Search results for "Natural killer"
showing 10 items of 153 documents
CXCR5 identifies a subset of Vγ9Vδ2 T cells which secrete IL-4 and IL-10 and help B cells for antibody production
2006
Abstract Vγ9Vδ2 T lymphocytes recognize nonpeptidic Ags and mount effector functions in cellular immune responses against microorganisms and tumors, but little is known about their role in Ab-mediated immune responses. We show here that expression of CXCR5 identifies a unique subset of Vγ9Vδ2 T cells which express the costimulatory molecules ICOS and CD40L, secrete IL-2, IL-4, and IL-10 and help B cells for Ab production. These properties portray CXCR5+Vγ9Vδ2 T cells as a distinct memory T cell subset with B cell helper function.
Clonal analysis of liver-infiltrating T cells in patients with LKM-1 antibody-positive autoimmune chronic active hepatitis
1991
SUMMARY Autoantibodies against microsomal antigen of liver and kidney (LKM-1) are diagnostic markers for a subgroup of autoimmune chronic active hepatitis (AI-CAH). Cytochrome P4S0dbl, now classified as cytochrome P450 IID6, is the major antigen of LKM-1 antibodies. Immunohistological studies suggest that hepatic injury in AI-CAH is mediated by liver-infiltrating T cells. In the present study the specificity and function of liver-infiltrating T cells was analysed at the clonal level. Phenotypical characterization of 189 T cell clones isolated from four liver biopsies of LKM-1 antibody-positive patients showed an enrichment of CD4+CD8- T cells. Five CD4+CD8- T cell clones proliferated specif…
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…
Granulocyte and natural killer activity in the elderly
1999
The deterioration of the immune system in ageing, 'immunosenescence', is thought to contribute to increased morbidity and mortality from infections and possibly autoimmune diseases and cancer. The most profound changes involve effector and immunoregulatory T-cell functions. Immunosenescence appears also to be related to changes in non specific immunity as well. In the present study we have assessed superoxide production, chemotaxis and the expression of the apoptosis-related molecule APO1/Fas (CD95) on neutrophils (PMN) from young and old subjects. Furthermore, we have measured the basal natural killer (NK) activity of young and elderly subjects and we have compared the number of CD16+ cell…
Phenotypical analysis and cytokine release of liver-infiltrating and peripheral blood T lymphocytes from patients with chronic hepatitis of different…
2008
Cytokines released by infiltrating T cells may contribute to the hepatic injury in chronic hepatitis. Therefore, we characterized peripheral blood- and liver-infiltrating T cells from patients with chronic hepatitis of different etiology and determined the T cell phenotypes and the cytokine release. Liver tissue and peripheral blood-derived T cells from patients with autoimmune hepatitis and primary biliary cirrhosis predominantly expressed CD4-molecules and the alpha- and beta-chains of the T cell receptor (TCR). In chronic viral hepatitis B and C, liver- and blood-derived T cells were preferentially CD8+ T cells expressing the alpha beta TCR. Mitogenic stimulation with irradiated Daudi ly…
Partial and Ineffective Activation of Vγ9Vδ2 T Cells by Mycobacterium tuberculosis-Infected Dendritic Cells
2010
Abstract γδ T cells and dendritic cells (DCs) participate in early phases of immune response against Mycobacterium tuberculosis. We investigated whether a close functional relationship exists between these two cell populations using an in vitro coculture in a human system. Vγ9Vδ2 T cells induce full maturation of M. tuberculosis-infected immature DCs, as demonstrated by upregulation of the costimulatory CD80, CD86, CD40, and HLA-DR molecules on infected DCs after 24 h of coculture. Reciprocally, infected DCs induced substantial activation of Vγ9Vδ2 T cells upon coculture, which was cell-to-cell contact and TCR dependent, as demonstrated in transwell experiments. However, infected DCs select…
Natural killer and lymphokine-activated killer activity in HLA-B8,DR3-positive subjects.
1993
Abstract The haplotype HLA-B8,DR3 is over-represented in several autoimmune diseases, implying that genes predisposing people to these disorders are linked to this haplotype. In these diseases, various dysfunctions reflecting an impairment of the immune system have been found. Several reports indicate also that in HLA-B8,DR3-positive healthy subjects similar disorders may be demonstrated. In the present work, we have evaluated NK and LAK activity in these subjects. The study has been performed on monocyte-depleted peripheral blood MNCs by using the K-562 cell line as a target for NK activity and the HL-60 cell line for as a target LAK activity. LAK cells were obtained by incubating MNCs for…
Reduction of plasma granzyme A correlates with severity of sepsis in burn patients.
2009
The risk of mortality is high in burn patients and correlates with age, burn area extent, and sepsis. Immunosuppression has been reported to occur after severe burn. Cytotoxic cells possess specialized granules containing perforin and a group of serine proteases (granzymes). Granzyme A is a serine protease constitutively expressed by gammadelta and NK cells, in agreement with their functional cytolytic potential. In vitro studies have shown that GrA may be released extracellularly during cytotoxic cell degranulation, indicating the activation of cytotoxic cells. The aim of our study was to determine plasma GrA activity in burned patients and to verify if decreased GrA levels were associated…
Phenotypic analysis of peripheral lymphocyte subpopulations in hydatid patients.
1999
Peripheral T-lymphocytes were analyzed in three groups of people: (1) individuals with current liver hydatid disease (hydatid patients, n = 20), (2) persons who had undergone surgical cyst removal at least 2 years previously (recovered patients, n = 9), and (3) a control group of healthy volunteers (uninfected controls, n = 13). Group 1 was subdivided according to cyst status, relapse of disease, and the presence or absence of symptoms. Percentages of lymphocytes expressing CD3, CD4, CD8, CD56, CD25, CD45RA, CD45RO, and HLA-DR were determined. Symptomatic patients had proportionally fewer CD3+ CD8 + lymphocytes than the control group (P=0.038). Hydatid patients with active cysts had proport…
Ovarian stimulation does not influence the uterine immune environment in healthy infertile women.
2019
Abstract Research question There is some controversy regarding the impact of ovarian stimulation on immune cells in women undergoing IVF. The study's aim was to determine whether ovarian stimulation affected immune uterine cells in healthy women undergoing IVF. Design This prospective cohort study included 28 patients undergoing IVF and 47 healthy oocyte donors. Endometrial biopsies were taken in a natural cycle and after ovarian stimulation. All participants had a normal karyotype, pelvic ultrasound and cervical cytology results and thyroid-stimulating hormone concentration, as well as normal glucose and insulin concentrations and inherited and acquired thrombophilia test results. Screenin…