Search results for "alpha-beta"
showing 10 items of 64 documents
Anti-Anisakis sp. antibodies in serum of healthy subjects. Relationship with αβ and γδ T cells
2016
Anisakiosis is nowadays one of the nematodoses more prevalent in Spain, with rates that oscillate between 0.43% in Galicia (N.W. Spain), and 15.7% and 22.1% in inland and southern regions, respectively. Likewise, it has been proved that Anisakis larvae have developed mechanisms to modulate the dichotomy of the host immune response for their own benefit. The experimental hypothesis of the present study was that Anisakis sp. larval products can be mediators of immune suppression and induce changes on the populations of αβ+ and γδ+ T cells. In the present study we determined the levels of anti-Anisakis antibodies in the serum of healthy people, and their relationship with the B and T cell subs…
Longitudinal analysis of the T-cell receptor (TCR)-VA and -VB repertoire in CD8+T cells from individuals immunized with recombinant hepatitis B surfa…
2002
SUMMARYRecent studies have suggested that vaccination induces alterations in the T cell receptor (TCR) repertoire. We investigate the diversity of the TCR repertoire after immunization with a recombinant hepatitis B surface vaccine in seven healthy subjects in CD8+ T cells in peripheral blood lymphocytes. Cellular immune responses were monitored over time by sorting CD8 T cells followed by TCR-VA and -VB complementarity determining region 3 (CDR3) analysis. Frequency of individual VB families was determined by flow cytometry. TCR-VA/VB repertoires obtained from CD8+ T cells drawn after vaccination were compared to the TCR repertoire determined prior to vaccination. Monoclonal TCR transcript…
Endogenous levels of mRNA for IFNs and IFN-related genes in hepatic biopsies of chronic HCV-infected and non-alcoholic steatohepatitis patients.
2003
To investigate the intra-hepatic activation of the IFN system in patients affected by chronic HCV-infection in comparison with that observed in a non-infectious liver disease such as non-alcoholic steatohepatitis, we measured the liver steady state mRNA levels of interferon-alpha, interferon-beta and interferon-gamma as well as of IFN-related genes (IFNAR-1, STAT1alpha, PKR, 2-5 AS, IRF-1, ICE and IL-18). In HCV-infected subjects, possible correlations of these parameters with viral load and liver injury were also analyzed. Twenty-four chronic untreated HCV-infected subjects and seven patients with non-alcoholic steatohepatitis were enrolled in the study. Liver biopsies were graded accordin…
Ankylosing spondylitis in monozygotic twins: studies on immunological parameters
1999
OBJECTIVE—To examine immunological parameters that might explain disease discordance in monozygotic twin pairs with ankylosing spondylitis (AS). METHODS—11 monozygotic twin pairs (nine with AS, two with undifferentiated spondyloarthropathy) were investigated. The peripheral T cell receptor Vβ repertoire was investigated using FACS analysis and 14 different Vβ antibodies. In addition serum samples were tested for antibodies to Klebsiella pneumoniae, Streptococcus pyogenes, Candida albicans, Proteus mirabilis, and Escherichia coli. Peripheral blood lymphocyte reactivity against a number of bacteria was investigated by interferon γ ELISPOT assays. RESULTS—Twins suffering from AS showed cellula…
Limited T cell receptor Vbeta-chain repertoire of liver-infiltrating T cells in autoimmune hepatitis.
1998
Abstract Background/Aims: To characterize the cellular immune reactions in autoimmune hepatitis, the T cell receptor repertoire of livre-infiltrating and circulating T cells was studied. Methods: Nucleic acids of liver-tissue and peripheral blood-derived T cells from 12 patients with untreated autoimmune hepatitis, four patients with chronic hepatitis C and three patients with toxic liver injury were extracted and analysed using a semiquantitative RT-PCR with a panel of T cell receptor Vβ family specific primers. After agarose gel electrophoresis, the distribution of T cell receptor (TCR) Vβ molecules was assessed by densitometry. Furthermore, results were compared to the TCR Vβ distributio…
The Transcription Factor T-bet Is Induced by IL-15 and Thymic Agonist Selection and Controls CD8αα+ Intraepithelial Lymphocyte Development
2014
Summary CD8αα + intraepithelial lymphocytes (IELs) are instrumental in maintaining the epithelial barrier in the intestine. Similar to natural killer cells and other innate lymphoid cells, CD8αα + IELs constitutively express the T-box transcription factor T-bet. However, the precise role of T-bet for the differentiation or function of IELs is unknown. Here we show that mice genetically deficient for T-bet lacked both TCRαβ + and TCRγδ + CD8αα + IELs and thus are more susceptible to chemically induced colitis. Although T-bet was induced in thymic IEL precursors (IELPs) as a result of agonist selection and interleukin-15 (IL-15) receptor signaling, it was dispensable for the generation of IEL…
Stimulation of human T cells by microbial 'superantigens'.
1991
The enterotoxins and the TSST of S. aureus, the erythrogenic toxins A and C of S. pyogenes and a still uncharacterized exoprotein of M. arthritidis belong to a family of exotoxins that have in common a potent mitogenic activity for T lymphocytes of several species. These proteins stimulate CD4+ and C8+ T cells, as well as a fraction of gamma delta TCR-bearing T cells by cross-linking variable parts of the T cell antigen receptor with MHC class II molecules on accessory or target cells. They are functionally bivalent molecules having distinct interaction sites for variable parts of the TCR and for nonpolymorphic parts of the MHC class II molecule. For alpha beta TCR-bearing T cells the V bet…
Granulysin‐Dependent Killing of Intracellular and ExtracellularMycobacterium tuberculosisby Vγ9/Vδ2 T Lymphocytes
2001
Contribution of Vgamma9/Vdelta2 T lymphocytes to immune protection against Mycobacterium tuberculosis is still a matter of debate. It was reported earlier that Vgamma9/Vdelta2 T lymphocytes kill macrophages harboring live M. tuberculosis through a granule-dependent mechanism that results in killing of intracellular bacilli. This study found that Vgamma9/Vdelta2 T lymphocytes reduce the viability of both extracellular and intracellular M. tuberculosis. Granulysin and perforin, both detected in Vgamma9/Vdelta2 T lymphocytes, play a major role, which indicates that Vgamma9/Vdelta2 T lymphocytes directly contribute to a protective host response against M. tuberculosis infection.
Antigen-independent in vitro expansion of T cells does not affect the T cell receptor V beta repertoire.
1997
Analysis of the variable chains (V alpha/V beta) of the specific T cell receptor (TCR) of organ-infiltrating T cells may provide further insights into the pathogenesis of many infectious diseases, malignancies, and autoimmune disorders. To determine the TCR V beta repertoire of these small T cell populations antigen-independent in vitro expansion is necessary but may select for certain T cell subpopulations. In this study various antigen independent T cell activation protocols were used to stimulate peripheral blood mononuclear cells (PBMC) of six healthy blood donors, and TCR V beta molecules were analyzed by flow cytometry and semiquantitative reverse-transcriptase polymerase chain reacti…
Anti-GD3 antibodies are potent activators of human gamma/delta and alpha/beta positive T cells.
1995
The ganglioside GD3 has a variety of biological functions. These include stimulatory effects on proliferation, natural killer activity and cytokine production by freshly isolated peripheral T cells. In this study we have characterized anti-GD3 antibody (MoAb Z21) mediated effects on T cell clones. Our data indicate that alpha/beta TCR CD4+ and CD8+ as well as gamma/delta TCR positive T cells can be stimulated resulting in proliferation and cytokine production. This effect could be blocked by cyclosporin A and did not involve the LFA-3 or CD4 molecule. Apart from IFN-gamma and IL-2 production by T helper 1 and T helper 0 cells we have observed production of IL-4 and IL-10 by T helper 2 cells…