Different subpopulations of regulatory T cells in human autoimmune disease, transplantation, and tumor immunity

Innate and Adaptive Immune Responses in Intestinal Transplant Rejection: Through the Lens of Inflammatory Bowel and Intestinal Graft-Versus-Host Diseases

Intestinal transplantation is a life-saving procedure utilized for patients failing total parenteral nutrition. However, intestinal transplantattion remains plagued with low survival rates and high risk of allograft rejection. The authors explore roles of innate (macrophages, natural killer cells, innate lymphoid cells) and adaptive immune cells (Th1, Th2, Th17, Tregs) in inflammatory responses, particularly inflammatory bowel disease and graft versus host disease, and correlate these findings to intestinal allograft rejection, highlighting which effectors exacerbate or suppress intestinal rejection. Better understanding of this immunology can open further investigation into potential biomolecular targets to develop improved therapeutic treatment options and immunomonitoring techniques to combat allograft rejection and enhance patient lives.

Many Faces of Regulatory T Cells: Heterogeneity or Plasticity?

Regulatory T cells (Tregs) are essential for maintaining the immune balance in normal and pathological conditions. In autoimmune diseases and transplantation, they restrain the loss of self-tolerance and promote engraftment, whereas in cancer, an increase in Treg numbers is mostly associated with tumor growth and poor prognosis. Numerous markers and their combinations have been used to identify Treg subsets, demonstrating the phenotypic diversity of Tregs. The complexity of Treg identification can be hampered by the unstable expression of some markers, the decrease in the expression of a specific marker over time or the emergence of a new marker. It remains unclear whether such phenotypic shifts are due to new conditions or whether the observed changes are due to initially different populations. In the first case, cellular plasticity is observed, whereas in the second, cellular heterogeneity is observed. The difference between these terms in relation to Tregs is rather blurred. Considering the promising perspectives of Tregs in regenerative cell-based therapy, the existing confusing data on Treg phenotypes require further investigation and analysis. In our review, we introduce criteria that allow us to distinguish between the heterogeneity and plasticity of Tregs normally and pathologically, taking a closer look at their diversity and drawing the line between two terms.

Proapoptotic protein Bim regulates the suppressive function of Treg cells

Regulatory T (Treg) cells are a special immunosuppressive subset of cluster of differentiation 4-positive (CD4+‍)‍-T lymphocytes and play a pivotal role in the establishment of immune homeostasis in vivo (Zhang et al., 2021). The transcription factor forkhead box protein P3 (Foxp3) is the master marker of Treg cells, which is highly expressed in Treg cells and is also essential for their suppressive function (Hori et al., 2003). In addition to Foxp3, other regulators of Treg cells have been discovered (Wu et al., 2017, 2022; Wu and Sun, 2023a, 2023b); however, a deeper understanding of the regulation of these cells is required.

Role of the immune system in liver transplantation and its implications for therapeutic interventions

Liver transplantation (LT) stands as the gold standard for treating end-stage liver disease and hepatocellular carcinoma, yet postoperative complications continue to impact survival rates. The liver's unique immune system, governed by a microenvironment of diverse immune cells, is disrupted during processes like ischemia-reperfusion injury posttransplantation, leading to immune imbalance, inflammation, and subsequent complications. In the posttransplantation period, immune cells within the liver collaboratively foster a tolerant environment, crucial for immune tolerance and liver regeneration. While clinical trials exploring cell therapy for LT complications exist, a comprehensive summary is lacking. This review provides an insight into the intricacies of the liver's immune microenvironment, with a specific focus on macrophages and T cells as primary immune players. Delving into the immunological dynamics at different stages of LT, we explore the disruptions after LT and subsequent immune responses. Focusing on immune cell targeting for treating liver transplant complications, we provide a comprehensive summary of ongoing clinical trials in this domain, especially cell therapies. Furthermore, we offer innovative treatment strategies that leverage the opportunities and prospects identified in the therapeutic landscape. This review seeks to advance our understanding of LT immunology and steer the development of precise therapies for postoperative complications.

Biomarkers and experimental models for cancer immunology investigation

The rapid advancement of tumor immunotherapies poses challenges for the tools used in cancer immunology research, highlighting the need for highly effective biomarkers and reproducible experimental models. Current immunotherapy biomarkers encompass surface protein markers such as PD-L1, genetic features such as microsatellite instability, tumor-infiltrating lymphocytes, and biomarkers in liquid biopsy such as circulating tumor DNAs. Experimental models, ranging from 3D in vitro cultures (spheroids, submerged models, air-liquid interface models, organ-on-a-chips) to advanced 3D bioprinting techniques, have emerged as valuable platforms for cancer immunology investigations and immunotherapy biomarker research. By preserving native immune components or coculturing with exogenous immune cells, these models replicate the tumor microenvironment in vitro. Animal models like syngeneic models, genetically engineered models, and patient-derived xenografts provide opportunities to study in vivo tumor-immune interactions. Humanized animal models further enable the simulation of the human-specific tumor microenvironment. Here, we provide a comprehensive overview of the advantages, limitations, and prospects of different biomarkers and experimental models, specifically focusing on the role of biomarkers in predicting immunotherapy outcomes and the ability of experimental models to replicate the tumor microenvironment. By integrating cutting-edge biomarkers and experimental models, this review serves as a valuable resource for accessing the forefront of cancer immunology investigation.

MAIT cells confer resistance to Lenvatinib plus anti-PD1 antibodies in hepatocellular carcinoma through TNF-TNFRSF1B pathway

The combination of antiangiogenic agents and immune checkpoint inhibitors is more efficient than monotherapy in the management of hepatocellular carcinoma (HCC). Lenvatinib plus anti-PD1 antibodies have become the mainstay in HCC treatment. However, more than half the patients with HCC are non-responsive, and the mechanisms underlying drug resistance are unknown. To address this issue, we performed single-cell sequencing on samples from six HCC patients, aiming to explore cellular signals and molecular pathways related to the effect of lenvatinib plus anti-PD1 antibody treatment. GSVA analysis revealed that treatment with lenvatinib plus anti-PD1 antibody led to an increase in the TNF-NFKB pathway across all immune cell types, as compared to the non-treatment group. Mucosal-associated invariant T (MAIT) cells were found to secrete TNF, which activates TNFRSF1B on regulatory T cells, thereby promoting immunosuppression. Additionally, TNFSF9 was highly expressed in anticancer immune cells, including CD8+ effector T cells, MAIT, and γδ T cells in the treatment group. We also detected CD3+ macrophages in both HCC and pan-cancer tissues. Overall, our findings shed light on the potential mechanisms behind the effectiveness of lenvatinib plus anti-PD1 antibody treatment in HCC patients. By understanding these mechanisms better, we may be able to develop more effective treatment strategies for patients who do not respond to current therapies.

Multi-omics analysis reveals the involvement of origin recognition complex subunit 6 in tumor immune regulation and malignant progression

Background

Origin recognition complex 6 (ORC6) is one of the six highly conserved subunit proteins required for DNA replication and is essential for maintaining genome stability during cell division. Recent research shows that ORC6 regulates the advancement of multiple cancers; however, it remains unclear what regulatory impact it has on the tumor immune microenvironment.

Methods

Unpaired Wilcoxon rank sum and signed rank tests were used to analyze the differences in the expression of ORC6 in normal tissues and corresponding tumor tissues. Multiple online databases have evaluated the genetic alterations, protein expression and localization, and clinical relevance of ORC6. To evaluate the potential prognostic impact and diagnostic significance of ORC6 expression, we carried out log-rank, univariate Cox regression, and receiver operating characteristic curve analysis. The ICGC-LIRI-JP cohort, CGGA-301 cohort, CGGA-325 cohort, CGGA-693 cohort, and GSE13041 cohort were used for external validation of the study findings. The associations between ORC6 expression and immune cell infiltration, immune checkpoint expression, and immunotherapy cohorts was further analyzed. To explore the functional and signaling pathways related to ORC6 expression, gene set enrichment analysis was performed. To clarify the expression and function of ORC6 in hepatocellular carcinoma (LIHC) and glioma, we conducted in vitro experiments.

Results

Expression of ORC6 is upregulated in the majority of cancer types and is associated with poor patient prognosis, notably in cases of LIHC and gliomas. In addition, ORC6 may be involved in multiple signaling pathways related to cancer progression and immune regulation. High expression of ORC6 correlates with an immunosuppressive state in the tumor microenvironment. The results of further immunotherapy cohort analysis suggested that patients in the ORC6 high-expression group benefited from immunotherapy. Inhibiting ORC6 expression suppressed the proliferative and migratory abilities of LIHC and glioma cells.

Conclusion

High expression of ORC6 may be used as a biomarker to predict the poor prognosis of most tumor patients. The high expression of ORC6 may be involved in the regulation of the tumor immunosuppressive environment, and it is expected to become a molecular target for inhibiting tumor progression.

A single-cell atlas of the multicellular ecosystem of primary and metastatic hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents a paradigm of the relation between tumor microenvironment (TME) and tumor development. Here, we generate a single-cell atlas of the multicellular ecosystem of HCC from four tissue sites. We show the enrichment of central memory T cells (T_CM) in the early tertiary lymphoid structures (E-TLSs) in HCC and assess the relationships between chronic HBV/HCV infection and T cell infiltration and exhaustion. We find the MMP9⁺ macrophages to be terminally differentiated tumor-associated macrophages (TAMs) and PPARγ to be the pivotal transcription factor driving their differentiation. We also characterize the heterogeneous subpopulations of malignant hepatocytes and their multifaceted functions in shaping the immune microenvironment of HCC. Finally, we identify seven microenvironment-based subtypes that can predict prognosis of HCC patients. Collectively, this large-scale atlas deepens our understanding of the HCC microenvironment, which might facilitate the development of new immune therapy strategies for this malignancy.

The immune cell constituents and localisation within human hepatocellular carcinoma is not fully understood. Here the authors use single cell RNA sequencing of HCC from four different tissue sites and show differences between primary and metastatic tumours, tumour associated macrophages and immune cell populations.

The Tower of Babel of Pharma-Food Study on Extra Virgin Olive Oil Polyphenols

Much research has been conducted to reveal the functional properties of extra virgin olive oil polyphenols on human health once EVOO is consumed regularly as part of a balanced diet, as in the Mediterranean lifestyle. Despite the huge variety of research conducted, only one effect of EVOO polyphenols has been formally approved by EFSA as a health claim. This is probably because EFSA’s scientific opinion is entrusted to scientific expertise about food and medical sciences, which adopt very different investigative methods and experimental languages, generating a gap in the scientific communication that is essential for the enhancement of the potentially useful effects of EVOO polyphenols on health. Through the model of the Tower of Babel, we propose a challenge for science communication, capable of disrupting the barriers between different scientific areas and building bridges through transparent data analysis from the different investigative methodologies at each stage of health benefits assessment. The goal of this work is the strategic, distinctive, and cost-effective integration of interdisciplinary experiences and technologies into a highly harmonious workflow, organized to build a factual understanding that translates, because of trade, into health benefits for buyers, promoting EVOOs as having certified health benefits, not just as condiments.