Search results for "D4 [Ratio D2]"

Modifications of general parameters of immune activation in the sera of Sicilian patients with Boutonneuse fever

1998

SUMMARYThe serum levels of β2-microglobulin (β2-M), soluble HLA class I antigen (sHLA-I), soluble CD4 (sCD4) and CD8 (sCD8) were studied in 98 Sicilian patients with Boutonneuse fever (BF). In different stages of infection all markers were significantly increased in sera from Sicilian patients with acute BF compared with healthy controls. sCD8 and sHLA-I reached the peak in the second week after the onset of symptoms, whereas sCD4 and β2-M reached the peak in the first week. Afterwards sCD8 decreased to the levels of controls within the third week, the other parameters decreased later and were unmodified until the third week of infection. Significant correlations were found between sCD4 and…

CD4-mediated regulatory T-cell activation inhibits the development of disease in a humanized mouse model of allergic airway disease

2012

Background Based on their potency to control allergic diseases, regulatory T (Treg) cells represent a promising target for novel strategies to interfere with allergic airway inflammation. We have previously demonstrated that stimulation of the CD4 molecule on human Treg cells activates their suppressive activity in vitro and in vivo . Objective We sought to determine the effect of CD4-mediated Treg-cell activation on pulmonary inflammation in a humanized mouse model of allergic airway inflammation. Methods PBMCs obtained from donors allergic to birch pollen or from healthy donors were injected into NOD-severe combined immunodeficiency γc −/− mice, followed by allergen airway challenges and …

Analysis of the in vitro cytokine production by liver-infiltrating T cells of patients with autoimmune hepatitis.

1993

SUMMARY The pathogenic mechanisms underlying the development of autoimmune hepatitis (AIH) are still unclear. Since AIH is associated with the presence of various autoantibodics and certain HLA subtypes, it is likely that T and B cells play a major role in this disease. In this study we have determined the functional capacities of in vivo preactivated liver-infiltrating T cells (LTC) from patients with AIH. As controls we used LTC from patients with non-autoimmune hepatitis (non-AIH). Our results show that preactivated LTC from patients with AIH predominantly (190/255 clones) reside in the CD4+ population, whereas LTC in non-AIH are dominated by the CD8+ phenotype (148/254 clones). In view …

Liver-infiltrating T helper cells in autoimmune chronic active hepatitis stimulate the production of autoantibodies against the human asialoglycoprot…

1992

SUMMARYAutoantibodies against the human asialoglycoprotein receptor (ASGPR) occur in the sera orpaticnts with autoimmune liver disorders. Live-nfiltrating T cell clones that specifically recognize the ASGPR have been described in patients with autoimmune chronic active hepatitis (A-AH) and primary biliary cirrhosis (PBC). Recently, we have shown that peripheral blood mononuclcar cells (PBMC) from patients with A-AH or PBC but not chronic viral hepatitis secreted ant-SGPR antibodies in vitro. In this study we characterized the influence of live-nfiltrating T cells on the secretion of ASGP-pecific autoantibodies by autologous B cells in cell culture supernatants. T cell clones from liver biop…

The role of regulatory T cell (Treg) subsets in gestational diabetes mellitus.

2014

Physiological changes during normal pregnancy are characterized by an inflammatory immune response and insulin resistance. Therefore, we hypothesize that gestational diabetes mellitus (GDM) may be caused by an inappropriate adaption of the maternal immune system to pregnancy. In this study we examined the role of regulatory T cell (Treg) differentiation for the development of GDM during pregnancy. We used six-colour flow cytometric analysis to demonstrate that the total CD4(+) CD127(low+/-) CD25(+) forkhead box protein 3 (FoxP3(+)) T(reg) pool consists of four different T(reg) subsets: naive CD45RA(+) T(regs), HLA-DR(-) CD45RA(-) memory T(regs) (DR(-) T(regs)) and the highly differentiated …

IL-21 Regulates the Differentiation of a Human γδ T Cell Subset Equipped with B Cell Helper Activity

2012

Vγ9Vδ2 T lymphocytes recognize nonpeptidic antigens without presentation by MHC molecules and display pleiotropic features. Here we report that coculture of Vγ9Vδ2 cells with phosphoantigen and IL-21 leads to selective expression of the transcription repressor Bcl-6 and polarization toward a lymphocyte subset displaying features of follicular B-helper T (T(FH)) cells. T(FH) like Vγ9Vδ2 cells have a predominant central memory (CD27(+)CD45RA(-)) phenotype and express ICOS, CD40L and CXCR5. Upon antigen activation, they secrete IL-4, IL-10 and CXCL13, and provide B-cell help for antibody production in vitro. Our findings delineate a subset of human Vγ9Vδ2 lymphocytes, which, upon interaction w…

Injection of donor-derived splenic dendritic cells plus a nondepleting anti-CD4 monoclonal antibody to prolong primary skin graft survival indefinite…

2010

Abstract We have previously shown that injection of donor-derived Fischer rat OX62+ dendritic cells plus an anti-CD4 monoclonal antibody generates donor-specific CD4+CD25+FoxP3+ regulatory T cells in Lewis rats spleens. The regulatory T cells indefinitely prolonged the survival of skin graft from Fischer rat and abrogated the antidonor antibody response. We have now shown that an injection of 2 × 10 6 donor-derived OX62+ dendritic cells plus 2 mg nondepleting anti-CD4 monoclonal antibody (W3/25) at 28 days before grafting induced indefinite skin graft survival in this combination; whereas an injection on day −1 prolonged it only to 50 days. This effect is donor specific. In both cases, we s…

In vitro study of alloreactivity and microchimerism after injection of dendritic cells and anti-CD4 monoclonal antibody in a combination of Lewis-Wis…

1998

Components of an antigen-/T cell receptor-independent pathway of lymphokine production

1991

The general way to induce the synthesis of lymphokines by T cells is the stimulation through the T cell receptor (TcR) complex which results in an increase of intracellular [Ca2+] and in the activation of a tyrosine kinase as well as of protein kinase C. Lymphokine production induced via the TcR is inhibited by the immunosuppressive drug cyclosporin A (CsA). However, an alternative pathway of lymphokine production exists. Several T lymphocyte clones can synthesize interferon-gamma (IFN-gamma), granulocyte-monocyte colony-stimulating factor, and small amounts of interleukin (IL3) when stimulated with syngeneic or allogeneic accessory cells (AC) plus IL2. In contrast to the TcR pathway the al…

Reduced CD4 and CD8 expression in human thymuses treated with soluble CD4.

1991

Recent data suggest that accessory molecules like CD4 and CD8 act as co-receptors in intrathymic T-cell development. Soluble CD4 (sCD4) molecules offer a novel experimental approach to investigate the relevance of CD4 interaction with its putative intrathymic receptor for T-cell maturation. We attempted to inhibit binding of surface CD4 on thymocytes to its intrathymic receptor competitively by introduction of human sCD4 into human thymus tissue cultures. Our results demonstrate that sCD4, while not affecting peripheral T-cell responses as shown in control experiments, significantly affects intrathymic development of T lymphocytes. Immature CD4CD8 double positive (DP) thymocytes responded w…