No abstract available.
Ascitic Fluid ; T-Lymphocytes, Regulatory

Foxp3 is a transcript factor for regulatory T cell development. Interestingly, Foxp3-expressing cells were identified in B cells, especially in CD19(+)CD5(+) B cells, while those were not examined in CD19(+)CD5(-) B cells. Foxp3-expressing CD5(+) B cells in this study were identified in human PBMCs and were found to consist of 8.5+/-3.5% of CD19(+)CD5(+) B cells. CD19(+)CD5(+)Foxp3(+) B cells showed spontaneous apoptosis. Rare CD19(+)CD5(+) Foxp3(+) regulatory B cell (Breg) population was unveiled in human peripheral blood mononuclear cells and suggested as possible regulatory B cells (Breg) as regulatory T cells (Treg). The immunologic and the clinical relevant of Breg needs to be further investigated.
Apoptosis ; B-Lymphocytes ; B-Lymphocytes, Regulatory ; Humans ; T-Lymphocytes, Regulatory

OBJECTIVE: To investigate the role of regulatory B cells (Breg) in pathogenesis of immune thrombocytopenia(ITP) and its clinical significance. METHODS: A total of 40 ITP patients and 20 normal controls were enrolled in this study. The content of Breg, Th1, Th2, Th17 and Treg cells were detected by flow cytometry (FCM). The expression level of IL-10,TGF-β, CD40 and CD40L was detected by AimPlex Flow High Throughput Screening Technology. RESULTS: The of Breg cells in ITP patients was significantly lower than that in normal controls (P<0.05)，the expression levels of IL-10,TGF-β and CD40L in ITP patients were also significantly lower than those in normal controls (P<0.05). The contents of Th1 cells in ITP patients were significantly higher than that in normal controls (P<0.05), whereas the contents of Th2, Th17 and Treg cells in ITP patients were significantly lower than those in normal controls (P<0.05). CONCLUSION The Breg cells may play an important role in the pathogenesis of ITP.
B-Lymphocytes, Regulatory ; Humans ; T-Lymphocytes, Regulatory ; Th17 Cells ; Thrombocytopenia

No abstract available.
Asthma ; Immune Tolerance ; T-Lymphocytes, Regulatory

CD4+ CD25+ regulatory T cells (Tregs) expressing the lineage-specific marker Foxp3 represent an important regulatory T cell that is essential for maintaining peripheral tolerance. Although it was believed that Treg development is solely dependent on the thymus, accumulating evidence demonstrates that Tregs can also be induced in the periphery. Considering the various origins of peripherally developed CD4+ CD25+ Foxp3+ regulatory T cells, it seems likely that multiple factors are involved in the peripheral generation of Tregs.
Peripheral Tolerance ; T-Lymphocytes, Regulatory* ; Thymus Gland

Regulatory T cells (Treg) are functionally mature T cell subpopulations which are key players of maintaining the balance of immunological defense system. Treg can proliferate in vivo or in vitro by antigen specific way or non-antigen specific way, and actively control the properties of other immune cells by suppressing their functional activity and their proliferation as well.
Humans ; Immune Tolerance ; T-Lymphocytes, Regulatory ; immunology

Understanding germinal center reactions is crucial not only for the design of effective vaccines against infectious agents and malignant cells but also for the development of therapeutic intervention for the treatment of antibody-mediated immune disorders. Recent advances in this field have revealed specialized subsets of T cells necessary for the control of B cell responses in the follicle. These cells include follicular regulatory T cells and Qa-1-restricted cluster of differentiation (CD)8+ regulatory T cells. In this review, we discuss the current knowledge related to the role of regulatory T cells in the B cell follicle.
Germinal Center ; Immune System Diseases ; T-Lymphocytes ; T-Lymphocytes, Helper-Inducer ; T-Lymphocytes, Regulatory* ; Vaccines

CD4-Positive T-Lymphocytes ; Cell Differentiation ; T-Lymphocyte Subsets ; T-Lymphocytes, Regulatory

PURPOSE OF REVIEW: Rheumatoid arthritis (RA) is characterized by a chronic T-cell response that has escaped normal control mechanisms. This review summarizes recent insights in pathways that are functional in RA and that favor continuous and pathogenic T-cell activation. RECENT FINDINGS: T-cell activation is ultimately determined by positive signals from costimulatory molecules and negative signals from regulatory T cells. Blockade of the classic costimulatory pathway, CD28-CD80 or CD86, is beneficial in RA. Additional pathways that predominantly control the activation of memory and effector T cells are functionally important in synovial inflammation. Some of these costimulatory molecules(such as stimulatory killer cell immunoglobulin-like receptors and NKG2D) appear to be relatively specific for RA and not to play a role in normal immune responses. In addition to this predominance of positive signals, age-disproportionate decline in thymic activity in RA may lead to a diminution of regulatory T cells and loss of their negative signals. SUMMARY: The successful treatment trial of RA with CTLA-4Ig clearly documents the importance of T-cell costimulation in RA disease activity. Novel costimulatory pathways may be of even greater significance than CD28 in RA and may represent promising new therapeutic targets. The finding of reduced thymic activity in RA is exciting and will stimulate further studies of T-cell homeostasis and the function of regulatory cells.
Arthritis, Rheumatoid* ; Autoimmunity ; Homeostasis ; Inflammation ; Lymphocytes* ; Memory ; Receptors, KIR ; T-Lymphocytes ; T-Lymphocytes, Regulatory ; United Nations

CD4+CD25+ regulatory T cells (CD4+CD25+ Tregs) have been shown to play a regulatory or suppressive role in the immune response and are possibly relevant to the pathogenesis of autoimmune diseases. In the present study, we attempted to investigate the frequency of CD4+CD25+ Tregs in peripheral blood (PB) of collagen-induced arthritis (CIA) rats during the development of arthritis, to determine whether their frequency is involved in the immunoregulation of this disease. The results showed that normal rats had similar frequencies of CD4+CD25+ Tregs in PB during the experiment time, expressed as a percentage of CD4+CD25+Foxp3+ T cells among the CD4+ T lymphocyte population. In contrast, the frequency of CD4+CD25+Foxp3+ T cells in CIA rats was found to change during the development of arthritis. In CIA rats, there is a significant negative correlation between the frequency of CD4+CD25+Foxp3+ T cells and paw swelling (r=-0.786, p< 0.01). The relationship between the frequency of CD4+CD25+Foxp3+ T and immune activation was not found in normal rats. During the time course, the frequency of CD4+CD25+Foxp3+ T was lower in CIA rats than in normal ones. The data suggest that the frequency of PB CD4+CD25+ Tregs may be a promising marker for arthritis activity.
Animals ; Arthritis ; Arthritis, Experimental* ; Autoimmune Diseases ; Lymphocytes ; Rats* ; T-Lymphocytes ; T-Lymphocytes, Regulatory*