Treg Cell Population Research Articles

Leukemia derived dendritic cell (DCleu) mediated immune response goes along with reduced (leukemia-specific) regulatory T-cells

The blastmodulatory Kit-M, composed of granulocyte-macrophage colony-stimulating-factor (GM-CSF) and Prostaglandin E1 (PGE1), is known to convert myeloid leukaemic blasts (from AML patients) into leukaemia derived dendritic cells (DCleu), which activate immunoreactive cells to gain antileukemic/leukaemia-specific activity. In this study we had a special focus on the influence of Kit-M treated, DC/DCleu containing patients’whole blood (WB, n = 16) on the provision of immunosuppressive regulatory T-cells.We could confirm that Kit-M significantly increased frequencies of (mature) dendritic cells (DC) and DCleu from leukemic whole blood (WB) without induction of blast proliferation. After mixed lymphocyte culture (MLC) with patients’ T-cells we confirmed that DCleu mediated leukemia-specific responses- going along with activated and leukemia-specific T- and NK-cells in an intracellular cytokine staining assay (ICS) and a degranulation assay (Deg)- resulted in an increased anti-leukemic cytotoxicity (Cytotoxicity Fluorolysis Assay = CTX). We could demonstrate that (leukemia-specific) CD4+ and CD8+ regulatory T-cell population (Treg) decreased significantly after MLC compared to controls. We found significant positive correlations of leukemia-specific CD3+CD4+ cells with frequencies of (mature) DCleu. Achieved anti-leukemic cytotoxicity correlated significantly positive with leukemia-specific CD3+CD8+ cells and significantly negatively with (leukemia-specific) Treg.In summary we demonstrate that immunesuppressive (leukemia-specific) regulatory T-cells are significantly downregulated after Kit-M triggered MLC- going along with a (reinstalled) antileukemic reactivity of the immune system (as demonstrated with functional assays ICS, Deg, CTX).

Household size, T regulatory cell development, and early allergic disease: a birth cohort study.

BackgroundChildren born to larger households have less allergic disease. T regulatory cell (Treg) development may be a relevant mechanism, but this has not been studied longitudinally.ObjectiveWe aim to (i) describe how prenatal and postnatal environmental factors are associated with Treg development and (ii) investigate whether serial Treg measures predict allergic outcomes at 1 year of age.MethodsA birth cohort (n = 1074) with information on prenatal and postnatal early life factors. Both naïve Treg (nTreg) and activated Treg (aTreg) cell populations (as a proportion of CD4+ T cells) were available in 463 infants at birth (cord blood), 600 at 6 months, and 675 at 12 months. 191 infants had serial measures. Measures of allergic status at 12 months were polysensitization (sensitization to 2 or more allergens), clinically proven food allergy, atopic eczema, and atopic wheeze.ResultsInfants born to larger households (3 or more residents) had higher longitudinal nTreg proportions over the first postnatal year with a mean difference (MD) of 0.67 (95% CI 0.30–1.04)%. Higher nTreg proportions at birth were associated with a reduced risk of infant allergic outcomes. Childcare attendance and breastfeeding were associated with higher longitudinal nTreg proportions (MD 0.48 (95% CI 0.08–0.80)%.ConclusionMultiple prenatal and postnatal microbial factors are associated with nTreg and aTreg development. Larger household size was associated with higher nTreg at birth which in turn was associated with reduced allergic sensitization and disease at 12 months of age.

Manual acupuncture at ST36 attenuates rheumatoid arthritis by inhibiting M1 macrophage polarization and enhancing Treg cell populations in adjuvant-induced arthritic rats.

Acupuncture has been found to be effective at relieving many inflammatory pain conditions, including rheumatoid arthritis (RA). We aimed to assess the anti-inflammatory potential of manual acupuncture (MA) treatment of RA using adjuvant-induced arthritic (AIA) rats and to explore the underlying mechanisms. The anti-inflammatory and analgesic actions of MA at ST36 (Zusanli) in AIA rats were assessed using paw withdrawal latency and swelling, histological examination and cytokine detection by enzyme-linked immunoassay (ELISA). The cell-cell communication (CCC) network was analyzed with a multiplex immunoassay of 24 immune factors expressed in the inflamed joints, and the macrophage and Treg populations and associated cytokines regulated by MA were investigated using reverse-transcription quantitative polymerase chain reaction (RT-qPCR), ELISA and flow cytometry. MA markedly decreased heat hyperalgesia and paw swelling in AIA rats. MA-treated rats also exhibited decreased levels of pro-inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β) coupled with increased anti-inflammatory cytokines (IL-10, transforming growth factor (TGF)-β1) in the ankle joints at protein and mRNA levels. CCC network analysis confirmed that macrophages are of critical importance and are potential therapeutic targets in RA. Repeated treatment with MA triggered a macrophage phenotypic switch in the paws, with fewer M1 macrophages. Prominent increases in the Treg cell population and TGF-β1 in the popliteal lymph nodes demonstrated the immunomodulatory effects of MA. Furthermore, a selective TGF-β1-receptor inhibitor, SB431542, attenuated the anti-inflammatory effects of MA and MA-induced suppression of the levels of M1-released cytokines. These findings provide novel evidence that the anti-inflammatory and analgesic effects of MA on RA act through phenotypic modulation involving the inhibition of M1 macrophage polarization and an increase in the Treg cell population, highlighting the potential therapeutic advantages of acupuncture in controlling pain and ameliorating inflammatory conditions.

Formaldehyde exposure induces differentiation of regulatory T cells via the NFAT-mediated T cell receptor signalling pathway in Yucatan minipigs

The use of minipigs (Sus scrofa) as a platform for toxicological and pharmacological research is well established. In the present study, we investigated the effect of formaldehyde (FA) exposure on helper T cell-mediated splenic immune responses in Yucatan minipigs. The minipigs were exposed to different inhaled concentrations of FA (0, 2.16, 4.62, or 10.48 mg/m3) for a period of 2 weeks. Immune responses elicited by exposure to FA were determined by assessing physiological parameters, mRNA expression, and cytokine production. Additionally, the distribution of helper T cells and regulatory T (Treg) cells and expression of NFAT families, which are well-known T cell receptor signalling proteins associated with regulatory T cell development, were evaluated. Exposure to FA suppressed the expression of genes associated with Th1 and Th2 cells in minipigs in a concentration-dependent manner. The subsequent production of cytokines also declined post-FA exposure. Furthermore, exposure to FA induced the differentiation of CD4+ Foxp3+ Treg cells with divergent expression levels of NFAT1 and NFAT2. These results indicated that exposure to FA increased the Treg cell population via the NFAT-mediated T cell receptor signalling pathway, leading to suppression of effector T cell activity with a decline in T cell-related cytokine production.

Oncolytic Viral Therapy Mediates its Effectiveness by Inducing and Enhancing CD4 cytotoxic T-cells

Abstract Malignant glioma remains a fatal disease with a dismal survival rate. To address this urgent medical need, we pioneered the concept of engineered oncolytic viruses for cancer. Using the herpes simplex virus (HSV)-1 as an experimental virus, our published Phase I trials have demonstrated the safety and efficacy of such oHSV-based therapy for treating brain tumor patients. In searching for biomarkers for better responses to this therapy, our preclinical studies using intracranial glioma models and an oHSV secreting murine IL-12 (M002) revealed that a subset of CD4+ T-cells expressing the cytolytic signatures, including granzyme B, were increased in M002-treated mice compared to vehicle-treated controls. Correspondingly, CD4+ T-cells isolated from brain tumors of M002-treated mice killed tumor cells better than cells isolated from control tumors. However, the factors and temporal requirements that direct the development of this CD4 cytotoxic T-cell (CTL) subset are not fully understood. To address this question, we performed single-cell RNA sequencing analysis of CD4+ T-cells isolated from brain tumors of M002-treated and control mice. The results revealed a complex change of the CD4+ T-cell compartment with CD4 CTLs being induced from two different precursors. The first CTL subset was derived from T helper-1 (Th1) cells and retained Th1 gene signatures while expressing high levels of CTL associated molecules. The second CTL subset was a reprogrammed regulatory T-cell population capable of producing high levels of cytokines and granzymes. Both CD4 CTL subsets were more prominent in M002-treated mice, suggesting that M002 therapy could induce CD4 CTLs with specialized functionality, which may account for its improved outcome. Supported by grants from DoD W81XH-18-1-0315 and UAB Start up Funds

PD-L1-PD-1 interactions limit effector regulatory T cell populations at homeostasis and during infection.

Phenotypic and transcriptional profiling of Treg cells at homeostasis reveals that TCR activation promotes Treg cells with an effector phenotype (eTreg) characterized by the production of IL-10 and expression of the inhibitory receptor PD-1. At homeostasis, blockade of the PD-1 pathway results in enhanced eTreg cell activity while during infection with T. gondii early IFN-γ upregulates myeloid cell expression of PD-L1 associated with reduced Treg cell populations. In infected mice, the blockade of PD-L1, complete deletion of PD-1, or lineage-specific deletion of PD-1 in Treg cells prevents loss of eTreg cells. These interventions resulted in a reduced ratio of pathogen-specific effector T cells : eTregs and increased levels of IL-10 that mitigated the development of immunopathology, but which could compromise parasite control. Thus, eTreg cell expression of PD-1 acts as a sensor to rapidly tune the pool of eTreg cells at homeostasis and during inflammatory processes.

IL-21 plays an important role in modulating "Th17-Treg" cell axis in leprosy Type 1 reactions.

Leprosy type 1 reaction (T1R) is a cell-mediated inflammatory reaction which involves skin and peripheral nerves in leprosy. Lesions with T1R have higher production of IL-17 cytokine from CD4+ T cells along with lower TGF-β producing FOXP3+ CD4+ Tregs. IL-21 is an important cytokine that promotes the development and stability of Th17 cells in an autocrine manner. It can play an important role in the pathogenesis of T1R in leprosy. However, the mechanism by which IL-21 influences the pathogenic progress of leprosy T1R remains poorly understood. In the present study, we evaluated the expression of IL-21 cytokine in skin lesions of both non-reactional (NR) and T1R via immuno-histochemistry and quantitative PCR (qPCR). Further, expression of various genes (IL-17A, IL-17F, TGF-β, FOXP3, RORC and IL-21) was also measured by qPCR in cultured cells. We also analyzed the secretion of various cytokines such as of IL-21, IL-17A/F and TGF-β in the culture supernatants by ELISA. In addition, differentiation of Th17 and Treg cells were studied in PBMC cultures after stimulation with Mycobacterium leprae sonicated antigens and rIL-21 for 48hrs and the phenotypes of Th17 and Tregs were determined by flowcytometric analysis. Our results clearly indicate that IL-21+T cells were significantly higher in both peripheral blood and skin lesions of T1R as compared to NR patients. Moreover, we observed that recombinant IL-21 cytokine inhibited TGF-β producing Treg cells differentiation along with up-regulating Th17 cells under in-vitro conditions. The gene expression of IL-21 was significantly negatively correlated with Treg and positively correlated with Th17 cell markers in T1R patients. Our results suggested that IL-21 promotes T1R mediated inflammation via modulating the balance of Th17 and Treg cell populations.

What prognostic information does flow cytometry provide in canine B-cell lymphoma?

PICO question
 In dogs with B-cell lymphoma, does the use of flow cytometry provide useful prognostic information?
 
 Clinical bottom line
 Category of research question
 Prognosis
 The number and type of study designs reviewed
 Twelve papers were critically reviewed. All were cohort studies
 Strength of evidence
 Moderate
 Outcomes reported
 There are multiple potential prognostic indicators in canine B-cell lymphoma that flow cytometry can be used to evaluate, including lymphoma stage, survival time and time to progression. There is promising evidence for the use of percentage expression of CD25 and Ki67 cellular markers in providing prognostic information in canine B-cell lymphoma and these should be assessed further in clinical practice. Flow cytometry has also been shown to be useful in assessing bone marrow infiltration and providing prognostic information relating to this. There is also evidence for the prognostic value of measuring expression of class II MHC and CTLA-4 cellular markers, peripheral lymphocyte / monocyte ratio, nodal regulatory T-cell populations and the ratio between T and B lymphocytes in extranodal locations. Peripheral regulatory T-cell populations and cellular size were also assessed, however further investigations are required before confirming their prognostic value
 Conclusion
 Flow cytometric analysis offers useful measures of prognosis in canine B-cell lymphoma, although further validation is required before introducing their routine use. Percentage expression of CD25 and Ki67 cellular markers from lymph node aspirates of dogs with B-cell lymphoma appear to be promising prognostic indicators in clinical investigations, however this needs to be translated into clinical practice. While there is evidence for the prognostic value of bone marrow infiltration measured flow cytometrically, expression of class II MHC and CTLA-4, peripheral lymphocyte / monocyte ratio, nodal regulatory T-cell populations and the ratio between T and B lymphocytes in extranodal locations, these need to be further investigated before introducing into clinical practice. As new antibodies against cellular targets in dogs become available, it is likely that flow cytometry will become even more useful in providing prognostic information
 
 How to apply this evidence in practice
 The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources.
 Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.
 

Plasma interleukin-23 and circulating IL-17A+IFN\u03b3+ ex-Th17 cells predict opposing outcomes of anti-TNF therapy in rheumatoid arthritis

ObjectivesTNF-α inhibitors are widely used in rheumatoid arthritis (RA) with varying success. Response to TNF-α inhibition may reflect the evolution of rheumatoid inflammation through fluctuating stages of TNF-α dependence. Our aim was to assess plasma concentrations of Th-17-related cytokines and the presence of circulating effector T-cells to identify predictors of response to TNF-α inhibitors.MethodsNinety-three people with RA were seen prior to and 4–6 months after commencing etanercept or adalimumab. Plasma concentrations of Th17-related cytokines, circulating effector T-cells, their production of relevant transcription factors and intracellular cytokines were measured at baseline. EULAR response criteria were used to define poor (ΔDAS28 ≤ 1.2 and/or DAS28 > 3.2) and good (ΔDAS28 > 1.2 and DAS28 ≤ 3.2) responders. Multivariate logistic regression was used to identify predictors of response.ResultsParticipants with plasma IL-23 present at baseline were more likely to be poor responders [15/20 (75%) of IL-23+ versus 36/73 (49.3%) of IL-23−; p = 0.041]. While frequencies of Th1, Th17, ex-Th17 and Treg cell populations were similar between good and poor responders to anti-TNF therapy, IL-17A+IFNγ+ ex-Th17 cells were more prevalent in good responders (0.83% of ex-TH17 cells) compared to poor responders (0.24% of ex-Th17 cells), p = 0.023. Both plasma IL-23 cytokine status (OR = 0.17 (95% CI 0.04–0.73)) and IL-17A+IFNγ+ ex-Th17 cell frequency (OR = 1.64 (95% CI 1.06 to 2.54)) were independently associated with a good response to anti-TNF therapy. Receiver operator characteristic (ROC) analysis, including both parameters, demonstrated an area under the ROC curve (AUC) of 0.70 (95% CI 0.60–0.82; p = 0.001).ConclusionsPlasma IL-23 and circulating IL-17A+IFNγ+ ex-Th17 cells are independently associated with response to anti-TNF therapy. In combination, plasma IL-23 and circulating IL-17A+IFNγ+ ex-Th17 cells provide additive value to the prediction of response to anti-TNF therapy in RA.

The effect of the multi-strain probiotic preparation EM Bokashi® on selected parameters of the cellular immune response in pigs

ABSTRACT The aim of the study was to assess the effect of effective microorganisms on selected parameters of the cellular immune response in the colostrum and milk of sows and in the serum of suckling piglets. A total of 60 female crossbred sows and 60 female piglets were used in the experiment. The material for analysis comprised colostrum and milk collected from sows and blood samples from piglets. Immune response parameters were determined by flow cytometry and ELISA kits. The results showed high expression of CD4-CD25-FoxP3, CD4, and CD25 in the colostrum and milk of sows and of CD4, CD8 in piglet blood. The use of EM Bokashi® as a feed supplement for sows during colostrogenesis stimulates cellular immune mechanisms, expressed by an increase in the Treg cell population in the colostrum and milk, which contributes to effective elimination of microorganisms in the first period of piglets’ life.

Potential role of inducible GPR3 expression under stimulated T cell conditions

G protein-coupled receptor 3 (GPR3) constitutively activates Gαs proteins without any ligands and is predominantly expressed in neurons. Since the expression and physiological role of GPR3 in immune cells is still unknown, we examined the possible role of GPR3 in T lymphocytes. The expression of GPR3 was upregulated 2 h after phorbol 12-myristate 13-acetate (PMA)/ionomycin stimulation and was sustained in Jurkat cells, a human T lymphocyte cell line. In addition, the expression of nuclear receptor 4 group A member 2 (NR4A2) was highly modulated by GPR3 expression. Additionally, GPR3 expression was linked with the transcriptional promoter activity of NR4A in Jurkat cells. In mouse CD4+ T cells, transient GPR3 expression was induced immediately after the antigen receptor stimulation. However, the expression of NR4A2 was not modulated in CD4+ T cells from GPR3-knockout mice after stimulation, and the population of Treg cells in thymocytes and splenocytes was not affected by GPR3 knockout. By contrast, spontaneous effector activation in both CD4+ T cells and CD8+ T cells was observed in GPR3-knockout mice. In summary, GPR3 is immediately induced by T cell stimulation and play an important role in the suppression of effector T cell activation.

Potential Therapeutic Application of Regulatory T Cells in Diabetes Mellitus Type 1.

The autoimmune reaction against the beta cells of the pancreatic islets in type 1 diabetes mellitus (T1DM) patients is active in prediabetes and during the development of the clinical manifestation of T1DM, but it decreases within a few years of the clinical manifestation of this disease. A key role in the pathogenesis of T1DM is played by regulatory T cell (Treg) deficiency or dysfunction. Immune interventions, such as potential therapeutic applications or the induction of the Treg-cell population in T1DM, will be important in the development of new types of treatment. The aim of this study was to evaluate innovative immune interventions as treatments for T1DM. After an evaluation of full-length papers from the PubMed database from 2010 to 2021, 20 trials were included for the final analysis. The analysis led to the following conclusions: Treg cells play an important role in the limitation of the development of T1DM, the activation or application of Tregs may be more effective in the early stages of T1DM development, and the therapeutic use of Treg cells in T1DM is promising but requires long-term observation in a large group of patients.

Regulatory T cells in acute and chronic human Chikungunya infection

Chikungunya virus (CHIKV) infection generates strong immune responses that are associated with the disease pathophysiology. Regulatory T cells (Treg-cluster of differentiation (CD)-4+CD25highforkhead box P3 (FOXP3+)) are essential for the induction and maintenance of peripheral tolerance. Thus, they play key roles in determining the patient prognosis by preventing excessive immune responses via different suppression immune mechanisms. However, the regulatory mechanisms involved in human CHIKV infection are still poorly understood. Here, we characterize for the first time the Treg cell molecule-associated-mechanism during acute and chronic human Chikungunya disease. Here, we assessed the Treg cell population and molecule-associated mechanism in the peripheral blood samples of acute and chronic patients with Chikungunya. Our results indicate that CHIKV infection is associated with reduced frequency of Tregs, along with the impaired expression and production of Treg functional markers, including CD39, CD73, perforin, granzyme, programmed death 1 (PD-1), cytotoxic T lymphocyte antigen (CTLA)-4, and transforming growth factor (TGF)-β. This observation suggests that Treg cells possess the poor regulatory capacity in both acute and chronic phases of the disease. Taken together, these data provide significant evidence that the imbalanced response of Treg cells plays an essential role in establishing the pathogenesis of Chikungunya.

A Novel Renoprotective Strategy: Upregulation of PD-L1 Mitigates Cisplatin-Induced Acute Kidney Injury.

The innate and adaptive immunities have been documented to participate in the pathogenesis of nephrotoxic acute kidney injury (AKI); however, the mechanisms controlling these processes have yet to be established. In our cisplatin-induced AKI mouse model, we show pathological damage to the kidneys, with the classical markers elevated, consistent with the response to cisplatin treatment. Through assessments of the components of the immune system, both locally and globally, we demonstrate that the immune microenvironment of injured kidneys was associated with an increased infiltration of CD4+ T cells and macrophages concomitant with decreased Treg cell populations. Our cell-based assays and animal studies further show that cisplatin exposure downregulated the protein levels of programmed death-ligand 1 (PD-L1), an immune checkpoint protein, in primary renal proximal tubular epithelial cells, and that these inhibitions were dose-dependent. After orthotopic delivery of PD-L1 gene into the kidneys, cisplatin-exposed mice displayed lower levels of both serum urea nitrogen and creatinine upon PD-L1 expression. Our data suggest a renoprotective effect of the immune checkpoint protein, and thereby provide a novel therapeutic strategy for cisplatin-induced AKI.

Deserters on the Atopic March: Risk Factors, Immune Profile and Clinical Outcomes of Food Sensitized-Tolerant Infants

To investigate the phenotypic features of infants who demonstrate immunoglobulin E sensitization to foods that they clinically tolerate. Such understanding may help elucidate strategies in the prevention of food allergies.A birth cohort of 1074 from southeastern Australia was composed of subjects <32 weeks’ gestation at time of enrollment and the mother planning to give birth at a local hospital. Participants were characterized as nonsensitized, sensitized-tolerant (ST), or food allergic (FA) on the basis of skin-prick testing and food challenge at 12 month of age.Environmental exposures were recorded throughout the study period of the cohort. Cord blood regulatory T-cell populations were measured at birth. Subsequent childhood allergic disease was assessed by parent report, clinical examination, and repeat skin-prick testing.Covariants were assessed among nonsensitized (n = 698), ST (n = 27), and FA (n = 61) groups and revealed that the ST group was more similar to the nonsensitized group than to the FA group in the following measures: family history of eczema (nonsensitized: 44.6%; ST: 44.6%; FA: 65.6%), pet ownership at 12 months (nonsensitized: 71.5%; ST: 81.5%; FA: 45.8%), eczema during the first 12 months (nonsensitized: 19%; ST: 32%; FA: 64%), and aeroallergen sensitivity at the age of 4 years (nonsensitized: 19.1%; ST 28.6%; FA 44.4%). At birth, a higher proportion of activated regulatory T cells was associated with the ST group.Infants who are sensitized but tolerant have similar pattern of exposures, immunity, and outcomes to nonsensitized infants. An elevated proportion of activated regulatory T cells at birth was specific to the ST infants and may be relevant to the clinical suppression of disease.Genetic and environmental factors are well known to play a role in the development of allergies. With this study, the authors compare prebirth cohorts to determine more specific factors that may put infants at higher risk for developing food allergies. A robust method of skin-prick testing plus an oral food challenge was used to confirm food allergies. The differences in proportion of cord blood naïve versus activated regulatory T cells in cohort groups provides insight into a mechanism for the prevention of food allergies.

CD103 integrin identifies a high IL-10-producing FoxP3+ regulatory T-cell population suppressing allergic airway inflammation.

Although FoxP3+ regulatory T (Treg) cells constitute a highly heterogeneous population, with different regulatory potential depending on the disease context, distinct subsets or phenotypes remain poorly defined. This hampers the development of immunotherapy for allergic and autoimmune disorders. The present study aimed at characterizing distinct FoxP3+ Treg subpopulations involved in the suppression of Th2-mediated allergic inflammation in the lung. We used an established mouse model of allergic airway disease based on ovalbumin sensitization and challenge to analyze FoxP3+ Tregs during the induction and resolution of inflammation, and identify markers that distinguish their most suppressive phenotypes. We also developed a new knock-in mouse model (Foxp3cre Cd103dtr ) enabling the specific ablation of CD103+ FoxP3+ Tregs for functional studies. We found that during resolution of allergic airway inflammation in mice >50% of FoxP3+ Treg cells expressed the integrin CD103 which marks FoxP3+ Treg cells of high IL-10 production, increased expression of immunoregulatory molecules such as KLRG1, ICOS and CD127, and enhanced suppressive capacity for Th2-mediated inflammatory responses. CD103+ FoxP3+ Tregs were essential for keeping allergic inflammation under control as their specific depletion in Foxp3cre Cd103dtr mice lead to severe alveocapillary damage, eosinophilic pneumonia, and markedly reduced lifespan of the animals. Conversely, adoptive transfer of CD103+ FoxP3+ Tregs effectively treated disease, attenuating Th2 responses and allergic inflammation in an IL-10-dependent manner. Our study identifies a novel regulatory T-cell population, defined by CD103 expression, programmed to prevent exuberant type 2 inflammation and keep homeostasis in the respiratory tract under control. This has important therapeutic implications.

Alphavirus-Driven Interferon Gamma (IFNg) Expression Inhibits Tumor Growth in Orthotopic 4T1 Breast Cancer Model.

Interferon gamma (IFNg) is a pleiotropic cytokine that can potentially reprogram the tumor microenvironment; however, the antitumor immunomodulatory properties of IFNg still need to be validated due to variable therapeutic outcomes in preclinical and clinical studies. We developed a replication-deficient Semliki Forest virus vector expressing IFNg (SFV/IFNg) and evaluated its immunomodulatory antitumor potential in vitro in a model of 3D spheroids and in vivo in an immunocompetent 4T1 mouse breast cancer model. We demonstrated that SFV-derived, IFN-g-stimulated bone marrow macrophages can be used to acquire the tumoricidal M1 phenotype in 3D nonattached conditions. Coculturing SFV/IFNg-infected 4T1 spheroids with BMDMs inhibited spheroid growth. In the orthotopic 4T1 mouse model, intratumoral administration of SFV/IFNg virus particles alone or in combination with the Pam3CSK4 TLR2/1 ligand led to significant inhibition of tumor growth compared to the administration of the control SFV/Luc virus particles. Analysis of the composition of intratumoral lymphoid cells isolated from tumors after SFV/IFNg treatment revealed increased CD4+ and CD8+ and decreased T-reg (CD4+/CD25+/FoxP3+) cell populations. Furthermore, a significant decrease in the populations of cells bearing myeloid cell markers CD11b, CD38, and CD206 was observed. In conclusion, the SFV/IFNg vector induces a therapeutic antitumor T-cell response and inhibits myeloid cell infiltration in treated tumors.

A2 adenosine receptor contributes to the development of cow's milk protein allergy via regulating regulatory T cells.

Objective(s):A2 adenosine receptor (A2AR) is a novel promising target for the treatment of inflammatory and allergic diseases. However, its role in the development of cow’s milk protein allergy (CMPA) has not been elucidated. The present study was designed to investigate the function of A2AR in CMPA development.Materials and Methods:BALB/c mice were sensitized and challenged with ovalbumin (OVA) to induce allergic responses. The model was assessed by detecting allergic responses and plasma-specific IgE levels. The levels of A2AR were measured by PCR and flow cytometry. The subpopulation of Treg cells was analysed.Results:The mice sensitized and challenged with OVA showed classic allergic symptoms, such as acute allergic skin responses, increased anaphylactic shock symptom scores, and higher levels of total IgE, OVA-specific IgE, IgG1 and IgG2a. OVA-sensitized mice and CMPA patients showed decreased levels of A2AR and Treg cells. Interestingly, we observed a positive correlation between A2AR expression and Treg levels in CMPA patients. Further study showed that the A2AR agonist CGS21680 blocked OVA-induced allergic reactions, and the A2AR antagonist KW-6002 amplified allergic responses. Interestingly, CGS21680 not only activated the A2AR-mediated signalling pathway but also caused an increase in the population of Treg cells. In contrast, KW-6002 therapy decreased the levels of Tregs in allergic mice.Conclusion:A2AR expression is downregulated in CMPA. The A2AR-mediated pathway negatively regulates the development of CMPA, at least in part, by amplifying the differentiation of Tregs.

Effects of Live and Pasteurized Forms of Akkermansia from the Human Gut on Obesity and Metabolic Dysregulation.

Akkermansia muciniphila (A. muciniphila) is a promising probiotic candidate owing to its health-promoting properties. A previous study reported that the pasteurized form of A. muciniphila strains isolated from human stool samples had a beneficial impact on high-fat diet-induced obese mice. On the other hand, the differences in the probiotic effects between live and pasteurized A. muciniphila on the metabolism and immune system of the host are still inconclusive. This study examines the differences between the live and pasteurized forms of A. muciniphila strains on the lipid and glucose metabolism and on regulating the inflammatory immune responses using a HFD-fed obese mouse model. The animals were administered the live and pasteurized forms of two A. muciniphila strains five times per week for the entire study period of 12 weeks. Both forms of the bacterial strains improved the HFD-induced obesity and metabolic dysregulation in the mice by preventing body-weight gains after one week. In addition, they cause a decrease in the weights of the major adipose tissues, adipogenesis/lipogenesis and serum TC levels, improvement in glucose homeostasis and suppression of inflammatory insults. Furthermore, these treatments restored the damaged gut architecture and integrity and improved the hepatic structure and function in HFD-induced animals. On the other hand, for both bacterial strains, the pasteurized form was more potent in improving glucose tolerance than the live form. Moreover, specific A. muciniphila preparations with either live or pasteurized bacteria decreased the number and population (%) of splenic Treg cells (CD4+ Foxp3+) significantly in the HFD-fed animals, further supporting the anti-inflammatory properties of these bacteria.

Donor BMSC-derived small extracellular vesicles relieve acute rejection post-renal allograft through transmitting Loc108349490 to dendritic cells.

Bone marrow‐derived mesenchymal stem cell (BMSC)‐derived small extracellular vesicles (sEVs) are potent candidates for the suppression of acute rejection post‐renal allograft and have been reported to halt dendritic cells (DCs) maturation. However, whether BMSC‐derived sEVs mitigate acute rejection post‐renal allograft by targeting DCs is still unclear. In this study, donor BMSC‐derived sEVs (sEVs) relieved the inflammatory response and suppressed mature DCs (mDCs) location in kidney grafts, and increased regulatory T (Treg) cell population in the spleens of the rats that underwent kidney allograft. In lipopolysaccharide (LPS)‐stimulated immature DCs (imDCs), sEVs suppressed the maturation and migration of DCs and inactivated toll‐like receptor 4 (TLR4) signaling. Compared with LPS‐treated imDCs, imDCs treated with LPS+sEVs promoted CD4+T cells differentiated toward Treg cells. Subsequently, we found that Loc108349490, a long non‐coding RNA (lncRNA) abundant in sEVs, mediated the inhibitory effect of sEVs on DC maturation and migration by promoting TLR4 ubiquitination. In rats that underwent an allograft, Loc108349490 deficiency weakened the therapeutic effect of sEVs on acute rejection. The present study firstly found that sEVs alleviated acute rejection post‐renal allograft by transferring lncRNA to DCs and screened out the functional lncRNA loaded in sEVs was Loc108349490.