Complementing T-cell Function: An Inhibitory Role of the Complement System in T-cell-Mediated Antitumor Immunity

Harnessing natural product polysaccharides against lung cancer and revisit its novel mechanism

The incidence and mortality of lung cancer are on the rise worldwide. However, the benefit of clinical treatment in lung cancer is limited. Owning to important sources of drug development, natural products have received constant attention around the world. Main ingredient polysaccharides in natural products have been found to have various activities in pharmacological research. In recent years, more and more scientists are looking for the effects and mechanisms of different natural product polysaccharides on lung cancer. In this review, we focus on the following aspects: First, natural product polysaccharides have been discovered to directly suppress the growth of lung cancer cells, which can be effective in limiting tumor progression. Additionally, polysaccharides have been considered to enhance immune function, which can play a pivotal role in fighting lung cancer. Lastly, polysaccharides can improve the efficacy of drugs in lung cancer treatment by regulating the gut microbiota. Overall, the research of natural product polysaccharides in the treatment of lung cancer is a promising area that has the potential to lead to new clinical treatments. With better understanding, natural product polysaccharides have the potential to become important components of future lung cancer treatments.

The Complement System: A Potential Therapeutic Target in Liver Cancer

Liver cancer is the sixth most common cancer and the fourth most fatal cancer in the world. Immunotherapy has already achieved modest results in the treatment of liver cancer. Meanwhile, the novel and optimal combinatorial strategies need further research. The complement system, which consists of mediators, receptors, cofactors and regulators, acts as the connection between innate and adaptive immunity. Recent studies demonstrate that complement system can influence tumor progression by regulating the tumor microenvironment, tumor cells, and cancer stem cells in liver cancer. Our review concentrates on the potential role of the complement system in cancer treatment, which is a promising strategy for killing tumor cells by the activation of complement components. Conclusions: Our review demonstrates that complement components and regulators might function as biomarkers and therapeutic targets for liver cancer diagnosis and treatment.

Investigating Cellular Trajectories in the Severity of COVID-19 and Their Transcriptional Programs Using Machine Learning Approaches

Single-cell RNA sequencing of the bronchoalveolar lavage fluid (BALF) samples from COVID-19 patients has enabled us to examine gene expression changes of human tissue in response to the SARS-CoV-2 virus infection. However, the underlying mechanisms of COVID-19 pathogenesis at single-cell resolution, its transcriptional drivers, and dynamics require further investigation. In this study, we applied machine learning algorithms to infer the trajectories of cellular changes and identify their transcriptional programs. Our study generated cellular trajectories that show the COVID-19 pathogenesis of healthy-to-moderate and healthy-to-severe on macrophages and T cells, and we observed more diverse trajectories in macrophages compared to T cells. Furthermore, our deep-learning algorithm DrivAER identified several pathways (e.g., xenobiotic pathway and complement pathway) and transcription factors (e.g., MITF and GATA3) that could be potential drivers of the transcriptomic changes for COVID-19 pathogenesis and the markers of the COVID-19 severity. Moreover, macrophages-related functions corresponded more to the disease severity compared to T cells-related functions. Our findings more proficiently dissected the transcriptomic changes leading to the severity of a COVID-19 infection.

Complement in Tumourigenesis and the Response to Cancer Therapy

In recent years, our knowledge of the complement system beyond innate immunity has progressed significantly. A modern understanding is that the complement system has a multifaceted role in malignancy, impacting carcinogenesis, the acquisition of a metastatic phenotype and response to therapies. The ability of local immune cells to produce and respond to complement components has provided valuable insights into their regulation, and the subsequent remodeling of the tumour microenvironment. These novel discoveries have advanced our understanding of the immunosuppressive mechanisms supporting tumour growth and uncovered potential therapeutic targets. This review discusses the current understanding of complement in cancer, outlining both direct and immune cell-mediated roles. The role of complement in response to therapies such as chemotherapy, radiation and immunotherapy is also presented. While complement activities are largely context and cancer type-dependent, it is evident that promising therapeutic avenues have been identified, in particular in combination therapies.

Evaluation of immune-biomarker expression in high-grade soft-tissue sarcoma: HLA-DQA1 expression as a prognostic marker

High-grade soft-tissue sarcoma (STS) is a highly malignant neoplasm with a poor overall prognosis. Numerous prognostic factors determine tumor progression and patient outcomes. Various immune-associated cells identified in the tumor microenvironment have important roles in various tumor types. The present study was performed to evaluate the expression of immune-associated genes and to elucidate the association between these genes and the prognosis in high-grade STS. A total of 12 formalin-fixed, paraffin-embedded tissue samples of high-grade STS were subjected to gene expression analysis using the NanoString nCounter^® System and another 35 samples were used for immunohistochemistry. For comparative analysis, the patients were divided into two groups according to overall survival (OS). The expression levels of 770 genes were first analyzed using the nCounter^® PanCancer Immune Profiling Panel. Immunohistochemistry was then performed for the most significantly altered genes. Subsequently, the association between gene expression and prognosis of high-grade STS was evaluated. Of the 770 immune-associated genes analyzed, several genes were identified as being differentially expressed between the two groups. Based on gene expression levels and fold change, 13 representative genes were identified; 7 of the 13 candidate genes (C3, CD36, DOCK9, FCER2, FOS, HLA-DRB4 and NCAM1) were significantly overexpressed in the poor prognosis group, while the other 6 immune-associated genes (BIRC5, DUSP4, FOXP3, HLA-DQA1, HLA-DQB1 and LAG3) were increased in the good prognosis group. By immunohistochemistry, the expression of the 13 immune-associated genes was confirmed to be significantly different between the two groups. Expression of HLA-DQA1, HLA-DQB1 and HLA-DRB4 was observed in 74.3, 34.3 and 48.6% of tumors, respectively. HLA-DQA1 and HLA-DQB1 were significantly decreased, whereas HLA-DRB4 was significantly increased in the poor prognosis group. Of note, expression of HLA-DQA1 was associated with a significantly longer OS (P=0.028). In conclusion, HLA-DQA1 expression was significantly associated with long-term survival and may therefore be an immune biomarker for good prognosis in high-grade STS.

High numbers of activated helper T cells are associated with better clinical outcome in early stage vulvar cancer, irrespective of HPV or p53 status

Background

Vulvar squamous cell carcinoma (VSCC) has been suggested to consist of three subtypes; HPV-positive, HPV-negative mutated TP53 or HPV-negative TP53 wildtype, with different clinical courses. To analyze the immune infiltrate in these molecular subtypes and its impact on clinical outcome, an in-depth study of the tumor immune microenvironment was performed.

Methods

Sixty-five patients with invasive VSCC matched for age, FIGO stage and treatment modality, were grouped according to the presence of HPV and p53 protein expression status. Archived tissues were analyzed for intraepithelial and stromal expression of CD3, CD8, Foxp3, PD-1, and pan-keratin in randomly selected areas using immunofluorescence. Additional phenotyping of T cells was performed ex-vivo on VSCC (n = 14) and blood samples by flow cytometry. Healthy vulvar samples and blood served as controls.

Results

Based on T-cell infiltration patterns about half of the VSCC were classified as inflamed or altered-excluded while one-third was immune-deserted. High intraepithelial helper T cell infiltration was observed in 78% of the HPV-induced VSCC, 60% of the HPVnegVSCC/p53wildtype and 40% of the HPVnegVSCC with abnormal p53 expression. A high intraepithelial infiltration with activated (CD3⁺PD-1⁺), specifically helper T cells (CD3⁺CD8⁻Foxp3⁻), was associated with a longer recurrence-free period and overall survival, irrespective of HPV and p53 status. Flow cytometry confirmed the tumor-specific presence of activated (CD4⁺PD-1⁺⁺CD161⁻CD38⁺HLA-DR⁺ and CD8⁺CD103⁺CD161⁻NKG2A^+/−PD1⁺⁺CD38⁺⁺HLA-DR⁺) effector memory T cells.

Conclusion

This is the first study demonstrating an association between intraepithelial T cells and clinical outcome in VSCC. Our data suggest that abnormal p53 expressing VSCCs mostly are cold tumors whereas HPV-driven VSCCs are strongly T-cell infiltrated.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0712-z) contains supplementary material, which is available to authorized users.

The Complement Receptors C3aR and C5aR Are a New Class of Immune Checkpoint Receptor in Cancer Immunotherapy

Cancer immunotherapy has made remarkable clinical advances in recent years. Antibodies targeting the immune checkpoint receptors PD-1 and CTLA-4 and adoptive cell therapy (ACT) based on ex vivo expanded peripheral CTLs, tumor infiltrating lymphocytes (TILs), gene-engineered TCR- and chimeric antigen receptor (CAR)-T cells have all shown durable clinical efficacies in multiple types of cancers. However, these immunotherapeutic approaches only benefit a small fraction of cancer patients as various immune resistance mechanisms and limitations make their effective use a challenge in the majority of cancer patients. For example, adaptive resistance to therapeutic PD-1 blockade is associated with an upregulation of some additional immune checkpoint receptors. The efficacy of transferred tumor-specific T cells under the current clinical ACT protocol is often limited by their inefficient engraftment, poor persistence, and weak capability to attack tumor cells. Recent studies demonstrate that the complement receptor C3aR and C5aR function as a new class of immune checkpoint receptors. Complement signaling through C3aR and C5aR expressed on effector T lymphocytes prevent the production of the cytokine interleukin-10 (IL-10). Removing C3aR/C5aR-mediated transcriptional suppression of IL-10 expression results in endogenous IL-10 production by antitumor effector T cells, which drives T cell expansion and enhances T cell-mediated antitumor immunity. Importantly, preclinical, and clinical data suggest that a signaling axis consisting of complement/C3aR/C5aR/IL-10 critically regulates T cell mediated antitumor immunity and manipulation of the pathway ex vivo and in vivo is an effective strategy for cancer immunotherapy. Furthermore, a combination of treatment strategies targeting the complement/C3aR/C5aR/IL-10 pathway with other treatment modalities may improve cancer therapeutic efficacy.

Epithelial-Mesenchymal Transition in Human Prostate Cancer Demonstrates Enhanced Immune Evasion Marked by IDO1 Expression

Cancer invasion and metastasis are driven by epithelial-mesenchymal transition (EMT), yet the exact mechanisms that account for EMT in clinical prostate cancer are not fully understood. Expression of N-cadherin is considered a hallmark of EMT in clinical prostate cancer. In this study, we determined the molecular mechanisms associated with N-cadherin expression in patients with prostate cancer. We performed laser capture microdissection of matched N-cadherin-positive and -negative prostate cancer areas from patient samples (n = 8), followed by RNA sequencing. N-cadherin expression was significantly associated with an immune-regulatory signature including profound upregulation of indoleamine 2,3-dioxygenase (IDO1; log₂-fold change = 5.1; P = 2.98E-04). Fluorescent immunostainings of patient samples confirmed expression of IDO1 protein and also its metabolite kynurenine in primarily N-cadherin-positive areas. N-cadherin-positive areas also exhibited a local decrease of intraepithelial cytotoxic (CD8⁺) T cells and an increase of immunosuppressive regulatory T cells (CD4⁺/FOXP3⁺). In conclusion, EMT in clinical prostate cancer is accompanied by upregulated expression of IDO1 and an increased number of regulatory T cells. These data indicate that EMT, which is an important step in tumor progression, can be protected from effective immune control in patients with prostate cancer.Significance: These findings demonstrate EMT is linked to an immunosuppressive environment in clinical prostate cancer, suggesting that patients with prostate cancer can potentially benefit from combinatorial drug therapy. Cancer Res; 78(16); 4671-9. ©2018 AACR.