Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.79 (granzyme B)
 3,301 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Natural Killer (NK) cells can induce apoptosis in target cells in at least four ways: by secretion of granzyme B/perforin (GrB/P) and via the CD95L, TRAIL and TNF-alpha pathways. In this study we examined the pathways used by interleukin-2 activated rat NK (A-NK) cells to induce apoptosis in the rat colon carcinoma cell line CC531s. Co-incubation of A-NK cells with CC531s cells for three hours resulted in 70% apoptosis in the latter. Addition of the GrB/P pathway-inhibitor concanamycin A reduced the number of apoptotic cells to 54%. Blockade of the CD95L, TRAIL and TNF-alpha pathways by specific antibodies hardly had an additional effect. However, co-incubation with transfected MEC cells that expressed CD95L or 2PK3-cells that expressed TRAIL did induce apoptosis in CC531s cells. Furthermore the A-NK cells contained CD95L and TRAIL. However, comparison of non- and permeabilized cells revealed that the majority of TRAIL was present in the cytosol of A-NK cells and was not available for induction of apoptosis. The presence of elevated levels of bcl-2 in CC531 cells reduced the sensitivity towards induction of apoptosis both by A-NK cells as well as the CD95L and TRAIL expressing cell lines. Using the caspase-inhibitors ac-IEPD-CHO, ac-DEVD-CHO and zVAD-fmk, it was shown that inhibition of the effector caspase-3 prevented A-NK cell induced apoptosis in CC531-bcl-2 cells, but not in CC531s cells. In conclusion, A-NK cells kill by secretion of GrB/P and not by the CD95L, TRAIL or TNF pathways albeit both CD95L and TRAIL are produced by the A-NK cells.
 ...
PMID:Interleukin-2 activated NK cells do not use the CD95L- and TRAIL-pathways in the rapid induction of apoptosis of rat colon carcinoma CC531s cells. 1267 69

The role of CD2 signaling in cytotoxic T lymphocyte (CTL) development was examined by stimulating mouse T cells with anti-CD3 monoclonal antibody (mAb) in the absence or presence of anti-CD2 mAb or anti-CD48 mAb or both. Induction of nonspecific CTL and interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) synthesis were impaired in the absence of CD2-CD48 interactions. Anti-CD2 mAb also inhibited activation-induced expression of the high-affinity IL-2 receptor (IL-2R). In contrast, IFN-gamma receptor (IFNGR) expression was increased in the presence of anti-CD2 mAb. Reduced cytotoxicity by CTL induced in the absence of CD2-CD48 interactions was associated with a diminished ability of CTL to conjugate with target cells and reduced expression of granzyme B and perforin. Anti-CD2 mAb did not affect expression of Fas ligand and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) by anti-CD3-activated T cells. Cytotoxic effector function and granzyme B and perforin expression were rescued when exogenous IL-2 and IFN-gamma were added in combination with anti-CD2 mAb to anti-CD3-activated T cells at initiation of culture. We conclude that CD2-CD48 interactions during T cell activation are critical for the synthesis of sufficient IL-2 and IFN-gamma to drive CD8(+) T cells to differentiate into functional cytotoxic effector cells.
 ...
PMID:CD2-CD48 interactions promote cytotoxic T lymphocyte induction and function: anti-CD2 and anti-CD48 antibodies impair cytokine synthesis, proliferation, target recognition/adhesion, and cytotoxicity. 1274 72

Curcumin (CCM; diferuoylmethane) is a dietary pigment in curry with known antineoplastic and anti-inflammatory effects. The immunosuppressive effects of CCM were studied in (1) rat heterotopic cardiac transplant models, using Brown-Norway (BN, RT1(n)) hearts to WKY (RT1(u)) hosts or Buffalo (BUF, RT1(b)) hearts to Wistar-Furth (WF, RT1(u)) hosts, (2) reverse transcriptase-polymerase chain reaction analysis of cytokines from transplanted specimens, and (3) mixed lymphocyte reactions (MLR). In the BN-to-WKY model, CCM alone significantly increased the mean survival time (MST) to 20.5 to 24.5 days, as compared to 9.1 days among nontreated controls. The combination of CCM and subtherapeutic doses of CsA produced further prolongation of the MST to 28.5 to 35.6 days, better than that of CCM or CsA alone (P <.05). In a BUF-to-WF model, CCM alone did not increased the MST, unless it was combined with subtherapeutic doses of CsA, wherein two thirds of the grafts survived for more than 60 days (P <.05 as compared to either treatment group). Cytokine analysis revealed significantly reduced expression of interleukin-2 (IL-2), interferon-gamma (IFN-gamma) and granzyme B in the day 3 specimens of the CCM and CCM CsA-treated allografts compared with the nontreated allograft controls. MLRs using the two MHC-incompatible rat strains (BNxWKY) showed an effect of increasing concentrations of CCM and/or CsA, which by combination index (CI) analysis showed a synergistic effect (CI = 0.22 to 0.81). This study for the first time demonstrates the effectiveness of CCM as a novel adjuvant immunosuppressant with cyclosporine both in vivo and in vitro.
 ...
PMID:Curcumin enhances the immunosuppressive activity of cyclosporine in rat cardiac allografts and in mixed lymphocyte reactions. 1282 32

The time kinetics of five cytokines [interleukin-2 (IL-2), IL-5, interferon-gamma (IFN-gamma), granulocyte macrophage-colony stimulating factor (GM-CSF) and tumour necrosis factor-alpha (TNF-alpha)] and one cytotoxic effector protein (granzyme B) was analysed by real-time quantitative polymerase chain reaction (PCR) following in vitro stimulation of human CD4 and CD8 T lymphocytes. Two stimuli were used, a mitogen [phytohemagglutinin (PHA)] and a recall antigen [purified protein derivative (PPD)]. The pattern of cytokine mRNA expression was found to be dependent on the T-cell subset and stimulus used. A wide interindividual variability in the cytokine gene expression pattern was demonstrated. Two expression patterns were observed. A bell-shaped expression profile was seen for most cytokines upon PHA activation in both subsets and PPD-activated CD4 T cells, whereas a biphasic/multiphasic expression pattern was noted in CD8 T cells upon PPD stimulation. For most cytokines, the time to induction was within 30 min of activation, and maximum accumulation seemed to be obtained after 4-8 h of activation. A sustained high level could, however, be noticed for up to 24 h. Granzyme B gene expression was also induced within 30 min of activation but showed a continuous gradual increase and late maximal accumulation (48-72 h). The findings of the present study are of importance when designing studies using the cytokine gene expression profile as a marker for antigen-specific T lymphocytes. It might be recommended that cytokine gene expression (IL-2, IL-5 and IFN-gamma) should be measured after 4-8 h of specific activation but also up to 24 h of stimulation is acceptable. Granzyme B should preferentially be measured after 48-72 h of activation.
 ...
PMID:Kinetics of cytokine gene expression in human CD4+ and CD8+ T-lymphocyte subsets using quantitative real-time PCR. 1463 15

Cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells use the perforin/granzyme pathway as a major mechanism to kill pathogen-containing cells and tumor cells.(1,2) Dysregulation of this pathway results in several human diseases, such as hemophagocytic lymphohistiocytosis. Here we characterize the single-cell expression pattern of granzymes A and B in human lymphocytes using a flow cytometry-based assay. We demonstrate that most circulating CD56(+)8(-) NK cells, and approximately half of circulating CD8(+) T lymphocytes, coexpressed both granzymes A and B. In contrast, few circulating CD4(+) T lymphocytes expressed granzymes A or B. Activation of CD8(+) T lymphocytes with concanavalin A (ConA)/interleukin-2 (IL-2), and activation of CD4(+) T lymphocytes with antibodies to CD3/CD28 or CD3/CD46 (to generate T regulatory [Tr1] cells), induced substantial expression of granzyme B, but not granzyme A. Naive CD4(+)CD45RA(+) cells stimulated with antibodies to CD3/CD46 strongly expressed granzyme B, while CD3/CD28 stimulation was ineffective. Finally, we show that granzyme B-expressing CD4(+) Tr1 cells are capable of killing target cells in a perforin-dependent, but major histocompatibility complex (MHC)/T-cell receptor (TCR)-independent, manner. Our results demonstrate discordant expression of granzymes A and B in human lymphocyte subsets and T regulatory cells, which suggests that different granzymes may play unique roles in immune system responses and regulation.
 ...
PMID:Differential expression of granzymes A and B in human cytotoxic lymphocyte subsets and T regulatory cells. 1523 16

Removab is a trifunctional bispecific antibody which can bridge CD3+ T cells and epithelial cell adhesion molecule positive (EpCAM+) tumor cells, and binds with its Fc fragment to antigen presenting cells. To explore a new approach for the treatment of patients with carcinoma of the upper aerodigestive tract, we investigated whether Removab can induce specific cellular responses to the EpCAM+ carcinoma cell line BHY. Particular emphasis was put on the opsonization of peripheral blood mononuclear cells (PBMN) with respect to clinical application. Tumor cells and allogeneic PBMN of healthy volunteers were incubated with or without Removab. In a third group, PBMN were opsonized with Removab and washed before incubation with tumor cells. Inverse microscopy, ELISPOT, flow cytometry analysis and cytotoxicity assays on the chorioallantois membrane (CAM) were performed. In comparison with PBMN alone, opsonization with Removab resulted in: a) activation of CD83+ antigen presenting cells, b) secretion of interferon gamma, and c) granzyme B mediated lysis of targeted BHY cells by EpCAM specific CD8+ T cells. The secretion of tumor necrosis factor alpha, interferon gamma and interleukin-2 by opsonized PBMN was significantly reduced after 24 h. Washed opsonized PBMN maintained their lytic activity against tumor cells as tested on the CAM. Removab is an appropriate agent for the therapeutic amplification of T cell responses against EpCAM+ tumor cells by opsonization of PBMN without putting patients at risk for severe adverse events caused by a cytokine storm.
 ...
PMID:Opsonization with a trifunctional bispecific (alphaCD3 x alphaEpCAM) antibody results in efficient lysis in vitro and in vivo of EpCAM positive tumor cells by cytotoxic T lymphocytes. 1537 31

Various arguments suggest that CD8+ T lymphocytes play a major role in the control of cytomegalovirus (CMV) infection. The detection of CMV-specific CD8+ T cells may therefore provide additional information about CMV virus detection to predict the risk of development of CMV disease, especially in immunodepressed transplant recipients. We compared and tested various experimental conditions to optimize an enzyme-linked immunospot assay (Elispot) assay for the detection of CMV-specific CD8+ T lymphocytes. The indirect Elispot assay with one six-day in vitro sensitization step was found to be the most sensitive method to detect CMV-specific CD8+ T cells compared to direct Elispot with unfractionated peripheral blood mononuclear cells or purified CD8+ T cells. We showed that low doses of interleukin-2 during the in vitro culture enhanced the sensitivity of this test, and tetramer staining was performed to verify the high efficiency of this in vitro stimulation step. We directly loaded the specific CMV peptide during the Elispot assay and demonstrated that the use of T2 cells did not improve its sensitivity. Elispot for the detection of interferon-gamma appears to be more sensitive and reliable than measurement of tumor necrosis factor alpha or granzyme B. This technique was successfully applied to detect CMV-specific CD8+ T cells in human leukocyte antigen A2 (HLA-A2) and HLA-B7 healthy patients and in one lymphopenic post-transplant patient with positive CMV serology. This highly sensitive test may be a useful tool to assess T-cell immunity directed against CMV in immunodepressed patients.
 ...
PMID:Optimization of an elispot assay to detect cytomegalovirus-specific CD8+ T lymphocytes. 1555 81

Emerging evidence indicates that Notch receptors and their ligands play important roles in the development of T cells and B cells. However, little is known about their possible roles in the development of other lymphoid cells. Here we demonstrate that Jagged2, a Notch ligand, stimulates the development of natural killer (NK) cells from Lin(-) Sca-1(+) c-kit(+) hematopoietic stem cells. Our culture system supports NK cell development for 2 to 3 months, often leading to the establishment of continuous NK cell lines. The prototype of such cell lines is designated as KIL. KIL depends on interleukin-7 for survival and proliferation and is NK1.1(+) CD3(-) TCRalphabeta(-) TCRdeltagamma(-) CD4(-) CD8(-) CD19(-) CD25(+) CD43(+) CD45(+) CD49b(-) CD51(+) CD94(+) NKG2D(+) Mac-1(-/low) B220(-) c-kit(+) perforin I(+) granzyme B(+) Notch-1(+), and cytotoxic. Like normal natural killer cells, the T-cell receptor-beta loci of KIL remain in the germ-line configuration. In response to interleukin-2, KIL proliferates extensively (increasing cell number by approximately 10(10)-fold) and terminally differentiates into adherent, hypergranular NK cells. Our findings indicate that Jagged2 stimulates the development of natural killer cells and the KIL cell line preserves most properties of the normal NK precursors. As such, KIL provides a valuable model system for NK cell research.
 ...
PMID:Jagged2 promotes the development of natural killer cells and the establishment of functional natural killer cell lines. 1565 53

In vitro comparisons of induction of perforin (PFP), granzyme B (GRB), production of cytokines, and cell-mediated cytotoxicity by interleukin-2 (IL-2), interleukin-15 (IL-15), or combinational IL-2/IL-15-induced lymphokine-activated killer cells were studied in this study. Whereas IL-2-induction was associated with a decrease in cultured cell population over a 7-day period, IL-15 alone or in combination with IL-2 resulted in significant increase including cytotoxic T lymphocytes and subsets of CD56+ lymphocytes, particularly cytokine-induced killer and cytolytic natural killer-T lymphocytes. The overall PFP, GRB, and tumor necrosis factor-alpha expression in different subtypes were also significantly higher with IL-15 alone or in combination with IL-2 induction with resultant superior cytotoxicity compared to IL-2 treatment. There was no significant advantage of addition of IL-2 over IL-15 induction. These results offer further information on the cytotoxic potency of these cytokines and their mechanisms of action implicating potential use of IL-15 as part of cytokine adoptive immunotherapy.
 ...
PMID:Combinational IL-2/IL-15 induction does not further enhance IL-15-induced lymphokine-activated killer cell cytotoxicity against human leukemia/lymphoma cells. 1589 91

We investigated whether HIV-1 antigen-specific CD4(+) T cells expressed the viral coreceptor CCR5 during primary HIV-1 infection (PHI). In the peripheral blood of subjects with very early PHI (< 22 days after onset of symptoms), there was a 10- to 20-fold increase in the proportion of highly activated (CD38(+++)) and proliferating (Ki-67(+)) CD4(+) T cells that expressed CCR5(+), and were mostly T-cell intracellular antigen-1 (TIA-1)(+) perforin(+) granzyme B(+). Inthe same patient samples, CD4(+) T cells producing interferon (IFN)-gamma in response to HIV group-specific antigen (Gag) peptides were readily detected (median, 0.58%) by intracellular cytokine assay-these cells were again predominantly CD38(+++), Ki-67(+), and TIA-(++), as well as Bcl-2(low). On average, 20% of the Gag-specific CD4(+) T cells also expressed interleukin-2 (IL-2) and were CD127 (IL-7R)(+). Taken together, these results suggest that Gag-specific T-helper 1 (Th1) effector cells express CCR5 during the primary response and may include precursors of long-term self-renewing memory cells. However, in PHI subjects with later presentation, antigen-specific CD4(+) T cells could not be readily detected (median, 0.08%), coinciding with a 5-fold lower level of the CCR5(+)CD38(+++) CD4(+) T cells. These results suggest that the antiviral response to HIV-1 infection includes highly activated CCR5(+)CD4(+) cytotoxic effector cells, which are susceptible to both apoptosis and cytopathic infection with HIV-1, and rapidly decline.
 ...
PMID:Early proliferation of CCR5(+) CD38(+++) antigen-specific CD4(+) Th1 effector cells during primary HIV-1 infection. 1590 89


<< Previous 1 2 3 4 5 6 7 8 9 Next >>