Survival advantage of native and engineered T cells is acquired by mitochondrial transfer from mesenchymal stem cells.

BACKGROUND: Apoptosis, a form of programmed cell death, is critical for the development and homeostasis of the immune system. Chimeric antigen receptor T (CAR-T) cell therapy, approved for hematologic cancers, retains several limitations and challenges associated with ex vivo manipulation, including CAR T-cell susceptibility to apoptosis. Therefore, strategies to improve T-cell survival and persistence are required. Mesenchymal stem/stromal cells (MSCs) exhibit immunoregulatory and tissue-restoring potential. We have previously shown that the transfer of umbilical cord MSC (UC-MSC)-derived mitochondrial (MitoT) prompts the genetic reprogramming of CD3+ T cells towards a Treg cell lineage. The potency of T cells plays an important role in effective immunotherapy, underscoring the need for improving their metabolic fitness. In the present work, we evaluate the effect of MitoT on apoptotis of native T lymphocytes and engineered CAR-T cells. METHODS: We used a cell-free approach using artificial MitoT (Mitoception) of UC-MSC derived MT to peripheral blood mononuclear cells (PBMCs) followed by RNA-seq analysis of CD3+ MitoTpos and MitoTneg sorted cells. Target cell apoptosis was induced with Staurosporine (STS), and cell viability was evaluated with Annexin V/7AAD and TUNEL assays. Changes in apoptotic regulators were assessed by flow cytometry, western blot, and qRT-PCR. The effect of MitoT on 19BBz CAR T-cell apoptosis in response to electroporation with a non-viral transposon-based vector was assessed with Annexin V/7AAD. RESULTS: Gene expression related to apoptosis, cell death and/or responses to different stimuli was modified in CD3+ T cells after Mitoception. CD3+MitoTpos cells were resistant to STS-induced apoptosis compared to MitoTneg cells, showing a decreased percentage in apoptotic T cells as well as in TUNEL+ cells. Additionally, MitoT prevented the STS-induced collapse of the mitochondrial membrane potential (MMP) levels, decreased caspase-3 cleavage, increased BCL2 transcript levels and BCL-2-related BARD1 expression in FACS-sorted CD3+ T cells. Furthermore, UC-MSC-derived MitoT reduced both early and late apoptosis in CAR-T cells following electroporation, and exhibited an increasing trend in cytotoxic activity levels. CONCLUSIONS: Artificial MitoT prevents STS-induced apoptosis of human CD3+ T cells by interfering with the caspase pathway. Furthermore, we observed that MitoT confers protection to apoptosis induced by electroporation in MitoTpos CAR T-engineered cells, potentially improving their metabolic fitness and resistance to environmental stress. These results widen the physiological perspective of organelle-based therapies in immune conditions while offering potential avenues to enhance CAR-T treatment outcomes where their viability is compromised.

Ex Vivo Analysis of the Association of GFP-Expressing L. aethiopica and L. mexicana with Human Peripheral Blood-Derived (PBD) Leukocytes over 24 Hours.

Leishmania parasites are transmitted to mammalian hosts through the bite of sandflies. These parasites can infect phagocytic cells (macrophages, dendritic cells, and neutrophils) and non-phagocytic cells (B cells and fibroblasts). In mice models, the disease development or resolution is linked to T cell responses involving inflammatory cytokines and the activation of macrophages with the M1/M2 phenotype. However, this mechanism does not apply to human infection where a more complex immunological response occurs. The understanding of interactions between immune cells during Leishmania infection in humans is still limited, as current infection models focus on individual cell types or late infection using controlled human infection models (CHIMs). This study investigated the early parasite infection in freshly isolated peripheral blood-derived (PBD) leukocytes over 24 h. Flow cytometer analysis is used in immunophenotyping to identify different subpopulations. The study found that among the L. aethiopicaGFP-associated leukocytes, most cells were neutrophils (55.87% ± 0.09 at 4 h) and monocytes (23.50% ± 0.05% at 24 h). B cells were 12.43% ± 0.10% at 24 h. Additionally, 10-20% of GFP+ leukocytes did not belong to the aforementioned cell types, and further investigation revealed their identity as CD4+ T cells. Data not only confirm previous findings of Leishmania infection with PBD leukocytes and association with B cells but also suggest that CD4+ T cells might influence the early-stage of infection.

Emerging immunologic approaches as cancer anti-angiogenic therapies.

Targeting tumor angiogenesis, the formation of new blood vessels supporting cancer growth and spread, has been an intense focus for therapy development. However, benefits from anti-angiogenic drugs like bevacizumab have been limited by resistance stemming from activation of compensatory pathways. Recent immunotherapy advances have sparked interest in novel immunologic approaches that can induce more durable vascular pruning and overcome limitations of existing angiogenesis inhibitors. This review comprehensively examines these emerging strategies, including modulating tumor-associated macrophages, therapeutic cancer vaccines, engineered nanobodies and T cells, anti-angiogenic cytokines/chemokines, and immunomodulatory drugs like thalidomide analogs. For each approach, the molecular mechanisms, preclinical/clinical data, and potential advantages over conventional drugs are discussed. Innovative therapeutic platforms like nanoparticle delivery systems are explored. Moreover, the importance of combining agents with distinct mechanisms to prevent resistance is evaluated. As tumors hijack angiogenesis for growth, harnessing the immune system's specificity to disrupt this process represents a promising anti-cancer strategy covered by this review.

Senescent CD4+ T-Cell Phenotypes and Inflammatory Milieu in the Coronary and Systemic Circulation in ST-Elevation Myocardial Infarction: An Exploratory Study.

INTRODUCTION: In ST-elevation myocardial infarction (STEMI), inflammation is pivotal, with early senescent CD4+CD28null cells implicated in its pathogenesis. However, the functional phenotype of these cells within the coronary circulation remains unclear. METHODS: We examined CD4+ cell subpopulations in blood samples from the coronary sinus and vena cava of 24 STEMI patients and the cephalic vein of seven healthy controls. RESULTS: Our findings revealed reduced CD4+ cell counts in STEMI patients compared to controls (1,998, 1,275-3,268 vs. 4,278, 3,595-4,449), alongside an increased proportion of CD4+ cells lacking CD28 expression (20.1 vs. 6.1%). These CD4+CD28null cells in STEMI predominantly exhibited a Th1 phenotype (47.8% vs. 6.6%). Intriguingly, no significant differences were detected in CD4+CD28null cells between coronary sinus and vena cava, and cytokine levels in these compartments remained similar. CONCLUSION: CD4+CD28null cells are increased in STEMI, mainly polarized toward a Th1 phenotype, and distributed equally between the different vascular beds.

Immunological biomarkers associated with survival in a cohort of Argentinian patients with common variable immunodeficiency.

Background: Common variable immunodeficiency (CVID) is the most common symptomatic syndrome among inborn errors of immunity. Although several aspects of CVID immunopathology have been elucidated, predictive factors for mortality are incompletely defined. A genetic cause can be identified only in approximately 30% of patients. Objective: We sought to develop a mortality predictive score on the basis of the immunophenotypes and genotypes of patients with CVID. Methods: Twenty-one patients diagnosed with CVID in Córdoba, Argentina, were analyzed for clinical and laboratory data. Immunophenotyping was done by flow cytometry. CVID-associated mutations were identified by whole-exome sequencing. Results: Alive (15) and deceased (6) patients were compared. Univariate analysis showed significant differences in CD4+ T cells (P = .002), natural killer (NK) cells (P = .001), and memory switched B cells (P = .001) between groups. Logistic regression analysis showed a negative correlation between CD4+, NK, and memory switched B-cell counts and probability of survival over a 10-year period (CD4+ T cells: odds ratio [OR], 1.01; 95% CI, 1.001-1.020; NK cells: OR, 1.07; 95% CI, 1.02-1.17; and memory switched B cells: OR, 26.23; 95% CI, 2.06-2651.96). Receiver-operating characteristic curve analysis identified a survival cutoff point for each parameter (CD4+ T cells: 546 cells/mL; AUC, 0.87; sensitivity, 60%; specificity, 100%; memory switched B cells: 0.84 cells/mL; AUC, 0.92; sensitivity, 100%; specificity, 85%; and NK cells: 45 cells/mL; AUC, 0.92; sensitivity, 83%; specificity, 100%). Genetic analysis on 14 (9 female and 5 male) patients from the cohort revealed mutations associated with inborn errors of immunity in 6 patients. Conclusions: A score to predict mortality is proposed on the basis of CD4+ T, NK, and memory switched B-cell counts in patients with CVID.

Chikungunya-Driven Gene Expression Linked to Osteoclast Survival and Chronic Arthralgia.

Chikungunya fever (CHIKF), caused by the Chikungunya virus (CHIKV), manifests as acute febrile illness often associated with polyarthritis and polyarthralgia. Although the acute symptoms resolve within two weeks, many patients experience prolonged joint pain and inflammation, resembling rheumatoid arthritis (RA). This study aimed to identify molecular markers related to joint pain and chronicity in CHIKV-infected individuals by analyzing blood transcriptomes using bulk RNA sequencing. B- and T-cell receptor (BCR and TCR) diversity was assessed through computational analysis of RNA-seq data, revealing a significant reduction in CDR3 diversity in CHIKV-infected individuals compared to healthy controls. This reduced diversity was associated with the upregulation of genes involved in osteoclast differentiation and activation, particularly through the RANK/RANKL signaling pathway. These findings suggest a potential link between immune dysregulation and enhanced osteoclast activity, which may contribute to the persistence of joint pain in chronic CHIKF. Targeting osteoclast-related pathways could offer therapeutic strategies for managing chronic symptoms in CHIKF patients.

CD19 CAR T cells for B cell malignancies: a systematic review and meta-analysis focused on clinical impacts of CAR structural domains, manufacturing conditions, cellular product, doses, patient's age, and tumor types.

CD19-targeted chimeric antigen receptors (CAR) T cells are one of the most remarkable cellular therapies for managing B cell malignancies. However, long-term disease-free survival is still a challenge to overcome. Here, we evaluated the influence of different hinge, transmembrane (TM), and costimulatory CAR domains, as well as manufacturing conditions, cellular product type, doses, patient's age, and tumor types on the clinical outcomes of patients with B cell cancers treated with CD19 CAR T cells. The primary outcome was defined as the best complete response (BCR), and the secondary outcomes were the best objective response (BOR) and 12-month overall survival (OS). The covariates considered were the type of hinge, TM, and costimulatory domains in the CAR, CAR T cell manufacturing conditions, cell population transduced with the CAR, the number of CAR T cell infusions, amount of CAR T cells injected/Kg, CD19 CAR type (name), tumor type, and age. Fifty-six studies (3493 patients) were included in the systematic review and 46 (3421 patients) in the meta-analysis. The overall BCR rate was 56%, with 60% OS and 75% BOR. Younger patients displayed remarkably higher BCR prevalence without differences in OS. The presence of CD28 in the CAR's hinge, TM, and costimulatory domains improved all outcomes evaluated. Doses from one to 4.9 million cells/kg resulted in better clinical outcomes. Our data also suggest that regardless of whether patients have had high objective responses, they might have survival benefits from CD19 CAR T therapy. This meta-analysis is a critical hypothesis-generating instrument, capturing effects in the CD19 CAR T cells literature lacking randomized clinical trials and large observational studies.

Characterization of ibrutinib's effects on the morphology, proliferation, phenotype, viability, and anti-inflammatory potential of adipose-derived mesenchymal stromal cells.

Ibrutinib (IB) is a tyrosine kinase inhibitor (TKI) that has immunomodulatory action and can be used as second-line therapy for steroid-refractory or steroid-resistant chronic Graft versus Host Disease (cGVHD). Mesenchymal stromal cells (MSCs) are distributed throughout the body and their infusion has also been explored as a second-line therapeutic alternative for the treatment of cGVHD. Considering the currently unknown effects of IB on endogenous MSCs, as well as the possible combined use of IB and MSCs for cGVHD, we investigated whether adipose tissue-derived MSCs present IB-targets, as well as the consequences of treating MSCs with this drug, regarding cell viability, proliferation, phenotype, and anti-inflammatory potential. Interestingly, we show for the first time that MSCs express several IB target genes. Also of note, the treatment of such cells with this TKI elevated the levels of CD90 and CD105 surface proteins, as well as VCAM-1. Furthermore, IB-treated MSCs presented increased mRNA expression of the anti-inflammatory genes PD-L1, TSG-6, and IL-10. However, continued exposure to IB, even at low doses, compromised the viability of MSCs. These data indicate that the use of IB can stimulate an anti-inflammatory profile in MSCs, but also that a continued exposure to IB can compromise MSC viability over time.

Regulatory T cells administration reduces anxiety-like behavior in mice submitted to chronic restraint stress.

Background: Major depression disorder (MDD) and anxiety are common mental disorders that significantly affect the quality of life of those who suffer from them, altering the person's normal functioning. From the biological perspective, the most classical hypothesis explaining their occurrence relies on neurotransmission and hippocampal excitability alterations. However, around 30% of MDD patients do not respond to medication targeting these processes. Over the last decade, the involvement of inflammatory responses in depression and anxiety pathogenesis has been strongly acknowledged, opening the possibility of tackling these disorders from an immunological point of view. In this context, regulatory T cells (Treg cells), which naturally maintain immune homeostasis by suppressing inflammation could be promising candidates for their therapeutic use in mental disorders. Methods: To test this hypothesis, C57BL/6 adult male mice were submitted to classical stress protocols to induce depressive and anxiety-like behavior; chronic restriction stress (CRS), and chronic unpredictable stress (CUS). Some of the stressed mice received a single adoptive transfer of Treg cells during stress protocols. Mouse behavior was analyzed through the open field (OFT) and forced swim test (FST). Blood and spleen samples were collected for T cell analysis using cell cytometry, while brains were collected to study changes in microglia by immunohistochemistry. Results: Mice submitted to CRS and CUS develop anxiety and depressive-like behavior, and only CRS mice exhibit lower frequencies of circulating Treg cells. Adoptive transfer of Treg cells decreased anxiety-like behavior in the OFT only in CRS model, but not depressive behavior in FST in neither of the two models. In CRS mice, Treg cells administration lowered the number of microglia in the hippocampus, which increased due this stress paradigm, and restored its arborization. However, in CUS mice, Treg cells administration increased microglia number with no significant effect on their arborization. Conclusion: Our results for effector CD4+ T cells in the spleen and microglia number and morphology in the hippocampus add new evidence in favor of the participation of inflammatory responses in the development of depressive and anxiety-like behavior and suggest that the modulation of key immune cells such as Treg cells, could have beneficial effects on these disorders.

Contribution of memory T cells to the generation of long-lasting immunity against COVID-19.

Humans are exposed every day to innumerable external stimuli, both environmental and microbial. Immunological memory recalls each specific stimulus and mounts a secondary response that is faster and of a larger magnitude than the primary response; this process constitutes the basis for vaccine development. The COVID-19 pandemic offers a unique opportunity to study the development of immune memory against an emergent microorganism. Memory T cells have an important role in the resolution of COVID-19, and they are key pillars of immunological memory. In this review, we summarize the main findings regarding anti-SARS-CoV-2 memory T cells after infection, after vaccination, and after the combination of these two events ("hybrid immunity"), and analyze how these cells can contribute to long-term protection against the infection with SARS-CoV-2 variants.

Los humanos se exponen cada día a innumerables estímulos externos, tanto ambientales como microbianos. La memoria inmunológica registra de manera específica un estímulo y articula una respuesta secundaria más rápida y de mayor magnitud que la respuesta primaria; este proceso constituye la base del desarrollo de vacunas. La pandemia de COVID-19 ofreció la oportunidad de estudiar el desarrollo de la memoria inmunológica contra un microorganismo emergente. Las células T de memoria tienen un papel importante en la resolución de COVID-19 y son pilares importantes de la memoria inmunológica. En esta revisión se resumen los principales hallazgos de la respuesta de las células T de memoria contra la infección por SARS-CoV-2, a la vacunación o a la combinación de ambos procesos ("inmunidad híbrida"), y se discute cómo estas células pueden contribuir a la protección a largo plazo contra distintas variantes del virus.

Obesity Influences T CD4 Lymphocytes Subsets Profiles in Children and Adolescent's Immune Response.

BACKGROUND: Evidence shows that CD4+ T cells are altered in obesity and play a significant role in the systemic inflammation in adults with the disease. OBJECTIVES: Because the profile of these cells is poorly understood in the pediatric population, this study aims to investigate the profile of CD4+ T lymphocytes and the plasma levels of cytokines in this population. METHODS: Using flow cytometry, we compared the expression profile of lymphocyte markers, master transcription factors, cytokines, and molecules involved in the regulation of the immune response in CD4+ T cells from children and adolescents with obesity (OB group, n = 20) with those with eutrophy group (EU group, n = 16). Plasma levels of cytokines in both groups were determined by cytometric bead array (CBA). RESULTS: The OB group presents a lower frequency of CD3+ T cells, as well as a decreased frequency of CD4+ T cells expressing CD28, IL-4, and FOXP3, but an increased frequency of CD4+IL-17A+ cells compared with the EU group. The frequency of CD28 is increased in Th2 and Treg cells in the OB group, whereas CTLA-4 is decreased in all subpopulations compared with the EU group. Furthermore, Th2, Th17, and Treg profiles can differentiate the EU and OB groups. IL-10 plasma levels are reduced in the OB group and negatively correlated with adiposity and inflammatory parameters. CONCLUSIONS: CD4+ T cells have an altered pattern of expression in children and adolescents with obesity, contributing to the inflammatory state and clinical characteristics of these patients.

Predominance of CD137+ And TNF-α Expressing CD8+ Central Memory T Cells in Mild COVID-19 Recovered Patients Upon SARS-CoV-2 Re-Exposure.

INTRODUCTION: Memory CD8+ T cells are essential for long-term immune protection in viral infections, including COVID-19. METHODS: This study examined the responses of CD8+ TEM, TEMRA, and TCM subsets from unvaccinated individuals who had recovered from mild and severe COVID-19 by flow cytometry. RESULTS AND DISCUSSION: The peptides triggered a higher frequency of CD8+ TCM cells in the recovered mild group. CD8+ TCM and TEM cells showed heterogeneity in CD137 expression between evaluated groups. In addition, a predominance of CD137 expression in naïve CD8+ T cells, TCM, and TEM was observed in the mild recovered group when stimulated with peptides. Furthermore, CD8+ TCM and TEM cell subsets from mild recovered volunteers had higher TNF-α expression. In contrast, the expression partner of IFN-γ, IL-10, and IL-17 indicated an antiviral signature by CD8+ TEMRA cells. These findings underscore the distinct functional capabilities of each memory T cell subset in individuals who have recovered from COVID-19 upon re-exposure to SARS-CoV-2 antigens.

Involvement of aryl hydrocarbon receptor in the aflatoxin B1 and fumonisin B1 effects on in vitro differentiation of murine regulatory-T and Th17 cells.

Aflatoxin B1 (AFB1) and fumonisin B1 (FB1) are mycotoxins widely found as cereal contaminants, and their co-consumption is associated with liver cancer. Both are immunotoxic, but their interactions have been little studied. This work was aimed to evaluate in mouse spleen mononuclear cells (SMC) the effects of the exposure to AFB1 (5-50 µM), FB1 (25-250 µM), and AFB1-FB1 mixtures (MIX) on the in vitro differentiation of regulatory T cells (Treg and Tr1-like) and Th17 cells, as well as elucidate the contribution of aryl hydrocarbon receptor (Ahr) in such effects. AFB1 and mainly MIX induced cytotoxicity in activated CD4 cells via Ahr signaling. AFB1 (5 µM) increased the Treg cell differentiation, but its combination with FB1 (25 µM) also reduced Th17 cell expansion by Ahr-dependent mechanisms. Therefore, this mixture could enhance the Treg/Th17 cell ratio and favor immunosuppression and escape from tumor immunosurveillance to a greater extent than individual mycotoxins. Whereas, AFB1-FB1 mixtures at medium-high doses inhibited the Tr1-like cell expansion induced by the individual mycotoxins and affected Treg and Th17 cell differentiation in Ahr-independent and dependent manners, respectively, which could alter anti-inflammatory and Th17 immune responses. Moreover, individual FB1 altered regulatory T and Th17 cell development independently of Ahr. In conclusion, AFB1 and FB1 interact by modifying Ahr signaling, which is involved in the immunotoxicity as well as in the alteration of the differentiation of Treg, Tr1-like, and Th17 cells induced by AFB1-FB1 mixtures. Therefore, Ahr is implicated in the regulation of the anti- and pro-inflammatory responses caused by the combination of AFB1 and FB1.

The Role of Senescent CD8+T Cells in the Pathogenesis of Disseminated Leishmaniasis.

Disseminated leishmaniasis (DL) caused by L. braziliensis is characterized by the presence of 10 to more than 1000 lesions spread on the body. While protection against Leishmania is mediated by macrophages upon activation by IFN-γ produced by CD4+T cells, the pathology of disseminated leishmaniasis (DL) could be mediated by macrophages, NK, and CD8+T cells. Herein, we evaluate the participation of senescent CD8+T cells in the pathogenesis of DL. Methods: Peripheral blood mononuclear cells (PBMCs), biopsies, co-cultures of CD8+T cells with uninfected and infected macrophages (MØ), and PBMC cultures stimulated with soluble L. braziliensis antigen (SLA) for 72 h from patients with cutaneous leishmaniasis (CL) and DL were used to characterize senescent CD8+T cells. Statistical analysis was performed using the Mann-Whitney and Kruskal-Wallis tests, followed by Dunn's. Results: Patients with DL have an increase in the frequency of circulating CD8+T cells that present a memory/senescent phenotype, while lesions from DL patients have an increase in the frequency of infiltrating CD8+T cells with a senescent/degranulation phenotype. In addition, after specific stimuli, DL patients' circulating CD8+T with memory/senescent profile, showing degranulation characteristics, increased upon SLA stimuli, and those specific CD8+T cells from DL patients had an increased degranulation phenotype, causing more apoptosis of infected target cells. Conclusions: DL patients show a higher frequency of cytotoxic senescent CD8+T cells compared to CL patients, and that could promote the lysis of infected cells, although without parasite killing, releasing Leishmania to the extracellular compartment, contributing to the spread of parasites.

Late events after anti-CD19 CAR T-cell therapy for relapsed/refractory B-cell non-Hodgkin lymphoma.

Background: The short-term complications from chimeric antigen receptor T-cell therapy (CART) are well characterized, but the long-term complications still need to be further investigated. Therefore, herein, we will review the currently available literature published on the late adverse events following CART. Methods: We reviewed published data available from pivotal trials and real-world experiences with anti-CD19 CART (CART19) for adults with lymphoma. We defined late events as occurring or persisting beyond 1 month after CART infusion. We focused our literature review on the following late-event outcomes post-CART19: cytopenia, immune reconstitution, infections, and subsequent malignancies. Results: Grade 3-4 cytopenia beyond 30 days occurs in 30%-40% of patients and beyond 90 days in 3%-22% of patients and is usually managed with growth-factor and transfusion support, along with neutropenic prophylaxis. B-cell aplasia and hypogammaglobulinemia are expected on-target off-tumor effects of CART19, 44%-53% of patients have IgG < 400 mg/dL, and approximately 27%-38% of patients receive intravenous immunoglobulin (IVIG) replacement. Infections beyond the initial month from CART19 are not frequent and rarely severe, but they are more prevalent and severe when patients receive subsequent therapies post-CART19 for their underlying disease. Late neurotoxicity and neurocognitive impairment are uncommon, and other causes should be considered. T-cell lymphoma (TCL) after CART is an extremely rare event and not necessarily related to CAR transgene. Myeloid neoplasm is not rare post-CART, but unclear causality given heavily pretreated patient population is already at risk for therapy-related myeloid neoplasm. Conclusion: CART19 is associated with clinically significant long-term effects such as prolonged cytopenia, hypogammaglobulinemia, and infections that warrant clinical surveillance, but they are mostly manageable with a low risk of non-relapse mortality. The risk of subsequent malignancies post-CART19 seems low, and the relationship with CART19 and/or prior therapies is unclear; but regardless of the possible causality, this should not impact the current benefit-risk ratio of CART19 for relapsed/refractory B-cell non-Hodgkin lymphoma (NHL).

Effect of photobiomodulation in the balance between effector and regulatory T cells in an experimental model of COPD.

Introduction: Currently, Chronic Obstructive Pulmonary Disease (COPD) has a high impact on morbidity and mortality worldwide. The increase of CD4+, CD8+ cells expressing NF-κB, STAT4, IFN-γ and perforin are related to smoking habit, smoking history, airflow rate, obstruction and pulmonary emphysema. Furthermore, a deficiency in CD4+CD25+Foxp3+ regulatory T cells (Tregs) may impair the normal function of the immune system and lead to respiratory immune disease. On the other hand, the anti-inflammatory cytokine IL-10, produced by Treg cells and macrophages, inhibits the synthesis of several pro-inflammatory cytokines that are expressed in COPD. Therefore, immunotherapeutic strategies, such as Photobiomodulation (PBM), aim to regulate the levels of cytokines, chemokines and transcription factors in COPD. Consequently, the objective of this study was to evaluate CD4+STAT4 and CD4+CD25+Foxp3+ cells as well as the production of CD4+IFN- γ and CD4+CD25+IL-10 in the lung after PBM therapy in a COPD mice model. Methods: We induced COPD in C57BL/6 mice through an orotracheal application of cigarette smoke extract. PMB treatment was applied for the entire 7 weeks and Bronchoalveolar lavage (BAL) and lungs were collected to study production of IFN- γ and IL-10 in the lung. After the last administration with cigarette smoke extract (end of 7 weeks), 24 h later, the animals were euthanized. One-way ANOVA followed by NewmanKeuls test were used for statistical analysis with significance levels adjusted to 5% (p < 0.05). Results: This result showed that PBM improves COPD symptomatology, reducing the number of inflammatory cells (macrophages, neutrophils and lymphocytes), the levels of IFN-γ among others, and increased IL-10. We also observed a decrease of collagen, mucus, bronchoconstriction index, alveolar enlargement, CD4+, CD8+, CD4+STAT4+, and CD4+IFN-γ+ cells. In addition, in the treated group, we found an increase in CD4+CD25+Foxp3+ and CD4+IL-10+ T cells. Conclusion: This study suggests that PBM treatment could be applied as an immunotherapeutic strategy for COPD.

Increased levels of regulatory T cells and IL-10-producing regulatory B cells are linked to improved clinical outcome in Parkinson's disease: a 1-year observational study.

Whilst the contribution of peripheral and central inflammation to neurodegeneration in Parkinson's disease and the role of the immune response in this disorder are well known, the effects of the anti-inflammatory response on the disease have not been described in depth. This study is aimed to assess the changes in the regulatory/inflammatory immune response in recently diagnosed, untreated PD patients and a year after. Twenty-one PD patients and 19 healthy controls were included and followed-up for 1 year. The levels of immunoregulatory cells (CD4+ Tregs, Bregs, and CD8+ Tregs); classical, nonclassical, and intermediate monocytes, and proinflammatory cells (Th1, Th2, and Th17) were measured by flow cytometry. Cytokine levels were determined by ELISA. Clinical follow-up was based on the Hoehn & Yahr and UDPRS scales. Our results indicate that the regulatory response in PD patients on follow-up was characterized by increased levels of active Tregs, functional Tregs, TR1, IL-10-producing functional Bregs, and IL-10-producing classical monocytes, along with decreased counts of Bregs and plasma cells. With respect to the proinflammatory immune response, peripheral levels of Th1 IFN-γ+ cells were decreased in treated PD patients, whilst the levels of CD4+ TBET+ cells, HLA-DR+ intermediate monocytes, IL-6, and IL-4 were increased after a 1-year follow-up. Our main finding was an increased regulatory T cell response after a 1-year follow-up and its link with clinical improvement in PD patients. In conclusion, after a 1-year follow-up, PD patients exhibited increased levels of regulatory populations, which correlated with clinical improvement. However, a persistent inflammatory environment and active immune response were observed.

Effector CD4+ T-cell subsets in Takayasu arteritis-differences between the peripheral blood and the aorta.

Takayasu arteritis (TAK) is a granulomatous vasculitis that affects large arteries. T cells are important in TAK pathophysiology as these cells orchestrate granulomatous infiltration in arteries. This study aims to evaluate effector CD4+ T cells in the peripheral blood and the aortic wall of TAK patients and to analyze associations with disease activity and therapy. We performed a longitudinal study including 30 TAK patients and 30 controls. CD3+ T cells, CD3+CD4- T cells, CD4+ T cells, and Th1, Th2, and Th17 cells were evaluated in peripheral blood by flow cytometry, and the expression of CD4, CD8, Tbet, GATA-3, and RORγT was analyzed in the aorta of six patients by immunohistochemistry. TAK patients presented lower CD3+ T cells and CD4+ T cells (P = 0.031 and P = 0.039, respectively) than controls. Patients with active disease and those in remission had higher proportions of Th17 cells than controls (P = 0.016 and P = 0.004, respectively). Therapy for TAK did not result in significant differences concerning CD4+ effector T-cell subpopulations. Disease duration correlated with the number and percentage of Th2 cells (rho = -0.610 and rho = -0.463, respectively) and with Th17 cells (rho = -0.365 and rho = -0.568). In the aorta, the expression of CD8 was higher than CD4, whereas GATA-3, Tbet, and RORγT were expressed in this order of frequency. In conclusion, TAK patients present an increased Th17 response in the peripheral blood regardless of disease activity, whereas in the aortic tissue CD8 cells and the Th2 response were predominant.

Dimethyl fumarate modulates the regulatory T cell response in the mesenteric lymph nodes of mice with experimental autoimmune encephalomyelitis.

Dimethyl fumarate (DMF, Tecfidera) is an oral drug utilized to treat relapsing-remitting multiple sclerosis (MS). DMF treatment reduces disease activity in MS. Gastrointestinal discomfort is a common adverse effect of the treatment with DMF. This study aimed to investigate the effect of DMF administration in the gut draining lymph nodes cells of C57BL6/J female mice with experimental autoimmune encephalomyelitis (EAE), an animal model of MS. We have demonstrated that the treatment with DMF (7.5 mg/kg) significantly reduces the severity of EAE. This reduction of the severity is accompanied by the increase of both proinflammatory and anti-inflammatory mechanisms at the beginning of the treatment. As the treatment progressed, we observed an increasing number of regulatory Foxp3 negative CD4 T cells (Tr1), and anti-inflammatory cytokines such as IL-27, as well as the reduction of PGE2 level in the mesenteric lymph nodes of mice with EAE. We provide evidence that DMF induces a gradual anti-inflammatory response in the gut draining lymph nodes, which might contribute to the reduction of both intestinal discomfort and the inflammatory response of EAE. These findings indicate that the gut is the first microenvironment of action of DMF, which may contribute to its effects of reducing disease severity in MS patients.

Therapeutic role of interferon-γ in experimental autoimmune encephalomyelitis is mediated through a tolerogenic subset of splenic CD11b+ myeloid cells.

Cumulative evidence has established that Interferon (IFN)-γ has both pathogenic and protective roles in Multiple Sclerosis and the animal model, Experimental Autoimmune Encephalomyelitis (EAE). However, the underlying mechanisms to the beneficial effects of IFN-γ are not well understood. In this study, we found that IFN-γ exerts therapeutic effects on chronic, relapsing-remitting, and chronic progressive EAE models. The frequency of regulatory T (Treg) cells in spinal cords from chronic EAE mice treated with IFN-γ was significantly increased with no effect on Th1 and Th17 cells. Consistently, depletion of FOXP3-expressing cells blocked the protective effects of IFN-γ, indicating that the therapeutic effect of IFN-γ depends on the presence of Treg cells. However, IFN-γ did not trigger direct in vitro differentiation of Treg cells. In vivo administration of blocking antibodies against either interleukin (IL)-10, transforming growth factor (TGF)-ß or program death (PD)-1, revealed that the protective effects of IFN-γ in EAE were also dependent on TGF-ß and PD-1, but not on IL-10, suggesting that IFN-γ might have an indirect role on Treg cells acting through antigen-presenting cells. Indeed, IFN-γ treatment increased the frequency of a subset of splenic CD11b+ myeloid cells expressing TGF-ß-Latency Associated Peptide (LAP) and program death ligand 1 (PD-L1) in a signal transducer and activator of transcription (STAT)-1-dependent manner. Furthermore, splenic CD11b+ cells from EAE mice preconditioned in vitro with IFN-γ and myelin oligodendrocyte glycoprotein (MOG) peptide exhibited a tolerogenic phenotype with the capability to induce conversion of naïve CD4+ T cells mediated by secretion of TGF-ß. Remarkably, adoptive transfer of splenic CD11b+ cells from IFN-γ-treated EAE mice into untreated recipient mice ameliorated clinical symptoms of EAE and limited central nervous system infiltration of mononuclear cells and effector helper T cells. These results reveal a novel cellular and molecular mechanism whereby IFN-γ promotes beneficial effects in EAE by endowing splenic CD11b+ myeloid cells with tolerogenic and therapeutic activities.