Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

The system of perforin-containing lytic granules of cytotoxic lymphocytes plays an important role in the immune defense machinery. Investigating the capacity and efficacy of this system in and ex vivo is helpful to understand immune responses and their modulation by therapeutic interventions. With regard to its pathophysiological function, we recently demonstrated a substantial increase of perforin-positive CD8+ T cells in the peripheral blood of patients with acute exacerbated psoriasis and severe generalized drug reactions, and, in marked contrast, a highly significant perforin-depletion and a perforin-hyperreleasability in atopic dermatitis (AD). To streamline the perforin staining procedure, isolation of peripheral blood mononuclear cells (PBMC) by Ficoll density centrifugation was to be replaced by lysis of erythrocytes. Ammonium chloride lysis, however, reduced the perforin content of CD8+ T cells substantially (up to 75-100%) as compared with Ficoll isolation of PMC. Incubation of cells in concanamycin A, a selective inhibitor of H+-ATPases, resulted in a similar loss of perforin staining pointing to the critical influence of lysosomal pH. Using diethylene glycol-mediated erythrocyte lysis, perforin was well preserved to be readily detectable by immuno flow cytometry. Representative examples of the application of this optimized perforin staining procedure as well as accumulated data are given for various dermatological disorders (psoriasis, atopic dermatitis, cutaneous drug reactions, graft-versus-host disease (GVHD) with strong involvement of the cytotoxic T-cell population. Our findings may help to explain recent conflicting reports about a widely varying range of the portion of perforin-positive cells in healthy individuals as a reflection of such artificial methodological influences.
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PMID:Routine flow cytometric immuno-staining of T-cell perforin is preserved using diethylene glycol for erythrocyte-lysis but lost by the use of ammonium chloride. 1471 63

In order to monitor the immunological status of patients after allogeneic hematopoietic stem cell transplantation(HSCT), granzyme B(GrB), perforin(PRF) and Fas ligand(L) antigens and mRNAs were measured by flow cytometry and real time RT-PCR, respectively. Cytoplasmic antigens were detected in whole blood after fixation and pretreatment with saponin. Real time PCR was carried out using extracted RNA from buffy coat. We measured these substances in a cytotoxic T cell clone, a natural killer cell line, and peripheral blood collected from 11 patients after HSCT. Although changes in antigen levels were not detected, increased levels of GrB and Fas L mRNAs were quantitatively measured in CTLs and NK cells stimulated by IL-2 combined with IL-12. Increased levels of GrB and/or PRF antigens were detected in four of five patients with chronic GVHD. Increased mRNA levels were also observed in one or more of GrB, PRF or Fas L in four of five patients with cGVHD, although there was a discrepancy between antigen and mRNA positivity. Four of six patients without cGVHD were positive for apoptosis-inducing factors, either by antigen detection or RT-PCR. One of these four had relapsing leukemia, and another had herpes zoster infection, while the reasons for positive results in the other two patients are not clear. Although changes in antigen levels did not parallel those in mRNA, measurement of these parameters may assist in predicting GVHD, GVL and infections following HSCT.
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PMID:[Levels of granzyme B, perforin and Fas ligand antigens and mRNAs in patients following allogeneic hematopoietic stem cell transplantation]. 1474 38

The administration of cyclosporin A (CsA) after autologous stem cell transplantation (SCT) paradoxically elicits a systemic autoimmune syndrome that resembles graft-versus-host disease (GVHD); this is termed autologous GVHD (autoGVHD). Although dominated by activated CD8+ cytotoxic T lymphocytes, the complex cellular reaction also includes CD4+ T cells and involves multiple effector mechanisms. To determine the temporal development and relative importance of these mechanisms in autoGVHD, perforin/granzyme, Fas ligand (FasL), interferon-gamma (IFN-gamma), tumor necrosis factor (TNF)-alpha, and interleukin-18 gene expression in peripheral blood mononuclear cells was examined in 36 patients treated with CsA after SCT. Quantitative real-time polymerase chain reaction analysis revealed that perforin/granzyme B, TNF-alpha, and interleukin-18 messenger RNA (mRNA) levels in peripheral blood mononuclear cells from patients in whom autoGVHD developed were markedly higher (and temporally associated with the onset of autoaggression) compared with the levels detected in healthy individuals and in control, non-CsA-treated SCT patients. It is interesting to note that patients in whom autoGVHD did not develop also demonstrated increased mRNA levels for these cytokines: however, expression was substantially lower compared with that in patients with autoGVHD. It is important to note that IFN-gamma mRNA levels were selectively increased in CD8+ cells only from patients in whom autoGVHD developed. The development of autocytolytic T cells in autoGVHD correlated with increased expression of perforin, IFN-gamma, and TNF-alpha mRNA. Furthermore, enhanced autoreactive T-cell activity and the induction of autoGVHD was also concordant with perforin and TNF-alpha mRNA upregulation in CD4+ cells. Surprisingly, FasL mRNA levels were significantly decreased, with a progressive loss of FasL mRNA expression as autocytolytic activity increased. These findings suggest that IFN-gamma/perforin-based CD8+ cytotoxic T lymphocytes seem to play a dominant role in autoGVHD and that TNF-alpha/perforin-based CD4+ cells may amplify this autoaggressive syndrome. The FasL pathway may play an important role in the regulation of this immune syndrome.
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PMID:Cytolytic effector mechanisms and gene expression in autologous graft-versus-host disease: distinct roles of perforin and Fas ligand. 1499 81

Graft-versus-host disease (GvHD) is a frequent impediment to therapeutically successful allogeneic bone-marrow transplantation (BMT). This investigation further examines the roles of two potential donor cytotoxic effector mechanisms previously implicated in tissue pathogenesis. Cytotoxically double deficient (B6-cdd) T cells (lacking functional fas ligand and perforin) and wild-type (B6-wt) donor T-cell transplantation in a minor antigen-mismatched BMT model (C57BL/6 --> C3H.SW) resulted in similar mortality and weight loss. Histopathologic findings revealed mononuclear infiltrates and cellular atrophy in GvHD target tissues (liver, stomach) in recipients of B6-wt and B6-cdd donor T cells. Both recipients also exhibited GvH-associated lymphohematopoietic compartment (LHC) alterations as evidenced by inverted CD4:CD8 ratios and B-cell hypoplasia. Notably, transplants using recombinant inbred mHAg disparate recipients demonstrated that B6-cdd T cells induced lethal GvHD in CXBE but not CXBG recipients: the same pattern induced by B6-wt T cells. This observation is consistent with previous findings that cytotoxic T lymphocyte (CTL) responses against CXBG and CXBE antigens did not correlate with GvH responses in these strains. In contrast with the typical pattern of donor T-cell expansion and contraction, T cells lacking perforin and FasL function exhibited extensive expansion postBMT. In summary, these findings support the notion that donor anti-host cytotoxicity by way of the two major pathways is not a prerequisite for induction of GvHD. In addition, the results suggest that this model will be useful to investigate the regulation of allogeneic donor T-cell expansion after major histocompatibility complex-matched allogeneic BMT.
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PMID:Donor T cells lacking Fas ligand and perforin retain the capacity to induce severe GvHD in minor histocompatibility antigen mismatched bone-marrow transplantation recipients. 1507 18

Although IFN-gamma is the archetypal Th1 cytokine, its role in CTL maturation is uncertain. We used an in vivo mouse model of CTL development, parent-into-F(1) acute graft-vs-host disease (AGVHD), to evaluate this issue. In AGVHD, transfer of naive parental T cells into F(1) hosts stimulates the development of allospecific CTL effectors that eliminate host lymphocytes, particularly B cells. Complete elimination of IFN-gamma, using IFN-gamma-deficient donors and administering anti-IFN-gamma mAb, suppressed B cell elimination, down-regulated TNF-alpha production, and enhanced Th2 cytokine production, but did not allow the B cell expansion characteristic of chronic GVHD (CGVHD). Because complete CTL inhibition results in full-blown CGVHD that is IFN-gamma independent, these observations indicate that IFN-gamma elimination only partially blocks CTL development. IFN-gamma elimination did not inhibit donor T cell engraftment or activation in the AGVHD model, but almost completely blocked Fas/Fas ligand (FasL) gene expression, protein up-regulation, and Fas/FasL-mediated CTL killing. In contrast, IFN-gamma elimination only partially inhibited perforin gene expression and perforin-mediated CTL activity. The contributions of IFN-gamma to CTL development were indirect, because IFN-gamma receptor-deficient donor cells differentiated normally into allospecific CTLs. Consistent with the view that the Fas/FasL and perforin pathways each mediate CTL killing in AGVHD, the absence of both perforin and IFN-gamma (perforin knockout donor cells and anti-IFN-gamma mAb) converted AGVHD to CGVHD. Thus, both IFN-gamma-dependent induction of Fas/FasL and IFN-gamma-independent induction of perforin contribute to CTL-mediated elimination of host B cells in AGVHD. Suppression of both pathways is required for typical CGVHD development.
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PMID:Differential requirement for IFN-gamma in CTL maturation in acute murine graft-versus-host disease. 1524 Jun 78

Infection, disease relapse, graft failure, and graft-versus-host disease (GVHD) are significant adverse events associated with allogeneic bone marrow transplantation. Donor natural killer (NK) cells may be an ideal cell type for prevention or treatment of all these adverse events. Therefore, we investigated the phenotype and function of human NK cells purified by using a clinical-scale immunomagnetic method. We found that the NK cell purification procedures did not adversely affect the expression of killer cell immunoglobulin-like receptors, adhesion molecules, intracellular cytokines, perforin, and granzyme B. Purified NK cells had extensive proliferative capacity and potent antitumor activity when assessed using an immunodeficient mouse model. While all mice transplanted with unpurified mononuclear cells developed GVHD, none of the mice transplanted with purified NK cells did. NK cells were highly susceptible to lysis by antithymocyte globulin (ATG), whereas G-CSF had a minimal effect on their natural cytotoxicity. These results support future clinical investigation of the use of purified NK cells for adoptive immunotherapy in the absence of ATG.
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PMID:Phenotype and function of human natural killer cells purified by using a clinical-scale immunomagnetic method. 1544 41

Fas ligand (FasL) and perforin pathways not only are the major mechanisms of T cell-mediated cytotoxicity but also are involved in homeostatic regulation of these T cells. In the present study, we tested whether CD8+ donor T cells that are deficient in both perforin and FasL (cytotoxic double deficient [cdd]) could induce graft-versus-host disease (GVHD) in a major histocompatibility complex class I-mismatched lethally irradiated murine model. Interestingly, recipients of cdd CD8+ T cells demonstrated significantly greater serum levels of interferon gamma and tumor necrosis factor alpha and histopathologic damage from GVHD than wild-type (wt) T cells on day 30 after allogeneic bone marrow transplantation (P<.05). Wt and either perforin-deficient or FasL-deficient CD8+ T cells expanded early after transplantation followed by a contraction phase in which the majority of expanded CD8+ T cells were eliminated. In contrast, cdd CD8+ T cells exhibited prolonged expansion and reduced apoptosis to alloantigen stimulation in vivo and in vitro. Together these results suggest that donor cdd CD8+ T cells expand continuously and cause lethal GVHD, and that both perforin and FasL are required for the contraction of allo-reactive CD8+ T cells.
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PMID:Both perforin and Fas ligand are required for the regulation of alloreactive CD8+ T cells during acute graft-versus-host disease. 1546 30

Perforin is known as a pore-forming cytotoxic granule released from cytotoxic T cells. Previous experiments in vitro revealed the presence of precursor cells that are capable of producing perforin in the immune system cells. The present study was undertaken to examine whether perforin-positive cells could be induced in the digestive tract and to characterize their precursor cells. Expression of perforin-positive cells in the intestine of Balb/c mice induced by OK-432 was analyzed by immunohistochemical staining and RT-PCR. Oral treatment of Balb/c mice with OK-432 resulted in the occurrence of perforin-positive cells in the inferior segment of small intestine, the superior segment of large intestine, mesenteric lymph nodes and spleen. In the small intestine, perforin-positive cells were found in the lamina propria mucosa. The presence of perforin-positive cells was also noted following long-term OK-432 treatment. Similar results were obtained following treatment with biological response modifiers such as lipopolysaccharide. In mice with GVHD (graft-versus-host disease), the presence of perforin-positive cells was noted in the small intestine and spleen. When the serial sections of the small intestinal mucosa from OK-432-treated mice were immunostained with anti-perforin, anti-CD8 and anti-asialo-GM1 antibodies, the perforin-positive cells were found to be CD8-positive. The results suggest that CD8(+) cells in lamina propria mucosa play a significant role as effectors in the mucosal immune system which is activated by various stimuli.
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PMID:Stable long-term induction of perforin-positive CD8+ T cells in gut by oral administration of streptococcal preparation OK-432. 1549 48

The biliary epithelium provides a physical barrier to ascending infection from the gastrointestinal tract and is also involved in actively regulating the immune response to invading pathogens. Cholangiocytes secrete chemokines and express adhesion molecules that attract effector leukocytes and promote the clearance of infected cells. However in the context of transplantation these properties make cholangiocytes targets for allogeneic cytotoxic T cells, and both graft-versus-host disease and liver allograft rejection are characterized by destruction of intrahepatic bile ducts by infiltrating lymphocytes. The mechanisms of cholangiocyte killing are complex but involve activation of apoptosis by the granzyme/perforin pathway and by activation of death receptors belonging to the tumor necrosis factor (TNF) receptor superfamily, most notably Fas. Fas-dependent apoptosis is carefully regulated by cooperative interactions with other TNF receptors, particularly CD40, that act to amplify autocrine and paracrine expression of Fas ligand and Fas-mediated killing. A better understanding of the molecular control of these processes may explain why bile duct loss continues despite conventional immunosuppression in the vanishing bile duct syndromes, and lead to novel therapies aimed at switching off the chronic inflammatory response and protecting cholangiocytes from apoptosis.
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PMID:Effector mechanisms of nonsuppurative destructive cholangitis in graft-versus-host disease and allograft rejection. 1614 44

NKT cells have pivotal roles in immune regulation and tumor immunosurveillance. We report that the G-CSF and FMS-like tyrosine kinase 3 ligand (Flt-3L) chimeric cytokine, progenipoietin-1, markedly expands the splenic and hepatic NKT cell population and enhances functional responses to alpha-galactosylceramide. In a murine model of allogeneic stem cell transplantation, donor NKT cells promoted host DC activation and enhanced perforin-restricted CD8+ T cell cytotoxicity against host-type antigens. Following leukemic challenge, donor treatment with progenipoietin-1 significantly improved overall survival when compared with G-CSF or control, attributable to reduced graft-versus-host disease mortality and paradoxical augmentation of graft-versus-leukemia (GVL) effects. Enhanced cellular cytotoxicity was dependent on donor NKT cells, and leukemia clearance was profoundly impaired in recipients of NKT cell-deficient grafts. Enhanced cytotoxicity and GVL effects were not associated with Flt-3L signaling or effects on DCs but were reproduced by prolonged G-CSF receptor engagement with pegylated G-CSF. Thus, modified G-CSF signaling during stem cell mobilization augments NKT cell-dependent CD8+ cytotoxicity, effectively separating graft-versus-host disease and GVL and greatly expanding the potential applicability of allogeneic stem cell transplantation for the therapy of malignant disease.
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PMID:NKT cell-dependent leukemia eradication following stem cell mobilization with potent G-CSF analogs. 1622 35


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