The proportion and phenotypic changes of CD4+CD25-Foxp3+ T cells in patients with untreated rheumatoid arthritis.

OBJECTIVE: CD4+CD25+Foxp3+ regulatory T (Treg) cell-mediated immunosuppression is an essential mechanism of rheumatoid arthritis (RA). However, little is known regarding the specific role of CD4+CD25-Foxp3+ Treg cells in RA. This study aimed to investigate the frequency of circulating CD4+CD25-Foxp3+ Treg cells and their role in RA. METHODS: Sixty-one untreated RA patients and 40 healthy controls (HCs) were enrolled in this study. The proportion of CD4+CD25-Foxp3+ T cells and CD4+CD25+Foxp3+ Tregs; the levels of CTLA4, GITR, Helios, and ICOS; and the production of IL-17A, IFN-γ, and IL-10 were assessed by flow cytometry. The correlation of CD4+CD25-Foxp3+ T cells and CD4+CD25+Foxp3+ Tregs with the clinical indicators was conducted by Spearman correlation analysis. RESULTS: The proportion of CD4+CD25-Foxp3+ T cells was elevated in RA and positively correlated with disease activity. CD4+CD25-Foxp3+ T cells expressed less Helios and produced more IFN-γ than conventional Tregs in RA. Additionally, the proportion of CD4+CD25-Foxp3+ T cells was positively correlated with DAS28 score, IgG titer, and anti-CCP titer. CONCLUSIONS: These data indicate that CD4+CD25-Foxp3+ T cells in RA exhibit several different functional properties from conventional Tregs and are correlated with RA disease activity.

A Praziquantel Treatment Study of Immune and Transcriptome Profiles in Schistosoma haematobium-Infected Gabonese Schoolchildren.

BACKGROUND: Although Schistosoma haematobium infection has been reported to be associated with alterations in immune function, in particular immune hyporesponsiveness, there have been only few studies that have used the approach of removing infection by drug treatment to establish this and to understand the underlying molecular mechanisms. METHODS: Schistosoma haematobium-infected schoolchildren were studied before and after praziquantel treatment and compared with uninfected controls. Cellular responses were characterized by cytokine production and flow cytometry, and in a subset of children RNA sequencing (RNA-Seq) transcriptome profiling was performed. RESULTS: Removal of S haematobium infection resulted in increased schistosome-specific cytokine responses that were negatively associated with CD4+CD25+FOXP3+ T-cells and accompanied by increased frequency of effector memory T-cells. Innate responses to Toll like receptor (TLR) ligation decreased with treatment and showed positive association with CD4+CD25+FOXP3+ T-cells. At the transcriptome level, schistosome infection was associated with enrichment in cell adhesion, whereas parasite removal was associated with a more quiescent profile. Further analysis indicated that alteration in cellular energy metabolism was associated with S haematobium infection and that the early growth response genes 2 and 3 (EGR 2 and EGR3), transcription factors that negatively regulate T-cell activation, may play a role in adaptive immune hyporesponsiveness. CONCLUSIONS: Using a longitudinal study design, we found contrasting effects of schistosome infection on innate and adaptive immune responses. Whereas the innate immune system appears more activated, the adaptive immunity is in a hyporesponsive state reflected in alterations in CD4+CD25+FOXP3+ T-cells, cellular metabolism, and transcription factors involved in anergy.

Antigen-specific over-expression of human cartilage glycoprotein 39 on CD4+ CD25+ forkhead box protein 3+ regulatory T cells in the generation of glucose-6-phosphate isomerase-induced arthritis.

Human cartilage gp-39 (HC gp-39) is a well-known autoantigen in rheumatoid arthritis (RA). However, the exact localization, fluctuation and function of HC gp-39 in RA are unknown. Therefore, using a glucose-6-phosphate isomerase (GPI)-induced model of arthritis, we investigated these aspects of HC gp-39 in arthritis. The rise in serum HC gp-39 levels was detected on the early phase of GPI-induced arthritis (day 7) and the HC gp-39 mRNA was increased significantly on splenic CD4(+) T cells on day7, but not on CD11b(+) cells. Moreover, to identify the characterization of HC gp-39(+) CD4(+) T cells, we assessed the analysis of T helper (Th) subsets. As a result, HC gp-39 was expressed dominantly in CD4(+) CD25(+) forkhead box protein 3 (FoxP3)(+) refulatory T cells (T(reg)), but not in Th1, Th2 or Th17 cells. Furthermore, to investigate the effect of HC gp-39 to CD4(+) T cells, T cell proliferation assay and cytokine production from CD4(+) T cells using recombinant HC gp-39 was assessed. We found that GPI-specific T cell proliferation and interferon (IFN)-γ or interleukin (IL)-17 production were clearly suppressed by addition of recombinant HC gp-39. Antigen-specific over-expression of HC gp-39 in splenic CD4(+) CD25(+) FoxP3(+) T(reg) cells occurs in the induction phase of GPI-induced arthritis, and addition of recombinant HC gp-39 suppresses antigen-specific T-cell proliferation and cytokine production, suggesting that HC gp-39 in CD4(+) T cells might play a regulatory role in arthritis.

Immunoprotective inference of experimental chronic Trichinella spiralis infection on house dust mites induced allergic airway remodeling.

Allergic bronchial asthma is characterized by chronic inflammation of the respiratory airways mediated by T-helper 2 (Th2), Th17 and their cytokines. Although most asthmatic patients suffer from allergic airway remodeling (AAR), aggressive anti-allergic treatment failed to reverse it. The hygiene hypothesis illuminated the counter relationship between allergy and helminthic infections. The immune system is modulated by Trichinella spiralis (T. spiralis) infection to maintain homeostasis. Therefore, this work aimed to investigate the impact of chronic T. spiralis infection on induced AAR in C57BL/6 mice sensitized by house dust mites (HDM) allergens. Forty mice were divided into 3 groups: I (10 healthy mice), IΙ (15 HDM sensitized mice), and ΙΙI (15 T. spiralis chronically infected mice and sensitized with HDM allergens). The assessment aimed to evaluate the effects of regulatory CD4+CD25+FOXP3+ cells (Tregs) and their cytokines comparative to hypersensitivity mediated cytokines. Chronic T. spiralis infection effectively prevented the host's AAR. This result was evidenced by upregulated Tregs in blood by flow cytometric analysis and increased interleukin-10 (IL-10) levels in bronchoalveolar lavage (BAL) by Enzyme linked immunosorbent assay (ELISA) as well as improved lung histopathological changes. Also, serum HDM specific immunoglobulin E (IgE), BAL eosinophils, BAL IL-5 levels, and IL-17 gene expression in lung tissues were significantly reduced in T. spiralis chronically infected mice. In conclusion, the immune response in chronic T. spiralis infection could provide a promising mechanistic tool for protection against AAR, which paves the way for innovative preventive measures of other immunological disorders.

Generation and Immune Regulation of CD4+CD25-Foxp3+ T Cells in Chronic Obstructive Pulmonary Disease.

The imbalance of CD4+Foxp3+ T cell subsets is reportedly involved in abnormal inflammatory immune responses in patients with chronic obstructive pulmonary disease (COPD). However, the possible role of CD4+CD25-Foxp3+ T cells in immune regulation in COPD remains to be investigated. In the current study, distribution and phenotypic characteristics of CD4+CD25-Foxp3+ T cells from peripheral blood were determined by flow cytometry; the origin, immune function and ultimate fate of CD4+CD25-Foxp3+ T cells were further explored in vitro. It was observed that circulating CD4+CD25-Foxp3+ T cells were significantly increased in stable COPD patients (SCOPD) and resembled central memory or effector memory T cells. Compared with peripheral CD4+CD25+Foxp3+ T cells, peripheral CD4+CD25-Foxp3+ T cells showed a lower expression of Foxp3, CTLA-4, HELIOS, and TIGIT, but a higher expression of CD127 and KI-67, suggesting that CD4+CD25-Foxp3+ T cells lost the expression of Tregs-associated molecules following the reduction in CD25. Unexpectedly, our study found that transforming growth factor-ß1 (TGFß1) decreased CD25 expression and played a critical role in the generation of CD4+CD25-Foxp3+ T cells from CD4+CD25+Foxp3+ T cells. Phenotypic analysis further revealed that both inducible and peripheral CD4+CD25-Foxp3+ T cells exhibited the features of activated conventional T cells. Importantly, memory CD4+CD25-Foxp3+ T cells facilitated the proliferation and differentiation of naïve CD4+ T cells into Th17 cells in the presence of IL-1ß, IL-6, IL-23, and TGFß1. Finally, a fraction of CD4+CD25-Foxp3+ T cells, exhibiting instability and plasticity, were converted to Th17 cells when subjected to Th17 cell-polarizing condition. Taken together, we propose that TGFß1 is responsible for the generation of CD4+CD25-Foxp3+ T cells, and these cells functionally exert an auxiliary effect on Th17 cells generation and might perpetuate chronic inflammation in COPD.

Advances in the Use of Regulatory T-Cells for the Prevention and Therapy of Graft-vs.-Host Disease.

Regulatory T (Tregs) cells play a crucial role in immunoregulation and promotion of immunological tolerance. Adoptive transfer of these cells has therefore been of interest in the field of bone marrow and solid organ transplantation, autoimmune diseases and allergy medicine. In bone marrow transplantation, Tregs play a pivotal role in the prevention of graft-verus-host disease (GvHD). This has generated interest in using adoptive Treg cellular therapy in the prevention and treatment of GvHD. There have been several barriers to the feasibility of Treg cellular therapy in the setting of hematopoietic stem cell transplantation (HSCT) which include low Treg concentration in peripheral blood, requiring expansion of the Treg population; instability of the expanded product with loss of FoxP3 expression; and issues related to the purity of the expanded product. Despite these challenges, investigators have been able to successfully expand these cells both in vivo and in vitro and have demonstrated that they can be safely infused in humans for the prevention and treatment of GvHD with no increase in relapse risk or infections risk.

Downmodulation of peripheral MOG-specific immunity by pVAXhsp65 treatment during EAE does not reach the CNS.

Most of the therapeutic strategies to control multiple sclerosis are directed to immune modulation and inflammation control. As heat shock proteins are able to induce immunoregulatory T cells, we investigated the therapeutic effect of a genetic vaccine containing the mycobacterial hsp65 gene on experimental autoimmune encephalomyelitis (EAE). Although pVAXhsp65 was immunogenic for mice with EAE and downmodulated specific cytokine induction by MOG, therapy was not able to decrease clinical severity nor to modify immunologic parameters in the CNS. These results indicate that hsp65, administered as a DNA vaccine, was not therapeutic for EAE.

Efeito da infecção com Strongyloides venezuelensis no desenvolvimento da encefalite autoimune (EAE) / Effect of infection with Strongyloides venezuelensis in the development of experimental autoimmune encephalitis (EAE)

A esclerose múltipla (EM) é uma doença inflamatória, crônica e desmielinizante do sistema nervoso central (SNC). A caracterização de uma estratégia profilática e/ou terapêutica na EM é necessária, já que não há cura para essa doença. No contexto da hipótese da higiene, a exposição diminuída a certos agentes infecciosos como os helmintos, os lactobacilos e as micobactérias saprófitas estaria relacionada com o aumento na incidência de doenças alérgicas e autoimunes. Assim, o objetivo deste trabalho foi caracterizar a infecção por Strongyloides venezuelensis em ratos Lewis e avaliar se a mesma modula as características clínicas, imunológicas e histopatológicas da encefalite autoimune experimental (EAE) nestes animais. Na primeira etapa, caracterizamos as fases aguda e de recuperação da infecção e avaliamos os padrões de resposta imune nestas duas fases. Na segunda etapa, avaliamos o efeito de uma ou várias infecções com S. venezuelensis na evolução da EAE. Os animais foram avaliados diariamente quanto ao peso e escore clínico da doença e a eutanásia foi realizada na fase de recuperação da EAE para avaliação da resposta imune (produção de citocinas e anticorpos) e do processo inflamatório no SNC. A frequência de células T CD4+CD25+Foxp3+ no baço e nos linfonodos (inguinais e poplíteos) também foi determinada após infecção única (fase aguda e de recuperação) ou múltipla com este helminto. De acordo com os diversos parâmetros avaliados, os resultados demonstraram que a infecção com S. venezuelensis não modificou a progressão da EAE em ratos Lewis e também não alterou a frequência de células T CD4+CD25+Foxp3+ nos órgãos linfóides secundários...