Interferon-γ production by Tfh cells is required for CXCR3+ pre-memory B cell differentiation and subsequent lung-resident memory B cell responses.

Lung-resident memory B cells (lung-BRMs) differentiate into plasma cells after reinfection, providing enhanced pulmonary protection. Here, we investigated the determinants of lung-BRM differentiation upon influenza infection. Kinetic analyses revealed that influenza nucleoprotein (NP)-specific BRMs preferentially differentiated early after infection and required T follicular helper (Tfh) cell help. BRM differentiation temporally coincided with transient interferon (IFN)-γ production by Tfh cells. Depletion of IFN-γ in Tfh cells prevented lung-BRM differentiation and impaired protection against heterosubtypic infection. IFN-γ was required for expression of the transcription factor T-bet by germinal center (GC) B cells, which promoted differentiation of a CXCR3+ GC B cell subset that were precursors of lung-BRMs and CXCR3+ memory B cells in the mediastinal lymph node. Absence of IFN-γ signaling or T-bet in GC B cells prevented CXCR3+ pre-memory precursor development and hampered CXCR3+ memory B cell differentiation and subsequent lung-BRM responses. Thus, Tfh-cell-derived IFN-γ is critical for lung-BRM development and pulmonary immunity, with implications for vaccination strategies targeting BRMs.

Fooling TLR4 to promote fungal virulence.

The invasive fungal pathogen Cryptococcus neoformans promotes type 2 immunity to escape host defenses by unknown mechanisms. In a recent issue of Nature, Dang and colleagues identify a secreted fungal protein that triggers TLR4 signaling and supports a type 2 permissive environment and C. neoformans growth.

Dynamic regulation of T follicular regulatory cell responses by interleukin 2 during influenza infection.

Interleukin 2 (IL-2) promotes Foxp3+ regulatory T (Treg) cell responses, but inhibits T follicular helper (TFH) cell development. However, it is not clear how IL-2 affects T follicular regulatory (TFR) cells, a cell type with properties of both Treg and TFH cells. Using an influenza infection model, we found that high IL-2 concentrations at the peak of the infection prevented TFR cell development by a Blimp-1-dependent mechanism. However, once the immune response resolved, some Treg cells downregulated CD25, upregulated Bcl-6 and differentiated into TFR cells, which then migrated into the B cell follicles to prevent the expansion of self-reactive B cell clones. Thus, unlike its effects on conventional Treg cells, IL-2 inhibits TFR cell responses.

Impaired Tumor-Necrosis-Factor-α-driven Dendritic Cell Activation Limits Lipopolysaccharide-Induced Protection from Allergic Inflammation in Infants.

Infants have a higher risk of developing allergic asthma than adults. However, the underlying mechanism remains unknown. We show here that sensitization of mice with house-dust mites (HDMs) in the presence of low-dose lipopolysaccharide (LPS) prevented T helper 2 (Th2) cell allergic responses in adult, but not infant, mice. Mechanistically, adult CD11b+ migratory dendritic cells (mDCs) upregulated the transcription factor T-bet in response to tumor necrosis factor-α (TNF-α), which was rapidly induced after HDM + LPS sensitization. Consequently, adult CD11b+ mDCs produced interleukin-12 (IL-12), which prevented Th2 cell development by promoting T-bet upregulation in responding T cells. Conversely, infants failed to induce TNF-α after HDM + LPS sensitization. Therefore, CD11b+ mDCs failed to upregulate T-bet and did not secrete IL-12 and Th2 cell responses normally developed in infant mice. Thus, the availability of TNF-α dictates the ability of CD11b+ mDCs to suppress allergic Th2-cell responses upon dose-dependent endotoxin sensitization and is a key mediator governing susceptibility to allergic airway inflammation in infant mice.

A model of Th2 differentiation based on polarizing cytokine repression.

Conventional dendritic cells (cDCs) can integrate multiple stimuli from the environment and provide three separate outputs in terms of antigen presentation, costimulation, and cytokine production; this guides the activation, expansion, and differentiation of distinct functional T helper subsets. Accordingly, the current dogma posits that T helper cell specification requires these three signals in sequence. Data show that T helper 2 (Th2) cell differentiation requires antigen presentation and costimulation from cDCs but does not require polarizing cytokines. In this opinion article, we propose that the 'third signal' driving Th2 cell responses is, in fact, the absence of polarizing cytokines; indeed, the secretion of the latter is actively suppressed in cDCs, concomitant with acquired pro-Th2 functions.

CCCTC-Binding Factor Translates Interleukin 2- and α-Ketoglutarate-Sensitive Metabolic Changes in T Cells into Context-Dependent Gene Programs.

Despite considerable research connecting cellular metabolism with differentiation decisions, the underlying mechanisms that translate metabolite-sensitive activities into unique gene programs are still unclear. We found that aspects of the interleukin-2 (IL-2)-sensitive effector gene program in CD4+ and CD8+ T cells in type 1 conditions (Th1) were regulated by glutamine and alpha-ketoglutarate (αKG)-induced events, in part through changes in DNA and histone methylation states. We further identified a mechanism by which IL-2- and αKG-sensitive metabolic changes regulated the association of CCCTC-binding factor (CTCF) with select genomic sites. αKG-sensitive CTCF sites were often associated with loci containing IL-2- and αKG-sensitive genome organization patterns and gene expression in T cells. IL-2- and αKG-sensitive CTCF sites in T cells were also associated with genes from developmental pathways that had αKG-sensitive expression in embryonic stem cells. The data collectively support a mechanism wherein CTCF serves to translate αKG-sensitive metabolic changes into context-dependent differentiation gene programs.

Cutting Edge: Low-dose Recombinant IL-2 Treatment Prevents Autoantibody Responses in Systemic Lupus Erythematosus via Regulatory T Cell-independent Depletion of T Follicular Helper Cells.

The expansion of T follicular helper (Tfh) cells correlates with disease progression in human and murine systemic lupus erythematosus (SLE). Unfortunately, there are no therapies to deplete Tfh cells. Importantly, low-dose rIL-2-based immunotherapy shows potent immunosuppressive effects in SLE patients and lupus-prone mice, primarily attributed to the expansion of regulatory T cells (Tregs). However, IL-2 can also inhibit Tfh cell differentiation. In this study, we investigate the potential of low-dose rIL-2 to deplete Tfh cells and prevent autoantibody responses in SLE. Our data demonstrate that low-dose rIL-2 efficiently depletes autoreactive Tfh cells and prevents autoantibody responses in lupus-prone mice. Importantly, this immunosuppressive effect was independent of the presence of Tregs. The therapeutic potential of eliminating Tfh cells was confirmed by selectively deleting Tfh cells in lupus-prone mice. Our findings demonstrate the critical role of Tfh cells in promoting autoantibody responses and unveil, (to our knowledge), a novel Treg-independent immunosuppressive function of IL-2 in SLE.

T Follicular Helper Cell Plasticity Shapes Pathogenic T Helper 2 Cell-Mediated Immunity to Inhaled House Dust Mite.

Exposure to environmental antigens, such as house dust mite (HDM), often leads to T helper 2 (Th2) cell-driven allergic responses. However, the mechanisms underlying the development of these responses are incompletely understood. We found that the initial exposure to HDM did not lead to Th2 cell development but instead promoted the formation of interleukin-4 (IL-4)-committed T follicular helper (Tfh) cells. Following challenge exposure to HDM, Tfh cells differentiated into IL-4 and IL-13 double-producing Th2 cells that accumulated in the lung and recruited eosinophils. B cells were required to expand IL-4-committed Tfh cells during the sensitization phase, but did not directly contribute to disease. Impairment of Tfh cell responses during the sensitization phase or Tfh cell depletion prevented Th2 cell-mediated responses following challenge. Thus, our data demonstrate that Tfh cells are precursors of HDM-specific Th2 cells and reveal an unexpected role of B cells and Tfh cells in the pathogenesis of allergic asthma.

Regulation of T(H)2 development by CXCR5+ dendritic cells and lymphotoxin-expressing B cells.

Although cognate encounters between antigen-bearing dendritic cells (DCs) that express the chemokine receptor CCR7 and CCR7(+) naive T cells take place in the T cell zone of lymph nodes, it is unknown whether the colocalization of DCs and T cells in the T cell area is required for the generation of effector cells. Here we found that after infection with an intestinal nematode, antigen-bearing DCs and CD4(+) T cells upregulated the chemokine receptor CXCR5 and localized together outside the T cell zone by a mechanism dependent on the chemokine CXCL13, B cells and lymphotoxin. Notably, lymphotoxin-expressing B cells, CXCR5-expressing DCs and T cells, and CXCL13 were also necessary for development of interleukin 4 (IL-4)-producing type 2 helper T cells (T(H)2 cells), which suggests that T(H)2 differentiation can initiate outside the T cell zone.

Is Satoyoshi syndrome an autoimmune disease? A systematic review.

OBJECTIVES: Satoyoshi syndrome is a rare multisystem disease of presumed autoimmune aetiology. We carried out a systematic review to evaluate the available evidence to support that autoimmune hypothesis. METHODS: We searched for Satoyoshi syndrome cases in PubMed, the Web of Science and Scopus up to January 2022, using keywords 'Satoyoshi syndrome' or 'Komuragaeri disease'. Data on symptoms, associated autoimmune diseases, presence of autoantibodies and response to treatment were collected. RESULTS: A total of 77 patients from 57 articles published between 1967 and 2021 were included; 59 patients were women. The mean age at diagnosis was 21.2 years. All cases had painful muscular spasms and alopecia. Frequent manifestations included: diarrhoea, malabsorption, growth retardation, amenorrhoea and bone deformity. Satoyoshi syndrome was associated with other autoimmune diseases: myasthenia gravis, autoimmune thyroiditis, idiopathic thrombocytopenic purpura, atopic dermatitis, bronchial and lupus erythematosus. Autoantibody determinations were performed in 39 patients, of which 27 had positive results. The most frequently detected autoantibodies were ANAs. Other less frequently found autoantibodies were: anti-acetylcholine receptor antibodies, anti-DNA antibodies, antithyroid antibodies, anti-glutamic acid decarboxylase (anti-GAD) and anti-gliadin antibodies. Pharmacological treatment was reported in 50 patients. Most of them improved with CS, immunosuppressants and immunoglobulins, or a combination of these medications. CONCLUSION: Satoyoshi syndrome is associated with other autoimmune diseases and a variety of autoantibodies. Improvement after CS or other immunosuppressant treatment was observed in 90% of cases. These data support an autoimmune aetiology for Satoyoshi syndrome. More studies including systematic determination of autoantibodies in all patients with Satoyoshi syndrome will help us advance in our understanding of this disease.

Epitope-specific regulation of memory programming by differential duration of antigen presentation to influenza-specific CD8(+) T cells.

Memory CD8(+) T cells are programmed during the primary response for robust secondary responsiveness. Here we show that CD8(+) T cells responding to different epitopes of influenza virus received qualitatively different signals during the primary response that altered their secondary responsiveness. Nucleoprotein (NP)-specific CD8(+) T cells encountered antigen on CD40-licensed, CD70-expressing, CD103(-)CD11b(hi) dendritic cells (DCs) at later times in the primary response. As a consequence, they maintained CD25 expression and responded to interleukin-2 (IL-2) and CD27, which together programmed their robust secondary proliferative capacity and interferon-γ (IFN-γ)-producing ability. In contrast, polymerase (PA)-specific CD8(+) T cells did not encounter antigen-bearing, CD40-activated DCs at later times in the primary response, did not receive CD27 and CD25 signals, and were not programmed to become memory CD8(+) T cells with strong proliferative and cytokine-producing ability. As a result, CD8(+) T cells responding to abundant antigens, like NP, dominated the secondary response.

Compartmentalization of dendritic cell and T-cell interactions in the lymph node: Anatomy of T-cell fate decisions.

Upon receiving cognate and co-stimulatory priming signals from antigen (Ag)-presenting dendritic cells (DCs) in secondary lymphoid tissues, naïve CD4+ T cells differentiate into distinct effector and memory populations. These alternate cell fate decisions, which ultimately control the T-cell functional attributes, are dictated by programming signals provided by Ag-bearing DCs and by other cells that are present in the microenvironment in which T-cell priming occurs. We know that DCs can be subdivided into multiple populations and that the various DC subsets exhibit differential capacities to initiate development of the different CD4+ T-helper populations. What is less well understood is why different subanatomic regions of secondary lymphoid tissues are colonized by distinct populations of Ag-presenting DCs and how the location of these DCs influences the type of T-cell response that will be generated. Here we review how chemokine receptors and their ligands, which position allergen and nematode-activated DCs within different microdomains of secondary lymphoid tissues, contribute to the establishment of IL-4 committed follicular helper T and type 2 helper cell responses.

Temporal changes in dendritic cell subsets, cross-priming and costimulation via CD70 control CD8(+) T cell responses to influenza.

The question of which dendritic cells (DCs) respond to pulmonary antigens and cross-prime CD8(+) T cells remains controversial. We show here that influenza-specific CD8(+) T cell priming was controlled by different DCs at different times after infection. Whereas early priming was controlled by both CD103(+)CD11b(lo) and CD103(-)CD11b(hi) DCs, CD103(-)CD11b(hi) DCs dominated antigen presentation at the peak of infection. Moreover, CD103(-)CD11b(hi) DCs captured exogenous antigens in the lungs and directly cross-primed CD8(+) T cells in the draining lymph nodes without transferring antigen to CD8alpha(+) DCs. Finally, we show that CD103(-)CD11b(hi) DCs were the only DCs to express CD70 after influenza infection and that CD70 expression on CD103(-)CD11b(hi) DCs licensed them to expand CD8(+) T cell populations responding to both influenza and exogenous ovalbumin.

Effectiveness of interventions to improve medication adherence in adults with depressive disorders: a meta-analysis.

BACKGROUND: Non-adherence to medication is a major obstacle in the treatment of depressive disorders. We systematically reviewed the literature to evaluate the effectiveness of interventions aimed at improving adherence to medication among adults with depressive disorders with emphasis on initiation and implementation phase. METHODS: We searched Medline, EMBASE, The Cochrane Central Register of Controlled Trials (CENTRAL), PsycINFO, Social Science Citation Index and Science Citation Index for randomized or non-randomized controlled trials up to January 2022. Risk of bias was assessed using the criteria of the Cochrane Collaboration. Meta-analyses, cumulative and meta-regression analyses for adherence were conducted. RESULTS: Forty-six trials (n = 24,324) were included. Pooled estimate indicates an increase in the probability of adherence to antidepressants at 6 months with the different types of interventions (OR 1.33; 95% CI: 1.09 to 1.62). The improvement in adherence is obtained from 3 months (OR 1.62, 95% CI: 1.25 to 2.10) but it is attenuated at 12 months (OR 1.25, 95% CI: 1.02 to 1.53). Selected articles show methodological differences, mainly the diversity of both the severity of the depressive disorder and intervention procedures. In the samples of these studies, patients with depression and anxiety seem to benefit most from intervention (OR 2.77, 95% CI: 1.74 to 4.42) and collaborative care is the most effective intervention to improve adherence (OR 1.88, 95% CI: 1.40 to 2.54). CONCLUSIONS: Our findings indicate that interventions aimed at improving adherence to medication among adults with depressive disorders are effective up to six months. However, the evidence on the effectiveness of long-term adherence is insufficient and supports the need for further research efforts. TRIAL REGISTRATION: International Prospective Register for Systematic Reviews (PROSPERO) number: CRD42017065723 .

Interleukin-2 inhibits germinal center formation by limiting T follicular helper cell differentiation.

T follicular helper (Tfh) cells promote T cell-dependent humoral immune responses by providing T cell help to B cells and by promoting germinal center (GC) formation and long-lived antibody responses. However, the cellular and molecular mechanisms that control Tfh cell differentiation in vivo are incompletely understood. Here we show that interleukin-2 (IL-2) administration impaired influenza-specific GCs, long-lived IgG responses, and Tfh cells. IL-2 did not directly inhibit GC formation, but instead suppressed the differentiation of Tfh cells, thereby hindering the maintenance of influenza-specific GC B cells. Our data demonstrate that IL-2 is a critical factor that regulates successful Tfh and B cell responses in vivo and regulates Tfh cell development.

[Mobile applications to improve drug adherence: Review and quality analysis]. / Aplicaciones móviles para mejorar la adherencia a la medicación: revisión y análisis de calidad.

OBJECTIVE: To review the mobile apps in the Spanish market to improve adherence to medications and evaluate their characteristics and quality to identify high-quality applications. METHOD: A review was carried out following a stepwise procedure similar to a systematic review of the scientific literature. Apple Apps Store and Google Play Store mobile application digital distribution platforms. Applications aimed at supporting self-management of treatment, which generate reminders, in Spanish, updated in the last 2 years and free. We evaluate the applications according to a set of characteristics considered desirable and the quality with the Mobile App Rating Scale tool. RESULTS: Out of 708 applications, 3 applications were selected. The Medisafe and Mytherapy applications had 89% and 78% of the desirable characteristics, respectively. Sergio Licea's application only had 56%. The highest global quality score was obtained by the MyTherapy application (3.79/5, IQR: 3-4), followed by Medisafe (3.72/5, (IQR: 3-4) and, finally, Sergio Licea (2.87/5, IQR: 2-4). The quality assessment coincides with the user assessment. There are many available applications, however, most did not meet the selection criteria. CONCLUSIONS: A systematic stepwise process was able to identify the quality application to be tested in a future study that will provide evidence on the use of a multicomponent intervention to improve medication adherence.

Use, knowledge, and effectiveness of nutritional traffic light label in an urban population from Ecuador: a pilot study.

BACKGROUND: The nutritional traffic light label (NTLL) has become one of the most used Front of Package labels (FOP's) around the world, for its simple and easy to understand graphical system. In Ecuador, this labelling system has recently been implemented; then, this research aims to evaluate the use and knowledge of NTLL and its effectiveness as a public health promotion strategy. METHOD: In a cross-sectional study at two different urban supermarkets in Quito-Ecuador, a survey was conducted in 73 participants to inquire about knowledge, perspectives and purchasing habits regarding the NTLL. Objective data obtained from pictures of the participants'purchase was compared with subjective data obtained from the survey. For categorical variables, Chi square or Fisher's Exact test were used and variables with a statistical significance at α = 0.1 were included in multivariate logistic regression models. RESULTS: 88.7% of participants knew about the NTTL. 27.4% reported using the NTLL, while 28.4% of participants were observed to really use it. Significant associations between self-knowledge of the NTLL and education level (p = 0.007) or knowledge level (p = 0.001) were found. A significant association was also found between the refered use of the NTLL and the shopping influencing factor (p = 0.02). In the multivariate analysis an association between knowledge of the NTLL and observed use was found only when adjusted for the supermarket (p = 0.038). CONCLUSION: This study found that the level of knowledge of the NTLL in the studied population was relatively high; however, both the referred and the observed use of the NTLL were low. Use and knowledge of the NTLL were associated with the socioeconomic and educational status of the participants. Thus, the change in nutritional patterns needs additional strategies to put the NTLL before the brand once customers make their purchases.

Dendritic cells and B cells: unexpected partners in Th2 development.

Although we have known for decades that B cells contribute to immune responses by secreting Ab, it is now clear that they are more than simply factories for Ig production, and they also play key roles as modulators of T cell-dependent immunity. Indeed, the evidence showing that Ag-presenting and cytokine-producing B cells can alter the magnitude and quality of CD4 T cell responses continues to grow. In this article, we review the data showing that B cells, working in partnership with dendritic cells, regulate the development of Th2 cells and the subsequent allergic response.

Rhupus syndrome in the pediatric population: A comprehensive systematic literature review.

INTRODUCTION: The term "Rhupus" was employed to descriptively illustrate the overlap observed in some pediatric patients displaying features of both juvenile idiopathic arthritis (JIA) and systemic lupus erythematosus (SLE). Although "Rhupus" is traditionally used in adults, we applied it broadly to emphasize this clinical overlap. METHODS: We sought to identify studies that registered signs, symptoms, imaging characteristics, and treatments given to patients with JIA and SLE. We searched four databases using a Boolean search string, resulting in 231 articles after duplicate removal. Title and abstract screening yielded 57 articles for full-text assessment. Full reviewed 13 extracted data regarding sex, age of onset, serologic and imaging findings, and management strategies. The NIH quality assessment tool was applied to ensure the internal validity of the articles. RESULTS: From the 13 articles evaluated that meet inclusion criteria, none had standardized diagnostic algorithms. The total number of patients in those articles is 26, without discussing treatment guidelines. DISCUSSION: Clinical presentation, diagnostic parameters, and treatment of pediatric Rhupus were synthesized in this review. Fundamental keys help distinguish the joint presentation when Juvenile Idiopathic Arthritis or Lupus is present, compared with the signs and symptoms when developing the overlapping syndrome. We highlight the importance of physicians knowing about this rare condition and call all specialists to report new cases of the disease so a consensus can be reached to establish standardized guidelines for diagnosing and treating Rhupus syndrome.