Search results for "Lymphocyte Activation"
showing 10 items of 414 documents
HLA-B8,DR3 phenotype and lymphocyte responses to phytohaemagglutinin.
1990
Several reports have shown that HLA-B8,DR3 positive subjects may display some changes in immune parameters when compared with HLA-B8,DR3 negative ones and are prone to develop several immunological diseases. In the present study we have analysed the proliferative response to phytohaemagglutin (PHA) in HLA-typed healthy subjects. A twin method was also employed to assess the role of genetic and environmental factors in the regulation of the response to the mitogen. It was not possible to demonstrate any difference in proliferative response to optimal doses of PHA between groups of subjects carrying or not carrying the HLA-B8,DR3 phenotype. When suboptimal responses were studied, however, the…
A case of agammaglobulinemia characterized by a defect of B-lymphocyte-differentiation to plasma cells
1974
Humoral and cell-mediated immune reactions of a 36-year old patient with a late onset of an agammaglobulinaemia and of his immediate relatives have been investigated. The immunoglobulins gamma-G, gamma-A, gamma-M, gamma-E and gamma-D, and plasma cells in the bone marrow could not be detected in the patient's serum. Immune reactions with PPD and tetanus toxoid as well as the stimulation of the lymphocytes with PHA indicate that the T-cell system was intact. The examination of the peripheral blood lymphocytes by immunofluorescence techniques gave a normal number of B-lymphocytes. These findings could be corroborated by the results of lymphocyte stimulations with anti-IgG. The data suggest tha…
Unique Characteristics of the Intestinal Immune System as an Inductive Site after Antigen Reencounter
2004
Background Immunization prepares the body for a reencounter with the microbe. Information on the targeting of immune effector cells during secondary immune response--that is, lymphocyte homing--is scarce. In the present study, the homing potentials of lymphocytes are examined after antigen reencounter at mucosal versus nonmucosal sites. Methods Orally or parenterally immunized volunteers were reimmunized orally or parenterally with Salmonella typhi Ty21a, and the expression of the gut homing receptor (HR), alpha(4)beta(7), and of the peripheral lymph node HR, L-selectin, was investigated in circulating antigen-specific antibody-secreting cells (ASCs). Lymphocytes were sorted by HR expressio…
Cellular Immunity in Adolescents and Adults following Acellular Pertussis Vaccine Administration
2007
ABSTRACT Cell-mediated immune (CMI) responses to an acellular pertussis vaccine administered to 49 subjects, a subset of participants in the National Institutes of Health-funded adult acellular pertussis vaccine efficacy trial, were evaluated and compared with antibody responses to vaccine antigens. Levels of proliferation of and cytokine secretion from lymphocytes cultured in the presence of pertussis toxin, filamentous hemagglutinin, or pertactin were measured before vaccination and 1 month and 1 year after vaccination. Statistically significant increases in lymphocyte stimulation indices and cytokine secretion were noted at both 1 month and 1 year after vaccination. Brisk pertussis antig…
A novel B cell population revealed by a CD38/CD24 gating strategy: CD38−CD24− B cells in centenarian offspring and elderly people
2012
The B cell arm of adaptive immunity undergoes significant modifications with age. Elderly people are characterized by impaired B cell responses reflected in a reduced ability to effectively respond against viruses and bacteria. Alterations of immunity with advancing age (immunosenescence) have been widely studied in centenarians who are considered a good example of successful aging. In recent years, attention has shifted to centenarian offspring (CO) as a model of people genetically advantaged for healthy aging and longevity. Here, we describe the preliminary characterization of a proposed new population of memory B cells, defined as CD19(+)CD38(-)CD24(-), which we find at higher frequencie…
Cellular Immunity and Retrobulbar Fibroblasts in Graves' Ophthalmopathy
1994
In Graves' ophthalmopathy (GO), retrobulbar connective tissue is infiltrated by T cells whose role in the pathogenesis of the disease was investigated in the present work. The aims included firstly to characterize subsets of blood lymphocytes and of sessile lymphocytes cloned from a retroorbital tissue specimen. Second, in counterstimulation assays, the ability of patients' T cells to influence cultivated retrobulbar fibroblasts and in turn the enhancement of lymphocyte proliferation by retrobulbar fibroblasts was investigated. Blood lymphocytes of 16 GO patients and 12 controls isolated by density gradient centrifugation and retrobulbar fibroblasts obtained from orbital decompression were …
Stimulation of T cells by autologous mononuclear leukocytes and epidermal cells in psoriasis.
1986
Based on reports suggesting aberrant cell-mediated immunity and altered infiltration of immunocompetent cells into the skin in psoriasis, we studied the stimulation of T cells by autologous non-T mononuclear leukocytes (autologous mixed lymphocyte reaction, AMLR) and by epidermal cells isolated from lesional and clinically uninvolved skin in psoriasis (autologous mixed epidermal cell lymphocyte reaction, AMECLR). Age- and sex-matched individuals served as controls. We found that the AMLR in psoriasis (n = 11) was similar to that in healthy controls (n = 16); furthermore, cell proliferation was alike in the presence of either 5% AB-serum or autologous serum. By contrast, while the AMECLR in …
Reactivity of infiltrating T lymphocytes with microbial antigens in Crohn's disease.
1991
Intestinal T lymphocytes are normally unresponsive to microbial and recall antigens in vitro, whereas the same antigens induce strong immune responses in peripheral-blood-derived T cells. We obtained T lymphocytes from peripheral blood and from the non-inflamed and inflamed intestinal mucosa of 6 patients (3 male, 3 female; mean age 33 years) with Crohn's disease. The T cells were stimulated in vitro with a range of microbial antigens. Whereas T cells from normal mucosa were unresponsive, those from inflamed mucosa had a proliferative response comparable to that of the peripheral-blood-derived T cells. These findings suggest that physiologic unresponsiveness to luminal antigens is abrogated…
Immunologic findings in workers formerly exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin and its congeners
1998
One hundred ninety-two workers in a German pesticide factory who were exposed to polychlorinated dibenzodioxins and -furans (PCDD/PCDF) were investigated for former and present diseases and laboratory changes of the immune system. Moreover, in a subgroup of 29 highly exposed and 28 control persons, proliferation studies were performed. In addition to assays such as blood count, immunoglobulins, serum electrophoresis, monoclonal bands, surface markers, autoantibodies, and lymphocyte proliferation, two new methods, the rise of tetanus antibody concentration after vaccination and the in vitro resistance of lymphocytes to chromate, were used to diagnose the morphologic and functional state of t…
Bacteria-specific T-cell clones are selective in their reactivity towards different enterobacteria or H. pylori and increased in inflammatory bowel d…
1996
In the present study the authors investigated the T-cell response to different enterobacteria or Helicobacter pylori and tested the hypothesis that the frequency of bacteria-specific T cells is increased in the intestine of patients with active inflammatory bowel disease (IBD), i.e. Crohn's disease (CD) and ulcerative colitis (UC). The analysis of a large panel of T-cell clones (Tc) (n = 888) from peripheral blood, non-inflamed and inflamed intestine from IBD patients and control individuals shows that both peripheral blood and intestinal T-cell clones were selectively stimulated by either Salmonella typhimurium, Yersinia enterocolitica 03, Escherichia coli or Helicobacter pylori sonicates,…