Innate αβ T Cells Mediate Antitumor Immunity by Orchestrating Immunogenic Macrophage Programming

C-C chemokine receptor 5 is essential for conventional NK cell trafficking and liver injury in a murine hepatitis virus-induced fulminant hepatic failure model

BACKGROUND

Previous studies have demonstrated that natural killer (NK) cells migrated into the liver from peripheral organs and exerted cytotoxic effects on hepatocytes in virus-induced liver failure.

AIM

This study aimed to investigate the potential therapeutic role of chemokine receptors in the migration of NK cells in a murine hepatitis  virus strain 3 (MHV-3)-induced fulminant hepatic failure (MHV-3-FHF) model and its mechanism.

RESULTS

By gene array analysis, chemokine (C-C motif) receptor 5 (CCR5) was found to have remarkably elevated expression levels in hepatic NK cells after MHV-3 infection. The number of hepatic CCR5+ conventional NK (cNK) cells increased and peaked at 48 h after MHV-3 infection, while the number of hepatic resident NK (rNK) cells steadily declined. Moreover, the expression of CCR5-related chemokines, including macrophage inflammatory protein (MIP)-1α, MIP-1β and regulated on activation, normal T-cell expressed and secreted (RANTES) was significantly upregulated in MHV-3-infected hepatocytes. In an in vitro Transwell migration assay, CCR5-blocked splenic cNK cells showed decreased migration towards MHV-3-infected hepatocytes, and inhibition of MIP-1β or RANTES but not MIP-1α decreased cNK cell migration. Moreover, CCR5 knockout (KO) mice displayed reduced infiltration of hepatic cNK cells after MHV-3 infection, accompanied by attenuated liver injury and improved mouse survival time. Adoptive transfer of cNK cells from wild-type mice into CCR5 KO mice resulted in the abundant accumulation of hepatic cNK cells and aggravated liver injury. Moreover, pharmacological inhibition of CCR5 by maraviroc reduced cNK cell infiltration in the liver and liver injury in the MHV-3-FHF model.

CONCLUSION

The CCR5-MIP-1β/RANTES axis played a critical role in the recruitment of cNK cells to the liver during MHV-3-induced liver injury. Targeted inhibition of CCR5 provides a therapeutic approach to ameliorate liver damage during virus-induced acute liver injury.

scRNA-Seq and imaging mass cytometry analyses unveil iNKT cells-mediated anti-tumor immunity in pancreatic cancer liver metastasis

Invariant natural killer T (iNKT) cells are innate-like T cells that are abundant in liver sinusoids and play a critical role in tumor immunity. However, the role of iNKT cells in pancreatic cancer liver metastasis (PCLM) has not been fully explored. In this study, we employed a hemi-spleen pancreatic tumor cell injection mouse model of PCLM, a model that closely mimics clinical conditions in humans, to explore the role of iNKT cells in PCLM. Activation of iNKT cells with α-galactosylceramide (αGC) markedly increased immune cell infiltration and suppressed PCLM progression. Via single cell RNA sequencing (scRNA-seq) we profiled over 30,000 immune cells from normal liver and PCLM with or without αGC treatment and were able to characterize the global changes of the immune cells in the tumor microenvironment upon αGC treatment, identifying a total of 12 subpopulations. Upon treatment with αGC, scRNA-Seq and flow cytometry analyses revealed increased cytotoxic activity of iNKT/NK cells and skewing CD4 T cells towards a cytotoxic Th1 profile and CD8 T cells towards a cytotoxic profile, characterized by higher proliferation and reduced exhaustion marker PD1 expression. Moreover, αGC treatment excluded tumor associated macrophages. Lastly, imaging mass cytometry analysis uncovered the reduced epithelial to mesenchymal transition related markers and increased active CD4 and CD8 T cells in PCLM with αGC treatment. Overall, our findings uncover the protective function of activated iNKT cells in pancreatic cancer liver metastasis through increased NK and T cell immunity and decreased tumor associated macrophages.

Targeting T cell checkpoints 41BB and LAG3 and myeloid cell CXCR1/CXCR2 results in antitumor immunity and durable response in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is considered non-immunogenic, with trials showing its recalcitrance to PD1 and CTLA4 immune checkpoint therapies (ICTs). Here, we sought to systematically characterize the mechanisms underlying de novo ICT resistance and to identify effective therapeutic options for PDAC. We report that agonist 41BB and antagonist LAG3 ICT alone and in combination, increased survival and antitumor immunity, characterized by modulating T cell subsets with antitumor activity, increased T cell clonality and diversification, decreased immunosuppressive myeloid cells and increased antigen presentation/decreased immunosuppressive capability of myeloid cells. Translational analyses confirmed the expression of 41BB and LAG3 in human PDAC. Since single and dual ICTs were not curative, T cell-activating ICTs were combined with a CXCR1/2 inhibitor targeting immunosuppressive myeloid cells. Triple therapy resulted in durable complete responses. Given similar profiles in human PDAC and the availability of these agents for clinical testing, our findings provide a testable hypothesis for this lethal disease.

Biophysical heterogeneity of myeloid-derived microenvironment to regulate resistance to cancer immunotherapy

Despite the advances in immunotherapy for cancer treatment, patients still obtain limited benefits, mostly owing to unrestrained tumour self-expansion and immune evasion that exploits immunoregulatory mechanisms. Traditionally, myeloid cells have a dominantly immunosuppressive role. However, the complicated populations of the myeloid cells and their multilateral interactions with tumour/stromal/lymphoid cells and physical abnormalities in the tumour microenvironment (TME) determine their heterogeneous functions in tumour development and immune response. Tumour-associated myeloid cells (TAMCs) include monocytes, tumour-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), dendritic cells (DCs), and granulocytes. Single-cell profiling revealed heterogeneous TAMCs composition, sub-types, and transcriptomic signatures across 15 human cancer types. We systematically reviewed the biophysical heterogeneity of TAMC composition and pro/anti-tumoral and immuno-suppressive/stimulating properties of myeloid-derived microenvironments. We also summarised comprehensive clinical strategies to overcome resistance to immunotherapy from three dimensions: targeting TAMCs, reversing physical abnormalities, utilising nanomedicines, and finally, put forward futuristic perspectives for scientific and clinical research.

N7-Methylguanosine-Related lncRNAs: Integrated Analysis Associated With Prognosis and Progression in Clear Cell Renal Cell Carcinoma

N7-Methylguanosine (m7G) and long non-coding RNAs (lncRNAs) have been widely reported to play an important role in cancer. However, there is little known about the relationship between m7G-related lncRNAs and clear cell renal cell carcinoma (ccRCC). To find new potential biomarkers and construct an m7G-related lncRNA prognostic signature for ccRCC, we retrieved transcriptome data and clinical data from The Cancer Genome Atlas (TCGA), and divided the entire set into train set and test set with the ratio of 1:1 randomly. The m7G-related lncRNAs were identified by Pearson correlation analysis (|coefficients| > 0.4, and p < 0.001). Then we performed the univariate Cox regression and least absolute shrinkage and selection operator (LASSO) Cox regression analysis to construct a 12 m7G-related lncRNA prognostic signature. Next, principal component analysis (PCA), the Kaplan–Meier method, time-dependent receiver operating characteristics (ROC) were made to verify and evaluate the risk signature. A nomogram based on the risk signature and clinical parameters was developed and showed high accuracy and reliability for predicting the overall survival (OS). Functional enrichment analysis (GO, KEGG and GSEA) was used to investigate the potential biological pathways. We also performed the analysis of tumor mutation burden (TMB), immunological analysis including immune scores, immune cell infiltration (ICI), immune function, tumor immune escape (TIE) and immunotherapeutic drug in our study. In conclusion, using the 12 m7G-related lncRNA risk signature as a prognostic indicator may offer us insight into the oncogenesis and treatment response prediction of ccRCC.

Leronlimab, a humanized monoclonal antibody to CCR5, blocks breast cancer cellular metastasis and enhances cell death induced by DNA damaging chemotherapy

Background

Triple-negative breast cancer (BCa) (TNBC) is a deadly form of human BCa with limited treatment options and poor prognosis. In our prior analysis of over 2200 breast cancer samples, the G protein-coupled receptor CCR5 was expressed in > 95% of TNBC samples. A humanized monoclonal antibody to CCR5 (leronlimab), used in the treatment of HIV-infected patients, has shown minimal side effects in large patient populations.

Methods

A humanized monoclonal antibody to CCR5, leronlimab, was used for the first time in tissue culture and in mice to determine binding characteristics to human breast cancer cells, intracellular signaling, and impact on (i) metastasis prevention and (ii) impact on established metastasis.

Results

Herein, leronlimab was shown to bind CCR5 in multiple breast cancer cell lines. Binding of leronlimab to CCR5 reduced ligand-induced Ca^+ 2 signaling, invasion of TNBC into Matrigel, and transwell migration. Leronlimab enhanced the BCa cell killing of the BCa chemotherapy reagent, doxorubicin. In xenografts conducted with Nu/Nu mice, leronlimab reduced lung metastasis of the TNBC cell line, MB-MDA-231, by > 98% at 6 weeks. Treatment with leronlimab reduced the metastatic tumor burden of established TNBC lung metastasis.

Conclusions

The safety profile of leronlimab, together with strong preclinical evidence to both prevent and reduce established breast cancer metastasis herein, suggests studies of clinical efficacy may be warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01391-1.

Pancreatic Cancer Immuno-oncology in the Era of Precision Medicine

Pancreatic malignancies carry a dismal prognosis globally, with pancreatic adenocarcinomas (PDAC) being particularly aggressive and stubborn. Unfortunately, several therapeutic strategies that show promise in other cancers have failed to make sizeable impact on pancreatic tumor outcomes. Responses to immunotherapies are especially rare in pancreatic cancer, and patients are in need of innovative approaches that can result in more durable responses. Current research in preclinical models and humans has suggested this resistance is due to a uniquely inflammatory and dysfunctional tumor microenvironment; these findings lay the groundwork for targeting these barriers and improving outcomes. Clinical analyses have also revealed unprecedented heterogeneity in tumor and stromal biology of PDAC, underscoring the need for more personalized approaches and combinatorial therapies. This review will highlight the current state of translational research focusing on PDAC immunity, summarize ongoing clinical efforts to tackle PDAC vulnerabilities, and underscore some unresolved challenges in implementing therapies more broadly. A better understanding of immune contexture and tumor heterogeneity in this disease will greatly accelerate drug discovery and implementation of precision medicine for PDAC.

Regulation and modulation of antitumor immunity in pancreatic cancer

Pancreatic ductal adenocarcinoma carries a dismal prognosis, and outcomes have improved little with modern therapeutics. Checkpoint-based immunotherapy has failed to elicit responses in the vast majority of patients with pancreatic cancer. Alongside tumor cell-intrinsic mechanisms associated with oncogenic KRAS-induced inflammation, the tolerogenic myeloid cell infiltrate has emerged as a critical impediment to adaptive antitumor immune responses. Furthermore, the discovery of an intratumoral microbiome and the elucidation of host-microbe interactions that curtail antitumor immunity also present opportunities for intervention. Here we review the mechanisms of immunotherapy resistance in pancreatic ductal adenocarcinoma and discuss strategies to directly augment T cell responses in parallel with myeloid cell- and microbiome-targeted approaches that may enable immune-mediated control of this malignancy.

Targeting the interleukin-17 immune axis for cancer immunotherapy

IL-17 plays versatile roles during tumorigenesis. Here, Vitiello and Miller summarize current knowledge in harnessing IL-17–producing γδ and Th17 cells for successful cancer immunotherapy.

The role of IL-17 in cancer remains controversial. Emerging evidence suggests that during early oncogenesis IL-17 supports tumor growth, whereas in established tumors IL-17 production by γδ and Th17 cells potentiates antitumor immunity. Consequently, γδ and Th17 cells are attractive targets for immunotherapy in the IL-17 immune axis. To optimize IL-17–based immunotherapy, a deeper understanding of the cytokines dictating IL-17 production and the polarity of γδ and Th17 cells is critical. Here, we delve into the dichotomous roles of IL-17 in cancer and provide insight into the tumor microenvironment conducive for successful IL-17–based γδ and Th17 cell immunotherapy.

Pancreatic Cancer and Its Microenvironment-Recent Advances and Current Controversies

Pancreatic ductal adenocarcinoma (PDAC) causes annually well over 400,000 deaths world-wide and remains one of the major unresolved health problems. This exocrine pancreatic cancer originates from the mutated epithelial cells: acinar and ductal cells. However, the epithelia-derived cancer component forms only a relatively small fraction of the tumor mass. The majority of the tumor consists of acellular fibrous stroma and diverse populations of the non-neoplastic cancer-associated cells. Importantly, the tumor microenvironment is maintained by dynamic cell-cell and cell-matrix interactions. In this article, we aim to review the most common drivers of PDAC. Then we summarize the current knowledge on PDAC microenvironment, particularly in relation to pancreatic cancer therapy. The focus is placed on the acellular stroma as well as cell populations that inhabit the matrix. We also describe the altered metabolism of PDAC and characterize cellular signaling in this cancer.

3D approaches to model the tumor microenvironment of pancreatic cancer

In tumor engineering, 3D approaches are used to model components of the tumor microenvironment and to test new treatments. Pancreatic cancers are a cancer of substantial unmet need and survival rates are lower compared to any other cancer. Bioengineering techniques are increasingly applied to understand the unique biology of pancreatic tumors and to design patient-specific models. Here we summarize how extracellular and cellular elements of the pancreatic tumor microenvironment and their interactions have been studied in 3D cell cultures. We review selected clinical trials, assess the benefits of therapies interfering with the tumor microenvironment and address their limitations and future perspectives.

The Agpat4/LPA axis in colorectal cancer cells regulates antitumor responses via p38/p65 signaling in macrophages

Lipid metabolic reprogramming plays an essential role in regulating the progression of colorectal cancer (CRC). However, the effect of lysophosphatidic acid (LPA) metabolism on CRC development is incompletely characterized. Here, we compared the mRNA levels of human CRC tissues to those of paracarcinoma tissues and focused on the notably enriched LPA metabolic pathways. We identified and verified that 1-acylglycerol-3-phosphate O-acyltransferase 4 (Agpat4) was aberrantly expressed in CRC tissues and predicted poor survival in CRC patients. Manipulating Agpat4 expression in CRC cells did not affect the growth or migration of CRC cells in vitro, whereas Agpat4 silencing suppressed CRC cell growth in subcutaneous and peritoneal xenograft models. Mechanistically, Agpat4 silencing-induced LPA release from CRC cells and polarized macrophages to an M1-like phenotype through LPA receptors 1 and 3. This M1 activation, characterized by elevated p38/p65 signaling and increased proinflammatory cytokines, promoted the infiltration and activation of CD4⁺ and CD8⁺ T cells in the tumor microenvironment. Modulation of the Agpat4/LPA/p38/p65 axis regulated macrophage polarization, T-cell activity and CRC progression. Notably, combined therapy with LPA and regular chemotherapy drugs synergistically suppressed CRC development. Taken together, our results showed that the Agpat4/LPA axis in CRC cells regulated p38/p65 signaling-dependent macrophage polarization, T-cell activation, and CRC progression. The Agpat4/LPA/p38/p65 axis might represent a potential target for therapy in the clinic.

Biology and therapeutic targeting of tumour-associated macrophages

Macrophages sustain tumour progression by facilitating angiogenesis, promoting immunosuppression, and enhancing cancer cell invasion and metastasis. They also modulate tumour response to anti-cancer therapy in pre-clinical models. This knowledge has motivated the development of agents that target tumour-associated macrophages (TAMs), some of which have been investigated in early clinical trials. Here, we provide a comprehensive overview of the biology and therapeutic targeting of TAMs, highlighting opportunities, setbacks, and new challenges that have emerged after a decade of intense translational and clinical research into these multifaceted immune cells. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Unconventional T Cells in the Pancreatic Tumor Microenvironment: Thinking Outside the Box

Unlike conventional MHC-reactive T cells, unconventional T cells have emerged as an abundant component of the human immune system because of their role in tumor immunology. In this issue of Cancer Discovery, Hundeyin and colleagues have identified a population of unconventional T cells in pancreatic tumors that can reprogram the immune evasive components of the tumor to promote immunogenicity and thus are critical for the development of novel cell-based therapy in pancreatic cancer.See related article by Hundeyin et al., p. 1288.