Low-dose radiotherapy synergizes with iRGD-antiCD3-modified T cells by facilitating T cell infiltration

BACKGROUND AND PURPOSE

Poor penetration of transferred T cells represents a critical factor impeding the development of adoptive cell therapy in solid tumors. We demonstrated that iRGD-antiCD3 modification promoted both T cell infiltration and activation in our previous work. Interest in low-dose radiotherapy has recently been renewed due to its immuno-stimulatory effects including T cell recruitment. This study aims to explore the synergistic effects between low-dose radiotherapy and iRGD-antiCD3-modified T cells.

MATERIALS AND METHODS

Flow cytometry was performed to assess the expression of iRGD receptors and chemokines. T cell infiltration was evaluated by immunohistofluorescence and in vivo real-time fluorescence imaging and antitumor effects were investigated by in vivo bioluminescence imaging in the gastric cancer peritoneal metastasis mouse model.

RESULTS

We found that 2 Gy irradiation upregulated the expression of all three iRGD receptors and T-cell chemokines. The addition of 2 Gy low-dose irradiation boosted the accumulation and penetration of iRGD-antiCD3-modified T cells in peritoneal tumor nodules. Combining 2 Gy low-dose irradiation with iRGD-antiCD3-modified T cells significantly inhibited tumor growth and prolonged survival in the peritoneal metastasis mouse model with a favorable safety profile.

CONCLUSION

Altogether, we demonstrated that low-dose radiotherapy could improve the antitumor potency of iRGD-antiCD3-modified T cells by promoting T cell infiltration, providing a rationale for exploring low-dose radiotherapy in combination of other adoptive T cell therapies in solid tumors.

Lung metastasis-Harnessed in-Situ adherent porous organic nanosponge-mediated antigen capture for A self-cascaded detained dendritic cells and T cell infiltration

The infiltration of cytotoxic T lymphocytes promises to suppress the most irresistible metastatic tumor for immunotherapy, yet immune privilege and low immunogenic responses in these aggressive clusters often restrict lymphocyte recruitment. Here, an in situ adherent porous organic nanosponge (APON) doubles as organ selection agent and antigen captor to overcome immune privilege is developed. With selective organ targeting, the geometric effect of APON composed of disc catechol-functionalized covalent organic framework (COF) boosts the drug delivery to lung metastases. Along with a self-cascaded immune therapy, the therapeutic agents promote tumor release of damage-associated molecular patterns (DAMPs), and then, in situ deposition of gels to capture these antigens. Furthermore, APON with catechol analogs functions as a reservoir of antigens and delivers autologous DAMPs to detain dendritic cells, resulting in a sustained enhancement of immunity. This disc sponges (APON) at lung metastasis as antigen reservoirs and immune modulators effectively suppress the tumor in 60 days and enhanced the survival rate.

Suppression of the METTL3-m6A-integrin β1 axis by extracellular acidification impairs T cell infiltration and antitumor activity

The acidic metabolic byproducts within the tumor microenvironment (TME) hinder T cell effector functions. However, their effects on T cell infiltration remain largely unexplored. Leveraging the comprehensive The Cancer Genome Atlas dataset, we pinpoint 16 genes that correlate with extracellular acidification and establish a metric known as the "tumor acidity (TuAci) score" for individual patients. We consistently observe a negative association between the TuAci score and T lymphocyte score (T score) across various human cancer types. Mechanistically, extracellular acidification significantly impedes T cell motility by suppressing podosome formation. This phenomenon can be attributed to the reduced expression of methyltransferase-like 3 (METTL3) and the modification of RNA N6-methyladenosine (m6A), resulting in a subsequent decrease in the expression of integrin β1 (ITGB1). Importantly, enforced ITGB1 expression leads to enhanced T cell infiltration and improved antitumor activity. Our study suggests that modulating METTL3 activity or boosting ITGB1 expression could augment T cell infiltration within the acidic TME, thereby improving the efficacy of cell therapy.

Downregulation of S100A11 promotes T cell infiltration by regulating cancer-associated fibroblasts in prostate cancer

OBJECTIVE

This study aims at revealing the relationship between S100A11 and cancer-associated fibroblasts (CAFs) in prostate cancer and improving T cell infiltration into solid tumors.

METHODS

H&E, IHC and Sirius red staining were used to detect the stroma content in prostate cancer tissues. Stable S100A11 knockdown cell lines DU 145, 22Rv1, RM-1 and NOR-10 were established by lentivirus transfection. Co-culture system of RM-1 and CAFs was established. CCK-8, wound healing and transwell were proceeded to determine proliferation, migration and invasion of prostate cancer cells. Stably knocked-down RM-1 and CAFs were co-injected into C57BL/6 mice to detect the role of S100A11 in vivo. CAFs, CD4+ T cell and CD8+ T cell in these tumors were assessed by IF. T cell profile was analyzed by flow cytometry.

RESULTS

A significant amount of stroma exists in prostate cancer tissues. Downregulation of S100A11 inhibits proliferation, migration and invasion of human prostate cancer cells in vitro, and suppresses the expression of cancer-associated fibroblasts (CAFs) in vivo. Knockdown of S100A11 enhances the inhibitory effect of Erdafitinib on CAFs in both the co-culture system and in vivo. The combined knockdown of S100A11 in tumor cells and CAFs shows a superior therapeutic effect compared to the individual knockdown in tumor cells alone. Knockdown of S100A11, both in RM-1 and CAFs, combined with Erdafitinib treatment reduces tumorigenicity by suppressing the content of CAFs and increasing the infiltration of CD4+ T cell and effective CD8+ T cell in tumor.

CONCLUSION

Downregulation of S100A11 plays a crucial role in enhancing the therapeutic response to Erdafitinib and reversing immunosuppressive tumor microenvironment.

Development of a monoclonal antibody to ITPRIPL1 for immunohistochemical diagnosis of non-small cell lung cancers: accuracy and correlation with CD8+ T cell infiltration

Introduction: Cancer biomarkers are substances or processes highly associated with the presence and progression of cancer, which are applicable for cancer screening, progression surveillance, and prognosis prediction in clinical practice. In our previous studies, we discovered that cancer cells upregulate inositol 1,4,5-triphosphate receptor-interacting protein-like 1 (ITPRIPL1), a natural CD3 ligand, to evade immune surveillance and promote tumor growth. We also developed a monoclonal ITPRIPL1 antibody with high sensitivity and specificity. Here, we explored the application of anti-ITPRIPL1 antibody for auxiliary diagnosis of non-small cell lung cancer (NSCLC). Methods: NSCLC patient tissue samples (n = 75) were collected and stained by anti-ITPRIPL1 or anti-CD8 antibodies. After excluding the flaked samples (n = 15), we evaluated the expression by intensity (0-3) and extent (0-100%) of staining to generate an h-score for each sample. The expression status was classified into negative (h-score < 20), low-positive (20-99), and high-positive (≥ 100). We compared the h-scores between the solid cancer tissue and stroma and analyzed the correlation between the h-scores of the ITPRIPL1 and CD8 expression in situ in adjacent tissue slices. Results: The data suggested ITPRIPL1 is widely overexpressed in NSCLC and positively correlates with tumor stages. We also found that ITPRIPL1 expression is negatively correlated with CD8 staining, which demonstrates that ITPRIPL1 overexpression is indicative of poorer immune infiltration and clinical prognosis. Therefore, we set 50 as the cutoff point of ITPRIPL1 expression H scores to differentiate normal and lung cancer tissues, which is of an excellent sensitivity and specificity score (100% within our sample collection). Discussion: These results highlight the potential of ITPRIPL1 as a proteomic immunohistochemical NSCLC biomarker with possible advantages over the existing NSCLC biomarkers, and the ITPRIPL1 antibody can be applied for accurate diagnosis and prognosis prediction.

Nanoparticles (NPs)-mediated Siglec15 silencing and macrophage repolarization for enhanced cancer immunotherapy

T cell infiltration and proliferation in tumor tissues are the main factors that significantly affect the therapeutic outcomes of cancer immunotherapy. Emerging evidence has shown that interferon-gamma (IFNγ) could enhance CXCL9 secretion from macrophages to recruit T cells, but Siglec15 expressed on TAMs can attenuate T cell proliferation. Therefore, targeted regulation of macrophage function could be a promising strategy to enhance cancer immunotherapy via concurrently promoting the infiltration and proliferation of T cells in tumor tissues. We herein developed reduction-responsive nanoparticles (NPs) made with poly (disulfide amide) (PDSA) and lipid-poly (ethylene glycol) (lipid-PEG) for systemic delivery of Siglec15 siRNA (siSiglec15) and IFNγ for enhanced cancer immunotherapy. After intravenous administration, these cargo-loaded could highly accumulate in the tumor tissues and be efficiently internalized by tumor-associated macrophages (TAMs). With the highly concentrated glutathione (GSH) in the cytoplasm to destroy the nanostructure, the loaded IFNγ and siSiglec15 could be rapidly released, which could respectively repolarize macrophage phenotype to enhance CXCL9 secretion for T cell infiltration and silence Siglec15 expression to promote T cell proliferation, leading to significant inhibition of hepatocellular carcinoma (HCC) growth when combining with the immune checkpoint inhibitor. The strategy developed herein could be used as an effective tool to enhance cancer immunotherapy.

Construction and Validation of a Prognostic Model Based on Novel Senescence-Related Genes in Non-Small Cell Lung Cancer Patients with Drug Sensitivity and Tumor Microenvironment

Cellular senescence contributes to cancer pathogenesis and immune regulation. Using the LASSO Cox regression, we developed a 12-gene prognostic signature for lung adenocarcinoma (LUAD) from The Cancer Genome Atlas (TCGA) and a Gene Expression Omnibus (GEO) dataset. We assessed gene expression, drug sensitivity, immune infiltration, and conducted cell line experiments. High-risk LUAD patients showed increased mortality risk and shorter survival (P < 0.001). Senescence-related gene analysis indicated differences in protein phosphorylation and DNA methylation between normal individuals and LUAD patients. The high-risk group showed a positive association with PD-L1 expression (P = 0.003). Single-cell sequencing data suggested PEBP1 might significantly impact T cell infiltration. We predicted potential sensitive compounds for 12 senescence genes and found GAPDH promoted cell line proliferation. We established a novel prognostic system based on a newly identified senescence gene. High-risk patients had elevated immunosuppressive markers, and PEBP1 might influence T cell infiltration significantly. GAPDH, expressed at higher levels in tumors, could affect cancer progression. Our drug prediction model may guide treatment selection.

Arf1 Ablation in Colorectal Cancer Cells Activates a Super Signal Complex in DC to Enhance Anti-Tumor Immunity

The anti-tumor immune response relies on interactions among tumor cells and immune cells. However, the molecular mechanisms by which tumor cells regulate DCs as well as DCs regulate T cells remain enigmatic. Here, the authors identify a super signaling complex in DCs that mediates the Arf1-ablation-induced anti-tumor immunity. They find that the Arf1-ablated tumor cells release OxLDL, HMGB1, and genomic DNA, which together bound to a coreceptor complex of CD36/TLR2/TLR6 on DC surface. The complex then is internalized into the Rab7-marked endosome in DCs, and further joined by components of the NF-κB, NLRP3 inflammasome and cGAS-STING triple pathways to form a super signal complex for producing different cytokines, which together promote CD8+ T cell tumor infiltration, cross-priming and stemness. Blockage of the HMGB1-gDNA complex or reducing expression in each member of the coreceptors or the cGAS/STING pathway prevents production of the cytokines. Moreover, depletion of the type I IFNs and IL-1β cytokines abrogate tumor regression in mice bearing the Arf1-ablated tumor cells. These findings reveal a new molecular mechanism by which dying tumor cells releasing several factors to activate the triple pathways in DC for producing multiple cytokines to simultaneously promote DC activation, T cell infiltration, cross-priming and stemness.

NSUN2 is a glucose sensor suppressing cGAS/STING to maintain tumorigenesis and immunotherapy resistance

Glucose metabolism is known to orchestrate oncogenesis. Whether glucose serves as a signaling molecule directly regulating oncoprotein activity for tumorigenesis remains elusive. Here, we report that glucose is a cofactor binding to methyltransferase NSUN2 at amino acid 1-28 to promote NSUN2 oligomerization and activation. NSUN2 activation maintains global m5C RNA methylation, including TREX2, and stabilizes TREX2 to restrict cytosolic dsDNA accumulation and cGAS/STING activation for promoting tumorigenesis and anti-PD-L1 immunotherapy resistance. An NSUN2 mutant defective in glucose binding or disrupting glucose/NSUN2 interaction abolishes NSUN2 activity and TREX2 induction leading to cGAS/STING activation for oncogenic suppression. Strikingly, genetic deletion of the glucose/NSUN2/TREX2 axis suppresses tumorigenesis and overcomes anti-PD-L1 immunotherapy resistance in those cold tumors through cGAS/STING activation to facilitate apoptosis and CD8+ T cell infiltration. Our study identifies NSUN2 as a direct glucose sensor whose activation by glucose drives tumorigenesis and immunotherapy resistance by maintaining TREX2 expression for cGAS/STING inactivation.

Machine learning integrations develop an antigen-presenting-cells and T-Cells-Infiltration derived LncRNA signature for improving clinical outcomes in hepatocellular carcinoma

As a highly heterogeneous cancer, the prognostic stratification and personalized management of hepatocellular carcinoma (HCC) are still challenging. Recently, Antigen-presenting-cells (APCs) and T-cells-infiltration (TCI) have been reported to be implicated in modifying immunology in HCC. Nevertheless, the clinical value of APCs and TCI-related long non-coding RNAs (LncRNAs) in the clinical outcomes and precision treatment of HCC is still obscure. In this study, a total of 805 HCC patients were enrolled from three public datasets and an external clinical cohort. 5 machine learning (ML) algorithms were transformed into 15 kinds of ML integrations, which was used to construct the preliminary APC-TCI related LncRNA signature (ATLS). According to the criterion with the largest average C-index in the validation sets, the optimal ML integration was selected to construct the optimal ATLS. By incorporating several vital clinical characteristics and molecular features for comparison, ATLS was demonstrated to have a relatively more significantly superior predictive capacity. Additionally, it was found that the patients with high ATLS score had dismal prognosis, relatively high frequency of tumor mutation, remarkable immune activation, high expression levels of T cell proliferation regulators and anti-PD-L1 response as well as extraordinary sensitivity to Oxaliplatin/Fluorouracil/Lenvatinib. In conclusion, ATLS may serve as a robust and powerful biomarker for improving the clinical outcomes and precision treatment of HCC.

Aging exacerbates the brain inflammatory micro-environment contributing to α-synuclein pathology and functional deficits in a mouse model of DLB/PD

Background

Although ɑ-synuclein (ɑ-syn) spreading in age-related neurodegenerative diseases such as Parkinson’s disease (PD) and Dementia with Lewy bodies (DLB) has been extensively investigated, the role of aging in the manifestation of disease remains unclear.

Methods

We explored the role of aging and inflammation in the pathogenesis of synucleinopathies in a mouse model of DLB/PD initiated by intrastriatal injection of ɑ-syn preformed fibrils (pff).

Results

We found that aged mice showed more extensive accumulation of ɑ-syn in selected brain regions and behavioral deficits that were associated with greater infiltration of T cells and microgliosis. Microglial inflammatory gene expression induced by ɑ-syn-pff injection in young mice had hallmarks of aged microglia, indicating that enhanced age-associated pathologies may result from inflammatory synergy between aging and the effects of ɑ-syn aggregation. Based on the transcriptomics analysis projected from Ingenuity Pathway Analysis, we found a network that included colony stimulating factor 2 (CSF2), LPS related genes, TNFɑ and poly rl:rC-RNA as common regulators.

Conclusions

We propose that aging related inflammation (eg: CSF2) influences outcomes of pathological spreading of ɑ-syn and suggest that targeting neuro-immune responses might be important in developing treatments for DLB/PD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13024-022-00564-6.

Study protocol of a phase II study to evaluate safety and efficacy of neo-adjuvant pembrolizumab and radiotherapy in localized rectal cancer

BACKGROUND

Reshaping the tumor microenvironment by novel immunotherapies represents a key strategy to improve cancer treatment. Nevertheless, responsiveness to these treatments is often correlated with the extent of T cell infiltration at the tumor site. Remarkably, microsatellite stable rectal cancer is characterized by poor T cell infiltration and, therefore, does not respond to immune checkpoint blockade. To date, the only available curative option for these patients relies on extensive surgery. With the aim to broaden the application of promising immunotherapies, it is necessary to develop alternative approaches to promote T cell infiltration into the tumor microenvironment of these tumors. In this regard, recent evidence shows that radiotherapy has profound immunostimulatory effects, hinting at the possibility of combining it with immunotherapy. The combination of long-course chemoradiotherapy and immune checkpoint inhibition was recently shown to be safe and yielded promising results in rectal cancer, however short-course radiotherapy and immune checkpoint inhibition have never been tested in these tumors.

METHODS

Our clinical trial investigates the clinical and biological impact of combining pembrolizumab with short-course radiotherapy in the neo-adjuvant treatment of localized rectal cancer. This phase II non-randomized study will recruit 25 patients who will receive short-course preoperative radiotherapy (5 Gy × 5 days) and four injections of pembrolizumab starting on the same day and on weeks 4, 7 and 10. Radical surgery will be performed three weeks after the last pembrolizumab injection. Our clinical trial includes an extensive translational research program involving the transcriptomic and proteomic analysis of tumor and blood samples throughout the course of the treatment.

DISCUSSION

Our study is the first clinical trial to combine short-course radiotherapy and immune checkpoint inhibition in rectal cancer, which could potentially result in a major breakthrough in the treatment of this cancer. Additionally, the translational research program will offer insights into immunological changes within the tumor and blood and their correlation with patient outcome. Taken together, our work will help optimizing future treatment combinations and, possibly, better selecting patients.

TRIAL REGISTRATION

This study was registered with www.

CLINICALTRIAL

gov : NCT04109755 . Registration date: June, 2020.

Enhanced Tumoricidal Immune Responses by Transarterial Chemotherapy Using Novel Nanocomplexes in a Rat Liver Cancer Model

BACKGROUND/AIM

Locoregional treatments for hepatocellular carcinoma (HCC) induce immunogenic cell death and a tumor-specific immune response, but infiltration and activation of immune cells in the liver have not been clearly described. Transarterial chemoembolization (TACE) or transarterial chemotherapy (TAC) without embolization have been used to treat intermediate or advanced stage HCC patients. The identification of intrahepatic immune cell changes after locoregional therapy provides a theoretical basis for the combination with immune checkpoint inhibitors (ICIs) in HCC. This study aimed to determine the anticancer effect and changes in the liver immune cell population and function after direct injection of polymerized phenylboronic acid-conjugated doxorubicin (pPBA-Dox) nanocomplexes into the liver through TAC.

MATERIALS AND METHODS

pPBA-Dox nanocomplexes were delivered directly to the liver cancer in a rat model by transarterial methods. Anticancer effect was confirmed by magnetic resonance imaging (MRI), and the immune cell population and functional changes were confirmed by flow cytometry (FACS).

RESULTS

We first established a rat liver cancer model by implanting McA-RH7777 into rats and confirmed the formation of liver cancer through MRI, pathological examinations, and biochemical tests. Transarterial injection of pPBA-Dox nanocomplexes had a stronger anticancer effect than conventional Dox alone. Higher numbers of CD8⁺ and CD4⁺ T cells with activated phenotypes were infiltrated into the tumor microenvironment after transarterial pPBA-Dox treatments than after Dox alone treatment, suggesting the induction of stronger local immune responses by pPBA-Dox than Dox alone.

CONCLUSION

This study provides a theoretical basis for TAC combined with ICIs and insight into novel targeted therapies using nanocomplexes for the treatment of HCC.

lncRNA EGFR-AS1 facilitates leiomyosarcoma progression and immune escape via the EGFR-MYC-PD-L1 axis

AIM

this study was aimed to investigate the role of lncRNA EGFR-AS1, an antisense transcript of EGFR, in leiomyosarcoma (LMS) and the underling mechanisms.

METHODS

levels of EGFR-AS1 and PD-L1 were measured in LMS tissues and cell lines using qRT-PCR, as well as western blotting and/or immunohistochemical staining; flow cytometry was employed to validate the role of EGFR-AS1 on altering the activity of CD8 + T cells; interaction of EGFR-AS1 and EGFR was determined by fluorescent in situ hybridization (FISH) and RNA pull-down; regulation of MYC on PD-L1 promoter was assessed by chromatin immunoprecipitation (ChIP); a xenograft in vivo tumor growth assay was applied to verify the EGFR-AS1/EGFR/MYC/PD-L1 axis in vivo.

RESULTS

up-regulation of EGFR-AS1 and PD-L1 in LMS tissues was negatively correlated with CD8 + T cell infiltration; EGFR-AS1 positively regulated PD-L1, thereby strengthening interaction of LMS cells and CD8 + T cells and triggering CD8 + T cells apoptosis via the PD-1/PD-L1 checkpoint; EGFR-AS1 co-localized and interacted with EGFR to promote MYC activity; MYC was identified as a transcriptional activator of PD-L1.

CONCLUSION

lncRNA EGFR-AS1 was demonstrated to increase PD-L1 expression through the EGFR/MYC pathway in LMS cells, thereby repressing T cell infiltration and contributing to immune escape.

Rabies Virus Glycoprotein-Mediated Transportation and T Cell Infiltration to Brain Tumor by Magnetoelectric Gold Yarnballs

T lymphocyte infiltration with immunotherapy potentially suppresses most devastating brain tumors. However, local immune privilege and tumor heterogeneity usually limit the penetration of immune cells and therapeutic agents into brain tumors, leading to tumor recurrence after treatment. Here, a rabies virus glycoprotein (RVG)-camouflaged gold yarnball (RVG@GY) that can boost the targeting efficiency at a brain tumor via dual hierarchy- and RVG-mediated spinal cord transportation, facilitating the decrease of tumor heterogeneity for T cell infiltration, is developed. Upon magnetoelectric irradiation, the electron current generated on the GYs activates the electrolytic penetration of palbociclib-loaded dendrimer (Den[Pb]) deep into tumors. In addition, the high-density GYs at brain tumors also induces the disruption of cell-cell interactions and T cell infiltration. The integration of the electrolytic effects and T cell infiltration promoted by drug-loaded RVG@GYs deep in the brain tumor elicits sufficient T cell numbers and effectively prolongs the survival rate of mice with orthotopic brain tumors.

Keratin 17 Promotes T Cell Response in Allergic Contact Dermatitis by Upregulating C-C Motif Chemokine Ligand 20

Allergic contact dermatitis (ACD) is a delayed-type hypersensitivity response to skin contact allergens in which keratinocytes are critical in the initiation of early responses. Keratin 17 (K17) is a cytoskeletal protein inducible under stressful conditions and regulates multiple cellular processes, especially in skin inflammatory diseases; however, knowledge regarding its contribution to ACD pathogenesis remains ill defined. In the present study, we clarified the proinflammatory role of K17 in an oxazolone (OXA)-induced contact hypersensitivity (CHS) murine model and identified the underlying molecular mechanisms. Our results showed that K17 was highly expressed in the lesional skin of ACD patients and OXA-induced CHS mice. Mice lacking K17 exhibited alleviated OXA-induced skin inflammation, including milder ear swelling, a reduced frequency of T cell infiltration, and decreased inflammatory cytokine levels. In vitro, K17 stimulated and activated human keratinocytes to produce plenty of proinflammatory mediators, especially the chemokine CCL20, and promoted keratinocyte-mediated T cell trafficking. The neutralization of CCL20 with a CCL20-neutralizing monoclonal antibody significantly alleviated OXA-induced skin inflammation in vivo. Moreover, K17 could translocate into the nucleus of activated keratinocytes through a process dependent on the nuclear-localization signal (NLS) and nuclear-export signal (NES) sequences, thus facilitating the activation and nuclear translocation of signal transducer and activator of transcription 3 (STAT3), further promoting the production of CCL20 and T cell trafficking to the lesional skin. Taken together, these results highlight the novel roles of K17 in driving allergen-induced skin inflammation and suggest targeting K17 as a potential strategy for ACD.

Axl regulated survival/proliferation network and its therapeutic intervention in mouse models of glomerulonephritis

BACKGROUND

Lupus nephritis (LN) is the most common and serious complication of systemic lupus erythematosus (SLE). LN pathogenesis is not fully understood. Axl receptor tyrosine kinase is upregulated and contributes to the pathogenic progress in LN. We have reported that Axl disruption attenuates nephritis development in mice.

METHODS

In this study, we analyzed the gene expression profiles with RNA-seq using renal cortical samples from nephritic mice. Axl-KO mice were bred onto a B6.lpr spontaneous lupus background, and renal disease development was followed and compared to the Axl-sufficient B6.lpr mice. Finally, anti-glomerular basement membrane (anti-GBM) Ab-induced nephritic mice were treated with Axl small molecule inhibitor, R428, at different stages of nephritis development. Blood urine nitrogen levels and renal pathologies were evaluated.

RESULTS

Transcriptome analysis revealed that renal Axl activation contributed to cell proliferation, survival, and motility through regulation of the Akt, c-Jun, and actin pathways. Spontaneous lupus-prone B6.lpr mice with Axl deficiency showed significantly reduced kidney damages and decreased T cell infiltration compared to the renal damage and T cell infiltration in Axl-sufficient B6.lpr mice. The improved kidney function was independent of autoAb production. Moreover, R428 significantly reduced anti-GBM glomerulonephritis at different stages of GN development compared to the untreated nephritic control mice. R428 administration reduced inflammatory cytokine (IL-6) production, T cell infiltration, and nephritis disease activity.

CONCLUSIONS

Results from this study emphasize the important role of Axl signaling in LN and highlight Axl as an attractive target in LN.

The oncolytic virus VT09X optimizes immune checkpoint therapy in low immunogenic melanoma

Tumors with a low level of pre-existing immune cell infiltration respond poorly to immune checkpoint therapies. Oncolytic viruses optimize immunotherapies by modulating the tumor microenvironment and affecting multiple steps in the cancer-immunity cycle, making them an attractive agent for combination strategies. We engineered an HSV-1-based oncolytic virus and investigated its antitumor effects in combination with the marketed PD-1 antibody Keytruda (pembrolizumab) in hPD-1 knock-in mice bearing non-immunogenic B16-F10 melanoma. Our results showed enhanced CD8⁺ and CD4⁺ T cell infiltration, IFN-γ secretion and PD-L1 expression in tumors, subsequently leading to the prolonged overall survival of mice. Systemic changes in lymphocyte cell proportions were also observed in the peripheral blood. In summary, these findings provide evidence that oncolytic viruses can be engineered as a potential platform for combination therapies, especially to treat tumors that are poorly responsive to immune checkpoint therapy.

Chemokine C-C motif ligand 21 synergized with programmed death-ligand 1 blockade restrains tumor growth

Programmed death‐ligand 1 (PD‐L1) blockade has revolutionized the prognosis of several cancers, but shows a weak effect on pancreatic cancer (PC) due to poor effective immune infiltration. Chemokine C‐C motif ligand 21 (CCL21), a chemokine promoting T cell immunity by recruiting and colocalizing dendritic cells (DCs) and T cells, serves as a potential antitumor agent in many cancers. However, its antitumor response and mechanism combined with PD‐L1 blockade in PC remain unclear. In our study, we found CCL21 played an important role in leukocyte chemotaxis, inflammatory response, and positive regulation of PI3K‐AKT signaling in PC using Metascape and gene set enrichment analysis. The CCL21 level was verified to be positively correlated with infiltration of CD8⁺ T cells by the CIBERSORT algorithm, but no significant difference in survival was observed in either The Cancer Genome Atlas or the International Cancer Genome Consortium cohort when stratified by CCL21 expression. Additionally, we found the growth rate of allograft tumors was reduced and T cell infiltration was increased, but tumor PD‐L1 abundance elevated simultaneously in the CCL21‐overexpressed tumors. Then, CCL21 was further verified to increase tumor PD‐L1 level through the AKT‐glycogen synthase kinase‐3β axis in human PC cells, which partly impaired the antitumor T cell immunity. Finally, the combination of CCL21 and PD‐L1 blockade showed superior synergistic tumor suppression in vitro and in vivo. Together, our findings suggested that CCL21 in combination with PD‐L1 blockade might be an efficient and promising option for the treatment of PC.

Circulating PD-L1 is associated with T cell infiltration and predicts prognosis in patients with CRLM following hepatic resection

BACKGROUND

Exosomal PD-L1 (exoPD-L1) could induce immunosuppression functionally, thus impairing patients' survival in melanoma, NSCLC, and gastric cancer. However, no evidence demonstrates the feasibility of circulating exoPD-L1 and soluble PD-L1 (sPD-L1) as biomarkers for prognosis and early recurrence in colorectal liver metastasis (CRLM) patients following hepatectomy or their association with T cell infiltration at liver metastases.

METHODS

In cohort 1, exoPD-L1 and sPD-L1 were preoperatively tested using ELISA. CD3, CD8, granzyme B (GB) and PD1 expressed at liver metastases were evaluated using immunohistochemistry. In cohort 2, exoPD-L1 and sPD-L1 were detected at baseline, before hepatectomy, after hepatectomy, and after disease progression.

RESULTS

In cohort 1, higher preoperative exoPD-L1 or sPD-L1 significantly impaired RFS (exoPD-L1, P = 0.0043; sPD-L1, P = 0.0041) and OS (exoPD-L1, P = 0.0034; sPD-L1, P = 0.0061). Furthermore, preoperative exoPD-L1 was negatively correlated with CD3 + T-lymphocytes infiltrated at tumor center (CT), and GB and PD1 were expressed at tumor invasive margin (IM). Preoperative sPD-L1 was negatively correlated with CD3 + and CD8 + T-lymphocytes' infiltration at IM and CT, GB and PD1 expression at IM. In cohort 2, exoPD-L1 and sPD-L1 levels decreased following hepatectomy but increased when tumor progressed. Moreover, higher postoperative exoPD-L1 and sPD-L1 or a small reduction in exoPD-L1 and sPD-L1 levels after hepatectomy suggested higher early recurrence rate.

CONCLUSIONS

Both preoperative exoPD-L1 and sPD-L1 had promising prognostic values and were associated with T cell infiltration at liver metastases in CRLM patients following hepatectomy. Dynamically tracking exoPD-L1 and sPD-L1 levels could monitor disease status and detect early recurrence.

Moderating hypoxia and promoting immunogenic photodynamic therapy by HER-2 nanobody conjugate nanoparticles for ovarian cancer treatment

Photodynamic therapy (PDT) and immunotherapy have been often adopted for ovarian cancer therapy, yet their application is limited by the high recurrence rate and toxic side effects. Intriguingly, nanoparticles contribute to enhancing the performance of PDT. Here, we investigated the synthesis of HER-2-Nanobody (Nb)-conjugated human serum albumin (HSA) incorporated with chlorin (Ce6) and catalase (CAT) (Nb@HCC), and analyzed the synergic effect of Nb@HCC-mediated PDT and immunotherapy for SK-OV-3 tumors. The Ce6 and CAT were incorporated into HSA to construct the HCC nanoparticles. HER-2-Nanobody was the purified bacterial crude extract, and conjugated with HCC to prepare Nb@HCC via heterodisulfide. The effects of Nb@HCC with near infrared ray (NIR) irradiation on moderating hypoxia and hypoxia inducible factor-1α(HIF-1α) expression were evaluated in the SK-OV-3 cells and tumor tissues. A SK-OV-3 tumor-bearing model was developed, where the synergistic effect of Nb@HCC-mediated PDT and anti-CTLA-4 therapy was investigated. Nb@HCC with a 660 nm laser irradiation could induce massive reactive oxygen species and trigger apoptosis in SK-OV-3 cells. Nb@HCC and PDT promoted danger-associated molecular patterns (DAMPs), which indicated immunogenic cell death and maturation of dendritic cells in the SK-OV-3 cells. Irradiated by NIR, Nb@HCC alleviated the hypoxia and decreased the expression of HIF-1α. The Nb@HCC-mediated PDT and anti-CTLA-4 therapy synergically inhibited the progression of distant tumor, and induced T cell infiltration. Biosafety tests suggested that Nb@HCC would not cause damage to the major organs with less toxicity and side effects. To conclude, a combination of Nb@HCC-mediated PDT and anti-CTLA-4 therapy could inhibit the progression of distant tumor to attain remarkable therapeutic outcomes.

A Reproducible Bioprinted 3D Tumor Model Serves as a Preselection Tool for CAR T Cell Therapy Optimization

Chimeric antigen receptor (CAR) T cell performance against solid tumors in mouse models and clinical trials is often less effective than predicted by CAR construct selection in two-dimensional (2D) cocultures. Three-dimensional (3D) solid tumor architecture is likely to be crucial for CAR T cell efficacy. We used a three-dimensional (3D) bioprinting approach for large-scale generation of highly reproducible 3D human tumor models for the test case, neuroblastoma, and compared these to 2D cocultures for evaluation of CAR T cells targeting the L1 cell adhesion molecule, L1CAM. CAR T cells infiltrated the model, and both CAR T and tumor cells were viable for long-term experiments and could be isolated as single-cell suspensions for whole-cell assays quantifying CAR T cell activation, effector function and tumor cell cytotoxicity. L1CAM-specific CAR T cell activation by neuroblastoma cells was stronger in the 3D model than in 2D cocultures, but neuroblastoma cell lysis was lower. The bioprinted 3D neuroblastoma model is highly reproducible and allows detection and quantification of CAR T cell tumor infiltration, representing a superior in vitro analysis tool for preclinical CAR T cell characterization likely to better select CAR T cells for in vivo performance than 2D cocultures.

Cocktail strategy for 'cold' tumors therapy via active recruitment of CD8+ T cells and enhancing their function

In immunotherapy, 'cold' tumors, with low T cells infiltration, hardly benefit from the treatment of immune checkpoint inhibitors (ICIs). To address this issue, we screened two 'cold' tumor models for mice with high expression of galectin-3 (Gal-3) and designed a cocktail strategy to actively recruit CD8+ T cells into the tumor microenvironment (TME), which reversed 'cold' tumors into 'hot' and remarkably elevated their ICIs-responsiveness. Gal-3, an important driving force of tumorigenesis, inhibits T cell infiltration into tumor tissue that shapes 'cold' tumor phenotype, and promotes tumor metastasis. In this respect, Gal-3 antagonist G3-C12 peptide was chosen and further loaded into poly(lactic-co-glycolic acid) (PLGA) microspheres, with the prepared G3-C12@PLGA playing a dual role of antitumor, namely, killing two birds with one stone. Specifically, G3-C12@PLGA actively recruit T cells into 'cold' tumors by rescuing IFN-γ, and simultaneously inhibit tumor metastasis induced by Gal-3. Moreover, when combined with chemotherapeutic agent (Oxaliplatin) and anti-PD-1 peptide (APP), the immunopotentiating effect of dendritic cells (DCs) was extremely improved, with T-cell depletion dramatically reversed. In vivo experiments showed that such cocktail therapy exerted remarkable antitumor effect on 'cold' breast cancer (BC) and ovarian serous cancer (OSC). These results indicated that our strategy might be promising in treating 'cold' tumors with high expression of Gal-3, which not only enhance cancer treatment outcome, but provide a new platform for the prevention of postoperative tumor recurrence/metastasis.

Lipophilic recombinant-protein insertion endows lymphocytes with enhanced targeting-infiltration ability in EGFR positive cancer

Adoptive T cell transfer is one of the most promising ways to combat solid tumors. However, the weak infiltration of T cells into tumor sites has restricted their antitumor efficacy. To overcome this obstacle, we used the lipophilic protein painting strategy to improve tumor targeting and penetrating capacity of lymphocytes for the first time. We synthesized the lipid anchor consisting of a bispecific recombinant protein iRGD-antiEGFR and DSPE-PEG derivates, then successfully inserted it into the membranes of T cells. This surface modification was non-invasive and could efficiently improve the infiltration ability of T cells into multicellular spheroids and tumor masses. The surface modified T cells also displayed superior antitumor activities in EGFR-positive tumor xenografts via systematic infusion. Moreover, the permeability and antitumor efficacy of these surface painted T cells could be remarkably enhanced when used in combination with local low-dose irradiation.

High TIL, HLA, and Immune Checkpoint Expression in Conventional High-Grade and Dedifferentiated Chondrosarcoma and Poor Clinical Course of the Disease

Purpose

The aim of this study was to characterize chondrosarcoma tumor infiltration by immune cells and the expression of immunologically relevant molecules. This information may contribute to our understanding of the role of immunological events in the pathogenesis of chondrosarcoma and to the rational design of immunotherapeutic strategies.

Patients and Methods

A tissue microarray (TMA) containing 52 conventional and 24 dedifferentiated chondrosarcoma specimens was analyzed by immunohistochemical staining for the expression of parameters associated with tumor antigen-specific immune responses, namely, CD4⁺ and CD8⁺ tumor infiltrating lymphocytes (TILs) and the expression of HLA class I heavy chain, beta-2 microglobulin (β2m), HLA class II and immune checkpoint molecules, B7-H3 and PD-1/PD-L1. The results were correlated with histopathological characteristics and the clinical course of the disease.

Results

CD8⁺ TILs were present in 21% of the conventional and 90% of the dedifferentiated chondrosarcoma tumors tested. B7-H3 was expressed in 69% of the conventional and 96% of the dedifferentiated chondrosarcoma tumors tested. PD-1 and PD-L1 were expressed 53% and 33% respectively of the dedifferentiated tumors tested. PD-L1 expression was associated with shorter time to metastasis.

Conclusion

The tumor infiltration by lymphocytes suggests that chondrosarcoma is immunogenic. Defects in HLA class I antigen and expression of the checkpoint molecules B7-H3 and PD-1/PD-L1 suggest that tumor cells utilize escape mechanisms to avoid immune recognition and destruction. This data implies that chondrosarcoma will benefit from strategies that enhance the immunogenicity of tumor antigens and/or counteract the escape mechanisms.

Marginative Delivery-Mediated Extracellular Leakiness and T Cell Infiltration in Lung Metastasis by a Biomimetic Nanoraspberry

T lymphocytes infiltrate the most devastating metastatic tumors for immunotherapy, allowing the potential for tumor metastasis suppression. However, tumor heterogeneity often restricts the infiltration of immune cells and possesses immune privilege that leads to protection from the immune attack, especially for invading metastatic clusters. Here, an exosome-camouflaged nanoraspberry (RB@Exo) doubling as a metastases-targeting agent and T cell-infiltration inducer that delivers an anticancer drug and energy is reported. The RB@Exo integrated an exosome-derived margination effect, and density-mediated nanoparticle-induced extracellular leakiness (nanoEL) exhibited more than a 70% colocalization of the RB@Exo to metastatic tumors in the lung in vivo. The release of cancer cell-cell interactions at the metastasis via nanoEL also elicited the 10-fold infiltration of T lymphocytes. The synergy of the T cell infiltration and photolytic effects transported by the RB@Exo deep into the metastatic tumors effectively inhibited the tumor in 60 days when treated with a single alternating magnetic field (AMF).

DNA Sensing in Mismatch Repair-Deficient Tumor Cells Is Essential for Anti-tumor Immunity

Increased neoantigens in hypermutated cancers with DNA mismatch repair deficiency (dMMR) are proposed as the major contributor to the high objective response rate in anti-PD-1 therapy. However, the mechanism of drug resistance is not fully understood. Using tumor models defective in the MMR gene Mlh1 (dMLH1), we show that dMLH1 tumor cells accumulate cytosolic DNA and produce IFN-β in a cGAS-STING-dependent manner, which renders dMLH1 tumors slowly progressive and highly sensitive to checkpoint blockade. In neoantigen-fixed models, dMLH1 tumors potently induce T cell priming and lose resistance to checkpoint therapy independent of tumor mutational burden. Accordingly, loss of STING or cGAS in tumor cells decreases tumor infiltration of T cells and endows resistance to checkpoint blockade. Clinically, downregulation of cGAS/STING in human dMMR cancers correlates with poor prognosis. We conclude that DNA sensing within tumor cells is essential for dMMR-triggered anti-tumor immunity. This study provides new mechanisms and biomarkers for anti-dMMR-cancer immunotherapy.

Polyvinyl Alcohol Carbazate as a Polymer-Based Antitumoral Agent

Development of treatment resistance is a major concern during treatment of cancer, and there is an unmet need for therapeutic strategies with novel modes of action. Polyvinyl alcohol carbazate (PVAC) is a polymer compound with unique biological properties. Herein, we describe the antitumoral effects of PVAC. Three well-established cell lines GIST-T1, B16.F10, and A375 were used to determine the in vitro antitumoral effects of PVAC. Assessments included light microscopy, cell viability, cell cycle, and apoptosis assays. In vivo treatment safety and efficacy were characterized in one immunocompetent (B16.F10) mouse model and one athymic nude (MDA-MB-231) mouse model. Excised tumors were measured, weighed, stained for Ki-67, CD3, and histopathologically evaluated. Intact PVAC expressed a non-linear dose-response antitumoral effect in vitro, whereas its separate components, PVA and carbazate, did not display antitumoral effects alone. In vivo, PVAC induced a significant intratumoral CD3⁺ T-cell recruitment in immunocompetent mice (B16.F10), which was associated with tumor growth inhibition. Although growth inhibition was not significant in athymic mice (MDA-MB-231), histopathological evaluation detected an increase in stromal tissue and leukocyte infiltration. In conclusion, we present evidence for PVAC antitumoral effects both in vitro and in vivo. The mode of action was not elucidated in vitro, but a potential mechanism of in vivo activity was observed, characterized by an increase of immune cells into both immunocompetent and athymic mice. This finding warrants further study to validate its possible role as an immunomodulatory polymeric agent.

Cancer-Associated Fibroblast Mediated Inhibition of CD8+ Cytotoxic T Cell Accumulation in Tumours: Mechanisms and Therapeutic Opportunities

Simple Summary

The ability of the immune system to kill tumour cells is a natural and extremely effective defence mechanism for fighting cancer. Cytotoxic-T-cells are a critical component of our immune system which function is to eliminate cancer cells. In some cancers, especially those with a rich tumour stroma, these cytotoxic-T-cells are unable to reach and kill the tumour cells. Cancer-associated fibroblasts are the most abundant cells in the tumour stroma and play a key role of the recruitment, infiltration and function of cytotoxic T-cells in the tumour, via several molecular mechanisms which we describe in this review.

Abstract

The tumour microenvironment (TME) is the complex environment in which various non-cancerous stromal cell populations co-exist, co-evolve and interact with tumour cells, having a profound impact on the progression of solid tumours. The TME is comprised of various extracellular matrix (ECM) proteins in addition to a variety of immune and stromal cells. These include tumour-associated macrophages, regulatory T cells (Tregs), myeloid-derived suppressor cells, as well as endothelial cells, pericytes and cancer-associated fibroblasts (CAFs). CAFs are the most abundant stromal cell population in many tumours and support cancer progression, metastasis and resistance to therapies through bidirectional signalling with both tumour cells and other cells within the TME. More recently, CAFs have been shown to also affect the anti-tumour immune response through direct and indirect interactions with immune cells. In this review, we specifically focus on the interactions between CAFs and cytotoxic CD8+ T cells, and on how these interactions affect T cell recruitment, infiltration and function in the tumour. We additionally provide insight into the therapeutic implications of targeting these interactions, particularly in the context of cancer immunotherapy.

Bayesian multiple instance regression for modeling immunogenic neoantigens

The relationship between tumor immune responses and tumor neoantigens is one of the most fundamental and unsolved questions in tumor immunology, and is the key to understanding the inefficiency of immunotherapy observed in many cancer patients. However, the properties of neoantigens that can elicit immune responses remain unclear. This biological problem can be represented and solved under a multiple instance learning framework, which seeks to model multiple instances (neoantigens) within each bag (patient specimen) with the continuous response (T cell infiltration) observed for each bag. To this end, we develop a Bayesian multiple instance regression method, named BMIR, using a Gaussian distribution to address continuous responses and latent binary variables to model primary instances in bags. By means of such Bayesian modeling, BMIR can learn a function for predicting the bag-level responses and for identifying the primary instances within bags, as well as give access to Bayesian statistical inference, which are elusive in existing works. We demonstrate the superiority of BMIR over previously proposed optimization-based methods for multiple instance regression through simulation and real data analyses. Our method is implemented in R package entitled "BayesianMIR" and is available at https://github.com/inmybrain/BayesianMIR.

miR-150 inhibitor ameliorates adriamycin-induced focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is the most common cause of adult nephrotic syndrome in USA. Its mechanisms remain unclear and the effective treatment lacks. We previously reported that upregulation of microRNA (miR)-150 in human podocytes increases profibrotic proteins and decreases anti-fibrotic suppressor of cytokine signaling 1 (SOCS1). We aimed to clarify whether miR-150 inhibitor can ameliorate glomerular injury and to identify its corresponding mechanisms in adriamycin-induced FSGS mice. We found that renal miR-150 increased in adriamycin-induced FSGS mice and FAM-labeled locked nucleic acid-anti-miR-150 (LNA-anti-miR-150) was absorbed by the animal kidneys 6 h after subcutaneous injection. The administration of LNA-anti-miR-150 (2 mg/kg BW twice weekly for 6 w) inhibited renal miR-150 levels without systemic toxicity. With renal miR-150 inhibition, proteinuria, hypoalbuminemia, and hyperlipemia were ameliorated in FSGS mice compared to the scrambled LNA. Meanwhile, the elevated profibrotic proteins and proinflammatory cytokines, decreased antifibrotic SOCS1, and the filtration of T cells in FSGS mice were reverted by LNA-anti-miR-150. Finally, we found that miR-150 most located on podocytes in renal biopsies of FSGS patients. We conclude that LNA-anti-miR-150 might be a novel promising therapeutic agent for FSGS. The renal protective mechanisms might be mediated by anti-fibrosis and anti-inflammation as well as reducing infiltration of T cells in the kidney.

Tumor-intrinsic signaling pathways: key roles in the regulation of the immunosuppressive tumor microenvironment

Immunotherapy is a currently popular treatment strategy for cancer patients. Although recent developments in cancer immunotherapy have had significant clinical impact, only a subset of patients exhibits clinical response. Therefore, understanding the molecular mechanisms of immunotherapy resistance is necessary. The mechanisms of immune escape appear to consist of two distinct tumor characteristics: a decrease in effective immunocyte infiltration and function and the accumulation of immunosuppressive cells in the tumor microenvironment. Several host-derived factors may also contribute to immune escape. Moreover, inter-patient heterogeneity predominantly results from differences in somatic mutations between cancers, which has led to the hypothesis that differential activation of specific tumor-intrinsic pathways may explain the phenomenon of immune exclusion in a subset of cancers. Increasing evidence has also shown that tumor-intrinsic signaling plays a key role in regulating the immunosuppressive tumor microenvironment and tumor immune escape. Therefore, understanding the mechanisms underlying immune avoidance mediated by tumor-intrinsic signaling may help identify new therapeutic targets for expanding the efficacy of cancer immunotherapies.

Preclinical rationale and clinical efficacy of antiangiogenic therapy and immune checkpoint blockade combination therapy in urogenital tumors

PURPOSE

In recent years, immune checkpoint blockade (ICB) therapies have shown good clinical responses in various solid cancers. However, a major challenge in the process of ICB treatment is when tumors do not have enough infiltrating T cells. Antiangiogenic drugs targeting vascular endothelial growth factor (VEGF) and its receptors have been approved for the treatment of various malignant solid tumors alone or in combination with other therapies. Our review mainly discusses the preclinical rationale and clinical efficacy of antiangiogenic and ICB combination therapy in urogenital tumors.

METHODS

We reviewed relevant literature on preclinical research and clinical trial results regarding antiangiogenic and ICB combination therapy in urogenital tumors from PubMed. In addition, we searched ongoing clinical trials on ClinicalTrials.gov to collect information related to this specific topic.

RESULTS

Antiangiogenesis therapy could enhance T cell recruitment and increase T cell infiltration into the tumor microenvironment by blocking VEGF-VEGF receptor 2 binding and downstream signaling pathways to normalize tumor blood vessels. The combination of ICB and antiangiogenesis therapy could improve antitumor activity according to subsequent preclinical experiments and several phase I/II/III clinical trials on urogenital tumors.

CONCLUSION

Combined therapy has shown some antitumor efficacy in several urogenital tumors, such as metastatic renal cell carcinoma, metastatic urothelial and genitourinary tumors, endometrial carcinoma, ovarian cancer, and fallopian tube cancer. Combination therapy is a promising strategy that can be used to improve the therapeutic efficacy, and the identification of precise biomarkers of this combined therapy is the direction of future studies.

Lung adenocarcinoma-intrinsic GBE1 signaling inhibits anti-tumor immunity

Background

Changes in glycogen metabolism is an essential feature among the various metabolic adaptations used by cancer cells to adjust to the conditions imposed by the tumor microenvironment. Our previous study showed that glycogen branching enzyme (GBE1) is downstream of the HIF1 pathway in hypoxia-conditioned lung cancer cells. In the present study, we investigated whether GBE1 is involved in the immune regulation of the tumor microenvironment in lung adenocarcinoma (LUAD).

Methods

We used RNA-sequencing analysis and the multiplex assay to determine changes in GBE1 knockdown cells. The role of GBE1 in LUAD was evaluated both in vitro and in vivo.

Results

GBE1 knockdown increased the expression of chemokines CCL5 and CXCL10 in A549 cells. CD8 expression correlated positively with CCL5 and CXCL10 expression in LUAD. The supernatants from the GBE1 knockdown cells increased recruitment of CD8⁺ T lymphocytes. However, the neutralizing antibodies of CCL5 or CXCL10 significantly inhibited cell migration induced by shGBE1 cell supernatants. STING/IFN-I pathway mediated the effect of GBE1 knockdown for CCL5 and CXCL10 upregulation. Moreover, PD-L1 increased significantly in shGBE1 A549 cells compared to those in control cells. Additionally, in LUAD tumor tissues, a negative link between PD-L1 and GBE1 was observed. Lastly, blockade of GBE1 signaling combined with anti-PD-L1 antibody significantly inhibited tumor growth in vivo.

Conclusions

GBE1 blockade promotes the secretion of CCL5 and CXCL10 to recruit CD8⁺ T lymphocytes to the tumor microenvironment via the IFN-I/STING signaling pathway, accompanied by upregulation of PD-L1 in LUAD cells, suggesting that GBE1 could be a promising target for achieving tumor regression through cancer immunotherapy in LUAD.

Electronic supplementary material

The online version of this article (10.1186/s12943-019-1027-x) contains supplementary material, which is available to authorized users.

Microglial priming of antigen presentation and adaptive stimulation in Alzheimer's disease

The prominent pathological consequences of Alzheimer's disease (AD) are the misfolding and mis-sorting of two cellular proteins, amyloid-β and microtubule-associated protein Tau. The accumulation of toxic phosphorylated Tau inside the neurons induces the increased processing of amyloid-β-associated signaling cascade and vice versa. Neuroinflammation-driven synaptic depletion and cognitive decline are substantiated by the cross talk of activated microglia and astroglia, leading to neuron degeneration. Microglia are the brain-resident immune effectors that prove their diverse functions in maintaining CNS homeostasis via collaboration with astrocytes and T lymphocytes. Age-related senescence and chronic inflammation activate microglia with increased pro-inflammatory markers, oxidative damage and phagocytosis. But the improper processing of misfolded protein via lysosomal pathway destines the spreading of 'seed' constituents to the nearby healthy neurons. Primed microglia process and present self-antigen such as amyloid-β and modified Tau to the infiltrated T lymphocytes through MHC I/II molecules. After an effective conversation with CD4⁺ T cells, microglial phenotype can be altered from pro-active M1 to neuro-protective M2 type, which corresponds to the tissue remodeling and homeostasis. In this review, we are focusing on the change in functionality of microglia from innate to adaptive immune response in the context of neuroprotection, which may help in the search of novel immune therapy in AD.

PD-L1 Expression and Immune Cell Infiltration in Gastroenteropancreatic (GEP) and Non-GEP Neuroendocrine Neoplasms With High Proliferative Activity

The potential of neuroendocrine neoplasms (NEN) to respond to checkpoint inhibitors is largely unknown and full of great expectations. Immunohistochemical (IHC) studies of programmed cell death ligand 1 (PD-L1) expression in the tumor microenvironment and its implications in predicting the response to checkpoint inhibition is a very active subject. Currently, the combined analysis of PD-L1 expression and tumor-associated immune cell (TAIC) infiltration is considered the best predictive marker of therapeutic response. Here we investigated the expression of PD-L1 on tumor cells (TC) and tumor-infiltrating immune cells (IC) by IHC in 68 NEN samples with a high proliferation rate (Ki-67 >20%) from 57 patients and in 22 samples we correlated it with TAIC density by assessing intratumoral infiltration of CD3+, CD8+, and CD68+ cells. Furthermore, the tumor microenvironment was evaluated according to the classification of Teng et al. We detected PD-L1 expression in 31.6% of NEN G3. Its expression usually was weak and more IC than TC expressed PD-L1. The proportion of tumors positive for PD-L1 was comparable in NEN from different sites of origin but varied depending on tumor differentiation and disease extension. No positive IHC staining was found in 3 well-differentiated neuroendocrine tumors (NETs) with a proliferation rate above 20% (NET G3). When analyzing TAIC, we rarely (18.2%) detected intratumoral CD8+ cells, whereas infiltration by CD3+ and CD68+ cells was more common (45.5 and 59.1%, respectively). By combining CD3+ cells and PD-L1 status, we identified the immune ignorant phenotype of tumor microenvironment as being the most common phenotype, supporting the concept of a preferably combined immunotherapeutic approach in neuroendocrine carcinoma (NEC).

Impact of autophagic regulation on splenic red pulp macrophages during cerebral malarial infection

Splenic red pulp macrophages play a critical role infiltration of infected RBC and elimination of pathogens during malarial infection. However, the efficiency of pathogenic processing and the intricate pathway followed by them to boost the downstream immune response has not been studied in details. We checked the status of autophagic regulation within the cells both before and after the infection and also modulated the autophagic flux with either its inducer or inhibitor. We found that the upregulation of autophagic gene and the corresponding pathway is correlated with better parasite clearance and survivability, with an enhanced downstream immune response. It also increases their phagocytic potential with better Lysosomal associated protein I and II synthesis. The autophagolysosome formation increases as well, and more vacuole bound LC3B protein are detected. Chemokine synthesized from Red Pulp macrophage helps in mediating the induction for recruiting neutrophil and CD4 + T cells to the splenic red pulp region. The skewing of M1 macrophage polarity is observed post autophagic induction with a better costimulatory molecule like CD80, CD86 expression and antigen presenting molecule MHC I, MHC II is observed. This study shows the possibility of an alternative or adjuvant therapy regimen for the malarial patient by inducing the autophagic pathway that targets the red pulp macrophages. This might be helpful for better pathogen degradation and processing. The subsequent clearance of parasite will result in a better outcome for the patients.

Resistance to anti-PD-1-based immunotherapy in basal cell carcinoma: a case report and review of the literature

BACKGROUND

Immunotherapy with immune checkpoint inhibitors has radically changed the management of a broad spectrum of tumors. In contrast, only very limited information is available about the efficacy of these therapies in non-melanoma skin cancers, especially in basal cell carcinoma. The latter malignancy is often associated with both an impairment of the host immune response and a high mutation burden, suggesting that immune checkpoint inhibitor-based immunotherapy may be effective in the treatment of this tumor.

CASE PRESENTATION

A 78-year-old woman was diagnosed with a metastatic non-small-cell-lung-cancer. Following the lack of response to two lines of systemic chemotherapy, she was treated with the anti-PD-1 monoclonal antibody nivolumab, obtaining a prolonged stable disease. Under nivolumab treatment, the patient developed a basal cell carcinoma of the nose. The latter was surgically resected. Immunohistochemical staining of tumor tissue showed a PD-L1 expression < 1% and lack of human leukocyte antigen class I subunit (i.e. heavy and light chain) expression on tumor cells. In addition, a limited number of T cells (CD3+) was present in the tumor microenvironment, with a higher number of regulatory T cells (Foxp3+) and macrophages (Cd11b+) as compared to a low infiltration of activated cytotoxic T cells (CD8+/ Granzyme B+). Two months following the surgical removal of the tumor, while still on nivolumab treatment, the patient relapsed with a basal cell carcinoma in the same anatomic site of the previous surgical excision. The tumor displayed the same pathological characteristics.

CONCLUSION

Preclinical lines of evidence suggest a potential role of immune checkpoint inhibitors for basal cell carcinoma treatment. However, limited clinical data is available. In the patient we have described administration of the immune checkpoint inhibitor nivolumab for the treatment of a responsive non-small cell carcinoma was associated with the development and relapse of a basal cell carcinoma tumor. This association is likely to reflect the resistance of basal cell carcinoma cells to anti-PD-1 based immunotherapy because of a "cold" tumor microenvironment characterized by lack of human leukocyte antigen class I expression, low PD-L1 expression and high number of immune regulatory cells.

LSD1 Ablation Stimulates Anti-tumor Immunity and Enables Checkpoint Blockade

Chromatin regulators play a broad role in regulating gene expression and, when gone awry, can lead to cancer. Here, we demonstrate that ablation of the histone demethylase LSD1 in cancer cells increases repetitive element expression, including endogenous retroviral elements (ERVs), and decreases expression of RNA-induced silencing complex (RISC) components. Significantly, this leads to double-stranded RNA (dsRNA) stress and activation of type 1 interferon, which stimulates anti-tumor T cell immunity and restrains tumor growth. Furthermore, LSD1 depletion enhances tumor immunogenicity and T cell infiltration in poorly immunogenic tumors and elicits significant responses of checkpoint blockade-refractory mouse melanoma to anti-PD-1 therapy. Consistently, TCGA data analysis shows an inverse correlation between LSD1 expression and CD8⁺ T cell infiltration in various human cancers. Our study identifies LSD1 as a potent inhibitor of anti-tumor immunity and responsiveness to immunotherapy and suggests LSD1 inhibition combined with PD-(L)1 blockade as a novel cancer treatment strategy.

Combination of radiotherapy and vaccination overcomes checkpoint blockade resistance

The majority of cancer patients respond poorly to either vaccine or checkpoint blockade, and even to the combination of both. They are often resistant to high doses of radiation therapy as well. We examined prognostic markers of immune cell infiltration in pancreatic cancer. Patients with low CD8⁺ T cell infiltration and high PD-L1 expression (CD8⁺ T^loPD-L1^hi) experienced poor outcomes. We developed a mouse tumor fragment model with a trackable model antigen (SIYRYYGL or SIY) to mimic CD8⁺ T^loPD-L1^hi cancers. Tumors arising from fragments contained few T cells, even after vaccination. Fragment tumors responded poorly to PD-L1 blockade, SIY vaccination or radiation individually. By contrast, local ionizing radiation coupled with vaccination increased CD8⁺ T cell infiltration that was associated with upregulation of CXCL10 and CCL5 chemokines in the tumor, but demonstrated modest inhibition of tumor growth. The addition of an anti-PD-L1 antibody enhanced the effector function of tumor-infiltrating T cells, leading to significantly improved tumor regression and increased survival compared to vaccination and radiation. These results indicate that sequential combination of radiation, vaccination and checkpoint blockade converts non-T cell-inflamed cancers to T cell-inflamed cancers, and mediates regression of established pancreatic tumors with an initial CD8⁺ T^loPD-L1^hi phenotype. This study has opened a new strategy for shifting “cold” to hot tumors that will respond to immunotherapy.

FOXP3 and CEACAM6 expression and T cell infiltration in the occurrence and development of colon cancer

The transcription factor forkhead box P3 (FOXP3) is involved in immune cell regulation, and carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) is an adhesion molecule of the immunoglobulin superfamily. These two genes are associated with cancer progression. In the current study, colon tissue specimens from 78 cases of colon cancer (including 40 of stage I-II and 38 of stage III-IV), 30 cases of colonic adenoma and 12 healthy controls were collected from the First Affiliated Hospital of Soochow University between January 2010 and December 2011. The expression of cluster of differentiation (CD) 3, CD4, CD8, CD45RO, CEACAM6 and FOXP3 in colon tissues was examined by immunohistochemical analysis. In addition, a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay, based on SYBR Green I, was used to detect CD3, CD4, CD8, CD45RO, CEACAM6 and FOXP3 mRNA levels in the paraffin block specimens. CD3⁺, CD8⁺ and CD45RO⁺ T cell infiltrations in colonic adenoma were significantly higher than in normal colonic mucosa (P<0.001, P=0.001 and P<0.001, respectively). However, CD3⁺, CD8⁺ and CD45RO⁺ lymphocytes in stage III-IV colon cancer tissues were lower than in normal control tissues (P=0.015, P=0.002 and P=0.041, respectively); consistently, CD3⁺, CD4⁺, CD8⁺ and CD45RO⁺ lymphocytes in stage III-IV tissues were even more markedly lower compared with adenoma (P=0.001, P<0.001, P<0.001 and P<0.001, respectively). Similarly, CD3⁺, CD8⁺ and CD45RO⁺ T cell infiltration was lower in stage I-II cancer tissues compared with adenoma (P=0.001, P<0.001 and P<0.001). CD3⁺, CD4⁺, CD8⁺ and CD45RO⁺ T cell infiltrations were also significantly higher in stage I-II compared with stage III-IV cancer tissues (P<0.001, P=0.045, P<0.001 and P<0.001, respectively). CEACAM6 was found to gradually increase from normal colon tissue to adenoma and cancer tissue. FOXP3 was expressed more highly in stage I-II compared with normal tissues (P=0.014), and was even higher in stage III-IV (P<0.001). These results were verified using RT-qPCR, which yielded almost identical results. In summary, the current study demonstrates that FOXP3, CEACAM6 and T cell infiltration are significantly associated with the occurrence and progression of colon cancer, and that immune reactions vary between different stages of colon cancer development.

Blocking IL-10 signalling at the time of immunization renders the tumour more accessible to T cell infiltration in mice

We recently reported that blockade of IL-10 signalling at the time of a human papillomavirus (HPV) long E7 peptide/LPS immunization leads to the regression of established HPV-16 immortalized tumours in mice similar to that induced by long E7 peptide/incomplete Freund's adjuvant (IFA)-based vaccination. In this paper, we demonstrated that blockade of IL-10 signalling at the time of long E7 peptide/LPS could elicit stronger T cells responses and render the tumour more accessible for immune cell infiltration than vaccination with long E7 peptide/IFA. Furthermore, priming with long E7 peptide/LPS and IL10 signalling blockade then boosting with long E7 peptide/IFA elicits stronger CD8+ T cell responses than long E7 peptide/IFA immunization. The results suggest that priming with long E7 peptide/LPS and IL10 signalling inhibitor, then boosting with long E7 peptide/IFA elicits may lead to better HPV infection related tumour regression in clinic.

Tumor-intrinsic oncogene pathways mediating immune avoidance

Immunotherapy is emerging as a major treatment for patients with cancer, predominantly via blocking immune inhibitory pathways and through adoptive T cell therapy. However, only a subset of patients shows clinical responses to these interventions. Emerging data indicates a correlation between clinical response and a pre-existing T cell-inflamed tumor microenvironment. Tumor-intrinsic β-catenin activation has been identified as mediating exclusion of T cells from the tumor microenvironment and other oncogene pathways are being explored similarly. Understanding the molecular mechanisms underlying immune avoidance should identify new therapeutic targets for expanding efficacy of immunotherapies.

Attenuation of microglial RANTES by NEMO-binding domain peptide inhibits the infiltration of CD8(+) T cells in the nigra of hemiparkinsonian monkey

Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). Despite intense investigations, little is known about its pathological mediators. Here, we report the marked upregulation of RANTES (regulated on activation, normal T cell expressed and secreted) and eotaxin, chemokines that are involved in T cell trafficking, in the serum of hemiparkinsonian monkeys. Interestingly, 1-methyl-4-phenylpyridinium (MPP(+)), a Parkinsonian toxin, increased the expression of RANTES and eotaxin in mouse microglial cells. The presence of NF-κB binding sites in promoters of RANTES and eotaxin and down-regulation of these genes by NEMO-binding domain (NBD) peptide, selective inhibitor of induced NF-κB activation, in MPP(+)-stimulated microglial cells suggest that the activation of NF-κB plays an important role in the upregulation of these two chemokines. Consistently, serum enzyme-linked immuno assay (ELISA) and nigral immunohistochemistry further confirmed that these chemokines were strongly upregulated in MPTP-induced hemiparkinsonian monkeys and that treatment with NBD peptides effectively inhibited the level of these chemokines. Furthermore, the microglial upregulation of RANTES in the nigra of hemiparkinsonian monkeys could be involved in the altered adaptive immune response in the brain as we observed greater infiltration of CD8(+) T cells around the perivascular niche and deep brain parenchyma of hemiparkinsonian monkeys as compared to control. The treatment of hemiparkinsonian monkeys with NBD peptides decreased the microglial expression of RANTES and attenuated the infiltration of CD8(+) T cells in nigra. These results indicate the possible involvement of chemokine-dependent adaptive immune response in Parkinsonism.

Suppression of soluble T cell-associated proteins by an anti-interferon-α monoclonal antibody in adult patients with dermatomyositis or polymyositis

OBJECTIVE

The aim of this study was to identify serum markers that are modulated by an investigational anti-IFN-α mAb, sifalimumab, in adult DM or PM patients.

METHODS

In a phase 1b clinical trial, sera were collected from a total of 48 DM or PM adult patients receiving either placebo for 3 months or sifalimumab for 6 months. Samples were tested for 128 selected proteins using a multiplex luminex immunoassay. Muscle biopsies from selected patients were stained for T cell infiltration using an anti-CD3 antibody.

RESULTS

A robust overexpression of multiple serum proteins in DM or PM patients was observed, particularly in patients with an elevated baseline type I IFN gene signature in the blood or muscle. Neutralization of the type I IFN gene signature by sifalimumab resulted in coordinated suppression of T cell-related proteins such as soluble IL-2RA, TNF receptor 2 (TNFR2) and IL-18. Muscle biopsies from two patients with the highest serum protein suppression were selected and found to have a pronounced reduction of muscle T cell infiltration. Down-regulation of IL-2RA correlated with favourable manual muscle test 8 (MMT-8) alterations in sifalimumab-dosed patients.

CONCLUSION

A reduced level of multiple T cell-associated proteins after sifalimumab but not placebo administration suggests a suppressive effect of blocking type I IFN signalling on T cell activation and chemoattraction that may lead to a reduction of T cell infiltration in the muscle of myositis patients. Further, soluble IL-2RA changes from baseline may serve as a responsive and/or predictive marker for type I IFN-targeted therapy in adult DM or PM patients.