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Granzyme B (granzyme + b)

Distribution by Scientific Domains

Medical Sciences	96%

Distribution within Medical Sciences

Transplantation	21%
Dermatology	18%
Immunology	15%
8 Other Subdomains	46%

Selected Abstracts

Granzyme B: a natural born killer

IMMUNOLOGICAL REVIEWS, Issue 1 2003
Sarah J. Lord
Summary:, A main pathway used by cytotoxic T lymphocytes (CTLs) and natural killer cells to eliminate pathogenic cells is via exocytosis of granule components in the direction of the target cell, delivering a lethal hit of cytolytic molecules. Amongst these, granzyme B and perforin have been shown to induce CTL-mediated target cell DNA fragmentation and apoptosis. Once released from the CTL, granzyme B binds its receptor, the mannose-6-phosphate/insulin-like growth factor II receptor, and is endocytosed but remains arrested in endocytic vesicles until released by perforin. Once in the cytosol, granzyme B targets caspase-3 directly or indirectly through the mitochondria, initiating the caspase cascade to DNA fragmentation and apoptosis. Caspase activity is required for apoptosis to occur; however, in the absence of caspase activity, granzyme B can still initiate mitochondrial events via the cleavage of Bid. Recent work shows that granzyme B-mediated release of apoptotic factors from the mitochondria is essential for the full activation of caspase-3. Thus, granzyme B acts at multiple points to initiate the death of the offending cell. Studies of the granzyme B death receptor and internal signaling pathways may lead to critical advances in cell transplantation and cancer therapy. [source]

Fetal Ethanol Exposure Disrupts the Daily Rhythms of Splenic Granzyme B, IFN- ,, and NK Cell Cytotoxicity in Adulthood

ALCOHOLISM, Issue 6 2006
Alvaro Arjona
Background: Circadian (and daily) rhythms are physiological events that oscillate with a 24-hour period. Circadian disruptions may hamper the immune response against infection and cancer. Several immune mechanisms, such as natural killer (NK) cell function, follow a daily rhythm. Although ethanol is known to be a potent toxin for many systems in the developing fetus, including the immune system, the long-term effects of fetal ethanol exposure on circadian immune function have not been explored. Methods: Daily rhythms of cytotoxic factors (granzyme B and perforin), interferon- , (IFN- ,), and NK cell cytotoxic activity were determined in the spleens of adult male rats obtained from mothers who were fed during pregnancy with chow food or an ethanol-containing liquid diet or pair-fed an isocaloric liquid diet. Results: We found that adult rats exposed to ethanol during their fetal life showed a significant alteration in the physiological rhythms of granzyme B and IFN- , that was associated with decreased NK cell cytotoxic activity. Conclusion: These data suggest that fetal ethanol exposure causes a permanent alteration of specific immune rhythms that may in part underlie the immune impairment observed in children prenatally exposed to alcohol. [source]

Reduction of Perforin, Granzyme B, and Cytokine Interferon , by Ethanol in Male Fischer 344 Rats

ALCOHOLISM, Issue 4 2003
Madhavi Dokur
Background: Chronic alcohol consumption can impair the immune system and predispose individuals to an increased risk of cancer and infection. Natural killer (NK) cells are the first line of defense against viral, bacterial, and fungal infections and play an important role in cellular resistance to malignancy and tumor metastasis. We have shown previously that ethanol administration suppresses NK cell cytolytic activity in male Fischer rats. This study analyzed the effects of ethanol on perforin, granzyme B, and the cytokine interferon (IFN)-,, factors that modulate NK cell cytolytic activity, to understand the molecular mechanism involved in ethanol's suppression of NK cell activity. Methods: A group of male Fischer rats was fed an ethanol-containing diet (8.7% v/v), whereas a control group was pair-fed an isocaloric diet. At the end of 2 weeks, animals were decapitated, and spleen tissues were immediately removed and used for analysis of NK cell cytolytic activity, perforin, granzyme B, and IFN-, messenger RNA (mRNA) or protein levels. The mRNA levels of perforin, granzyme B, and IFN-, were evaluated by quantitative real-time polymerase chain reaction, and protein levels of these factors were analyzed by Western blot, enzyme-linked immunosorbent assay, or enzymatic activity assay. Results: Ethanol reduced the NK cell cytolytic activity and decreased the mRNA expression of perforin, granzyme B, and IFN-, in ethanol-fed animals when compared with pair-fed animals. Ethanol also significantly reduced the protein levels of perforin and IFN-, and the enzyme activity of granzyme B in alcohol-fed animals as compared with pair-fed animals. Conclusions: These data suggest that chronic ethanol consumption may suppress NK cell cytolytic activity in male Fischer rats by decreasing the production, activity, or both of granzyme B, perforin, and IFN-,. [source]

Predominant Th1 and Cytotoxic Phenotype in Biopsies from Renal Transplant Recipients with Transplant Glomerulopathy

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 5 2009
S. Homs
Transplant glomerulopathy (TGP) appears to be a pathogenic feature of chronic antibody-mediated rejection, but the pathogenesis of this histologic entity is still poorly understood. Previous studies suggest the involvement of lymphocytes but the phenotypes of these cells have never been analyzed. Here, we report the first study of mRNAs for specific markers of CD4+ T cells including Th1 (T-bet and INF,), Th2 (IL4 and GATA3), Treg (Foxp3) and Th17 (IL-17 and ROR,t) subsets, cytotoxic CD8 T cells (Granzyme B) and B-cell markers (CD20) in renal biopsies from renal transplant recipients suffering interstitial fibrosis and tubular atrophy (IF/TA) with or without TGP but with a similar inflammatory score and controls including transplant recipients with normal renal function. Only INF,, T-bet (both functionally defined markers of Th1 CD4 T cells) and granzyme B (a CD8 cytotoxic marker) were significantly more strongly expressed in patients with TGP than in patients without TGP and normal controls. These results indicate a role of an active T-mediated inflammatory and cytotoxic process in the pathogenesis of TGP. [source]

Functional impairment of cytotoxic T cells in the lung airways following respiratory virus infections

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 6 2006
Simone Vallbracht
Abstract We investigated the differentiation phenotype and function of virus-specific and non-specific CTL that were recruited to the lung parenchyma and the bronchoalveolar space after respiratory virus infections. Soon after virus elimination, we observed functional impairment of CTL isolated from the airways in their ability to produce IFN-, and TNF-, and to lyse target cells. Impaired cytotoxicity was due to a reduced content of granzyme B and a reduced ability to mobilize lytic granules. This impairment in effector functions (a) was largely restricted to CTL in the lung airways, (b) affected both CTL specific for the infecting virus as well as those that were recruited non-specifically to the inflamed lung, (c) was independent of contact between CTL and their specific viral antigen, (d) was not restricted to terminally differentiated CTL but also affected resting memory CTL and (e) could be elicited by both respiratory syncytial virus and influenza virus and thus seemed to be largely independent of the infecting virus. These observations suggest that functional impairment of antiviral T cells in the lung is not the consequence of a viral escape strategy. It may rather result from the particular milieu in the bronchoalveolar space and reflect a host mechanism to prevent excessive pulmonary inflammation. [source]

Increase of granzyme B-positive cells in ascitic fluid of patients with spontaneous bacterial peritonitis

HEPATOLOGY RESEARCH, Issue 4 2008
Alessandro Perrella
Spontaneous bacterial peritonitis (SBP) occurs as a direct consequence of bacteria entering ascitic fluid (AF) from the intestinal lumen trough in several ways, including the hematogenous and mesenteric lymph nodes route. There are few studies on the cytokine profile of ascitic-derived mononuclear cells of patients with SBP, particularly on granzyme B (GZB). The aim of the present study was to verify whether patients with SBP have GZB-positive cells, whether they are increased in patients with aseptic ascites, and their trend after antibiotic treatment. We enrolled 36 consecutive patients (24 males and 12 females) with SBP on histologically-proven hepatitis C virus cirrhosis (group A) and 20 patients (11 males and nine females with ascites, but without evidences of SBP (group B). The diagnosis of SBP was made according to the following criteria: positive colture in AF or blood (at least two cultures) and neutrophils in AF (>250 mL polymorphonuclear leukocytes). For these patients we used ELISpot to assay GZB production on purified mononuclear cells in ascitesand peripheral blood, coupled with tumor necrosis factor-, tested using ELISA. A non-parametric statistical analysis was used to assess significant differences and correlations. We found positive culture in all of the patients with SBP (80% Escherichia coli; 20% Enterococcus faecium). Furthermore, the patients in group A had a higher number of GZB spot-forming colonies than the patients in group B (P < 0.001). GZB-positive cells were lower in the peripheral blood than those found in the AF of patients with SBP, while no differences were found between blood and AF in group B. Furthermore, after antibiotic treatment, GZB was reduced in the patients with SBP (P < 0.05). In conclusion, GZB may be an important mediator of the immune response towards bacteria in AF and could be used as a diagnostic tool. [source]

Protease,proteoglycan complexes of mouse and human mast cells and importance of their ,-tryptase,heparin complexes in inflammation and innate immunity

IMMUNOLOGICAL REVIEWS, Issue 1 2007
Richard L. Stevens
Summary:, Approximately 50% of the weight of a mature mast cell (MC) consists of varied neutral proteases stored in the cell's secretory granules ionically bound to serglycin proteoglycans that contain heparin and/or chondroitin sulfate E/diB chains. Mouse MCs express the exopeptidase carboxypeptidase A3 and at least 15 serine proteases [designated as mouse MC protease (mMCP) 1,11, transmembrane tryptase/tryptase ,/protease serine member S (Prss) 31, cathepsin G, granzyme B, and neuropsin/Prss19]. mMCP-6, mMCP-7, mMCP-11/Prss34, and Prss31 are the four members of the chromosome 17A3.3 family of tryptases that are preferentially expressed in MCs. One of the challenges ahead is to understand why MCs express so many different protease,proteoglycan macromolecular complexes. MC-like cells that contain tryptase,heparin complexes in their secretory granules have been identified in the Ciona intestinalis and Styela plicata urochordates that appeared approximately 500 million years ago. Because sea squirts lack B cells and T cells, it is likely that MCs and their tryptase,proteoglycan granule mediators initially appeared in lower organisms as part of their innate immune system. The conservation of MCs throughout evolution suggests that some of these protease,proteoglycan complexes are essential to our survival. In support of this conclusion, no human has been identified that lacks MCs. Moreover, transgenic mice lacking the ,-tryptase mMCP-6 are unable to combat a Klebsiella pneumoniae infection effectively. Here we summarize the nature and function of some of the tryptase,serglycin proteoglycan complexes found in mouse and human MCs. [source]

Granzyme B: a natural born killer

Apoptosis induction by interleukin-2-activated cytotoxic lymphocytes in a squamous cell carcinoma cell line and Daudi cells , involvement of reactive oxygen species-dependent cytochrome c and reactive oxygen species-independent apoptosis-inducing factors

IMMUNOLOGY, Issue 2 2003
Tetsuya Yamamoto
Summary Investigation of the induction of apoptosis by cytotoxic lymphocytes has mainly focused on the signalling associated with Fas and its adaptor proteins. The signal pathway via mitochondria, however, has not been sufficiently elucidated in cytotoxic lymphocyte-induced apoptosis. We examined the release of mitochondrial proapoptotic factors by lymphokine-activated killer (LAK) cells in two cell lines. LAK cell-induced DNA fragmentation of the target cells was suppressed to approximately 50% of control levels by the addition of neutralizing monoclonal antibody to Fas and a granzyme B inhibitor. When intracellular reactive oxygen species (ROS) were scavenged, the LAK cell-induced DNA fragmentation was decreased to approximately 60% of the non-treated cell level. Co-cultivation of Daudi cells with LAK cells increased cytosolic and mitochondrial ROS levels. Activation of procaspase-3 and apoptosis by treatment of oral squamous cell carcinoma cells (OSC) with LAK cells was partially inhibited by pretreatment of OSC cells with ROS scavengers and mitochondrial complex inhibitors. Furthermore, cytochrome c and apoptosis-inducing factor (AIF) were released from mitochondria by OSC cell treatment with supernatants of LAK cells. The supernatant-induced cytochrome c release was suppressed by mitochondrial complex inhibitors, but the inhibitors did not inhibit the release of AIF. These results indicate that LAK cells induce target cell apoptosis via not only the Fas/Fas ligand system and granzyme B, but also ROS-dependent cytochrome c and ROS-independent AIF release. [source]

Natural killer cell-mediated ablation of metastatic liver tumors by hydrodynamic injection of IFN, gene to mice

INTERNATIONAL JOURNAL OF CANCER, Issue 6 2007
Tetsuo Takehara
Abstract Interferon (IFN) , is a pleiotropic cytokine acting as an antiviral substance, cell growth inhibitor and immunomodulator. To evaluate the therapeutic efficacy and mechanisms of IFN, on hepatic metastasis of tumor cells, we hydrodynamically injected naked plasmid DNA encoding IFN,1 (pCMV-IFNa1) into Balb/cA mice having 2 days hepatic metastasis of CT-26 cells. Single injection of pCMV-IFNa1 efficiently enhanced the natural killer (NK) activity of hepatic mononuclear cells, induced production of IFN, in serum and led to complete rejection of tumors in the liver. Mice protected from hepatic metastasis by IFN, therapy displayed a tumor-specific cytotoxic T cell response and were resistant to subcutaneous challenge of CT-26 cells. NK cells were critically required for IFN,-mediated rejection of hepatic metastasis, because their depletion by injecting anti-asialo GM1 antibody completely abolished the antimetastatic effect. To find whether NK cells are directly activated by IFN, and are sufficient for the antimetastatic effect, the responses to IFN, were examined in SCID mice lacking T cells, B cells and NKT cells. IFN, completely rejected hepatic metastasis in SCID mice and efficiently activated SCID mononuclear cells, as evidenced by activation of STAT1 and a variety of genes, such as MHC class I, granzyme B, tumor necrosis factor-related apoptosis-inducing ligand and IFN,, and also enhanced Yac1 lytic ability. Study of IFN, knockout mice revealed that IFN, was not necessary for IFN,-mediated NK cell activation and metastasis protection. In conclusion, IFN, efficiently activates both innate and adaptive immune responses, but NK cells are critically required and sufficient for IFN,-mediated initial rejection of hepatic metastasis of microdisseminated tumors. © 2006 Wiley-Liss, Inc. [source]

Fetal Ethanol Exposure Disrupts the Daily Rhythms of Splenic Granzyme B, IFN- ,, and NK Cell Cytotoxicity in Adulthood

Reduction of Perforin, Granzyme B, and Cytokine Interferon , by Ethanol in Male Fischer 344 Rats

Extracorporeal photochemotherapy in patients with cutaneous T-cell lymphoma: is clinical response predictable?

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 9 2006
V Rao
Abstract Background, Extracorporeal photochemotherapy (ECP) has been accepted as a standard therapy in cutaneous T-cell lymphomas (CTCL), a category of lymphomas mainly resistant to conventional therapies. Approximately one half of patients demonstrate a reduction in skin affliction by at least 50% within 12 months of therapy and are categorized as responders to ECP. Predictive criteria for selecting patients who will respond to ECP are lacking. Such criteria would however, be of great benefit. Objectives, This study compared T-cell clonality and serum levels of soluble interleukin-2 receptor (sIL-2R), lactate dehydrogenase (LD), neopterin, beta2-microglobulin (,2 -M) and granzyme B in CTCL patients in order to evaluate their potential usefulness as predictive markers. Patients/methods, Serum and T lymphocytes obtained from 16 patients with CTCL receiving ECP treatment were evaluated in an open retrospective study. Results, We found no evident correlation between detected T-cell clonality and response to ECP. The non-responding group had on average a higher level of serum sIL-2R. This difference was significant after 6 and 12 months of therapy, but not pretreatment. An individual reduction in serum sIL-2R, neopterin and ,2 -M during a 6-month course of ECP was well correlated to clinical remission. Conclusions, Seven out of 16 patients were classified as responders. Neither T-cell clonality nor any of the serum markers assessed pretreatment could reliably predict the response to ECP treatment. However, the individual relative changes in sIL-2R, neopterin and ,2 -M during 6 months of ECP treatment coherently displayed correlation to the clinical response, as assessed after 12 months of ECP treatment. [source]

Psoriasis confined strictly to vitiligo areas , a Koebner-like phenomenon?

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 2 2006
TG Berger
Abstract Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-,) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-, and interferon-, (IFN-,), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis. [source]

von Willebrand factor activation, granzyme-B and thrombocytopenia in meningococcal disease

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 5 2010
M. J. HOLLESTELLE
Summary.,Background:,During invasive meningococcal disease, severe thrombocytopenia is strongly associated with a poor outcome. Objectives:,In order to elucidate the pathophysiological mechanism behind the development of thrombocytopenia, we studied the role of von Willebrand factor (VWF) in meningococcal disease. Patients/methods:,Thirty-two children with severe meningococcal disease admitted to our university hospital were included in this study. VWF and related parameters were measured and results were correlated with the development of shock and thrombocytopenia. Results:,At admission, all patients had increased levels of (active) VWF and VWF propeptide. The highest VWF propeptide levels were observed in patients with shock, indicating acute endothelial activation. Although VWF propeptide levels in patients with shock, with or without thrombocytopenia, were similar, increased active VWF was significantly lower in patients with thrombocytopenia as compared with patients without thrombocytopenia. ADAMTS13 was moderately decreased. However, the VWF multimeric pattern was minimally increased. We assume that these findings are explained by VWF consumption and perhaps by granzyme B (GrB). In vitro experiments showed that GrB is able to cleave VWF multimers in plasma, whereas GrB was high in patients with shock, who developed thrombocytopenia. Conclusions:,Our results demonstrate that consumption of VWF, derived from endothelial cells, could be a key feature of meningococcal disease and primary to the development of thrombocytopenia during shock. [source]

Hepatocellular apoptosis associated with cytotoxic T/natural killer-cell infiltration in chronic active EBV infection

PATHOLOGY INTERNATIONAL, Issue 7 2009
Yuko Nomura
The aim of the present study was to identify the mechanism of hepatocellular apoptosis induced by EBV-infected cytotoxic T/natural killer (NK) cells in chronic active EBV infection (CAEBV). Eight patients with CAEBV were studied, and infected T-cell expansion and NK-cell expansion were detected in four patients each. Biopsy or necropsy was performed on lymph node, liver, or spleen, and each specimen was subjected to immunohistochemical double staining of CD3 plus caspase-3 with the addition of cytotoxic markers of T-cell restricted intracellular antigen-1 (TIA-1), perforin, and granzyme B, as well as EBV in situ hybridization (EBV-ISH). In the liver, some of the infiltrating CD3-positive lymphocytes stained positively for EBV-ISH and cytotoxic markers. Double staining of CD3 plus caspase-3 indicated caspase-3 positive hepatocytes with apoptotic features, accompanied by extensive infiltration of CD3-positive cells, which were directly attached to the apoptotic caspase-3 positive hepatocytes. In contrast, far fewer cells stained positive for caspase-3 in lymph node and spleen than in liver. The present findings suggest that in patients with CAEBV, cytotoxic T/NK cells may directly induce hepatocytes to undergo apoptosis more frequently than they do cells in other organs of the reticulo-endothelial system. [source]

Increased expression of cytotoxic effector molecules: Different interpretations for steroid-based and steroid-free immunosuppression

PEDIATRIC TRANSPLANTATION, Issue 1 2003
Thomas Satterwhite
Abstract: Cytotoxic T lymphocyte (CTL) effector molecules have been studied as markers of acute rejection in renal allograft recipients on steroid-based immunosuppression. We hypothesized that basal CTL gene expression may vary with time post-transplantation as well as with different immunosuppression protocols (steroid-based or steroid-free). Variations in CTL gene expression may thus impact on the ability to predict acute allograft rejection. We used the non-invasive method of quantitative competitive-reverse transcription-polymerase chain reaction (QC-RT-PCR) to quantify the amounts of CTL effector molecules (granulysin, GL; perforin, P; granzyme B, GB) in serial peripheral blood lymphocyte (PBL) samples from steroid-free and steroid-based adult and pediatric renal allograft recipients. Patients on both protocols were clinically monitored by protocol biopsies at 1, 3, 6, and 12 months post-transplantation and for graft function at 1 yr post-transplantation in a separate clinical study. Steroid-free patients with stable graft function showed an increase in GL, P, and GB gene expression over time post-transplantation with the increase being seen largely by the first post-transplant month. A further increase in GL expression was noted at the end of the first post-transplant year in the absence of acute rejection, whereas GB and P levels were unchanged. At comparative time-points post-transplantation, CTL genes were found to be higher in steroid-free patients with stable graft function, compared to steroid-based recipients with either clinically stable graft function or acute rejection. This study suggests that levels of CTL gene expression, although important in a steroid-based regimen to monitor the risk of acute rejection, may not be similarly applied in patients on steroid-free immunosuppression. The early increase in levels seen in steroid-free patients appears to correlate with the total absence of steroids. As steroid-free patients seem to have a lower incidence of acute rejection and better long-term graft function at 1 yr, the early increase in CTL genes in the absence of acute rejection may suggest an early adaptive immune activation response, promoting early graft acceptance in this protocol. [source]

PD-1/B7-H1 Interaction Contribute to the Spontaneous Acceptance of Mouse Liver Allograft

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2010
M. Morita
The programmed death-1 (PD-1)/B7-H1 pathway acts as an important negative regulator of immune responses. We herein investigated the role of the PD-1/B7-H1 pathway in establishing an immunological spontaneous tolerance status in mouse liver allografting. B7-H1 is highly expressed on the donor-derived tissue cells and it is also associated with the apoptosis of infiltrating T cells in the allografts. Strikingly, a blockade of the PD-1/B7-H1 pathway via anti-B7-H1mAb or using B7-H1 knockout mice as a donor led to severe cell infiltration as well as hemorrhaging and necrosis, thus resulting in mortality within 12 days. Furthermore, the expression of the FasL, perforin, granzyme B, iNOS and OPN mRNA in the liver allografts increased in the antibody-treated group in comparison to the controls. Taken together, these data revealed that the B7-H1 upregulation on the tissue cells of liver allografts thus plays an important role in the apoptosis of infiltrating cells, which might play a critical role of the induction of the spontaneous tolerance after hepatic transplantation in mice. [source]

Predominant Th1 and Cytotoxic Phenotype in Biopsies from Renal Transplant Recipients with Transplant Glomerulopathy

Effects of Donor Age and Cell Senescence on Kidney Allograft Survival

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2009
A. Melk
The biological processes responsible for somatic cell senescence contribute to organ aging and progression of chronic diseases, and this may contribute to kidney transplant outcomes. We examined the effect of pre-existing donor aging on the performance of kidney transplants, comparing mouse kidney isografts and allografts from old versus young donors. Before transplantation, old kidneys were histologically normal, but displayed an increased expression of senescence marker p16INK4a. Old allografts at day 7 showed a more rapid emergence of epithelial changes and a further increase in the expression of p16INK4a. Similar but much milder changes occurred in old isografts. These changes were absent in young allografts at day 7, but emerged by day 21. The expression of p16INK4a remained low in young kidney allografts at day 7, but increased with severe rejection at day 21. Isografts from young donors showed no epithelial changes and no increase in p16INK4a. The measurements of the alloimmune response,infiltrate, cytology, expression of perforin, granzyme B, IFN-, and MHC,were not increased in old allografts. Thus, old donor kidneys display abnormal parenchymal susceptibility to transplant stresses and enhanced induction of senescence marker p16INK4a, but were not more immunogenic. These data are compatible with a key role of somatic cell senescence mechanisms in kidney transplant outcomes by contributing to donor aging, being accelerated by transplant stresses, and imposing limits on the capacity of the tissue to proliferate. [source]

Heightened Expression of the Cytotoxicity Receptor NKG2D Correlates with Acute and Chronic Nephropathy After Kidney Transplantation

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2007
M. Seiler
The activating cytotoxicity receptor NKG2D binds to stress-regulated molecules encoded by the major histocompatibility complex class I chain-related (MIC) and UL-16-binding protein (ULBP)/retinoic acid early transcript (RAET) gene family. To assess whether acute allograft rejection leads to an induction of these inducible ligands and their receptor NKG2D, we examined the mRNA profiles in kidney transplant biopsies. Expression levels were correlated with the incidence of acute rejection (aRx) episodes and chronic allograft nephropathy (CAN) proven by histology. Whereas MICA, ULBP1/3 and RAET1-E did not display heightened gene expression, elevated levels of NKG2D mRNA could be associated with aRx (p < 0.001). Immunohistology of kidney biopsies diagnosed with aRx revealed NKG2D+ cells in tubulointerstitial areas positive for CD8+ cells. Most importantly, elevated levels of NKG2D mRNA were associated with restricted long-term graft function assessed by the glomerular filtration rate at 6, 12 and 18 months posttransplantation. Induced NKG2D mRNA expression was still observable in biopsies diagnosed with CAN (p < 0.001), demonstrating a higher sensitivity and specificity compared to CD3, granzyme B and granulysin mRNA measurement. Significant elevated levels of NKG2D mRNA could be further detected in urine sediment prior to aRx, suggesting this receptor as a new candidate marker for the diagnosis of acute and chronic allograft rejection. [source]

Monoclonal anti-CD8 therapy induces disease amelioration in the K/BxN mouse model of spontaneous chronic polyarthritis

ARTHRITIS & RHEUMATISM, Issue 10 2010
Bruno R. Raposo
Objective CD8+ T cells are part of the T cell pool infiltrating the synovium in rheumatoid arthritis (RA). However, their role in the pathogenesis of RA has not been fully delineated. Using the K/BxN mouse model of spontaneous chronic arthritis, which shares many similarities with RA, we studied the potential of CD8+ T cell depletion with monoclonal antibodies (mAb) to stop and reverse the progression of experimental arthritis. Methods CD8+ T cells from the blood and articular infiltrate of K/BxN mice were characterized for cell surface phenotypic markers and for cytokine production. Additionally, mice were treated with specific anti-CD8 mAb (YTS105 and YTS169.4), with and without thymectomy. Results CD8+ T cells from the peripheral blood and joints of K/BxN mice were mainly CD69+ and CD62L,CD27+ T cells expressing proinflammatory cytokines (interferon-, [IFN,], tumor necrosis factor , [TNF,], interleukin-17a [IL-17A], and IL-4), and granzyme B. In mice receiving anti-CD8 mAb, the arthritis score improved 5 days after treatment. Recovery of the CD8+ T cells was associated with a new increase in the arthritis score after 20 days. In thymectomized and anti-CD8 mAb,treated mice, the arthritis score improved permanently. Histologic analysis showed an absence of inflammatory infiltrate in the anti-CD8 mAb,treated mice. In anti-CD8 mAb,treated mice, the serologic levels of TNF,, IFN,, IL-6, and IL-5 normalized. The levels of the disease-related anti,glucose-6-phosphate isomerase antibodies did not change. Conclusion These results indicate that synovial activated effector CD8+ T cells locally synthesize proinflammatory cytokines (IFN,, TNF,, IL-17, IL-6) and granzyme B in the arthritic joint, thus playing a pivotal role in maintaining chronic synovitis in the K/BxN mouse model of arthritis. [source]

HLA,B27,restricted antigen presentation by human chondrocytes to CD8+ T cells: Potential contribution to local immunopathologic processes in ankylosing spondylitis

ARTHRITIS & RHEUMATISM, Issue 6 2009
Maren Kuhne
Objective Analysis of the histopathologic features of hip arthritis in patients with ankylosing spondylitis (AS) has revealed accumulation of infiltrating mononuclear cells in the bone end plate and presence of hyaline articular cartilage that is not found in areas of total cartilage destruction. This study was undertaken to assess whether chondrocytes attract lymphocytes and whether cartilage chondrocytes from patients with AS have the potential to directly stimulate T cells in an HLA-restricted manner. Methods Human HLA,B27+ T cell lines, specific for the Epstein-Barr virus,derived peptide EBNA258,266, and autologous chondrocytes, serving as nonprofessional antigen-presenting cells (APCs), were available for use in a model system to study chondrocyte functions in femoral head joint cartilage of patients with AS. Peptide functionality of cytotoxic T cells was assessed by flow cytometry, and cellular interactions were detected by fluorescence confocal microscopy. Results When maintained in an alginate matrix, chondrocytes isolated from the femoral heads of patients with AS constitutively expressed type II collagen and CD80. When pulsed with the EBNA258,266 peptide, autologous chondrocytes functioned as APCs and, specifically, induced interferon-, production in CD8+ T cells. In mixed chondrocyte,T cell cultures, cell,cell contacts were dependent on the presence of the EBNA258,266 peptide. T cells adjacent to chondrocytes produced perforin and granzyme B; both molecules were found in focal aggregates, a prerequisite for antigen-specific lysis of target cells. Conclusion Antigen presentation through human chondrocytes allows the stimulation of peptide-specific CD8+ T cells. These results indicate that human chondrocytes can act as nonprofessional APCs, and suggest that there is an interferon-,,triggered autocrine loop of immune cell,mediated chondrocyte activation in the already inflamed environment. Thus, local HLA-dependent activation of peptide-specific cytotoxic CD8+ T cells by chondrocytes might contribute to inflammatory processes in the spondylarthritides. [source]

Antiangiogenic plasma activity in patients with systemic sclerosis

ARTHRITIS & RHEUMATISM, Issue 10 2007
Mary Jo Mulligan-Kehoe
Objective Systemic sclerosis (SSc; scleroderma) is a systemic connective tissue disease with an extensive vascular component that includes aberrant microvasculature and impaired wound healing. The aim of this study was to investigate the presence of antiangiogenic factors in patients with SSc. Methods Plasma samples were obtained from 30 patients with SSc and from 10 control patients without SSc. The samples were analyzed for the ability of plasma to affect endothelial cell migration and vascular structure formation and for the presence of antiangiogenic activity. Results Exposure of normal human microvascular dermal endothelial cells to plasma from patients with SSc resulted in decreased cell migration (mean ± SEM 52 ± 5%) and tube formation (34 ± 6%) compared with that in plasma from control patients (P < 0.001 for both). SSc plasma contained 2.9-fold more plasminogen kringle 1,3 fragments (angiostatin) than that in control plasma. The addition of angiostatin to control plasma resulted in inhibition of endothelial cell migration and proliferation similar to that observed in SSc plasma. In vitro studies demonstrated that granzyme B and other proteases contained in T cell granule content cleave plasminogen and plasmin into angiostatin fragments. Conclusion Plasminogen conformation in patients with SSc enables granzyme B and granule content protease to limit the proangiogenic effects of plasmin and increase the levels of antiangiogenic angiostatin. This increase in angiostatin production may account for some of the vascular defects observed in patients with SSc. [source]

Characterising the local immune responses in cervical intraepithelial neoplasia: a cross-sectional and longitudinal analysis

BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 13 2008
YL Woo
Introduction, Immunological competence influences the progression of cervical intraepithelial neoplasia (CIN) to invasive cancer. Information on the local immunological changes during the natural course of CIN is central for the development of new therapies. Objective, This study defines the populations of tissue-infiltrating immune cells in a cross-sectional cohort of different grades of CIN and also in a longitudinal cohort of regressing, persistent and progressing low-grade (LG)-CIN. Design, A cohort of 125 women with LG cytological atypia was recruited, of which 64/125 (51%) women with LG-CIN were followed prospectively for 1 year. Paraffin-embedded entry and exit cervical biopsies were used for immunohistochemistry analysis (CD4, CD8, CD56, FOXP3, CD1a and granzyme B). Results, At recruitment, 74/125 (59%), 39/125 (31%) and 12/125 (10%) women referred with LG smears had histologically proven LG-CIN, high-grade (HG) and normal biopsies, respectively. Seventeen of 64 (24.6%) women with LG-CIN progressed to HG-CIN within 1 year. In both LG-CIN and HG-CIN, the predominant intraepithelial cell population were cytotoxic T cells, while CD4+ and FOXP3+ T cells predominated the stromal compartment. Women with LG-CIN who later on regressed displayed a significantly higher number of cytotoxic (granzyme B+) cells in their entry samples. In addition, the ratio between CD8+ cells and granzyme B+ cells was close to 1, suggesting that all infiltrating CD8+ T cells were highly active. In contrast, this ratio was three-fold lower in women, in whom the lesions persisted or progressed. Conclusions, This study suggests that the early infiltration of lesions by highly cytotoxic effector cells protects against progression. [source]

The expression pattern of interferon-inducible proteins reflects the characteristic histological distribution of infiltrating immune cells in different cutaneous lupus erythematosus subsets

BRITISH JOURNAL OF DERMATOLOGY, Issue 4 2007
J. Wenzel
Summary Background, Plasmacytoid dendritic cells and type I interferons (IFNs) are supposed to play a central proinflammatory role in the pathogenesis of cutaneous lupus erythematosus (LE). The IFN-inducible chemokines CXCL9 and CXCL10 are involved in recruiting CXCR3+ effector lymphocytes from the peripheral blood into skin lesions of LE. We hypothesized that the expression pattern of IFN-inducible proteins reflects the characteristic distribution of the inflammatory infiltrate in different subsets of cutaneous LE. Objectives, To test this hypothesis in patients with LE. Methods, Lesional skin biopsies taken from patients with different subsets of LE [chronic discoid LE (CDLE), n = 12; subacute cutaneous LE (SCLE), n = 5; LE tumidus (LET), n = 4; LE profundus (LEP), n = 6] were investigated by immunohistochemistry using monoclonal antibodies to the lymphocyte surface markers CD3, CD4, CD8, CD20 and CD68, the cytotoxic proteins Tia1 and granzyme B, the chemokine receptor CXCR3, the specifically type I IFN-inducible protein myxovirus protein A (MxA) and the chemokines CXCL9 and CXCL10. Results, The expression pattern of MxA followed the distribution of the inflammatory infiltrate typically seen in the investigated cutaneous LE subsets. In CDLE and SCLE, expression was focused in the epidermis and upper dermis, while in LET a perivascular and in LEP a subcutaneous pattern was found. Similar findings were obtained for CXCL9 and CXCL10. Conclusions, Our results demonstrate a close morphological association between the expression pattern of IFN-inducible proteins and the distribution of CXCR3+ CD3+ lymphocytes in all investigated subsets of cutaneous LE. This supports the importance of an IFN-driven inflammation in this condition. Infiltrating lymphocytes carrying CXCL10 in their granules might amplify the lesional inflammation and be responsible for the chronic course of this disease. [source]

Proapoptotic and antiapoptotic markers in cutaneous T-cell lymphoma skin infiltrates and lymphomatoid papulosis

BRITISH JOURNAL OF DERMATOLOGY, Issue 6 2001
H. Nevala
Background In cutaneous T-cell lymphoma (CTCL) lesions, both reactive T cells and malignant T cells intermingle. The disease progression is mostly slow. Recent evidence suggests that even if clinical remission is reached, malignant cells persist and a relapse follows sooner or later. To what extent tumour cell apoptosis occurs in the skin lesions either due to the reactive T cells or to therapeutic efforts is not known. Objectives To determine the extent of tumour cell apoptosis and the expression of proapoptotic and antiapoptotic markers in serial skin lesion samples from patients with CTCL, and to compare the findings with those in patients with lymphomatoid papulosis (LyP). Methods Thirty-four skin samples were obtained from 12 patients with CTCL at the time of diagnosis and at a mean of 1·6, 3 and 6 years later. The patients received psoralen plus ultraviolet A (PUVA), electron beam or cytostatic treatments. In addition, fresh post-treatment samples from three patients with CTCL undergoing PUVA therapy were obtained. For comparison, skin biopsies of five patients with LyP were studied. Immunohistochemical demonstration of the expression of the following markers was performed on formalin-fixed skin sections: Fas (CD95), Fas ligand (FasL), bcl-2, granzyme B, the tumour-suppressor protein PTEN and the effector caspase, caspase-3. The malignant cells were identified morphologically, and apoptotic cells were identified with the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling method on parallel sections. Results In untreated CTCL lesions, apoptotic lymphocytes were extremely rare, and no increase in the number of apoptotic cells was observed after any of the treatments used. In LyP, apoptotic cells were more frequent, comprising on average 5% of the infiltrate. The apoptosis-associated markers Fas, FasL, caspase-3 and granzyme B were expressed by morphologically neoplastic cells in CTCL and by large atypical cells in LyP, with no significant differences. However, only a few reactive cells in CTCL infiltrates expressed granzyme B while about 10% of the corresponding cells were positive in LyP. The expression of antiapoptotic bcl-2 was more frequent in CTCL than in LyP, while PTEN expression was high in both instances. The number of bcl-2+ cells tended to decrease after therapy. When comparing the findings between the first and the last samples, a decrease in the number of bcl-2+ cells and an increase in Fas+ cells was associated with disease progression, despite therapy, while the opposite was true for remissions. Conclusions Apoptosis was found to be a rare event in CTCL lesions irrespective of preceding therapy. During patient follow-up, no significant differences in the expression of apoptotic markers was observed while in most cases a lower level of antiapoptotic bcl-2 expression was observed after all types of therapies and in association with disease progression when compared with high expression in the untreated lesions. The absence of apoptosis and high expression of bcl-2 together with a low expression of apoptosis-inducing granzyme B in the reactive lymphocytes in CTCL could explain the chronic nature of the disease and the poor response to therapy, while the more frequent occurrence of granzyme B and apoptosis together with a lower level of expression of bcl-2 by the large atypical cells in LyP could contribute to the favourable outcome of the latter. [source]

Demonstration of aberrant T-cell and natural killer-cell antigen expression in all cases of granular lymphocytic leukaemia

BRITISH JOURNAL OF HAEMATOLOGY, Issue 6 2003
William G. Morice
Summary. The diagnosis of granular lymphocytic leukaemia (GLL) requires the presence of an immunophenotypically distinct T-cell (T-GLL) or natural killer-cell (NK-GLL) population. Flow cytometric immunophenotyping was performed on 21 T-GLL patients, 11 NK-GLL patients and 20 normal control subjects using antibodies to T and NK cell-associated antigens in order to accurately identify the distinguishing features of T-GLL and NK-GLL. The NK antigens evaluated included: CD16, CD57, CD94, CD161, and the killing inhibitory receptors (KIRs) CD158a, CD158b and CD158e (p70). Abnormal T-antigen expression was present in all T-GLL patients. CD57 was frequently expressed in T-GLL, however, one-third of patients showed partial CD57 expression similar to that seen in T cells from normal control subjects. Ten T-GLL were KIR positive; all expressed a single KIR isoform. All NK-GLL showed a distinctive, abnormal immunophenotype. Four NK-GLL expressed a single KIR isoform; the remaining seven patients lacked all tested KIRs, which is also a distinct, abnormal finding. Immunoperoxidase staining of bone marrow biopsy specimens from NK-GLL patients with antibodies to CD8, TIA-1 and granzyme B revealed the disease-specific distinctive staining patterns previously found in T-GLL. These studies delineate the unique immunophenotypic features diagnostic of T-GLL and provide strong evidence that NK-GLL, like T-GLL, represents a clonal lymphoproliferative disorder. [source]

The Fas/Fas ligand system, rather than granzyme B, may represent the main mediator of epidermal apoptosis in dermatomyositis

CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 6 2010
D. Torchia
No abstract is available for this article. [source]

Contribution of Naïve and Memory T-Cell Populations to the Human Alloimmune Response

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2009
C. Macedo
T-cell alloimmunity plays a dominant role in allograft rejection. The precise contribution of naïve and memory T cells to this response however remains unclear. To address this question, we established an ex vivo flow-cytometric assay that simultaneously measures proliferation, precursor frequency and effector molecule (IFN,, granzyme B/perforin) production of alloreactive T cells. By applying this assay to peripheral blood mononuclear cells from healthy volunteers, we demonstrate that the CD4+ and CD8+ populations mount similar proliferative responses and contain comparable frequencies of alloreactive precursors. Effector molecule expression, however, was significantly higher among CD8+ T cells. Analysis of sorted naïve and memory T cells showed that alloreactive precursors were equally present in both populations. The CD8+ effector and terminally differentiated effector memory subsets contained the highest proportion of granzyme B/perforin after allostimulation, suggesting that these cells present a significant threat to transplanted organs. Finally, we demonstrate that virus-specific lymphocytes contribute significantly to the alloresponse in certain responder,stimulator HLA combinations, underscoring the importance of T-cell cross-reactivity in alloimmunity. These results provide a quantitative assessment of the roles of naïve and memory T-cell subsets in the normal human alloimmune response and establish a platform for measuring T-cell alloreactivity pre- and posttransplantation. [source]