Although it was thought that apoptotic cells, when rapidly phagocytosed, underwent a silent death that did not trigger an immune response, in recent years a new concept of immunogenic cell death (ICD) has emerged. The immunogenic characteristics of ICD are mainly mediated by damage-associated molecular patterns (DAMPs), which include surface-exposed calreticulin (CRT), secreted ATP and released high mobility group protein B1 (HMGB1). Most DAMPs can be recognized by pattern recognition receptors (PRRs). In this Review, we discuss the role of endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) in regulating the immunogenicity of dying cancer cells and the effect of therapy-resistant cancer microevolution on ICD.

Immunogenic cell death and DAMPs in cancer therapy.

Following the discovery of T helper 17 (TH17) cells, the past decade has witnessed a major revision of the TH subset paradigm and substantial progress has been made in deciphering the molecular mechanisms of T cell lineage commitment and function. In this Review, we focus on the recent advances that have been made regarding the transcriptional control of TH17 cell plasticity and stability, as well as the effector functions of TH17 cells, and we highlight the mechanisms of IL-17 signalling in mesenchymal and barrier epithelial tissues. We also discuss the emerging clinical data showing that IL-17-specific and IL-23-specific antibody treatments are remarkably effective for treating many immune-mediated inflammatory diseases.

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The IL-23-IL-17 immune axis: from mechanisms to therapeutic testing

The key role of interleukin-17 (IL-17) and T helper 17 (T(H)17) cells in tissue inflammation, autoimmunity and host defence led to the experimental targeting of these molecules in mouse models of diseases as well as in clinical settings. Moreover, the demonstration that IL-17 and T(H)17 cells contribute to local and systemic aspects of disease pathogenesis, as well as the finding that the IL-17-T(H)17 cell pathway is regulated by IL-23, prompted the identification of inhibitors. These inhibitors include biotechnology products that target IL-23 as well as the leading member of the IL-17 family, IL-17A, and one of its receptors, IL-17 receptor A. Several clinical trials of these inhibitors are underway, and positive results have been obtained in psoriasis, rheumatoid arthritis and ankylosing spondylitis. This Review focuses on the current knowledge of the IL-17-T(H)17 cell pathway to better understand the positive as well as potential negative consequences of targeting them.

Targeting IL-17 and TH17 cells in chronic inflammation.

Viral infection during pregnancy has been correlated with increased frequency of autism spectrum disorder (ASD) in offspring. This observation has been modeled in rodents subjected to maternal immune activation (MIA). The immune cell populations critical in the MIA model have not been identified. Using both genetic mutants and blocking antibodies in mice, we show that retinoic acid receptor-related orphan nuclear receptor gamma t (RORγt)-dependent effector T lymphocytes [for example, T helper 17 (TH17) cells] and the effector cytokine interleukin-17a (IL-17a) are required in mothers for MIA-induced behavioral abnormalities in offspring. We find that MIA induces an abnormal cortical phenotype, which is also dependent on maternal IL-17a, in the fetal brain. Our data suggest that therapeutic targeting of TH17 cells in susceptible pregnant mothers may reduce the likelihood of bearing children with inflammation-induced ASD-like phenotypes.

/pdf/the-maternal-interleukin-17a-pathway-in-mice-promotes-autism-gu3g7fcw91.pdf

The maternal interleukin-17a pathway in mice promotes autism-like phenotypes in offspring

The mammalian alimentary tract harbors hundreds of species of commensal microorganisms (microbiota) that intimately interact with the host and provide it with genetic, metabolic, and immunological attributes. Recent reports have indicated that the microbiota composition and its collective genomes (microbiome) are major factors in predetermining the type and robustness of mucosal immune responses. In this review, we discuss the recent advances in our understanding of host-microbiota interactions and their effect on the health and disease susceptibility of the host.

/pdf/the-microbiome-in-infectious-disease-and-inflammation-2kjlaltd5e.pdf

The microbiome in infectious disease and inflammation.

CD4(+) T helper lymphocytes that express interleukin-17 (T(H)17 cells) have critical roles in mouse models of autoimmunity, and there is mounting evidence that they also influence inflammatory processes in humans. Genome-wide association studies in humans have linked genes involved in T(H)17 cell differentiation and function with susceptibility to Crohn's disease, rheumatoid arthritis and psoriasis. Thus, the pathway towards differentiation of T(H)17 cells and, perhaps, of related innate lymphoid cells with similar effector functions, is an attractive target for therapeutic applications. Mouse and human T(H)17 cells are distinguished by expression of the retinoic acid receptor-related orphan nuclear receptor RORγt, which is required for induction of IL-17 transcription and for the manifestation of T(H)17-dependent autoimmune disease in mice. By performing a chemical screen with an insect cell-based reporter system, we identified the cardiac glycoside digoxin as a specific inhibitor of RORγt transcriptional activity. Digoxin inhibited murine T(H)17 cell differentiation without affecting differentiation of other T cell lineages and was effective in delaying the onset and reducing the severity of autoimmune disease in mice. At high concentrations, digoxin is toxic for human cells, but non-toxic synthetic derivatives 20,22-dihydrodigoxin-21,23-diol and digoxin-21-salicylidene specifically inhibited induction of IL-17 in human CD4(+) T cells. Using these small-molecule compounds, we demonstrate that RORγt is important for the maintenance of IL-17 expression in mouse and human effector T cells. These data indicate that derivatives of digoxin can be used as chemical templates for the development of RORγt-targeted therapeutic agents that attenuate inflammatory lymphocyte function and autoimmune disease.

/pdf/digoxin-and-its-derivatives-suppress-th17-cell-1hbrh2ukw3.pdf

Digoxin and its derivatives suppress Th17 cell differentiation by antagonizing RORγt activity

The stereoselective formation of the α-GalNAc-Ser linkage via the ring opening of aziridine-2-carboxamides with pyranose C1-O-nucleophiles is described. The process is tolerant to the native C2-NHAc group, can be modulated to provide either the α- or β-glycoside through judicious choice of solvent and metal counterion, and is amenable to other classes of O-glycosyl-Ser constructs such as the β-GlcNAc-Ser and α-Man-Ser linkages. This coupling reaction also led to the development of the o-allylbenzyl (ABn) moiety as a new C-terminus carboxyl protective group, which allows for the use of novel methods for N- and C-terminus extension of amino acids following carbohydrate conjugation.

/pdf/ring-opening-of-aziridine-2-carboxamides-with-carbohydrate-1lv016fike.pdf

Ring-Opening of Aziridine-2-Carboxamides with Carbohydrate C1-O-Nucleophiles. Stereoselective Preparation of α- and β-O-Glycosyl Serine Conjugates

Steroid compounds are disclosed that have a formula represented by the following: and wherein m, n, t, u1, u2, v1, v2, R 1a, R 1b , R 2a , R 2b , R 3a , R 3b , R 3c , R3d, and Y are as described herein. The compounds may be prepared as pharmaceutical compositions, and may be used for the treatment or prevention of a variety of conditions in mammals including humans, including by way of non-limiting example, inflammatory conditions, autoimmune disorders, cancer, and graft-versus-host disease.

STEROID COMPOUNDS AS RORγt MODULATORS AND USES THEREOF

Glycoside Synthesis from 1‐Oxygen Substituted Glycosyl Donors: Sections 3.1 and 3.2

Steroid compounds are disclosed that have a formula represented by the following: 
and wherein m, n, t, u1, u2, v1, v2, R 1a , R 1b , R 2a , R 2b , R 3a , R 3b , R 3c , R 3d , and Y are as described herein. The compounds may be prepared as pharmaceutical compositions, and may be used for the treatment or prevention of a variety of conditions in mammals including humans, including by way of non-limiting example, inflammatory conditions, autoimmune disorders, cancer, and graft-versus-host disease.

Daniel A. Ryan

Papers

Digoxin and its derivatives suppress Th17 cell differentiation by antagonizing RORγt activity

Ring-Opening of Aziridine-2-Carboxamides with Carbohydrate C1-O-Nucleophiles. Stereoselective Preparation of α- and β-O-Glycosyl Serine Conjugates

STEROID COMPOUNDS AS RORγt MODULATORS AND USES THEREOF

Glycoside Synthesis from 1‐Oxygen Substituted Glycosyl Donors: Sections 3.1 and 3.2

STEROID COMPOUNDS AS RORyt MODULATORS AND USES THEREOF