of hot and cold CRC tumors, and an eight-gene signature prognostic risk model was developed, which may serve as an independent prognostic indicator for patients with stage II CRC (T3-4N0M0).

Anti-CTLA-4 m2a Antibody Exacerbates Cardiac Injury in Experimental Autoimmune Myocarditis Mice By Promoting Ccl5-Neutrophil Infiltration

The risk for suffering immune checkpoint inhibitors (ICIs)-associated myocarditis increases in patients with pre-existing conditions and the mechanisms remain to be clarified. Spatial transcriptomics, single-cell RNA sequencing, and flow cytometry are used to decipher how anti-cytotoxic T lymphocyte antigen-4 m2a antibody (anti-CTLA-4 m2a antibody) aggravated cardiac injury in experimental autoimmune myocarditis (EAM) mice. It is found that anti-CTLA-4 m2a antibody increases cardiac fibroblast-derived C-X-C motif chemokine ligand 1 (Cxcl1), which promots neutrophil infiltration to the myocarditic zones (MZs) of EAM mice via enhanced Cxcl1-Cxcr2 chemotaxis. It is identified that the C-C motif chemokine ligand 5 (Ccl5)-neutrophil subpopulation is responsible for high activity of cytokine production, adaptive immune response, NF-κB signaling, and cellular response to interferon-gamma and that the Ccl5-neutrophil subpopulation and its-associated proinflammatory cytokines/chemokines promoted macrophage (Mφ) polarization to M1 Mφ. These altered infiltrating landscape and phenotypic switch of immune cells, and proinflammatory factors synergistically aggravated anti-CTLA-4 m2a antibody-induced cardiac injury in EAM mice. Neutralizing neutrophils, Cxcl1, and applying Cxcr2 antagonist dramatically alleviates anti-CTLA-4 m2a antibody-induced leukocyte infiltration, cardiac fibrosis, and dysfunction. It is suggested that Ccl5-neutrophil subpopulation plays a critical role in aggravating anti-CTLA-4 m2a antibody-induced cardiac injury in EAM mice. This data may provide a strategic rational for preventing/curing ICIs-associated myocarditis.

Prospects of Synergy: Local Interventions and CAR T Cell Therapy in Solid Tumors

Chimeric antigen receptor T cell therapy has been established in the treatment of various B cell malignancies. However, translating this therapeutic effect to treat solid tumors has been challenging because of their inter-tumoral as well as intratumoral heterogeneity and immunosuppressive microenvironment. Local interventions, such as surgery, radiotherapy, local ablation, and locoregional drug delivery, can enhance chimeric antigen receptor T cell therapy in solid tumors by improving tumor infiltration and reducing systemic toxicities. Additionally, ablation and radiotherapy have proven to (re-)activate systemic immune responses via abscopal effects and reprogram the tumor microenvironment on a physical, cellular, and chemical level. This review highlights the potential synergy of the combined approaches to overcome barriers of chimeric antigen receptor T cell therapy and summarizes recent studies that may pave the way for new treatment regimens.

Oncolytic herpes simplex virus propagates tertiary lymphoid structure formation via CXCL10/CXCR3 to boost antitumor immunity

Inducing tertiary lymphoid structure (TLS) formation can fuel antitumor immunity. It is necessary to create mouse models containing TLS to explore strategies of TLS formation. Oncolytic herpes simplex virus-1 (oHSV) exhibited intense effects in preclinical and clinical trials. However, the role of oHSV in TLS formation remains to be elucidated. Here, we observed the presence of TLS in 4MOSC1 and MC38 subcutaneous tumour models. Interestingly, oHSV evoked TLS formation, and increased infiltration of B cells and stem-like TCF1+CD8+ T cells proliferation. Mechanistically, oHSV increased the expression of TLS-related chemokines, along with upregulated CXCL10/CXCR3 to facilitate TLS formation. Notably, CXCL10 and CXCR3 were favourable prognostic factors for cancer patients, and closely related with immune cells infiltration. Inhibiting CXCL10/CXCR3 reduced TCF1+CD8+ T cells and granzyme B expression, and impaired oHSV-mediated TLS formation. Furthermore, oHSV-mediated TLS formation revealed superior response and survival rate when combined with αPD-1 treatment. Collectively, these findings indicate that oHSV recruits stem-like TCF1+CD8+ T cells through CXCL10/CXCR3 pathway to propagate TLS formation, and warrants future antitumor immunity development.

Anatomical classification of advanced biliary tract cancer predicts programmed cell death protein 1 blockade efficacy

Background

Immune checkpoint blockade (ICB)-based immunotherapy has inspired new hope for advanced biliary tract cancer (BTC) treatment; however, there are no prior studies that primarily focus on different anatomical types of unresectable BTCs reacting differently to ICB.

Methods

We retrospectively collected data on advanced BTC patients who received anti-programmed cell death protein 1 (anti-PD1) therapy from two affiliated hospitals of Sun Yat-Sen university. The effects of anti-PD1 were compared for different anatomical sites. The GSE32225 and GSE132305 datasets were used to further analyze differences in the immune microenvironments between intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC).

Results

A total of 198 advanced BTC patients were enrolled in this study, comprising 142 patients with ICC and 56 with other cancer types ("Others" group), including ECC and gallbladder cancer. In the anti-PD1 treated patients, the ICC group (n = 90) achieved longer median progression-free survival (mPFS) (9.5 vs. 6.2 months, p = 0.02) and median overall survival (mOS) (15.1 vs. 10.7 months, p = 0.02) than the Others group (n = 26). However, chemotherapy did not show different effects between the two groups (mOS: 10.6 vs. 12.1 months, p = 0.20; mPFS: 4.9 vs. 5.7 months, p = 0.83). For the first-line anti-PD1 therapy, the ICC group (n = 70) achieved higher mOS (16.0 vs. 11.8 months, p = 0.04) than the Others group (n = 19). Moreover, most chemokines, chemokine receptors, major histocompatibility complex molecules, immunostimulators, and immunoinhibitors were stronger in ICC than ECC; furthermore, CD8+ T cells and M1 macrophages were higher in ICC than ECC for most algorithms. The immune differential genes were mainly enriched in antigen processing and presentation as well as the cytokine receptors.

Conclusions

This study shows that the efficacy of anti-PD1 therapy was higher in ICC than in other types of BTCs. Differences in the immune-related molecules and cells between ICC and ECC indicate that ICC could benefit more from immunotherapy.

Irradiated tumor cell-released microparticles enhance the therapeutic efficacy of PD-1 inhibitors by promoting M1-TAMs polarization in NSCLC brain metastases

Brain metastases (BMs) are the most common sites of metastasis in patients with non-small cell lung cancer (NSCLC). However, BMs are not responsive to immunotherapy because of the blood-brain barrier. This is because intracranial immune cells such as M2 tumor-associated macrophages (TAMs) accumulate, creating an immunosuppressive tumor microenvironment. In this study, we focused on irradiated tumor cell-released microparticles (RT-MPs) that can cross the blood-brain barrier and influence the intracranial immune microenvironment. Using animal models of BMs, we observed that RT-MPs could penetrate the blood-brain barrier and be swallowed by TAMs. Then the microenvironment of TAMs is shifted from the M2 phenotype to the M1 phenotype, thereby modulating the interactions between TAMs and tumor cells. Single-cell sequencing analysis demonstrated that TAMs, after internalizing RT-MPs, active chemokine signaling pathways and secrete more chemokines, such as CCL5, CXCL2, CXCL1, CCL3, CCL4, and CCL22, attracting more CD4+ T cells and CD8+ T cells, improving immune-mediated killing, and enhancing subsequent combination anti-PD-1 therapy. These findings provide a preclinical foundation for exploring alternative treatments for patients with immunoresistant NSCLC BMs.

Validation of the C-X-C chemokine receptor 3 (CXCR3) as a target for PET imaging of T cell activation

PURPOSE

CXCR3 is expressed on activated T cells and plays a crucial role in T-cell recruitment to the tumor microenvironment (TME) during cell-based and immune checkpoint inhibitor (ICI) immunotherapy. This study utilized a 64Cu-labeled NOTA-α-CXCR3 antibody to assess CXCR3 expression in the TME and validate it as a potential T cell activation biomarker in vivo.

PROCEDURES

CXCR3+ cells infiltrating MC38 tumors (B57BL/6 mice, untreated and treated with αPD-1/αCTLA-4 ICI) were quantified using fluorescence microscopy and flow cytometry. A commercial anti-mouse CXCR3 antibody (α-CXCR3) was site-specifically conjugated with 2,2,2-(1,4,7-triazacyclononane-1,4,7-triyl)triacetic acid (NOTA) and radiolabeled with 64Cu. Saturation binding of [64Cu]Cu-NOTA-α-CXCR3 was investigated using CHO cells stably transfected with murine CXCR3. Biodistribution and PET imaging studies both at baseline and after 1 to 3 cycles of ICI, respectively, were carried out using different molar activities (10 GBq/µmol to 300 GBq/µmol) of [64Cu]Cu-NOTA-α-CXCR3.

RESULTS

Flow cytometry analysis at baseline confirmed the presence of CXCR3 + T-cells in MC38 tumors, which was significantly increased at day five after ICI (treated 33.8 ± 17.4 vs. control 8.8 ± 6.2 CD3+CXCR3+ cells/mg). These results were qualitatively and quantitatively confirmed by immunofluorescence of tumor cryoslices. In vivo PET imaging of MC38 tumor bearing mice before, during and after ICI using [64Cu]Cu-NOTA-α-CXCR3 (Kd = 3.3 nM) revealed a strong dependence of CXCR3-specificity of tracer accumulation in secondary lymphoid organs on molar activity. At 300 GBq/µmol (1.5 µg of antibody/mouse), a specific signal was observed in lymph nodes (6.33 ± 1.25 control vs. 3.95 ± 1.23%IA/g blocking) and the spleen (6.04 ± 1.02 control vs. 3.84 ± 0.79%IA/g blocking) at 48 h p.i. Spleen-to-liver ratios indicated a time dependent systemic immune response showing a steady increase from 1.08 ± 0.19 (untreated control) to 1.54 ± 0.14 (three ICI cycles).

CONCLUSIONS

This study demonstrates the feasibility of in vivo imaging of CXCR3 upregulation under immunotherapy using antibodies. However, high molar activities and low antibody doses are essential for sensitive detection in lymph nodes and spleen. Detecting therapy-induced changes in CXCR3+ T cell numbers in tumors was challenging due to secondary antibody-related effects. Nonetheless, CXCR3 remains a promising target for imaging T cell activation, with anticipated improvements in sensitivity using alternative tracers with high affinities and favorable pharmacokinetics.

The significance of CD8+ tumor-infiltrating lymphocytes exhaustion heterogeneity and its underlying mechanism in diffuse large B-cell lymphoma

CD8+ tumor-infiltrating lymphocytes (TILs) exhaustion is a major barrier to effective tumor control in diffuse large B-cell lymphoma (DLBCL) and may consist of heterogeneous populations with different functional states. We profiled the CD8+TILs exhaustion heterogeneity and explored its clinical significance as well as the underlying mechanism through single-cell RNA sequencing (n = 7), bulk RNA sequencing (n = 3300), immunohistochemistry (n = 116), and reverse transcription-quantitative polymerase chain reaction (n = 95), and somatic mutation data (n = 48). Our results demonstrated that exhausted CD8+TILs in DLBCL were composed of progenitor and terminal states characterized by CCL5 and TUBA1B, respectively. High terminally exhausted CD8+TILs indicated an immunosuppressive tumor microenvironment, activated B-cell-like subtype, inferior prognosis, and poor response to immune checkpoint blockade therapy in DLBCL. Our study further demonstrated that the CD39/A2AR-related signaling may be the potential pathway that promoted the transition of progenitor toward terminally exhausted CD8+TILs in DLBCL. Furthermore, the CD39/A2AR-related pathway in DLBCL may be regulated by BATF and STAT3 in exhausted CD8+TILs, and MYD88 mutation in tumor cells. Our study highlights CD8+TILs exhaustion heterogeneity and its possible regulatory mechanism provides a novel prognostic indicator and can facilitate the optimization of individualized immunotherapy.

Stem-like CD8+ T cells in cancer

Stem-like CD8+ T cells (TSL) are a subset of immune cells with superior persistence and antitumor immunity. They are TCF1+ PD-1+ and important for the expansion of tumor specific CD8+ T cells in response to checkpoint blockade immunotherapy. In acute infections, naïve CD8+ T cells differentiate into effector and memory CD8+ T cells; in cancer and chronic infections, persistent antigen stimulation can lead to T cell exhaustion. Recent studies have highlighted the dichotomy between late dysfunctional (or exhausted) T cells (TLD) that are TCF1- PD-1+ and self-renewing TCF1+ PD-1+ TSL from which they derive. TCF1+ TSL cells are considered to have stem cell-like properties akin to memory T cell populations and can give rise to cytotoxic effector and transitory T cell phenotypes (TTE) which mediate tumor control. In this review, we will discuss recent advances made in research on the formation and expansion of TSL, as well as distinct niches required for their differentiation and maintenance in the setting of cancer. We will also discuss potential strategies to generate these cells, with clinical implications for stemness enhancement in vaccine design, immune checkpoint blockade (ICB), and adoptive T cell therapies.

FAM122A functions as a tumor suppressor in oral squamous cell carcinoma

Family with sequence similarity 122a (FAM122A), identified as an endogenous inhibitor of protein phosphatase 2A (PP2A) previously, is involved in multiple important physiological processes, and essential for the growth of acute myeloid leukemia and hepatocellular carcinoma cells. However, the function of FAM122A in oral squamous cell carcinoma (OSCC) is undetermined. In this study, by analyzing TCGA and GEO databases, we found that the expression of FAM122A was significantly down-regulated in head and neck squamous cell carcinoma and OSCC patients, meanwhile this low expression was tightly associated with the poor prognosis and advanced clinical stage during OSCC development. The similar low expression pattern of FAM122A could also been seen in OSCC cell lines compared with normal human oral keratinocytes. Further, we demonstrated that FAM122A knockdown significantly promoted the growth, clonogenic potential as well as migration capabilities of OSCC cells, while these alterations could be rescued by the re-expression of FAM122A. Over-expression of FAM122A suppressed OSCC cell proliferation and migration. FAM122A also inhibited the epithelial-mesenchymal transition (EMT) in OSCC cells by the up-regulation of epithelial marker E-cadherin and down-regulation of mesenchymal markers Fibronectin and Vimentin, which is presumably mediated by transforming growth factor β receptor 3 (TGFBR3), a novel tumor suppressor. In addition, FAM122A could induce T cell infiltration in OSCC, indicating that FAM122A might influence the immune cell activity of tumor environment and further interfere the tumor development. Collectively, our results suggest that FAM122A functions as a tumor suppressor in OSCC and possibly acts as a predictive biomarker for the diagnosis and/or treatment of OSCC.

Dual Role of Necroptosis in Cervical Cancer: Promoting Tumor Aggression and Modulating the Immune Microenvironment via the JAK2-STAT3 Pathway

In the dynamic landscape of cervical cancer (CC) pathophysiology, this study aimed to elucidate the role of necroptosis in modulating tumor proliferation, invasion, and the immune microenvironment in CC. In this study, the impact of necroptosis on CC was evaluated through a series of bioinformatical analyses and experimental approaches. The impact of necroptosis on CC was illustrated by analyzing its effects on tumor aggression, immune responses, and the JAK2-STAT3 signaling pathway. Bevacizumab, a monoclonal antibody targeting vascular endothelial growth factor (VEGF), was also evaluated for its potential induction of necroptosis in CC cells and its interaction with necroptosis inhibitors. Additionally, the study assessed the influence of necroptosis on the immune microenvironment, particularly in T-cell-related pathways and the expression of tumor suppressor genes in CC. Necroptosis was found to enhance VEGFA expression through the activation of the JAK2-STAT3 pathway, promoting tumor proliferative and invasive capabilities in CC. Bevacizumab induced necroptosis in CC cells, potentially leading to resistance to therapy. The combination of bevacizumab with necroptosis inhibitors attenuated VEGFA expression, suggesting a novel therapeutic strategy. Additionally, necroptosis activated T-cell-related pathways and promoted the infiltration and activation of Jurkat T cells. CD3D-a tumor suppressor gene in CC-was identified as a critical marker and its expression could be upregulated by necroptosis via the JAK2-STAT3 pathway in Jurkat T cells. Treatment of CC cells with supernatants from necroptosis-induced Jurkat cells resulted in reduced tumor cell proliferation and invasion. This study reveals a complex interaction between necroptosis, tumor progression, and the immune response in CC. The findings propose a nuanced approach to leveraging necroptosis for therapeutic interventions, highlighting the potential of combining necroptosis inhibitors with existing therapies to improve treatment outcomes in CC.

Preclinical Efficacy of VTX-0811: A Humanized First-in-Class PSGL-1 mAb Targeting TAMs to Suppress Tumor Growth

Omnipresent suppressive myeloid populations in the tumor microenvironment limit the efficacy of T-cell-directed immunotherapies, become more inhibitory after administration of T-cell checkpoint inhibitors, and are overall associated with worse survival of cancer patients. In early clinical trials, positive outcomes have been demonstrated for therapies aimed at repolarizing suppressive myeloid populations in the tumor microenvironment. We have previously described the key role of P-selectin glycoprotein ligand-1 (PSGL-1) in maintaining an inhibitory state of tumor-associated macrophages (TAMs), most of which express high levels of PSGL-1. Here we describe a novel, first-in-class humanized high-affinity monoclonal antibody VTX-0811 that repolarizes human macrophages from an M2-suppressive phenotype towards an M1 inflammatory phenotype, similar to siRNA-mediated knockdown of PSGL-1. VTX-0811 binds to PSGL-1 of human and cynomolgus macaque origins without inhibiting PSGL-1 interaction with P- and L-Selectins or VISTA. In multi-cellular assays and in patient-derived human tumor cultures, VTX-0811 leads to the induction of pro-inflammatory mediators. RNAseq data from VTX-0811 treated ex vivo tumor cultures and M2c macrophages show similar pathways being modulated, indicating that the mechanism of action translates from isolated macrophages to tumors. A chimeric version of VTX-0811, consisting of the parental murine antibody in a human IgG4 backbone, inhibits tumor growth in a humanized mouse model of cancer. VTX-0811 is exceptionally well tolerated in NHP toxicology assessment and is heading into clinical evaluation after successful IND clearance.

Inhibition of insulin-like growth factors increases production of CXCL9/10 by macrophages and fibroblasts and facilitates CD8+ cytotoxic T cell recruitment to pancreatic tumours

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with an urgent unmet clinical need for new therapies. Using a combination of in vitro assays and in vivo preclinical models we demonstrate that therapeutic inhibition of the IGF signalling axis promotes the accumulation of CD8+ cytotoxic T cells within the tumour microenvironment of PDAC tumours. Mechanistically, we show that IGF blockade promotes macrophage and fibroblast production of the chemokines CXCL9 and CXCL10 to facilitate CD8+ T cell recruitment and trafficking towards the PDAC tumour. Exploring this pathway further, we show that IGF inhibition leads to increased STAT1 transcriptional activity, correlating with a downregulation of the AKT/STAT3 signalling axis, in turn promoting Cxcl9 and Cxcl10 gene transcription. Using patient derived tumour explants, we also demonstrate that our findings translate into the human setting. PDAC tumours are frequently described as "immunologically cold", therefore bolstering CD8+ T cell recruitment to PDAC tumours through IGF inhibition may serve to improve the efficacy of immune checkpoint inhibitors which rely on the presence of CD8+ T cells in tumours.

Estrogen Receptor Blockade Potentiates Immunotherapy for Liver Metastases by Altering the Liver Immunosuppressive Microenvironment

Liver metastases (LM) remain a major cause of cancer-related death and are a major clinical challenge. LM and the female sex are predictors of a poorer response to immunotherapy but the underlying mechanisms remain unclear. We previously reported on a sexual dimorphism in the control of the tumor microenvironment (TME) of colorectal carcinoma liver metastases (CRCLM) and identified estrogen as a regulator of an immunosuppressive TME in the liver. Here we aimed to assess the effect of estrogen deprivation on the cytokine/chemokine profile associated with CRCLM, using a multiplex cytokine array and the RNAscope technology, and its effects on the innate and adaptive immune responses in the liver. We also evaluated the benefit of combining the selective estrogen-receptor degrader Fulvestrant with immune checkpoint blockade for the treatment of CRCLM. We show that estrogen depletion altered the cytokine/chemokine repertoire of the liver, decreased macrophage polarization, as reflected in reduced accumulation of tumor infiltrating M2 macrophages and increased the accumulation of CCL5+/CCR5+ CD8+ T and NKT cells in the liver TME. Similar results were obtained in a murine pancreatic ductal adenocarcinoma model. Importantly, treatment with Fulvestrant also increased the accumulation of CD8+CCL5+, CD8+CCR5+ T and NK cells in the liver TME and enhanced the therapeutic benefit of anti-PD1 immunotherapy, resulting in a significant reduction in the outgrowth of LM. Taken together, our results show that estrogen regulates immune cell recruitment to the liver and suggest that inhibition of estrogen action could potentiate the tumor-inhibitory effect of immunotherapy in hormone-independent and immunotherapy-resistant metastatic cancer.

SIGNIFICANCE

The immune microenvironment of the liver plays a major role in controlling the expansion of hepatic metastases and is regulated by estrogen. We show that treatment of tumor-bearing mice with an estrogen receptor degrader potentiated an anti-metastatic effect of immunotherapy. Our results provide mechanistic insight into clinical findings and a rationale for evaluating the efficacy of combination anti-estrogen and immunotherapy for prevention and/or treatment of hepatic metastases in female patients.

CCL22 Induces the Polarization of Immature Dendritic Cells into Tolerogenic Dendritic Cells in Radiation-Induced Lung Injury through the CCR4-Dectin2-PLC-γ2-NFATC2-Nr4a2-PD-L1 Signaling Pathway

Recruitment of immune cells to the injury site plays a pivotal role in the pathology of radiation-associated diseases. In this study, we investigated the impact of the chemokine CCL22 released from alveolar type II epithelial (AT2) cells after irradiation on the recruitment and functional changes of dendritic cells (DCs) in the development of radiation-induced lung injury (RILI). By examining changes in CCL22 protein levels in lung tissue of C57BL/6N mice with RILI, we discovered that ionizing radiation increased CCL22 expression in irradiated alveolar AT2 cells, as did MLE-12 cells after irradiation. A transwell migration assay revealed that CCL22 promoted the migration of CCR4-positive DCs to the injury site, which explained the migration of pulmonary CCR4-positive DCs in RILI mice in vivo. Coculture experiments demonstrated that, consistent with the response of regulatory T cells in the lung tissue of RILI mice, exogenous CCL22-induced DCs promoted regulatory T cell proliferation. Mechanistically, we demonstrated that Dectin2 and Nr4a2 are key targets in the CCL22 signaling pathway, which was confirmed in pulmonary DCs of RILI mice. As a result, CCL22 upregulated the expression of PD-L1, IL-6, and IL-10 in DCs. Consequently, we identified a mechanism in which CCL22 induced DC tolerance through the CCR4-Dectin2-PLC-γ2-NFATC2-Nr4a2-PD-L1 pathway. Collectively, these findings demonstrated that ionizing radiation stimulates the expression of CCL22 in AT2 cells to recruit DCs to the injury site and further polarizes them into a tolerant subgroup of CCL22 DCs to regulate lung immunity, ultimately providing potential therapeutic targets for DC-mediated RILI.

PPAR-γ/NF-kB/AQP3 axis in M2 macrophage orchestrates lung adenocarcinoma progression by upregulating IL-6

Aquaporin 3 (AQP3), which is mostly expressed in pulmonary epithelial cells, was linked to lung adenocarcinoma (LUAD). However, the underlying functions and mechanisms of AQP3 in the tumor microenvironment (TME) of LUAD have not been elucidated. Single-cell RNA sequencing (scRNA-seq) was used to study the composition, lineage, and functional states of TME-infiltrating immune cells and discover AQP3-expressing subpopulations in five LUAD patients. Then the identifications of its function on TME were examined in vitro and in vivo. AQP3 was associated with TNM stages and lymph node metastasis of LUAD patients. We classified inter- and intra-tumor diversity of LUAD into twelve subpopulations using scRNA-seq analyses. The analysis showed AQP3 was mainly enriched in subpopulations of M2 macrophages. Importantly, mechanistic investigations indicated that AQP3 promoted M2 macrophage polarization by the PPAR-γ/NF-κB axis, which affected tumor growth and migration via modulating IL-6 production. Mixed subcutaneous transplanted tumor mice and Aqp3 knockout mice models were further utilized, and revealed that AQP3 played a critical role in mediating M2 macrophage polarization, modulating glucose metabolism in tumors, and regulating both upstream and downstream pathways. Overall, our study demonstrated that AQP3 could regulate the proliferation, migration, and glycometabolism of tumor cells by modulating M2 macrophages polarization through the PPAR-γ/NF-κB axis and IL-6/IL-6R signaling pathway, providing new insight into the early detection and potential therapeutic target of LUAD.

Identification and validation of CCL5 as a key gene in HIV infection and pulmonary arterial hypertension

Background

The relationship between human immunodeficiency virus (HIV) infection and pulmonary arterial hypertension (PAH) has garnered significant scrutiny. Individuals with HIV infection have a higher risk of developing PAH. However, the specific mechanism of HIV-associated PAH remains unclear. Our study aims at investigating the shared biomarkers in HIV infection and PAH and predicting the potential therapeutic target for HIV-associated PAH.

Methods

Data for HIV infection and PAH were downloaded from Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) analysis was performed to detect shared genes in HIV infection and PAH. Enrichment analysis was conducted to identify the function of common DEGs. Protein-protein interaction (PPI) analysis was used to detect key genes. These crucial genes were subsequently verified by RT-qPCR. Finally, candidate drugs were identified by using the Drug Signatures Database (DSigDB).

Results

Nineteen common DEGs were identified in HIV infection and PAH. Enrichment analysis exhibited that the functions of these genes were mainly enriched in inflammatory responses, mainly including cellular immunity and interaction between viral proteins and cytokines. By constructing PPI networks, we identified the key gene CC-type chemokine ligand 5 (CCL5), and we verified that CCL5 was highly expressed in hypoxia induced human pulmonary artery endothelial cells (hPAECs) and human pulmonary artery smooth muscle cells (hPASMCs). In addition, we predicted 10 potential drugs targeting CCL5 by Autodock Vina.

Conclusion

This study revealed that CCL5 might be a common biomarker of HIV infection and PAH and provided a new therapeutic target for HIV-associated PAH. However, further clinical validation is still indispensable.

The COMPASS complex maintains the metastatic capacity imparted by a subpopulation of cells in UPS

Intratumoral heterogeneity is common in cancer, particularly in sarcomas like undifferentiated pleomorphic sarcoma (UPS), where individual cells demonstrate a high degree of cytogenic diversity. Previous studies showed that a small subset of cells within UPS, known as the metastatic clone (MC), as responsible for metastasis. Using a CRISPR-based genomic screen in-vivo, we identified the COMPASS complex member Setd1a as a key regulator maintaining the metastatic phenotype of the MC in murine UPS. Depletion of Setd1a inhibited metastasis development in the MC. Transcriptome and chromatin sequencing revealed COMPASS complex target genes in UPS, such as Cxcl10, downregulated in the MC. Deleting Cxcl10 in non-MC cells increased their metastatic potential. Treating mice with human UPS xenografts with a COMPASS complex inhibitor suppressed metastasis without affecting tumor growth in the primary tumor. Our data identified an epigenetic program in a subpopulation of sarcoma cells that maintains metastatic potential.

Chemokines in the tumor microenvironment: implications for lung cancer and immunotherapy

The tumor microenvironment (TME) is a complex interconnected network of immune cells, fibroblasts, blood vessels, and extracellular matrix surrounding the tumor. Because of its immunosuppressive nature, the TME can pose a challenge for cancer immunotherapies targeting solid tumors. Chemokines have emerged as a crucial element in enhancing the efficacy of cancer immunotherapy, playing a direct role in immune cell signaling within the TME and facilitating immune cell migration towards cancer cells. However, chemokine ligands and their receptors exhibit context-dependent diversity, necessitating evaluation of their tumor-promoting or inhibitory effects based on tumor type and immune cell characteristics. This review explores the role of chemokines in tumor immunity and metastasis in the context of the TME. We also discuss current chemokine-related advances in cancer immunotherapy research, with a particular focus on lung cancer, a common cancer with a low survival rate and limited immunotherapy options.

Adeno-associated virus delivered CXCL9 sensitizes glioblastoma to anti-PD-1 immune checkpoint blockade

There are numerous mechanisms by which glioblastoma cells evade immunological detection, underscoring the need for strategic combinatorial treatments to achieve appreciable therapeutic effects. However, developing combination therapies is difficult due to dose-limiting toxicities, blood-brain-barrier, and suppressive tumor microenvironment. Glioblastoma is notoriously devoid of lymphocytes driven in part by a paucity of lymphocyte trafficking factors necessary to prompt their recruitment and activation. Herein, we develop a recombinant adeno-associated virus (AAV) gene therapy that enables focal and stable reconstitution of the tumor microenvironment with C-X-C motif ligand 9 (CXCL9), a powerful call-and-receive chemokine for lymphocytes. By manipulating local chemokine directional guidance, AAV-CXCL9 increases tumor infiltration by cytotoxic lymphocytes, sensitizing glioblastoma to anti-PD-1 immune checkpoint blockade in female preclinical tumor models. These effects are accompanied by immunologic signatures evocative of an inflamed tumor microenvironment. These findings support AAV gene therapy as an adjuvant for reconditioning glioblastoma immunogenicity given its safety profile, tropism, modularity, and off-the-shelf capability.

Systemic delivery of oncolytic herpes virus using CAR-T cells enhances targeting of antitumor immuno-virotherapy

Recent studies have indicated that combining oncolytic viruses with CAR-T cells in therapy has shown superior anti-tumor effects, representing a promising approach. Nonetheless, the localized delivery method of intratumoral injection poses challenges for treating metastatic tumors or distal tumors that are difficult to reach. To address this obstacle, we employed HSV-1-infected CAR-T cells, which systemically delivery HSV into solid tumors. The biological function of CAR-T cells remained intact after loading them with HSV for a period of three days. In both immunocompromised and immunocompetent GBM orthotopic mouse models, B7-H3 CAR-T cells effectively delivered HSV to tumor lesions, resulting in enhanced T-cell infiltration and significantly prolonged survival in mice. We also employed a bilateral subcutaneous tumor model and observed that the group receiving intratumoral virus injection exhibited a significant reduction in tumor volume on the injected side, while the group receiving intravenous infusion of CAR-T cells carrying HSV displayed suppressed tumor growth on both sides. Hence, CAR-THSV cells offer notable advantages in the systemic delivery of HSV to distant tumors. In conclusion, our findings emphasize the potential of CAR-T cells as carriers for HSV, presenting significant advantages for oncolytic virotherapy targeting distant tumors.

Orchestrated Codelivery of Peptide Antigen and Adjuvant to Antigen-Presenting Cells by Using an Engineered Chimeric Peptide Enhances Antitumor T-Cell Immunity

The intrinsic pharmacokinetic limitations of traditional peptide-based cancer vaccines hamper effective cross-presentation and codelivery of antigens (Ag) and adjuvants, which are crucial for inducing robust antitumor CD8+ T-cell responses. In this study, we report the development of a versatile strategy that simultaneously addresses the different pharmacokinetic challenges of soluble subunit vaccines composed of Ags and cytosine-guanosine oligodeoxynucleotide (CpG) to modulate vaccine efficacy via translating an engineered chimeric peptide, eTAT, as an intramolecular adjuvant. Linking Ags to eTAT enhanced cytosolic delivery of the Ags. This, in turn, led to improved activation and lymph node-trafficking of Ag-presenting cells and Ag cross-presentation, thus promoting Ag-specific T-cell immune responses. Simple mixing of eTAT-linked Ags and CpG significantly enhanced codelivery of Ags and CpG to the Ag-presenting cells, and this substantially augmented the adjuvant effect of CpG, maximized vaccine immunogenicity, and elicited robust and durable CD8+ T-cell responses. Vaccination with this formulation altered the tumor microenvironment and exhibited potent antitumor effects, with generally further enhanced therapeutic efficacy when used in combination with anti-PD1. Altogether, the engineered chimeric peptide-based orchestrated codelivery of Ag and adjuvant may serve as a promising but simple strategy to improve the efficacy of peptide-based cancer vaccines.

Microwave ablation combined with PD-L1 blockade synergistically promotes Cxcl9-mediated antitumor immunity

Although microwave ablation (MWA) is an important curative therapy in colorectal cancer liver metastasis, recurrence still occurs clinically. Our previous studies have shown that the expression of programmed cell death 1 ligand 1 (PD-L1) is upregulated following MWA, suggesting that MWA combined with anti-PD-L1 treatment can serve as a promising clinical therapeutic strategy against cancer. Using MWA-treated preclinical mice models, MWA combined with αPD-L1 treatment decreased tumor growth and prolonged overall survival (OS). Furthermore, through flow cytometry and single-cell RNA sequencing analysis, we determined that the MWA plus αPD-L1 therapy significantly suppressed CD8+ T cell exhaustion and enhanced their effector function. A significant increase in γ-interferon (IFN-γ) stimulated transcription factors, specifically Irf8, was observed. This enhancement facilitated the polarization of tumor-associated macrophages (TAM1s and TAM2s) through the nuclear factor-κB/JAK-STAT1 signaling pathway. Furthermore, the combination therapy stimulated the production of CXC motif chemokine ligand (CXCL9) by TAM1s and tumor cells, potentially increasing the chemotaxis of CD8 T cells and Th1 cells. Knocking out Cxcl9 in MC38 tumor cells or using CXCL9 blockade enhanced tumor growth of untreated tumors and shortened OS. Taken together, our study showed that blocking the IFN-γ-Cxcl9-CD8+ T axis promoted tumor progression and discovered a potential involvement of IRF8-regulated TAMs in preventing T cell exhaustion. Collectively, we identified that the combination of MWA with anti-PD-L1 treatment holds promise as a therapeutic strategy to rejuvenate the immune response against tumors. This merits further exploration in clinical studies.