Search results for "alpha-beta"
showing 10 items of 64 documents
Modulation of Contact Sensitivity Responses by Bacterial Superantigen
1995
Superantigens are potent modulators of the immune system, especially T cells. Therefore, we determined the influence of superantigens on the T-cell-mediated immune response, contact sensitivity. We chose the combination of staphylococcal enterotoxin B (SEB) as superantigen and 2,4-dinitrofluorbenzene (DNFB) as the contact sensitizer, because in BALB/c mice SEB reacts almost exclusively with V beta 8+ T cells, and these cells are capable of transferring contact sensitivity to DNFB from sensitized donors to naive syngeneic recipients. Pretreatment with a single intradermal injection of 50 ng SEB 24 h before DNFB exposure at the same site on the lower abdomen enhanced the induction of contact …
Fibroblast Growth Factor 21 (FGF21) Protects against High Fat Diet Induced Inflammation and Islet Hyperplasia in Pancreas
2015
Fibroblast growth factor 21 (FGF21) is an important endocrine metabolic regulator expressed in multiple tissues including liver and adipose tissue. Although highest levels of expression are in pancreas, little is known about the function of FGF21 in this tissue. In order to understand the physiology of FGF21 in the pancreas, we analyzed its expression and regulation in both acinar and islet tissues. We found that acinar tissue express 20-fold higher levels than that observed in islets. We also observed that pancreatic FGF21 is nutritionally regulated; a marked reduction in FGF21 expression was noted with fasting while obesity is associated with 3–4 fold higher expression. Acinar and islet c…
Three cell subsets are required for the transfer of delayed-type hypersensitivity reaction by antigen-specific T cell lines.
1997
Antigen (trinitrochlorobenzene)-specific T cell lines were obtained by repeated stimulation of lymph node cells from immune mice with antigen in vitro. These T cell lines, consisting of more than 90% CD4+ Vbeta8.2+ and 6 to 9% gammadelta+ T lymphocytes, transfer contact sensitivity (CS) locally when injected at the same site as the challenge antigen, but fail to mediate a systemic passive transfer when injected i.v. Injection of T cell lines together with spleen cells from mice immunized 1 day beforehand (1-day cells) allowed a successful, specific systemic transfer of CS. Phenotypic analysis showed that the 1-day immune cell was alphabeta+, gammadelta-, sIg-, CD3+, CD4-, CD8-, CD5+, B220 (…
Ligand‐Specific αβ and γδ T Cell Responses in Childhood Tuberculosis
2000
The alphabeta and gammadelta T cell responses were analyzed in the peripheral blood of children affected by active tuberculosis (TB) and in healthy children who tested positive (PPD+) or negative (PPD-) for purified protein derivative. PPD+ healthy and diseased children responded equally well to PPD in vitro. In contrast, only 18% of PPD+ TB patients responded to peptide p38G derived from the 38-kDa protein of Mycobacterium tuberculosis. Analysis of the whole gammadelta T cell population and of its Vgamma9/Vdelta2 subset showed similar frequencies in PPD+ children with TB and in healthy PPD+ and PPD- children. Vgamma9/Vdelta2 cells from children with TB responded to 5 different phosphoantig…
Identical T-cell expansions in the colon mucosa and the synovium of a patient with enterogenic spondyloarthropathy.
2000
Abstract Intestinal T lymphocytes activated by antigen are suspected to play a key role in enterogenic spondyloarthropathies (SpA). Therefore, we aimed to identify and functionally characterize T-cell clones that are coexpanded in the intestinal mucosa and the synovium. Colon, peripheral blood, and synovium of a patient with enterogenic SpA were screened for clonal T-cell expansions by TCRB-CDR3 length analysis and sequencing. T-cell clones expanded in vivo were isolated from archived synovial cells by targeted T-cell cloning and characterized for phenotype, cytokine production, and antigen specificity. The synovial TCRBV18 + T-cell repertoire of the patient was dominated by 2 CD8 + T-cell …
The effect of cyclosporin A, FK506 and rapamycin on the murine contact sensitivity reaction
1998
We have evaluated the effects of three potent immunosuppressive agents, cyclosporin A (CsA), FK506 and rapamycin, on the murine contact sensitivity (CS) reaction to the hapten trinitrochlorobenzene. Development of CS reaction requires participation of three distinct T cell subsets: alphabeta+, CD4+ T lymphocytes, which are the classical effector cell of the CS reaction, gammadelta+ T lymphocytes, and alphabeta+, double-negative (CD4- CD8-) T lymphocytes that express the B220 molecule and produce IL-4. We found that all three drugs inhibit the development of the CS reaction, but they affect different target cells. In fact, rapamycin and FK-506 block both alphabeta+, CD4+ and gammadelta+ T ly…
Autoimmune skin inflammation is dependent on plasmacytoid dendritic cell activation by nucleic acids via TLR7 and TLR9
2010
Lupus-prone mice develop a chronic inflammatory response to cutaneous injury that depends on the production of type I interferon, TLR7, and TLR9.
Association of γδ T Cells with Disease Severity and Mortality in Septic Patients
2013
ABSTRACTGamma-delta T cells are the most abundant of all epithelial-resident lymphocytes and are considered a first line of defense against pathogens in the mucosa. Our objective was to confirm the reduction in γδ T cell subsets and its relationship with mortality in patients with sepsis. We studied 135 patients with sepsis attended in the emergency department and intensive care unit of two hospitals and compared them with a similar control group of healthy subjects. The αβ and γδ T cell subsets were determined via flow cytometry according to the stage of the sepsis and its relationship with mortality. All the lymphocyte subsets were reduced with respect to the corresponding subsets in the …
Microbiota-Induced Type I Interferons Instruct a Poised Basal State of Dendritic Cells
2019
Summary Environmental signals shape host physiology and fitness. Microbiota-derived cues are required to program conventional dendritic cells (cDCs) during the steady state so that they can promptly respond and initiate adaptive immune responses when encountering pathogens. However, the molecular underpinnings of microbiota-guided instructive programs are not well understood. Here, we report that the indigenous microbiota controls constitutive production of type I interferons (IFN-I) by plasmacytoid DCs. Using genome-wide analysis of transcriptional and epigenetic regulomes of cDCs from germ-free and IFN-I receptor (IFNAR)-deficient mice, we found that tonic IFNAR signaling instructs a spec…
β2Integrin deficiency yields unconventional double-negative T cells distinct from mature classical natural killer T cells in mice
2009
Expressed on leucocytes, beta(2) integrins (CD11/CD18) are specifically involved in leucocyte function. Using a CD18-deficient (CD18(-/-)) mouse model, we here report on their physiological role in lymphocyte differentiation and trafficking. CD18(-/-) mice present with a defect in the distribution of lymphocytes with highly reduced numbers of naïve B and T lymphocytes in inguinal and axillary lymph nodes. In contrast, cervical lymph nodes were fourfold enlarged harbouring unconventional T-cell receptor-alphabeta (TCR-alphabeta) and TCR-gammadelta CD3(+) CD4(-) CD8(-) (double-negative; DN) T cells that expanded in situ. Using adoptive transfer experiments, we found that these cells did not h…