Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018133 (graft-versus-host disease)
 18,032 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Immunologic evaluation of two unrelated male infants with clinical and laboratory evidence of severe combined immunodeficiency (SCID) revealed T cells with a mature phenotype in the peripheral circulation of both patients although both had biopsy evidence of thymic alymphoplasia. Both had a normal number of T cells with a cytotoxic/suppressor surface marker (OKT8) but very few T helper cells (OKT4). Lymphocyte stimulation with the mitogens PHA, Con A, and pokeweed or with allogeneic cells resulted in no proliferation. However, addition of T cell growth factor, plus the phorbol ester TPA, to lymphocytes cultured with the T cell mitogen PHA did result in some proliferation of T cells. In both cases these T cells demonstrated an XX female karyotype and were probably of maternal origin. In contrast, proliferating B cells stimulated with Epstein-Barr virus demonstrated a normal XY male karyotype. The possibility that severe combined immune deficiency in these patients was the result of graft-versus-host disease induced by maternal lymphocytes is discussed.
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PMID:XX T cells and XY B cells in two patients with severe combined immune deficiency. 660 7

Following autologous bone marrow transplantation (ABMT), both impaired T cell activation and defective production of the principal T cell growth factor, interleukin-2 (IL-2), has been observed. These processes are dependent on a rise of intracellular calcium ([Ca2+]i), a step which follows binding of T cell receptor (TCR) and transduction of signal via the generation of cytoplasmic second messengers. In order to better understand the nature of defective cellular immunity in ABMT, in the present study we investigated the rise of [Ca2+]i in T cells of recipients of ABMT. By concomitant labelling lymphocytes with anti-CD4 antibody and addition of fluo-3 as fluorescent calcium indicator, we have selected for the T cell subset which is the principal source of IL-2. Short-term (less than 1 year post-transplantation) recipients of ABMT show a statistically significant blunted rise in [Ca2+]i in response to concanavalin A as compared to normal controls not accounted for solely by a decreased percentage of CD4+ cells in these patients. The [Ca2+]i response of CD4+ cells from long-term (greater than 1 year post-transplant) recipients was lower than that of the normal group although not to a statistically significant level. These findings suggest that following ABMT is a defect in the early stages of T cell activation involving either T cell receptor binding or early signal transduction ultimately resulting in depressed transcription of IL-2 mRNA. These defects are analogous to findings in both allogeneic transplantation where factors of histoincompatibility and graft-versus-host disease (GVHD) come into play, as well as in the defective T cell activation of the normal ageing process.
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PMID:Blunted rise in intracellular calcium in CD4+ T cells in response to mitogen following autologous bone marrow transplantation. 810 19

Induction of an optimal immune response will likely be a prerequisite for successful immunotherapy of human leukemias and other malignancies. Dendritic cells are highly effective at inducing an immune response to antigens to which the host is unresponsive, while transgenic expression of the costimulator molecule CD40 ligand (gp39/CD154) and the T cell growth factor interleukin 2 (IL2) are also able to augment immune responsiveness. We therefore investigated whether a combination of these two distinctive approaches to immunostimulation could safely increase the anti-tumor immune response compared to each stimulus alone. We injected BALB/CBYJ mice with syngeneic dendritic cells (DC) exposed to A20 lymphoblastic leukemia cell-derived peptides and proteins which had been acid-eluted from the cell surface. In additional mice, the pulsed DC were mixed with genetically modified syngeneic fibroblasts that were expressing CD40 ligand or secreting interleukin 2 (IL2). Three days after their third, weekly, vaccination, they were challenged with parental A20 cells. Tumor growth was suppressed by responses to pulsed DC alone (P < 0.02). This suppression was further enhanced when pulsed DC were coinjected with fibroblasts expressing CD40 ligand and IL2 (P < 0.0005 compared to DC alone) even though CD40 ligand and IL2-expressing fibroblasts alone offered no significant protection in this model. Mice receiving the full complement of immunostimulants either failed to develop visible tumors or developed small tumors which quickly necrosed and regressed, allowing the mice to become long term tumor-free survivors. Antibody mediated depletion of either CD4+ or CD8+ T-cell subset significantly reduced the level of protection afforded by the vaccination. However, it became evident that this intensive stimulation of the immune system lead not only to tumor eradication but also to destruction of cells bearing normal self antigens. Hence, 60 days after challenge with A20 cells all mice in the DC/IL2/CD40 ligand group developed a severe, systemic autoimmune disorder that resembled graft versus host disease and manifest itself by significant peripheral blood cytotoxicity against autologous fibroblasts, blood dyscrasias, gross hepatosplenomegaly, cachexia and fur loss. This phenomenon depended on CD8+ cytotoxic T lymphocytes. Our results therefore suggest that the most effective strategies of immunotherapy against leukemia may also exceed the threshold of anergic cells, leading to a loss of self tolerance to normal self-antigens and the induction of an CD8+ anti-self effector response.
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PMID:Autoimmune disease induced by dendritic cell immunization against leukemia. 1037 48