Activation of benign autoimmunity as both tumor and autoimmune disease immunotherapy: A comprehensive review

Understanding the Specific Implications of Amino Acids in the Antibody Development

As the demand for immunotherapy to treat and manage cancers, infectious diseases and other disorders grows, a comprehensive understanding of amino acids and their intricate role in antibody engineering has become a prime requirement. Naturally produced antibodies may not have the most suitable amino acids at the complementarity determining regions (CDR) and framework regions, for therapeutic purposes. Therefore, to enhance the binding affinity and therapeutic properties of an antibody, the specific impact of certain amino acids on the antibody's architecture must be thoroughly studied. In antibody engineering, it is crucial to identify the key amino acid residues that significantly contribute to improving antibody properties. Therapeutic antibodies with higher binding affinity and improved functionality can be achieved through modifications or substitutions with highly suitable amino acid residues. Here, we have indicated the frequency of amino acids and their association with the binding free energy in CDRs. The review also analyzes the experimental outcome of two studies that reveal the frequency of amino acids in CDRs and provides their significant correlation between the outcomes. Additionally, it discusses the various bond interactions within the antibody structure and antigen binding. A detailed understanding of these amino acid properties should assist in the analysis of antibody sequences and structures needed for designing and enhancing the overall performance of therapeutic antibodies.

T Cell and Natural Killer Cell Membrane-Camouflaged Nanoparticles for Cancer and Viral Therapies

Extensive research has been conducted on the application of nanoparticles in the treatment of cancer and infectious diseases. Due to their exceptional characteristics and flexible structure, they are classified as highly efficient drug delivery systems, ensuring both safety and targeted delivery. Nevertheless, nanoparticles still encounter obstacles, such as biological instability, absence of selectivity, recognition as unfamiliar elements, and quick elimination, which restrict their remedial capacity. To surmount these drawbacks, biomimetic nanotechnology has been developed that utilizes T cell and natural killer (NK) cell membrane-encased nanoparticles as sophisticated methods of administering drugs. These nanoparticles can extend the duration of drug circulation and avoid immune system clearance. During the membrane extraction and coating procedure, the surface proteins of immunological cells are transferred to the biomimetic nanoparticles. Such proteins present on the surface of cells confer several benefits to nanoparticles, including prolonged circulation, enhanced targeting, controlled release, specific cellular contact, and reduced in vivo toxicity. This review focuses on biomimetic nanosystems that are derived from the membranes of T cells and NK cells and their comprehensive extraction procedure, manufacture, and applications in cancer treatment and viral infections. Furthermore, potential applications, prospects, and existing challenges in their medical implementation are highlighted.

Antibody diversity in IVIG: Therapeutic opportunities for novel immunotherapeutic drugs

Significant progress has been made in the elucidation of human antibody repertoires. Furthermore, non-canonical functions of antibodies have been identified that reach beyond classical functions linked to protection from pathogens. Polyclonal immunoglobulin preparations such as IVIG and SCIG represent the IgG repertoire of the donor population and will likely remain the cornerstone of antibody replacement therapy in immunodeficiencies. However, novel evidence suggests that pooled IgA might promote orthobiotic microbial colonization in gut dysbiosis linked to mucosal IgA immunodeficiency. Plasma-derived polyclonal IgG and IgA exhibit immunoregulatory effects by a diversity of different mechanisms, which have inspired the development of novel drugs. Here we highlight recent insights into IgG and IgA repertoires and discuss potential implications for polyclonal immunoglobulin therapy and inspired drugs.

Significance of antibody numbering systems in the development of antibody engineering

Immunotherapy has become increasingly popular in recent years for treating a variety of diseases including inflammatory, neurological, oncological, and auto-immune disorders. The significant interest in antibody development is due to the high binding affinity and specificity of an antibody against a specific antigen. Recent advances in antibody engineering have provided a different view on how to engineer antibodies in silico for therapeutic and diagnostic applications. In order to improve the clinical utility of therapeutic antibodies, it is of paramount importance to understand the various molecular properties which impact antigen targeting and its potency. In antibody engineering, antibody numbering (AbN) systems play an important role to identify the complementarity determining regions (CDRs) and the framework regions (FR). Hence, it is crucial to accurately define and understand the CDR, FR and the crucial residues of heavy and light chains that aid in the binding of the antibody to the antigenic site. Detailed understanding of amino acids positions are useful for modifying the binding affinity, specificity, physicochemical features, and half-life of an antibody. In this review, we have summarized the different antibody numbering systems that are widely used in antibody engineering and highlighted their significance. Here, we have systematically explored and mentioned the various tools and servers that harness different AbN systems.

Drug Repurposing at the Interface of Melanoma Immunotherapy and Autoimmune Disease

Cancer cells have a remarkable ability to evade recognition and destruction by the immune system. At the same time, cancer has been associated with chronic inflammation, while certain autoimmune diseases predispose to the development of neoplasia. Although cancer immunotherapy has revolutionized antitumor treatment, immune-related toxicities and adverse events detract from the clinical utility of even the most advanced drugs, especially in patients with both, metastatic cancer and pre-existing autoimmune diseases. Here, the combination of multi-omics, data-driven computational approaches with the application of network concepts enables in-depth analyses of the dynamic links between cancer, autoimmune diseases, and drugs. In this review, we focus on molecular and epigenetic metastasis-related processes within cancer cells and the immune microenvironment. With melanoma as a model, we uncover vulnerabilities for drug development to control cancer progression and immune responses. Thereby, drug repurposing allows taking advantage of existing safety profiles and established pharmacokinetic properties of approved agents. These procedures promise faster access and optimal management for cancer treatment. Together, these approaches provide new disease-based and data-driven opportunities for the prediction and application of targeted and clinically used drugs at the interface of immune-mediated diseases and cancer towards next-generation immunotherapies.

Immunoglobulin genes, reproductive isolation and vertebrate speciation

Reproductive isolation drives the formation of new species, and many genes contribute to this through Dobzhansky–Muller incompatibilities (DMIs). These incompatibilities occur when gene divergence affects loci encoding interacting products such as receptors and their ligands. We suggest here that the nature of vertebrate immunoglobulin (IG) genes must make them prone to DMIs. The genes of these complex loci form functional genes through the process of recombination, giving rise to a repertoire of heterodimeric receptors of incredible diversity. This repertoire, within individuals and within species, must defend against pathogens but must also avoid pathogenic self‐reactivity. We suggest that this avoidance of autoimmunity is only achieved through a coordination of evolution between heavy‐ and light‐chain genes, and between these genes and the rest of the genome. Without coordinated evolution, the hybrid offspring of two diverging populations will carry a heavy burden of DMIs, resulting in a loss of fitness. Critical incompatibilities could manifest as incompatibilities between a mother and her divergent offspring. During fetal development, biochemical differences between the parents of hybrid offspring could make their offspring a target of the maternal immune system. This hypothesis was conceived in the light of recent insights into the population genetics of IG genes. This has suggested that antibody genes are probably as susceptible to evolutionary forces as other parts of the genome. Further repertoire studies in human and nonhuman species should now help determine whether antibody genes have been part of the evolutionary forces that drive the development of species.

Autoimmunity and its expression in the analytic situation: A contemporary reflection on our inherent self-destructiveness

This article explores the psychical expression of autoimmunity in the analytic situation; it is informed by biological theories of autoimmunity in contemporary immunology. Several of my patients developed autoimmune conditions in the course of their analyses, leading me to consider the role of psychical change in disrupting one's somatopsychic equilibrium. In the psychoanalytic literature, autoimmunity is used metaphorically for attack against what is foreign or unwanted in ourselves. Contemporary immunology, however, suggests a somewhat different metaphor. "Self-reactive" cells present in the body may attack self unless suppressed by inhibitory mechanisms. Biologically, limited self-destructiveness is necessary, but in autoimmune disease it becomes excessive and pathological. I suggest that the presence of biological "self-reactivity" implies an inherent self-destructiveness in line with Freud's thinking on the death instinct; the notion that this self-destructiveness also has adaptive aspects may contribute to our understanding of Freud's ideas. In three vignettes I illustrate clinical application of a modified metaphor of autoimmunity, finding that not only is the fusion of life and death instincts important for psychic development, but so is defusion when contained within the analytic relationship. The analytic task is to restore the balance between constructive and pathological self-destructiveness. Implications regarding controversies in psychosomatic theory are briefly considered.

Transcriptional and post-transcriptional regulation of checkpoint genes on the tumour side of the immunological synapse

Cancer is a disease of the genome, therefore, its development has a clear Mendelian component, demonstrated by well-studied genes such as BRCA1 and BRCA2 in breast cancer risk. However, it is known that a single genetic variant is not enough for cancer to develop leading to the theory of multistage carcinogenesis. In many cases, it is a sequence of events, acquired somatic mutations, or simply polygenic components with strong epigenetic effects, such as in the case of brain tumours. The expression of many genes is the product of the complex interplay between several factors, including the organism’s genotype (in most cases Mendelian-inherited), genetic instability, epigenetic factors (non-Mendelian-inherited) as well as the immune response of the host, to name just a few. In recent years the importance of the immune system has been elevated, especially in the light of the immune checkpoint genes discovery and the subsequent development of their inhibitors. As the expression of these genes normally suppresses self-immunoreactivity, their expression by tumour cells prevents the elimination of the tumour by the immune system. These discoveries led to the rapid growth of the field of immuno-oncology that offers new possibilities of long-lasting and effective treatment options. Here we discuss the recent advances in the understanding of the key mechanisms controlling the expression of immune checkpoint genes in tumour cells.

Struggle within: evolution and ecology of somatic cell populations

The extent to which normal (nonmalignant) cells of the body can evolve through mutation and selection during the lifetime of the organism has been a major unresolved issue in evolutionary and developmental studies. On the one hand, stable multicellular individuality seems to depend on genetic homogeneity and suppression of evolutionary conflicts at the cellular level. On the other hand, the example of clonal selection of lymphocytes indicates that certain forms of somatic mutation and selection are concordant with the organism-level fitness. Recent DNA sequencing and tissue physiology studies suggest that in addition to adaptive immune cells also neurons, epithelial cells, epidermal cells, hematopoietic stem cells and functional cells in solid bodily organs are subject to evolutionary forces during the lifetime of an organism. Here we refer to these recent studies and suggest that the expanding list of somatically evolving cells modifies idealized views of biological individuals as radically different from collectives.

B and T Cell Immunity in Tissues and Across the Ages

B and T cells are key components of the adaptive immune system and coordinate multiple facets of immunity including responses to infection, vaccines, allergens, and the environment. In humans, B- and T-cell immunity has been determined using primarily peripheral blood specimens. Conversely, human tissues have scarcely been studied but they host multiple adaptive immune cells capable of mounting immune responses to pathogens and participate in tissue homeostasis. Mucosal tissues, such as the intestines and respiratory track, are constantly bombarded by foreign antigens and contain tissue-resident memory T (T_RM) cells that exhibit superior protective capacity to pathogens. Also, tissue-resident memory B (B_RM) cells have been identified in mice but whether humans have a similar population remains to be confirmed. Moreover, the immune system evolves throughout the lifespan of humans and undergoes multiple changes in its immunobiology. Recent studies have shown that age-related changes in tissues are not necessarily reflected in peripheral blood specimens, highlighting the importance of tissue localization and subset delineation as essential determinants of functional B and T cells at different life stages. This review describes our current knowledge of the main B- and T-cell subsets in peripheral blood and tissues across age groups.

Prospects of the Use of Cell Therapy to Induce Immune Tolerance

Conditions in which abnormal or excessive immune responses exist, such as autoimmune diseases (ADs), graft-versus-host disease, transplant rejection, and hypersensitivity reactions, are serious hazards to human health and well-being. The traditional immunosuppressive drugs used to treat these conditions can lead to decreased immune function, a higher risk of infection, and increased tumor susceptibility. As an alternative therapeutic approach, cell therapy, in which generally intact and living cells are injected, grafted, or implanted into a patient, has the potential to overcome the limitations of traditional drug treatment and to alleviate the symptoms of many refractory diseases. Cell therapy could be a powerful approach to induce immune tolerance and restore immune homeostasis with a deeper understanding of immune tolerance mechanisms and the development of new techniques. The purpose of this review is to describe the current panoramic scope of cell therapy for immune-mediated disorders, discuss the advantages and disadvantages of different types of cell therapy, and explore novel directions and future prospects for these tolerogenic therapies.

CD26-Related Serum Biomarkers: sCD26 Protein, DPP4 Activity, and Anti-CD26 Isotype Levels in a Colorectal Cancer-Screening Context

Current screening trials are showing reduction in colorectal cancer incidence and mortality. However, participation rates are often low, and blood-based tests could complement existing screening strategies. CD26 protein (sCD26) and its dipeptidyl peptidase IV (DPP4) enzymatic activity in circulation have been proposed as biomarkers for colorectal cancer and other diseases. However, changes in sCD26 and DPP4 levels show complex degrees of correlation, and their physiological or pathophysiological role is unclear. The aim of this study was to analyse if anti-CD26 autoantibodies are related to sCD26 and DPP4 and to determine their relevance in a context of colorectal cancer screening for complementing the value of sCD26 and DPP4 as biomarkers. These biomarkers were measured in a large prospective cohort (n = 497, except the anti-CD26 antibodies, evaluated in 125 samples) that included a subgroup of individuals that were positive for the faecal immunological occult blood test (FIT) (n = 86) and underwent a colonoscopy (n = 47). We confirmed for the first time higher DPP4 activity in men compared to women (Student's t test, p = 0.002), though this difference between sexes was not seen for serum sCD26 protein. These biomarkers correlated (R = 0.246, p = 0.003) only in women. Correlations were found between anti-CD26 isotypes but not with DPP4 activity or sCD26 concentration, except for a negative correlation only in men between anti-CD26 IgA isotype and sCD26 (R = -0.232, p = 0.044), and an almost significant negative correlation between anti-CD26 IgG and sCD26 limited to FIT-positive men. Interestingly, patients with advanced adenomas displayed the most elevated mean levels of anti-CD26 IgA, IgM, and particularly IgG (Mann-Whitney U test, p = 0.030) in comparison with the other FIT positives without adenomas, and these levels did not correlate with sCD26 or its DPP4 activity. Our preliminary results suggest that the combination of these measures using sex as confounder could perhaps be used as biomarkers for colorectal disease. It also suggests that events affecting the gut influence the levels of anti-CD26 antibodies, which show little or no effect in antigen clearance. These findings should be confirmed in a larger cohort of individuals with colonoscopy. The physiological origin of the sex differences observed should be further addressed.

Occurrence of major anti-retinal autoantibodies associated with paraneoplastic autoimmune retinopathy

Autoantibodies (AAbs) against retinal antigens can be found in patients with cancer and unexplained vision loss unrelated to the cancer metastasis. Cancer-associated retinopathy (CAR) is a rare paraneoplastic visual syndrome mediated by AAbs. Our goal was to determine whether CAR patients with different malignancies have a specific AAb or repertoire of AAbs that could serve as biomarkers for retinal disease. We found AAbs against 12 confirmed retinal antigens, with α-enolase being the most frequently recognized. The significant finding of the study was a high incidence of anti-aldolase AAbs in colon-CAR, anti-CAII in prostate-CAR, and anti-arrestin in skin melanoma patients thus these AAbs could serve as biomarkers in the context of clinical presentation and could support the diagnosis of CAR. However, a lack of AAb restriction to any one antigenic protein or to one retinal cellular location makes screening for a CAR biomarker challenging.

Identification of circulating MOG-specific B cells in patients with MOG antibodies

OBJECTIVE

To identify circulating myelin oligodendrocyte glycoprotein (MOG)-specific B cells in the blood of patients with MOG antibodies (Abs) and to determine whether circulating MOG-specific B cells are linked to levels and epitope specificity of serum anti-MOG-Abs.

METHODS

We compared peripheral blood from 21 patients with MOG-Abs and 26 controls for the presence of MOG-specific B cells. We differentiated blood-derived B cells in vitro in separate culture wells to Ab-producing cells via engagement of Toll-like receptors 7 and 8. We quantified the anti-MOG reactivity with a live cell-based assay by flow cytometry. We determined the recognition of MOG epitopes with a panel of mutated variants of MOG.

RESULTS

MOG-Ab-positive patients had a higher frequency of MOG-specific B cells in blood than controls, but MOG-specific B cells were only detected in about 60% of these patients. MOG-specific B cells in blood showed no correlation with anti-MOG Ab levels in serum, neither in the whole group nor in the untreated patients. Epitope analysis of MOG-Abs secreted from MOG-specific B cells cultured in different wells revealed an intraindividual heterogeneity of the anti-MOG autoimmunity.

CONCLUSIONS

This study shows that patients with MOG-Abs greatly differ in the abundance of circulating MOG-specific B cells, which are not linked to levels of MOG-Abs in serum suggesting different sources of MOG-Abs. Identification of MOG-specific B cells in blood could be of future relevance for selecting patients with MOG-Abs for B cell-directed therapy.

STAT3 and STAT5 Targeting for Simultaneous Management of Melanoma and Autoimmune Diseases

Melanoma is a skin cancer which can become metastatic, drug-refractory, and lethal if managed late or inappropriately. An increasing number of melanoma patients exhibits autoimmune diseases, either as pre-existing conditions or as sequelae of immune-based anti-melanoma therapies, which complicate patient management and raise the need for more personalized treatments. STAT3 and/or STAT5 cascades are commonly activated during melanoma progression and mediate the metastatic effects of key oncogenic factors. Deactivation of these cascades enhances antitumor-immune responses, is efficient against metastatic melanoma in the preclinical setting and emerges as a promising targeting strategy, especially for patients resistant to immunotherapies. In the light of the recent realization that cancer and autoimmune diseases share common mechanisms of immune dysregulation, we suggest that the systemic delivery of STAT3 or STAT5 inhibitors could simultaneously target both, melanoma and associated autoimmune diseases, thereby decreasing the overall disease burden and improving quality of life of this patient subpopulation. Herein, we review the recent advances of STAT3 and STAT5 targeting in melanoma, explore which autoimmune diseases are causatively linked to STAT3 and/or STAT5 signaling, and propose that these patients may particularly benefit from treatment with STAT3/STAT5 inhibitors.

Top-down Mass Spectrometry Analysis of Human Serum Autoantibody Antigen-Binding Fragments

Detecting autoimmune diseases at an early stage is crucial for effective treatment and disease management to slow disease progression and prevent irreversible organ damage. In many autoimmune diseases, disease-specific autoantibodies are produced by B cells in response to soluble autoantigens due to defects in B cell tolerance mechanisms. Autoantibodies accrue early in disease development, and several are so disease-specific they serve as classification criteria. In this study, we established a high-throughput, sensitive, intact serum autoantibody analysis platform based on the optimization of a one dimensional ultra-high-pressure liquid chromatography top-down mass spectrometry platform (1D UPLC-TDMS). This approach has been successfully applied to a 12 standard monoclonal antibody antigen-binding fragment (Fab) mixture, demonstrating the feasibility to separate and sequence intact antibodies with high sequence coverage and high sensitivity. We then applied the optimized platform to characterize total serum antibody Fabs in a systemic lupus erythematosus (SLE) patient sample and compared it to healthy control samples. From this analysis, we show that the SLE sample has many dominant antibody Fab-related mass features unlike the healthy controls. To our knowledge, this is the first top-down demonstration of serum autoantibody pool analysis. Our proposed approach holds great promise for discovering novel serum autoantibody biomarkers that are of interest for diagnosis, prognosis, and tolerance induction, as well as improving our understanding of pathogenic autoimmune processes.

The Immune System Computes the State of the Body: Crowd Wisdom, Machine Learning, and Immune Cell Reference Repertoires Help Manage Inflammation

Here, we outline an overview of the mammalian immune system that updates and extends the classical clonal selection paradigm. Rather than focusing on strict self-not-self discrimination, we propose that the system orchestrates variable inflammatory responses that maintain the body and its symbiosis with the microbiome while eliminating the threat from pathogenic infectious agents and from tumors. The paper makes four points:

The immune system classifies healthy and pathologic states of the body—including both self and foreign elements—by deploying individual lymphocytes as cellular computing machines; immune cells transform input signals from the body into an output of specific immune reactions.

Rather than independent clonal responses, groups of individually activated immune-system cells co-react in lymphoid organs to make collective decisions through a type of self-organizing swarm intelligence or crowd wisdom.

Collective choices by swarms of immune cells, like those of schools of fish, are modified by relatively small numbers of individual regulators responding to shifting conditions—such collective inflammatory responses are dynamically responsive.

Self-reactive autoantibody and T-cell receptor (TCR) repertoires shared by healthy individuals function in a biological version of experience-based supervised machine learning. Immune system decisions are primed by formative experience with training sets of self-antigens encountered during lymphocyte development; these initially trained T cell and B cell repertoires form a Wellness Profile that then guides immune responses to test sets of antigens encountered later. This experience-based machine learning strategy is analogous to that deployed by supervised machine-learning algorithms.

We propose experiments to test these ideas. This overview of the immune system bears clinical implications for monitoring wellness and for treating autoimmune disease, cancer, and allograft reactions.

Human T Cell Development, Localization, and Function throughout Life

Throughout life, T cells coordinate multiple aspects of adaptive immunity, including responses to pathogens, allergens, and tumors. In mouse models, the role of T cells is studied in the context of a specific type of pathogen, antigen, or disease condition over a limited time frame, whereas in humans, T cells control multiple insults simultaneously throughout the body and maintain immune homeostasis over decades. In this review, we discuss how human T cells develop and provide essential immune protection at different life stages and highlight tissue localization and subset delineation as key determinants of the T cell functional role in immune responses. We also discuss how anatomic compartments undergo distinct age-associated changes in T cell subset composition and function over a lifetime. It is important to consider age and tissue influences on human T cells when developing targeted strategies to modulate T cell-mediated immunity in vaccines and immunotherapies.

Immunosurveillance of cancer and the heat shock protein-CD91 pathway

The intracellular functions of heat shock proteins (HSPs) as chaperones of macromolecules are well known. Current observations point to a role of these chaperones in initiating and modulating immune responses to tumors via receptor(s) on dendritic cells. In this article we provide an insight into, and a basis for, the importance of these HSP-mediated immune responses in rejecting nascent and emerging tumors.

Immunization with α-synuclein/Grp94 reshapes peripheral immunity and suppresses microgliosis in a chronic Parkinsonism model

Neuroinflammation mediated by chronically activated microglia, largely caused by abnormal accumulation of misfolded α-synuclein (αSyn) protein, is known to contribute to the pathophysiology of Parkinson's disease (PD). In this work, based on the immunomodulatory activities displayed by particular heat-shock proteins (HSPs), we tested a novel vaccination strategy that used a combination of αSyn and Grp94 (HSPC4 or Gp96) chaperone and a murine PD model. We used two different procedures, first, the adoptive transfer of splenocytes from αSyn/Grp94-immunized mice to recipient animals, and second, direct immunization with αSyn/Grp94, to study the effects in a chronic mouse MPTP-model of parkinsonism. We found that both approaches promoted a distinct profile in the peripheral system-supported by humoral and cellular immunity-consisting of a Th1-shifted αSyn-specific response accompanied by an immune-regulatory/Th2-skewed general phenotype. Remarkably, this mixed profile sustained by αSyn/Grp94 immunization led to strong suppression of microglial activation in the substantia nigra and striatum, pointing to a newly described positive effect of anti-αSyn Th1-responses in the context of PD. This strategy is the first to target αSyn and report the suppression of PD-associated microgliosis. Overall, we show that the αSyn/Grp94 combination supports a distinct and long-lasting immune profile in the peripheral system, which has an impact at the CNS level by suppressing chronic microglial activation in an MPTP model of PD. Furthermore, our study demonstrates that reshaping peripheral immunity by vaccination with appropriate misfolding protein/HSP combinations could be highly beneficial as a treatment for neurodegenerative misfolding diseases.

Impact of Autoantibodies against Glycolytic Enzymes on Pathogenicity of Autoimmune Retinopathy and Other Autoimmune Disorders

Autoantibodies (AAbs) against glycolytic enzymes: aldolase, α-enolase, glyceraldehyde-3-phosphate dehydrogenase, and pyruvate kinase are prevalent in sera of patients with blinding retinal diseases, such as paraneoplastic [cancer-associated retinopathy (CAR)] and non-paraneoplastic autoimmune retinopathies, as well as in many other autoimmune diseases. CAR is a degenerative disease of the retina characterized by sudden vision loss in patients with cancer and serum anti-retinal AAbs. In this review, we discuss the widespread serum presence of anti-glycolytic enzyme AAbs and their significance in autoimmune diseases. There are multiple mechanisms responsible for antibody generation, including the innate anti-microbial response, anti-tumor response, or autoimmune response against released self-antigens from damaged, inflamed tissue. AAbs against enolase, GADPH, and aldolase exist in a single patient in elevated titers, suggesting their participation in pathogenicity. The lack of restriction of AAbs to one disease may be related to an increased expression of glycolytic enzymes in various metabolically active tissues that triggers an autoimmune response and generation of AAbs with the same specificity in several chronic and autoimmune conditions. In CAR, the importance of serum anti-glycolytic enzyme AAbs had been previously dismissed, but the retina may be without pathological consequence until a failure of the blood–retinal barrier function, which would then allow pathogenic AAbs access to their retinal targets, ultimately leading to damaging effects.

Evolution, immunity and the emergence of brain superautoantigens

While some autoimmune disorders remain extremely rare, others largely predominate the epidemiology of human autoimmunity. Notably, these include psoriasis, diabetes, vitiligo, thyroiditis, rheumatoid arthritis and multiple sclerosis. Thus, despite the quasi-infinite number of "self" antigens that could theoretically trigger autoimmune responses, only a limited set of antigens, referred here as superautoantigens, induce pathogenic adaptive responses. Several lines of evidence reviewed in this paper indicate that, irrespective of the targeted organ (e.g. thyroid, pancreas, joints, brain or skin), a significant proportion of superautoantigens are highly expressed in the synaptic compartment of the central nervous system (CNS). Such an observation applies notably for GAD65, AchR, ribonucleoproteins, heat shock proteins, collagen IV, laminin, tyrosine hydroxylase and the acetylcholinesterase domain of thyroglobulin. It is also argued that cognitive alterations have been described in a number of autoimmune disorders, including psoriasis, rheumatoid arthritis, lupus, Crohn's disease and autoimmune thyroiditis. Finally, the present paper points out that a great majority of the "incidental" autoimmune conditions notably triggered by neoplasms, vaccinations or microbial infections are targeting the synaptic or myelin compartments. On this basis, the concept of an immunological homunculus, proposed by Irun Cohen more than 25 years ago, is extended here in a model where physiological autoimmunity against brain superautoantigens confers both: i) a crucial evolutionary-determined advantage via cognition-promoting autoimmunity; and ii) a major evolutionary-determined vulnerability, leading to the emergence of autoimmune disorders in Homo sapiens. Moreover, in this theoretical framework, the so called co-development/co-evolution model, both the development (at the scale of an individual) and evolution (at the scale of species) of the antibody and T-cell repertoires are coupled to those of the neural repertoires (i.e. the distinct neuronal populations and synaptic circuits supporting cognitive and sensorimotor functions). Clinical implications and future experimental insights are also presented and discussed.

Therapeutic effect of the immunomodulatory drug lenalidomide, but not pomalidomide, in experimental models of rheumatoid arthritis and inflammatory bowel disease

Thalidomide is an immunomodulatory drug (IMiD) with proven therapeutic action in several autoimmune/inflammatory diseases; however, its inherent high toxicity has led to the development of more powerful and safer thalidomide analogs, including lenalidomide and pomalidomide. These are new generation IMiDs that exhibit direct antitumor activity as well as anti-inflammatory/immunomodulatory properties, and are FDA-approved for the treatment of several hematological malignances. Here we investigated the potential therapeutic effects of lenalidomide and pomalidomide in several experimental murine models of autoimmune/inflammatory diseases: 2,4,6-trinitrobenzene sulfonic acid- and dextran sulfate sodium-induced inflammatory bowel disease and type II collagen-induced arthritis. Lenalidomide displayed a strong therapeutic effect in all these models of autoimmune/inflammatory diseases, while the effect of pomalidomide was less pronounced. In vitro experiments confirmed the immunosuppressive effect of both IMiDs on the proliferative response of stimulated human lymphocytes and on the balance of secreted cytokines toward an anti-inflammatory profile. We conclude that lenalidomide may offer a therapeutic opportunity against autoimmune/inflammatory diseases.

Autoimmunity in 2014

Our PubMed search for peer-reviewed articles published in the 2014 solar year retrieved a significantly higher number of hits compared to 2013 with a net 28 % increase. Importantly, full articles related to autoimmunity constitute approximately 5 % of immunology articles. We confirm that our understanding of autoimmunity is becoming a translational paradigm with pathogenetic elements rapidly followed by new treatment options. Furthermore, numerous clinical and pathogenetic elements and features are shared among autoimmune diseases, and this is well illustrated in the recent literature. More specifically, the past year witnessed critical revisions of our understanding and management of antiphospholipid syndrome with new exciting data on the pathogenicity of the serum anti-beta2 glycoprotein autoantibody, a better understanding of the current and new treatments for rheumatoid arthritis, and new position papers on important clinical questions such as vaccinations in patients with autoimmune disease, comorbidities, or new classification criteria. Furthermore, data confirming the important connections between innate immunity and autoimmunity via toll-like receptors or the critical role of T regulatory cells in tolerance breakdown and autoimmunity perpetuation were also reported. Lastly, genetic and epigenetic data were provided to confirm that the mosaic of autoimmunity warrants a susceptible individual background which may be geographically determined and contribute to the geoepidemiology of diseases. The 2014 literature in the autoimmunity world should be cumulatively regarded as part of an annus mirabilis in which, on a different level, the 2014 Annual Meeting of the American College of Rheumatology in Boston was attended by over 16,000 participants with over selected 3000 abstracts.

An Arthritis-Suppressive and Treg Cell-Inducing CD4+ T Cell Epitope Is Functional in the Context of HLA-Restricted T Cell Responses

OBJECTIVE

We previously showed that mycobacterial Hsp70-derived peptide B29 induced B29-specific Treg cells that suppressed experimental arthritis in mice via cross-recognition of their mammalian Hsp70 homologs. The aim of the current study was to characterize B29 binding and specific CD4+ T cell responses in the context of human major histocompatibility complex (MHC) molecules.

METHODS

Competitive binding assays were performed to examine binding of peptide B29 and its mammalian homologs to HLA molecules. The effect of B29 immunization in HLA-DQ8-transgenic mice with proteoglycan-induced arthritis was assessed, followed by ex vivo restimulation with B29 to examine the T cell response. Human peripheral blood mononuclear cells were used to investigate the presence of B29-specific T cells with immunoregulatory potential.

RESULTS

The binding affinity of the B29 peptide was high to moderate for multiple HLA-DR and HLA-DQ molecules, including those highly associated with rheumatoid arthritis. This binding was considered to be functional, because B29 immunization resulted in the suppression of arthritis and T cell responses in HLA-DQ8-transgenic mice. In humans, we demonstrated the presence and expansion of B29-specific CD4+ T cells, which were cross-reactive with the mammalian homologs. Using HLA-DR4+ tetramers specific for B29 or the mammalian homolog mB29b, we showed expansion of cross-reactive T cells, especially the human FoxP3+ CD4+CD25+ T cell population, after in vitro stimulation with B29.

CONCLUSION

These results demonstrated a conserved fine specificity and functionality of B29-induced Treg cell responses in the context of the human MHC. Based on these findings, a path for translation of the experimental findings for B29 into a clinical immunomodulatory therapeutic approach is within reach.

Gut feelings of safety: tolerance to the microbiota mediated by innate immune receptors

To enable microbial colonization of the gut mucosa, the intestinal immune system must not only react to danger signals but also recognize cues that indicate safety. Recognition of safety, paradoxically, is mediated by the same environmental sensors that are involved in signaling danger. Indeed, in addition to their well-established role in inducing inflammation in response to stress signals, pattern recognition receptors and a variety of metabolic sensors also promote gut-microbiota symbiosis by responding to "microbial symbiosis factors", "resolution-associated molecular patterns", markers of energy extraction and other signals indicating the absence of pathogenic infection and tissue damage. Here we focus on how the paradoxical roles of immune receptors and other environmental sensors define the microbiota signature of an individual.

Dendritic Cells Guide Islet Autoimmunity through a Restricted and Uniquely Processed Peptidome Presented by High-Risk HLA-DR

Identifying T cell epitopes of islet autoantigens is important for understanding type 1 diabetes (T1D) immunopathogenesis and to design immune monitoring and intervention strategies in relationship to disease progression. Naturally processed T cell epitopes have been discovered by elution from HLA-DR4 of pulsed B lymphocytes. The designated professional APC directing immune responses is the dendritic cell (DC). To identify naturally processed epitopes, monocyte-derived DC were pulsed with preproinsulin (PPI), glutamic acid decarboxylase (65-kDa isoform; GAD65), and insulinoma-associated Ag-2 (IA-2), and peptides were eluted of HLA-DR3 and -DR4, which are associated with highest risk for T1D development. Proteome analysis confirmed uptake and processing of islet Ags by DC. PPI peptides generated by DC differed from those processed by B lymphocytes; PPI signal-sequence peptides were eluted from HLA-DR4 and -DR3/4 that proved completely identical to a primary target epitope of diabetogenic HLA-A2-restricted CD8 T cells. HLA-DR4 binding was confirmed. GAD65 peptides, eluted from HLA-DR3 and -DR4, encompassed two core regions overlapping the two most immunodominant and frequently studied CD4 T cell targets. GAD65 peptides bound to HLA-DR3. Strikingly, the IA-2 ligandome of HLA-DR was exclusively generated from the extracellular part of IA-2, whereas most previous immune studies have focused on intracellular IA-2 epitopes. The newly identified IA-2 peptides bound to HLA-DR3 and -DR4. Differential T cell responses were detected against the newly identified IA-2 epitopes in blood from T1D patients. The core regions to which DC may draw attention from autoreactive T cells are largely distinct and more restricted than are those of B cells. GAD65 peptides presented by DC focus on highly immunogenic T cell targets, whereas HLA-DR-binding peptides derived from IA-2 are distinct from the target regions of IA-2 autoantibodies.

Btn2a2, a T cell immunomodulatory molecule coregulated with MHC class II genes

Butyrophilins are proteins secreted during lactation and thought to influence immune function. Sarter et al. generated butyrophilin-2a2–deficient mice to show enhanced effector T cell responses, antitumor responses, and exacerbated EAE due to the impaired APC modulation of T cell immunity.

Evidence has recently emerged that butyrophilins, which are members of the extended B7 family of co-stimulatory molecules, have diverse functions in the immune system. We found that the human and mouse genes encoding butyrophilin-2A2 (BTN2A2) are regulated by the class II trans-activator and regulatory factor X, two transcription factors dedicated to major histocompatibility complex class II expression, suggesting a role in T cell immunity. To address this, we generated Btn2a2-deficient mice. Btn2a2^−/− mice exhibited enhanced effector CD4⁺ and CD8⁺ T cell responses, impaired CD4⁺ regulatory T cell induction, potentiated antitumor responses, and exacerbated experimental autoimmune encephalomyelitis. Altered immune responses were attributed to Btn2a2 deficiency in antigen-presenting cells rather than T cells or nonhematopoietic cells. These results provide the first genetic evidence that BTN2A2 is a co-inhibitory molecule that modulates T cell–mediated immunity.

Association Between Immunoglobulin G4-related Disease and Malignancy within 12 Years after Diagnosis: An Analysis after Longterm Followup

OBJECTIVE

Because it is uncertain whether immunoglobulin G4-related disease (IgG4-RD) is associated with malignancy, we evaluated the incidence of cancer development in a large cohort of patients with IgG4-RD.

METHODS

The study enrolled 158 patients diagnosed as having IgG4-RD between 1992 and 2012. We calculated the standardized incidence ratio (SIR) and cumulative rate of malignancies in this group and searched for risk factors associated with the occurrence of tumors.

RESULTS

A total of 34 malignancies were observed in the patients with IgG4-RD over a mean followup period of 5.95 ± 4.48 years. The overall SIR of malignancies was 2.01 (95% CI 1.34-2.69). The SIR of patients who exhibited a tumor within 1 year after IgG4-RD diagnosis was 3.53 (95% CI 1.23-5.83), while that of subjects forming a malignancy in subsequent years was 1.48 (95% CI 0.99-1.98). The cumulative rate of malignancy development was significantly higher in patients with IgG4-RD within 12 years after diagnosis than in the Japanese general population. Comparable results were obtained for an autoimmune pancreatitis subgroup. The serum concentrations of several disease activity markers at diagnosis were significantly higher in patients with malignancies than in those without.

CONCLUSION

We identified a close association between IgG4-RD and malignancy formation within 12 years after diagnosis, particularly during the first year. An active IgG4-RD state is presumed to be a strong risk factor for malignancy development.

Hinokitiol Negatively Regulates Immune Responses through Cell Cycle Arrest in Concanavalin A-Activated Lymphocytes

Autoimmune diseases are a group of chronic inflammatory diseases that arise from inappropriate inflammatory responses. Hinokitiol, isolated from the wood of Chamaecyparis taiwanensis, engages in multiple biological activities. Although hinokitiol has been reported to inhibit inflammation, its immunological regulation in lymphocytes remains incomplete. Thus, we determined the effects of hinokitiol on concanavalin A- (ConA-) stimulated T lymphocytes from the spleens of mice. In the present study, the MTT assay revealed that hinokitiol (1–5 μM) alone did not affect cell viability of lymphocytes, but at the concentration of 5 μM it could reduce ConA-stimulated T lymphocyte proliferation. Moreover, propidium iodide (PI) staining revealed that hinokitiol arrested cell cycle of T lymphocytes at the G0/G1 phase. Hinokitiol also reduced interferon gamma (IFN-γ) secretion from ConA-activated T lymphocytes, as detected by an ELISA assay. In addition, hinokitiol also downregulated cyclin D3, E2F1, and Cdk4 expression and upregulated p21 expression. These results revealed that hinokitiol may regulate immune responses. In conclusion, we for the first time demonstrated that hinokitiol upregulates p21 expression and attenuates IFN-γ secretion in ConA-stimulated T lymphocytes, thereby arresting cell cycle at the G0/G1 phase. In addition, our findings also indicated that hinokitiol may provide benefits to treating patients with autoimmune diseases.

Tumor-associated and disease-associated autoantibody repertoires in healthy colostrum and maternal and newborn cord sera

In this work, we studied autoantibody repertoires and Ig isotypes in 71 mothers and their 104 healthy newborns (including twins and triplets delivered term or premature). Newborns receive maternal IgG Abs via the placenta before birth, but developing infants must produce their own IgM and IgA Abs. We used an Ag microarray analysis to detect binding to a selection of 295 self-Ags, compared with 27 standard foreign Ags. The magnitude of binding to specific self-Ags was found to be not less than that to the foreign Ags. As expected, each newborn shared with its mother a similar IgG repertoire-manifest as early as the 24th week of gestation. IgM and IgA autoantibody repertoires in cord sera were highly correlated among the newborns and differed from their mothers' repertoires; the latter differed in sera and milk. The autoantibodies bound to self-Ags known to be associated with tumors and to autoimmune diseases. Thus, autoantibody repertoires in healthy humans--the immunological homunculus--arise congenitally, differ in maternal milk and sera, and mark the potential of the immune system to attack tumors, beneficially, or healthy tissues, harmfully; regulation of the tissue site, the dynamics, and the response phenotype of homuncular autoimmunity very likely affects health.

The mechanisms and applications of T cell vaccination for autoimmune diseases: a comprehensive review

Autoimmune diseases (ADs) are a spectrum of diseases originating from loss of immunologic self-tolerance and T cell abnormal autoreactivity, causing organ damage and death. However, the pathogenic mechanism of ADs remains unclear. The current treatments of ADs include nonsteroidal anti-inflammatory drugs (NSAIDS), antimalarials, corticosteroids, immunosuppressive drugs, and biological therapies. With the need to prevent side effects resulting from current treatments and acquire better clinical remission, developing a novel pharmaceutical treatment is extremely urgent. The concept of T cell vaccination (TCV) has been raised as the finding that immunization with attenuated autoreactive T cells is capable of inducing T cell-dependent inhibition of autoimmune responses. TCV may act as an approach to control unwanted adaptive immune response through eliminating the autoreactive T cells. Over the past decades, the effect of TCV has been justified in several animal models of autoimmune diseases including experimental autoimmune encephalomyelitis (EAE), murine autoimmune diabetes in nonobese diabetic (NOD) mice, collagen-induced arthritis (CIA), and so on. Meanwhile, clinical trials of TCV have confirmed the safety and efficacy in corresponding autoimmune diseases ranging from multiple sclerosis (MS) to systemic lupus erythematosus (SLE). This review aims to summarize the ongoing experimental and clinical trials and elucidate possible molecule mechanisms of TCV.

Exosomes as nanocarriers for immunotherapy of cancer and inflammatory diseases

Cell secreted exosomes (30-100nm vesicles) play a major role in intercellular communication due to their ability to transfer proteins and nucleic acids from one cell to another. Depending on the originating cell type and the cargo, exosomes can have immunosuppressive or immunostimulatory effects, which have potential application as immunotherapies for cancer and autoimmune diseases. Cellular components shed from tumor cells or antigen presenting cells (APCs), such as dendritic cells, macrophages and B cells, have been shown to be efficiently packaged in exosomes. In this review, we focus on the application of exosomes as nanocarriers and immunological agents for cancer and autoimmune immunotherapy. APC-derived exosomes demonstrate effective therapeutic efficacy for the treatment of cancer and experimental autoimmune diseases such as rheumatoid arthritis, inflammatory bowel disease, and multiple sclerosis. In addition to their intrinsic immunomodulating activity, exosomes have many advantages over conventional nanocarriers for drug and gene delivery.