CD8+ regulatory T cells are critical in prevention of autoimmune-mediated diabetes

Helminth-virus interactions: determinants of coinfection outcomes

Viral infections are often studied in model mammalian organisms under specific pathogen-free conditions. However, in nature, coinfections are common, and infection with one organism can alter host susceptibility to infection with another. Helminth parasites share a long coevolutionary history with mammalian hosts and have shaped host physiology, metabolism, immunity, and the composition of the microbiome. Published studies suggest that helminth infection can either be beneficial or detrimental during viral infection. Here, we discuss coinfection studies in mouse models and use them to define key determinants that impact outcomes, including the type of antiviral immunity, the tissue tropism of both the helminth and the virus, and the timing of viral infection in relation to the helminth lifecycle. We also explore the current mechanistic understanding of how helminth-virus coinfection impacts host immunity and viral pathogenesis. While much attention has been placed on the impact of the gut bacterial microbiome on immunity to infection, we suggest that enteric helminths, as a part of the eukaryotic macrobiome, also represent an important modulator of disease pathogenesis and severity following virus infection.

The double-edged sword of probiotic supplementation on gut microbiota structure in Helicobacter pylori management

As Helicobacter pylori management has become more challenging and less efficient over the last decade, the interest in innovative interventions is growing by the day. Probiotic co-supplementation to antibiotic therapies is reported in several studies, presenting a moderate reduction in drug-related side effects and a promotion in positive treatment outcomes. However, the significance of gut microbiota involvement in the competence of probiotic co-supplementation is emphasized by a few researchers, indicating the alteration in the host gastrointestinal microbiota following probiotic and drug uptake. Due to the lack of long-term follow-up studies to determine the efficiency of probiotic intervention in H. pylori eradication, and the delicate interaction of the gut microbiota with the host wellness, this review aims to discuss the gut microbiota alteration by probiotic co-supplementation in H. pylori management to predict the comprehensive effectiveness of probiotic oral administration.Abbreviations: acyl-CoA- acyl-coenzyme A; AMP- antimicrobial peptide; AMPK- AMP-activated protein kinase; AP-1- activator protein 1; BA- bile acid; BAR- bile acid receptor; BCAA- branched-chain amino acid; C2- acetate; C3- propionate; C4- butyrate; C5- valeric acid; CagA- Cytotoxin-associated gene A; cAMP- cyclic adenosine monophosphate; CD- Crohn's disease; CDI- C. difficile infection; COX-2- cyclooxygenase-2; DC- dendritic cell; EMT- epithelial-mesenchymal transition; FMO- flavin monooxygenases; FXR- farnesoid X receptor; GPBAR1- G-protein-coupled bile acid receptor 1; GPR4- G protein-coupled receptor 4; H2O2- hydrogen peroxide; HCC- hepatocellular carcinoma; HSC- hepatic stellate cell; IBD- inflammatory bowel disease; IBS- irritable bowel syndrome; IFN-γ- interferon-gamma; IgA immunoglobulin A; IL- interleukin; iNOS- induced nitric oxide synthase; JAK1- janus kinase 1; JAM-A- junctional adhesion molecule A; LAB- lactic acid bacteria; LPS- lipopolysaccharide; MALT- mucosa-associated lymphoid tissue; MAMP- microbe-associated molecular pattern; MCP-1- monocyte chemoattractant protein-1; MDR- multiple drug resistance; mTOR- mammalian target of rapamycin; MUC- mucin; NAFLD- nonalcoholic fatty liver disease; NF-κB- nuclear factor kappa B; NK- natural killer; NLRP3- NLR family pyrin domain containing 3; NOC- N-nitroso compounds; NOD- nucleotide-binding oligomerization domain; PICRUSt- phylogenetic investigation of communities by reconstruction of unobserved states; PRR- pattern recognition receptor; RA- retinoic acid; RNS- reactive nitrogen species; ROS- reactive oxygen species; rRNA- ribosomal RNA; SCFA- short-chain fatty acids; SDR- single drug resistance; SIgA- secretory immunoglobulin A; STAT3- signal transducer and activator of transcription 3; T1D- type 1 diabetes; T2D- type 2 diabetes; Th17- T helper 17; TLR- toll-like receptor; TMAO- trimethylamine N-oxide; TML- trimethyllysine; TNF-α- tumor necrosis factor-alpha; Tr1- type 1 regulatory T cell; Treg- regulatory T cell; UC- ulcerative colitis; VacA- Vacuolating toxin A.

Class Ib MHC-Mediated Immune Interactions Play a Critical Role in Maintaining Mucosal Homeostasis in the Mammalian Large Intestine

Lymphocytes within the intestinal epithelial layer (IEL) in mammals have unique composition compared with their counterparts in the lamina propria. Little is known about the role of some of the key colonic IEL subsets, such as TCRαβ⁺CD8⁺ T cells, in inflammation. We have recently described liver-enriched innate-like TCRαβ⁺CD8αα regulatory T cells, partly controlled by the non-classical MHC molecule, Qa-1^b, that upon adoptive transfer protect from T cell-induced colitis. In this study, we found that TCRαβ⁺CD8αα T cells are reduced among the colonic IEL during inflammation, and that their activation with an agonistic peptide leads to significant Qa-1^b-dependent protection in an acute model of colitis. Cellular expression of Qa-1^b during inflammation and corresponding dependency in peptide-mediated protection suggest that Batf3-dependent CD103⁺CD11b^- type 1 conventional dendritic cells control the protective function of TCRαβ⁺CD8αα T cells in the colonic epithelium. In the colitis model, expression of the potential barrier-protective gene, Muc2, is enhanced upon administration of a Qa-1b agonistic peptide. Notably, in steady state, the mucin metabolizing Akkermansia muciniphila was found in significantly lower abundance amid a dramatic change in overall microbiome and metabolome, increased IL-6 in explant culture, and enhanced sensitivity to dextran sulfate sodium in Qa-1b deficiency. Finally, in patients with inflammatory bowel disease, we found upregulation of HLA-E, a Qa-1^b analog with inflammation and biologic non-response, in silico, suggesting the importance of this regulatory mechanism across species.

Newly Found Peacekeeper: Potential of CD8+ Tregs for Graft-Versus-Host Disease

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the most effective and potentially curative treatment for a variety of hematologic malignancies. However, graft-versus-host disease (GVHD) is a major obstacle that limits wide application of allo-HSCT, despite the development of prophylactic strategies. Owing to experimental and clinical advances in the field, GVHD is characterized by disruption of the balance between effector and regulatory immune cells, resulting in higher inflammatory cytokine levels. A reduction in regulatory T cells (Tregs) has been associated with limiting recalibration of inflammatory overaction and maintaining immune tolerance. Moreover, accumulating evidence suggests that immunoregulation may be useful for preventing GVHD. As opposed to CD4⁺ Tregs, the CD8⁺ Tregs population, which constitutes an important proportion of all Tregs, efficiently attenuates GVHD while sparing graft-versus-leukemic (GVL) effects. CD8⁺ Tregs may provide another form of cellular therapy for preventing GVHD and preserving GVL effects, and understanding the underlying mechanisms that different from those of CD4⁺ Tregs is significant. In this review, we summarize preclinical experiments that have demonstrated the role of CD8⁺ Tregs during GVHD and attempted to obtain optimized CD8⁺ Tregs. Notably, although optimized CD8⁺ Tregs have obvious advantages, more exploration is needed to determine how to apply them in the clinic.

Effectiveness comparison between Endometrial Receptivity Array, Immune Profiling and the combination in treating patients with multiple implantation failure

PROBLEM

The clinical value of endometrial receptivity array (ERA), endometrial immune profiling, or a combination of both for multiple implantation failure patients is unclear.

METHOD OF STUDY

One hundred and seventy-two women with a history of at least two or more consecutive implantation failures in IVF/ICSI treatment were included. According to patients' willingness, they were divided into four groups, 'no treatment', 'Immune Profiling', 'ERA' and 'ERA + Immune Profiling'. Endometrial biopsy was examined by ERA, immune profiling alone, or combination, and intention was adopted accordingly. Pregnancy outcomes were compared, and the association between ERA phases and endometrial immune profiling was also assessed.

RESULTS

The overall incidence rate of the displaced window of implantation (WOI) and endometrial immune dysregulations were 84.9% and 75.3%, respectively. Implantation rate was significantly higher in the 'ERA + Immune Profiling' group than the 'no treatment' group (P = 0.007). Clinical pregnancy rate was somewhat improved in the three treatment groups but with a borderline significance (P = 0.071). After controlling for other confounders, 'ERA + Immune Profiling' treatment was associated with a higher pregnancy rate [aOR (95%CI)  =  3.412 (1.387-8.395), P = 0.008]. There was no association between endometrial immune profiling and ERA phases.

CONCLUSIONS

Our findings highlight the high incidence of displaced WOI and endometrial immune dysregulation in multiple implantation failure patients. The combination of ERA and endometrial immune profiling is more likely to have clinical value than ERA or immune profiling alone. These data suggested the unsubstitutability of ERA and endometrial immune profiling on the treatment outcome for multiple implantation failure patients. This article is protected by copyright. All rights reserved.

Harnessing CD8+CD28- Regulatory T Cells as a Tool to Treat Autoimmune Disease

T regulatory cell therapy presents a novel therapeutic strategy for patients with autoimmune diseases or who are undergoing transplantation. At present, the CD4+ Treg population has been extensively characterized, as a result of defined phenotypic and functional readouts. In this review article, we discuss the development and biology of CD8+ Tregs and their role in murine and human disease indications. A subset of CD8+ Tregs that lack the surface expression of CD28 (CD8+CD28- Treg) has proved efficacious in preclinical models. CD8+CD28- Tregs are present in healthy individuals, but their impaired functionality in disease renders them less effective in mediating immunosuppression. We primarily focus on harnessing CD8+ Treg cell therapy in the clinic to support current treatment for patients with autoimmune or inflammatory conditions.

Virus Infection Is an Instigator of Intestinal Dysbiosis Leading to Type 1 Diabetes

In addition to genetic predisposition, environmental determinants contribute to a complex etiology leading to onset of type 1 diabetes (T1D). Multiple studies have established the gut as an important site for immune modulation that can directly impact development of autoreactive cell populations against pancreatic self-antigens. Significant efforts have been made to unravel how changes in the microbiome function as a contributor to autoimmune responses and can serve as a biomarker for diabetes development. Large-scale longitudinal studies reveal that common environmental exposures precede diabetes pathology. Virus infections, particularly those associated with the gut, have been prominently identified as risk factors for T1D development. Evidence suggests recent-onset T1D patients experience pre-existing subclinical enteropathy and dysbiosis leading up to development of diabetes. The start of these dysbiotic events coincide with detection of virus infections. Thus viral infection may be a contributing driver for microbiome dysbiosis and disruption of intestinal homeostasis prior to T1D onset. Ultimately, understanding the cross-talk between viral infection, the microbiome, and the immune system is key for the development of preventative measures against T1D.

Novel Roles of the Tim Family in Immune Regulation and Autoimmune Diseases

T cell Ig and mucin domain (Tim) protein family members were identified to be important regulators of the immune response. As their name indicates, Tim proteins were originally considered a T cell-specific markers, and they mainly regulate the responses of T helper cells. However, accumulating evidence indicates that Tims are also expressed on antigen-presenting cells (APCs), such as monocytes, macrophages, dendritic cells (DCs) and B cells, and even plays various roles in natural killer cells (NKs) and mast cells. In recent years, the expression and function of Tims on different cells and the identification of new ligands for the Tim family have suggested that the Tim family plays a crucial role in immune regulation. In addition, the relationship between Tim family gene polymorphisms and susceptibility to several autoimmune diseases has expanded our knowledge of the role of Tim proteins in immune regulation. In this review, we discuss how the Tim family affects immunomodulatory function and the potential role of the Tim family in typical autoimmune diseases, including multiple sclerosis (MS), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and type 1 diabetes (T1D). A deeper understanding of the immunoregulatory mechanism of the Tim family might provide new insights into the clinical diagnosis and treatment of autoimmune diseases.

Helminth protection against type-1 diabetes: an insight into immunomodulatory effect of helminth-induced infection

Helminths are the old dirty friends of humans from decades and may live undetected by the immune system for years in the tissues. They have evolved as good experts at subverting the immune system. Despite of their pathogenicity, they provide protection to their host against certain inflammatory diseases such as diabetes by modulating the immune mechanisms. These parasites are extra-cellular and induce Th2 response which triggers the adaptive immune cells as well as innate immune cells to work synergistically allowing Tregs to work in a toll-like receptor-dependent manure. T-helper cells type-2 also secrete certain anti-inflammatory cytokines including IL-4, IL-10, IL-13 and TGF-β which also provide protection against type-1 diabetes. Several helminths such as T. crassiceps, S. venezuelensis, filarial worms, Schistosoma spp. and T. spiralis have been reported to prevent diabetes in mouse models as well as in some clinical trials. Immunomodulatory talent of helminths is receiving greater attention to prevent diabetes. Herein, an attempt has been made to review and highlight the possible immuno-modulatory mechanisms by which helminths provide protection against diabetes. Moreover, this review also emphasizes on the use of helminth-derived molecules or synthetic derivatives of helminth-antigens in clinical trials to overcome rapidly growing autoimmune disorders including diabetes.

CD8+ Regulatory T Cell - A Mystery to Be Revealed

Regulatory T cells (Treg) are essential to maintain immune homeostasis and prevent autoimmune disorders. While the function and molecular regulation of Foxp3+CD4+ Tregs are well established, much of CD8+ Treg biology remains to be revealed. Here, we will review the heterogenous subsets of CD8+ T cells have been named "CD8+ Treg" and mainly focus on CD122hiLy49+CD8+ Tregs present in naïve mice. CD122hiLy49+CD8+ Tregs, which depends on transcription factor Helios and homeostatic cytokine IL-15, have been established as a non-redundant regulator of germinal center (GC) reaction. Recently, we have demonstrated that TGF-β (Transforming growth factor-β) and transcription factor Eomes (Eomesodermin) are essential for the function and homeostasis of CD8+ Tregs. In addition, we will discuss several open questions regarding the differentiation, function and true identity of CD8+ Tregs as well as a brief comparison between two regulatory T cell subsets critical to control GC reaction, namely CD4+ TFR (follicular regulatory T cells) and CD8+ Tregs.

Gut Microbiota in Bone Health and Diabetes

PURPOSE OF REVIEW

Patients with diabetes mellitus (DM) are at increased risk of developing osteopathogenesis and skeletal fragility. The role of the gut microbiota in both DM and osteopathy is not fully explored and may be involved in the pathology of both diseases.

RECENT FINDINGS

Gut microbiota alterations have been observed in DM and osteopathogenic disorders as compared with healthy controls, such as significantly lower abundance of Prevotella and higher abundance of Lactobacillus, with a diminished bacterial diversity. Other overlapping gastro-intestinal features include the loss of intestinal barrier function with translocation of bacterial metabolites to the blood stream, induction of immunological deficits and changes in hormonal and endocrinal signalling, which may lead to the development of diabetic osteopathy. Signalling pathways involved in both DM and osteopathy are affected by gut bacteria and their metabolites. Future studies should focus on gut microbiota involvement in both diseases.

Immune Equilibrium Depends on the Interaction Between Recognition and Presentation Landscapes

In this review, we described the structure and organization of antigen-recognizing repertoires of B and T cells from the standpoint of modern immunology. We summarized the latest advances in bioinformatics analysis of sequencing data from T and B cell repertoires and also presented contemporary ideas about the mechanisms of clonal diversity formation at different stages of organism development. At the same time, we focused on the importance of the allelic variants of the HLA genes and spectra of presented antigens for the formation of T-cell receptors (TCR) landscapes. The main idea of this review is that immune equilibrium and proper functioning of immunity are highly dependent on the interaction between the recognition and the presentation landscapes of antigens. Certain changes in these landscapes can occur during life, which can affect the protective function of adaptive immunity. We described some mechanisms associated with these changes, for example, the conversion of effector cells into regulatory cells and vice versa due to the trans-differentiation or bystander effect, changes in the clonal organization of the general TCR repertoire due to homeostatic proliferation or aging, and the background for the altered presentation of some antigens due to SNP mutations of MHC, or the alteration of the presenting antigens due to post-translational modifications. The authors suggest that such alterations can lead to an increase in the risk of the development of oncological and autoimmune diseases and influence the sensitivity of the organism to different infectious agents.

Strategies to Use Nanoparticles to Generate CD4 and CD8 Regulatory T Cells for the Treatment of SLE and Other Autoimmune Diseases

Autoimmune diseases are disorders of immune regulation where the mechanisms responsible for self-tolerance break down and pathologic T cells overcome the protective effects of T regulatory cells (Tregs) that normally control them. The result can be the initiation of chronic inflammatory diseases. Systemic lupus erythematosus (SLE) and other autoimmune diseases are generally treated with pharmacologic or biological agents that have broad suppressive effects. These agents can halt disease progression, yet rarely cure while carrying serious adverse side effects. Recently, nanoparticles have been engineered to correct homeostatic regulatory defects and regenerate therapeutic antigen-specific Tregs. Some approaches have used nanoparticles targeted to antigen presenting cells to switch their support from pathogenic T cells to protective Tregs. Others have used nanoparticles targeted directly to T cells for the induction and expansion of CD4+ and CD8+ Tregs. Some of these T cell targeted nanoparticles have been formulated to act as tolerogenic artificial antigen presenting cells. This article discusses the properties of these various nanoparticle formulations and the strategies to use them in the treatment of autoimmune diseases. The restoration and maintenance of Treg predominance over effector cells should promote long-term autoimmune disease remission and ultimately prevent them in susceptible individuals.

Effects of GLP-1 receptor agonist on changes in the gut bacterium and the underlying mechanisms

There is a close relationship between the gut microbiota and metabolic disorders. In this study, acute administration of the glucagon-like peptide-1 receptor agonist (GLP-1RA) liraglutide to mice increased the cecal levels of caseinolytic protease B, a component of Escherichia coli, and of norepinephrine. Chemical sympathectomy blocked these events. Norepinephrine was found to pass into the intestinal lumen in vitro. c-Fos staining of the intermediolateral nucleus was identified as indirect evidence of sympathetic nervous system activation of the intestinal tract by GLP-1RA. Under normal conditions, the increase in E. coli did not affect the host. However, in mice with colitis, bacterial translocation was observed with attenuation of tight junction gene expression. This is the first study to investigate the unique underlying mechanisms related the effects of GLP-1RA on changes in the gut bacterium.

Targeted regulation of lymphocytic ER stress response with an overall immunosuppression to alleviate allograft rejection

Transplantation is the most effective, and sometimes the only resort for end-stage organ failure. However, allogeneic graft suffers greatly from lymphocyte-mediated immunorejection, which bears close relationship with a hyperactivation of endoplasmic reticulum (ER) stress response in host lymphocytes, especially in CD8⁺ T cells (T-8). Therefore, regulating lymphocytic ER unfolded protein response (UPR) might be a potential therapeutic breakthrough in alleviating graft rejection. Here, ER-targetable liposome is prepared via the surface modification of ER-targeting peptide (Pardaxin), which efficiently loads and directly delivers small molecule inhibitor of UPR sensor IRE1α into the ER of lymphocytes, inducing a systemic immunosuppression that facilitates tumorigenesis and metastasis in the tumor inoculation challenge in vivo. And in vitro, a stage-differential dependency of IRE1α in the phase transition of T-8 is identified. Specifically, inhibiting IRE1α at the early responding stages of T-8, especially at the activation phase, results in a shrunk proliferation, impaired effector function, and limited memory commitment, which might contribute centrally to the induced overall immunosuppression. Based on this, a classical acute rejection model, murine full-thickness trunk skin allograft that primary arises from the hyperactivity of T-lymphocyte, is used. Results suggest that lymphocytic IRE1α inactivation attenuates transplant rejection and prolongs graft survival, with a limited effector function and memory commitment of host T-8. Moreover, an even higher immunosuppressive effect is obtained when IRE1α inhibition is used in combination with immunosuppressant tacrolimus (FK506), which might owe to a synergistic regulation of inflammatory transcription factors. These findings provide a deeper insight into the biological polarization and stress response of lymphocytes, which might guide the future development of allogeneic transplantation.

CD8+ Tregs revisited: A heterogeneous population with different phenotypes and properties

Regulatory T cells (Tregs) play a key role in the peripheral self-tolerance and preventing autoimmunity. While classical CD4⁺ Foxp3⁺ Tregs are well established, their CD8⁺ counterparts are still controversial in many aspects including their phenotypic identity and their mechanisms of suppression. Because of these controversies and because of only a limited number of studies documenting the immunoregulatory function of CD8⁺ Tregs in vivo, the concept of CD8⁺ Tregs is still not unanimously accepted. We propose that any T-cell subset considered as true regulatory must be distinguishable from other cell types and must suppress in vivo immune responses via a known mechanism. In this article, we revisit the concept of CD8⁺ Tregs by focusing on the characterization of individual CD8⁺ T-cell subsets with proposed regulatory capacity separately. Therefore, we review the phenotype and function of CD8⁺ FOXP3⁺ T cells, CD8⁺ CD122⁺ T cells, CD8⁺ CD28^low/- T cells, CD8⁺ CD45RC^low T cells, T cells expressing CD8αα homodimer and Qa-1-restricted CD8⁺ T cells to show whether there is sufficient evidence to establish these subsets as bona fide Tregs. Based on the intrinsic ability of CD8⁺ Treg subsets to promote immune tolerance in animal models, we elaborate on their potential use in clinics.

Revisiting the Hygiene Hypothesis in the Context of Autoimmunity

Initially described for allergic diseases, the hygiene hypothesis was extended to autoimmune diseases in the early 2000s. A historical overview allows appreciation of the development of this concept over the last two decades and its discussion in the context of evolution. While the epidemiological data are convergent, with a few exceptions, the underlying mechanisms are multiple and complex. A major question is to determine what is the respective role of pathogens, bacteria, viruses, and parasites, versus commensals. The role of the intestinal microbiota has elicited much interest, but is it a cause or a consequence of autoimmune-mediated inflammation? Our hypothesis is that both pathogens and commensals intervene. Another question is to dissect what are the underlying cellular and molecular mechanisms. The role of immunoregulatory cytokines, in particular interleukin-10 and TGF beta is probably essential. An important place should also be given to ligands of innate immunity receptors present in bacteria, viruses or parasites acting independently of their immunogenicity. The role of Toll-Like Receptor (TLR) ligands is well documented including via TLR ligand desensitization.

Induced regulatory T cells suppress Tc1 cells through TGF-β signaling to ameliorate STZ-induced type 1 diabetes mellitus

Type 1 diabetes mellitus (T1D) is a chronic autoimmune condition in which the immune system destroys insulin-producing pancreatic β cells. In addition to well-established pathogenic effector T cells, regulatory T cells (Tregs) have also been shown to be defective in T1D. Thus, an increasing number of therapeutic approaches are being developed to target Tregs. However, the role and mechanisms of TGF-β-induced Tregs (iTregs) in T1D remain poorly understood. Here, using a streptozotocin (STZ)-induced preclinical T1D mouse model, we found that iTregs could ameliorate the development of T1D and preserve β cell function. The preventive effect was associated with the inhibition of type 1 cytotoxic T (Tc1) cell function and rebalancing the Treg/Tc1 cell ratio in recipients. Furthermore, we showed that the underlying mechanisms were due to the TGF-β-mediated combinatorial actions of mTOR and TCF1. In addition to the preventive role, the therapeutic effects of iTregs on the established STZ-T1D and nonobese diabetic (NOD) mouse models were tested, which revealed improved β cell function. Our findings therefore provide key new insights into the basic mechanisms involved in the therapeutic role of iTregs in T1D.

Immunomodulating role of the JAKs inhibitor tofacitinib in a mouse model of bleomycin-induced scleroderma

BACKGROUND

Janus kinase (JAK)-signal transducer and activator of transcription (STAT) was hyperactivated in biopsies from patients with systemic sclerosis (SSc) and in several autoimmune disease models. Tofacitinib, a pan-JAK inhibitor, blocks the downstream signaling of multiple cytokines and has exhibited therapeutic efficacy in various autoimmune diseases, although its immunomodulating property in scleroderma is unclear.

OBJECTIVE

To evaluate the effect of tofacitinib on the modulation of cytokine-producing T and B cells, and proinflammatory cells in a mouse model of SSc.

METHODS

Bleomycin (BLM)-induced SSc was generated by intradermal injection of BLM or PBS for control. Mice received intraperitoneal tofacitinib (20 mg/kg) or vehicle 3 times per week from day 0-28. Mice were sacrificed at day 28 after the last BLM/PBS injection.

RESULTS

Tofacitinib administration significantly alleviated fibrosis of the skin and lungs in scleroderma mouse model. Furthermore, tofacitinib suppressed adaptive and innate immune responses by reducing splenocytes, total lymphocytes, CD4⁺ T helper cells (especially Th2 and Th17 subtypes), IL-6-producing effector B cells, PDCA-1⁺ dendritic cells in the spleen, and infiltration of F4/80⁺, CD206⁺ and CD163⁺ macrophages in the skin and lungs. Conversely, tofacitinib increased the proportions of splenic regulatory T and B cells. The mRNA expression of extracellular matrix proteins and fibrogenic cytokines was downregulated by tofacitinib in both the skin and lungs.

CONCLUSION

These observations suggest JAK inhibition as a therapeutic approach for the treatment of inflammatory and fibrotic diseases, and highlight the potential of tofacitinib as a promising candidate for treating patients with scleroderma.

CD8+ T cells: The past and future of immune regulation

Regulation of the adaptive immune response is critical for health. Regulatory activity can be found in multiple components of the immune system, however, the focus on particular components of the immune regulatory network has left many aspects of this critical immune component understudied. Here we review the evidence for activities of CD8+ T cells in immune homeostasis and regulation of autoimmune reactivity. The heterogeneous nature of identified CD8+ cell types are examined, and common phenotypes associated with functional activities are defined. The varying types of antigen signal crucial for CD8+ T cell regulatory activity are identified and the implications of these activation pathways for control of adaptive responses is considered. Finally, the promising capacity for transgenic antigen receptor directed cytotoxicity as a mechanism for modulation of autoimmunity is detailed.

Newborn BCG vaccination complemented by boosting correlates better with reduced juvenile diabetes in females, than vaccination alone

Type 1 diabetes (T1D), like other autoimmune diseases, is on the rise since the second half of the 20th century. Hypothetically this has been ascribed to restricted exposure to microbial diversity due to advanced hygienic practices accompanying modernization, and increasing prosperity in urban versus rural habitats. The autoimmune animal model of T1D, inhibited by Bacillus Calmette Guerine (BCG), motivated testing the impact of BCG on T1D incidence in humans. Several epidemiological analyses, short of one, failed to demonstrate a protective effect of BCG against T1D. The present retrospective analysis of two data sets reevaluates the hypothetic inhibitory effect of BCG on human T1D. Reassessment of data from a Swedish study reveals that a single BCG vaccination provided a small but significant protection against T1D. A second data set of T1D prevalence/1000 Israeli military conscripts, from a doctoral thesis presenting 17 birth cohorts at age 17 is evaluated against the national schedule of vaccination related to years of birth. To correct for the annual increasing T1D trend the mean urbanization (census) rate was set as an annual moving average and factored into the prevalence (T1D/1000) of respective birth cohorts. Three groups of cohorts corresponding to BCG vaccination are presently identified; Group A corresponds to the years in which newborns were vaccinated and boosted if necessary, at age 12. Group B corresponds to the period when boosting was discontinued. Group C corresponds to years when newborn BCG vaccination was discontinued. T1D (only in females) was slightly but significantly lower in group B (n = 5 cohorts) versus C (n = 8 cohorts, p = 0.0475, by Mann Whitney U test). T1D in group A (n = 4 cohorts) was lower than in group B (p = 0.02). This analysis supports the hypothesis that in human females postnatal BCG vaccination, reinforced by boosting, has a protective impact on T1D being superior to omitted boosting, which in its turn is still better than stopping vaccination altogether. This analysis further suggests that upon advanced modernization the BCG vaccine compensates for reduced exposure to microbial diversity early in life.

Neuroendocrine and Metabolic Effects of Low-Calorie and Non-Calorie Sweeteners

Since excessive sugar consumption has been related to the development of chronic metabolic diseases prevalent in the western world, the use of sweeteners has gradually increased worldwide over the last few years. Although low- and non-calorie sweeteners may represent a valuable tool to reduce calorie intake and prevent weight gain, studies investigating the safety and efficacy of these compounds in the short- and long-term period are scarce and controversial. Therefore, future studies will need to elucidate the potential beneficial and/or detrimental effects of different types of sweeteners on metabolic health (energy balance, appetite, body weight, cardiometabolic risk factors) in healthy subjects and patients with diabetes, obesity and metabolic syndrome. In this regard, the impact of different sweeteners on central nervous system, gut hormones and gut microbiota is important, given the strong implications that changes in such systems may have for human health. The aim of this narrative review is to summarize the current evidence for the neuroendocrine and metabolic effects of sweeteners, as well as their impact on gut microbiota. Finally, we briefly discuss the advantages of the use of sweeteners in the context of very-low calorie ketogenic diets.