Understanding Immune Tolerance of Cancer: Re-Purposing Insights from Fetal Allografts and Microbes

Exploring genetic and immune underpinnings of the sexual dimorphism in tumor response to immune checkpoints inhibitors: A narrative review

Introduction

In spite of the undisputed relevance of sex as critical biologic variable of the immune landscape, still limited is our understanding of the basic mechanisms implicated in sex-biased immune response thereby conditioning the therapeutic outcome in cancer patients. This hindrance delays the actual attempts to decipher the heterogeneity of cancer and its immune surveillance, further digressing the achievement of predictive biomarkers in the current immunotherapy-driven scenario. Body: The present review concisely reports on genetic, chromosomal, hormonal, and immune features underlying sex-differences in the response to immune checkpoint inhibitors (ICIs). In addition to outline the need of robust data on ICI pharmaco-kinetics/dynamics, our survey might provide new insights on sex determinants of ICI efficacy and suggests uncovered pathways that warrant prospective investigations.

Conclusion

According to a sharable view, we propose to widely include sex among the co-variates when assessing the clinical response to ICI in cancer patients.

Effects of gut microbiota on immune responses and immunotherapy in colorectal cancer

Accumulating evidence suggests that gut microbial dysbiosis is implicated in colorectal cancer (CRC) initiation and progression through interaction with host immune system. Given the intimate relationship between the gut microbiota and the antitumor immune responses, the microbiota has proven to be effective targets in modulating immunotherapy responses of preclinical CRC models. However, the proposed putative mechanisms of how these bacteria affect immune responses and immunotherapy efficacy remains obscure. In this review, we summarize recent findings of clinical gut microbial dysbiosis in CRC patients, the reciprocal interactions between gut microbiota and the innate and/or the adaptive immune system, as well as the effect of gut microbiota on immunotherapy response in CRC. Increased understanding of the gut microbiota-immune system interactions will benefit the rational application of microbiota to the clinical promising biomarker or therapeutic strategy as a cancer immunotherapy adjuvant.

Insights Into the Host Contribution of Endocrine Associated Immune-Related Adverse Events to Immune Checkpoint Inhibition Therapy

Blockade of immune checkpoints transformed the paradigm of systemic cancer therapy, enabling substitution of a cytotoxic chemotherapy backbone to one of immunostimulation in many settings. Invigorating host immune cells against tumor neo-antigens, however, can induce severe autoimmune toxicity which in many cases requires ongoing management. Many immune-related adverse events (irAEs) are clinically and pathologically indistinguishable from inborn errors of immunity arising from genetic polymorphisms of immune checkpoint genes, suggesting a possible shared driver for both conditions. Many endocrine irAEs, for example, have analogous primary genetic conditions with varied penetrance and severity despite consistent genetic change. This is akin to onset of irAEs in response to immune checkpoint inhibitors (ICIs), which vary in timing, severity and nature despite a consistent drug target. Host contribution to ICI response and irAEs, particularly those of endocrine origin, such as thyroiditis, hypophysitis, adrenalitis and diabetes mellitus, remains poorly defined. Improved understanding of host factors contributing to ICI outcomes is essential for tailoring care to an individual’s unique genetic predisposition to response and toxicity, and are discussed in detail in this review.

β3-Adrenoceptor, a novel player in the round-trip from neonatal diseases to cancer: Suggestive clues from embryo

The role of the β-adrenoceptors (β-ARs) in hypoxia-driven diseases has gained visibility after the demonstration that propranolol promotes the regression of infantile hemangiomas and ameliorates the signs of retinopathy of prematurity (ROP). Besides the role of β2-ARs, preclinical studies in ROP have also revealed that β3-ARs are upregulated by hypoxia and that they are possibly involved in retinal angiogenesis. In a sort of figurative round trip, peculiarities typical of ROP, where hypoxia drives retinal neovascularization, have been then translated to cancer, a disease equally characterized by hypoxia-driven angiogenesis. In this step, investigating the role of β3-ARs has taken advantage of the assumption that cancer growth uses a set of strategies in common with embryo development. The possibility that hypoxic induction of β3-ARs may represent one of the mechanisms through which primarily embryo (and then cancer, as an astute imitator) adapts to grow in an otherwise hostile environment, has grown evidence. In both cancer and embryo, β3-ARs exert similar functions by exploiting a metabolic shift known as the Warburg effect, by acquiring resistance against xenobiotics, and by inducing a local immune tolerance. An additional potential role of β3-AR as a marker of stemness has been suggested by the finding that its antagonism induces cancer cell differentiation evoking that β3-ARs may help cancer to grow in a nonhospital environment, a strategy also exploited by embryos. From cancer, the round trip goes back to neonatal diseases for which new possible interpretative keys and potential pharmacological perspectives have been suggested.

Applications of brain organoids in neurodevelopment and neurological diseases

A brain organoid is a self-organizing three-dimensional tissue derived from human embryonic stem cells or pluripotent stem cells and is able to simulate the architecture and functionality of the human brain. Brain organoid generation methods are abundant and continue to improve, and now, an in vivo vascularized brain organoid has been encouragingly reported. The combination of brain organoids with immune-staining and single-cell sequencing technology facilitates our understanding of brain organoids, including the structural organization and the diversity of cell types. Recent publications have reported that brain organoids can mimic the dynamic spatiotemporal process of early brain development, model various human brain disorders, and serve as an effective preclinical platform to test and guide personalized treatment. In this review, we introduce the current state of brain organoid differentiation strategies, summarize current progress and applications in the medical domain, and discuss the challenges and prospects of this promising technology.

Viral Nanoparticles: Cancer Vaccines and Immune Modulators

In the last decades, viruses have gained great interest in the field of immuno-oncology (I-O) for their ability of interacting both with the immune system and the tumour microenvironment. Those pathogens have naturally evolved and been evolutionary to specifically infect hosts, replicate, deliver their genome, and spread. These properties, initially considered a disadvantage, have been investigated and edited to turn viruses into precious allies for molecular biology serving as gene therapy vectors, adjuvants for the immune system, drug cargos, and, lately, anticancer therapeutics. As anticancer drug, one interesting option is viral engineering. Modification of either the viral genome or the outer shell of viruses can change infectivity and tissue targeting and add new functions to the viral particle. Remarkably, in the field of cancer virotherapy, scientists realized that a specific viral genomic depletion would turn the normal tropism of viruses to conditionally replicate in cancer cells only. This category of viruses, named 'Oncolytic viruses', have been investigated and used for cancer treatment in the past decades resulting in the approval of the first oncolytic virus, a herpes simplex virus expressing a stimulating factor, named T-Vec, in 2015. As such, oncolytic viruses achieved positive outcome but still are not able to completely eradicate the disease. This has brought the scientific community to edit those agents, adding to their ability to directly lysate cancer cells, few modifications to mainly boost their interaction with the immune system. Viruses experienced then a renaissance not only as infecting agent but as nanoparticle and cancer vaccines too. These strategies bring new life to the concept of using viruses as viral particles for therapeutic applications.

Epithelial Ovarian Cancer and the Immune System: Biology, Interactions, Challenges and Potential Advances for Immunotherapy

Recent advances in the understanding of immune function and the interactions with tumour cells have led to the development of various cancer immunotherapies and strategies for specific cancer types. However, despite some stunning successes with some malignancies such as melanomas and lung cancer, most patients receive little or no benefit from immunotherapy, which has been attributed to the tumour microenvironment and immune evasion. Although the US Food and Drug Administration have approved immunotherapies for some cancers, to date, only the anti-angiogenic antibody bevacizumab is approved for the treatment of epithelial ovarian cancer. Immunotherapeutic strategies for ovarian cancer are still under development and being tested in numerous clinical trials. A detailed understanding of the interactions between cancer and the immune system is vital for optimisation of immunotherapies either alone or when combined with chemotherapy and other therapies. This article, in two main parts, provides an overview of: (1) components of the normal immune system and current knowledge regarding tumour immunology, biology and their interactions; (2) strategies, and targets, together with challenges and potential innovative approaches for cancer immunotherapy, with attention given to epithelial ovarian cancer.

Immunological memory and tolerance at the maternal-fetal interface: Implications for reproductive management of mares

The development of placentation that coincided with the evolution of mammals presented new challenges to the transmission of life from one generation to the next, particularly with regard to the possibility of maternal immunological recognition and destruction of the developing conceptus. The balance between immunity and tolerance dominates the immunological relationship between mother and fetus during mammalian pregnancy, and the focal point of this relationship lies at the interface between the trophoblast cells that comprise the outermost layer of the placenta and the maternal endometrial tissues. Immune memory and tolerance are two of the cardinal characteristics of the immune system. Immune memory is essential in preventing or lessening the effect of infections to the mother or conceptus, but may also be a threat to the semi-allogeneic tissues of the fetus and placenta. The mother must develop functional immune tolerance to her fetus, but at the same time retain her ability to combat infections while pregnant. To address this imperative, mammals have developed overlapping and independent mechanisms for evading maternal anti-fetal immune responses that could result in pregnancy loss. Studies of the unusual component of equine invasive trophoblast in the epitheliochorial placenta have illuminated aspects of immune memory and tolerance that have relevance to fertility in the horse and other mammalian species.