Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cell lines of myeloid origin have been shown to express interleukin-2 receptors (IL-2R). Here, we demonstrate the expression of IL-2R alpha and IL-R beta on the CML blast cell line K562 by FACS analysis and cross-linking assay. Furthermore, we examined the effect of IL-2 on leukemic progenitor growth, employing K562 as a model. Clonogenic growth was assessed after 3 days of culture by colony formation in a serum-free, semi-solid assay system. IL-2 was found to exhibit a dose-dependent suppressive effect on K562 clonogenicity with 48% inhibition of colony formation at 250 U IL-2 and 60% inhibition at 1000 U IL-2. Philadelphia chromosome (Ph)-positive K562 cells possess multiple copies of the bcr/abl fusion gene whose transcript and protein product (p210) is thought to confer growth advantage to CML cells. We therefore investigated IL-2-dependent modulation of bcr/abl mRNA accumulation and p210 protein levels in K562 cells. After 4 h of culture in the presence of IL-2, a 3-15-fold reduction of bcr/abl mRNA accumulation was demonstrated by competitive reverse PCR. Reduction of bcr/abl fusion protein levels was demonstrated at 24 h of IL-2-supplemented cell culture, employing p210 recognizing monoclonal antibodies (mAbs) in FACS analysis. Levels of proliferation marker Ki67 were only marginally affected. We conclude: (1) K562 cells express both IL-2R alpha and IL-R beta; (2) IL-2 inhibits clonogenic growth of K562 in a dose-dependent manner; and (3) IL-2-mediated inhibition of K562 proliferation is preceded by a reduction of bcr/abl mRNA accumulation and p210 protein levels.
 ...
PMID:IL-2 inhibits proliferation of K562 cells and reduces accumulation of bcr/abl mRNA and oncoprotein. 788 40

Our previous studies have shown that IL-2 activated bone marrow cells develop potent tumoricidal activity in vitro and in vivo. With the dual aim of in vitro purging and generation of effectors which could mediate graft-versus-leukemia effects in vivo, IL-2 activation of human bone marrow in long-term cultures (LTC) was tested. Marked cytotoxicity was seen against A375 (melanoma), K562 (CML) and Daudi (lymphoma) cell lines in IL-2 (1000 U/ml) stimulated cultures. Hematopoietic progenitor cell number in these cultures was assessed by day 14 clonogenic assays. In 1-week-old IL-2 stimulated cultures a higher number of clonogenic cells was seen than control LTCs without IL-2. However, thereafter accelerated decrease in the number of clonogenic cells was seen in IL-2 cultures. In vitro purging efficacy was tested by elimination of A375 and K562 cells mixed with normal marrow at 1:10 and 1:100 ratios and co-cultured for 10 days. In IL-2 stimulated cultures, A375 cells capable of proliferation were not detectable at both mixing ratios. K562 elimination was complete only at 1:100 ratio. After 10 days in culture, no Ph1-positive metaphases were seen in IL-2 stimulated BM cultures of 4 patients with CML. These results indicate that IL-2 activation of BM in 1-2 week cultures can lead to generation of marked anti-tumor cytotoxicity and effective in vitro purging in a variety of tumor types.
 ...
PMID:Interleukin-2 activation of human bone marrow in long-term cultures: an effective strategy for purging and generation of anti-tumor cytotoxic effectors. 820 79

A graft-versus-leukemia effect has been well documented to prevent relapse in chronic myelogenous leukemia (CML) after allogeneic marrow transplantation. One type of lymphocytes that may contribute to this effect are natural killer cells (NK), which after activation with interleukin (IL)-2, exhibit a broad range of cytolytic activity against allogeneic and autologous cells. We have previously demonstrated that IL-2-activated NK (ANK) can be generated from blood of patients with CML and are benign in origin. Their proliferation and function, however, diminish with disease progression in CML, suggesting a role in tumor surveillance. We studied the effect of IL-2-activated NK (ANK) on normal and malignant primitive and committed progenitors in a novel long-term bone marrow culture (LTBMC) assay. Because ANK destroy marrow stromal layers, the use of classic stroma-dependent long-term cultures is not possible. Therefore, we used the stroma noncontact LTBMC system developed in our laboratory to analyze the effect of autologous ANK cells on primitive hematopoietic progenitors. Autologous ANK (CD56+/CD3-) were generated from the peripheral blood of 10 patients with chronic phase CML and from six normal individuals by culturing CD5/CD8-depleted mononuclear cells for 14 days in 1,000 U/mL IL-2. At the same time ANK cultures were initiated, sorted normal (CD34+/DR+) marrow populations were plated in Transwell inserts of the stroma noncontact culture. On day 15, hydrocortisone, which rapidly inhibits ANK function, was removed, and autologous ANK were added to the Transwell inserts with fresh LTBMC medium without hydrocortisone but supplemented with 1,000 U/mL IL-2. After 48 hours, the number of colony-forming cells (CFC) was enumerated in methylcellulose culture. To determine the effect of ANK on more primitive long-term culture-initiating cells (LTCIC), the IL-2-supplemented LTBMC medium was replaced with fresh hydrocortisone containing LTBMC medium, and cultures were maintained for an additional 5 weeks. We demonstrate that autologous ANK did not suppress normal CFC or LTCIC. In contrast, ANK from eight patients with CML with potent cytotoxicity against NK-sensitive (K562) NK-resistant (Raji) tumor targets exhibited an ANK dose-dependent suppression of both CFC and LTCIC. Interestingly, ANK from two patients with CML who exhibited diminished cytotoxicity also did not suppress autologous CFC and LTCIC. These studies indicate that ANK with potent major histocompatibility complex unrestricted cytotoxic activity suppress malignant hematopoiesis. This effect was not mediated by soluble factors and was absolutely dependent on direct cell-to-cell contact. We further demonstrate that the beta2 integrin receptor is involved in ANK recognition of CML targets. These observations support the use of autologous ANK therapy to prevent relapse of CML after autologous marrow transplantation or use of ANK to purge CML marrow for autologous transplantation.
 ...
PMID:Autologous activated natural killer cells suppress primitive chronic myelogenous leukemia progenitors in long-term culture. 863 Apr 14

Donor-derived cell-mediated immunotherapy has been shown to be an effective tool for reinduction of remission in chronic myeloid leukaemia (CML) patients who have relapsed post-bone marrow transplantation (BMT). Linomide, quinoline-3-carboxamine (LS 2616), is a new immunomodulator shown to increase the number of NK precursors in mice in addition to upregulating the quantity of CD56(+), CD3(-) and CD16(+) NK cells in the peripheral blood of patients following autologous BMT (ABMT). We investigated the in vitro effects of Linomide on NK activity of normal human donors. Large granular lymphocytes (LGLs) and NK cells were incubated overnight with Linomide (0.02-4.8 mg/ml), recombinant human interleukin-2 (IL-2, 75 IU/ml), or a combination of both. Linomide, at 0.02-0.3 mg/ml, augmented IL-2-induced proliferation of LGLs and NK cells in an inversely proportional manner. In contrast, Linomide at 0.6-4.8 mg/ml inhibited IL-2-induced proliferation of LGLs and NK cells in a dose-dependent manner. Linomide was able to potentiate phytohemaglutinin-induced CD3(+) cell proliferation. In addition, supernatants derived from Linomide treated CD3(+) T cells were able to mimic the direct stimulatory effect of Linomide on activated NK cell proliferation. These supernatants were found to have low levels of tissue necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) and therefore Linomide stimulation of NK and T cell proliferation may be due to its inhibitory effect on the secretion of these cytokines by activated CD3(+) T cells. Linomide had no effect on cytotoxicity nor on the phenotypic expression of resting and IL-2-activated LGLs or NK cells. In view of our results, Linomide could possibly play a potential role in adoptive cell-mediated immunotherapy post-BMT.
 ...
PMID:The novel immunomodulator, Linomide, stimulates interleukin-2-induced human natural killer (NK) cell and PHA-stimulated T cell proliferation from normal donors. 863 78

Twenty-three patients with chronic myelogenous leukemia in early chronic phase (ECP) and not previously treated with alpha-interferon (IFN-alpha) (10 patients), in ECP but pretreated with IFN-alpha (<12 months) (seven patients) and in late chronic phase (LCP) pretreated with IFN-alpha (>12 months) (six patients) underwent autografting with Philadelphia (Ph) chromosome-negative blood progenitor cells (BPCs) (20 patients), or partially/totally Ph-positive BPCs (three patients), previously mobilized during the early phase of recovery after aplasia induced by intensive chemotherapy. The conditioning regimen consisted of high-dose chemotherapy alone or followed by total body irradiation (TBI). Recombinant G-CSF was given after BPCs infusion on day +8. All patients in ECP not pretreated with IFN-alpha are alive and five of them are Ph-negative in the marrow after autografting. Six of seven patients autografted with Ph-negative BPCs in the group of ECP pretreated with IFN-alpha (<12 months) are alive and two of them are still Ph-negative in the marrow. In the same group, the only patient transplanted with partially Ph-positive BPCs, died of blastic transformation 2 months after reinfusion. Three patients (two patients autografted with Ph-negative BPCs and one patient with Ph-positive BPC) in the group of LCP pretreated with IFN-alpha >12 months are alive but Ph-positive after autografting. The other three patients of the same group died of procedure-related toxicity (two patients) and blastic transformation (one patient). Seventeen patients (10/10 ECP not pretreated with IFN-alpha; 5/7 ECP pretreated with IFN-alpha and 2/6 LCP pretreated with IFN-alpha) of 23 autografted patients were treated with IFN-alpha +/- IL-2. Toxicities after autografting were mostly related to myelosuppression, particularly thrombocytopenia. All patients of the two groups pretreated with IFN-alpha developed febrile episodes during the aplastic phase following BPCs reinfusion. No patient autografted in ECP and those not pretreated with IFN-alpha developed febrile episodes. This is also probably due to the use of i.v. antibiotic and antimicotic prophylaxis when neutrophils were < or = 1 x 10(9)/l after autografting. Greater toxicity was observed in patients pretreated with IFN-alpha, being lethal in two cases in LCF. In conclusion, the "in vivo' manipulation approach employed in our institution is a safe procedure and it results in a high collection of Ph-negative cells in the blood if the cells are harvested: (1) in early chronic phase; (2) in early phase of recovery after chemotherapy-inducing aplasia; (3) in patients not extensively pretreated with IFN-alpha. The data presented here have shown encouraging trends in chronic phase of CML and offer new perspective for patients without an HLA-identical donor or for patients who do not respond to IFN-alpha.
 ...
PMID:High-dose chemo-radiotherapy followed by autologous Philadelphia chromosome-negative blood progenitor cell transplantation in patients with chronic myelogenous leukemia. 864 Jan 67

A patient, who was treated twice with donor lymphocyte infusions for relapse of CML after an allogeneic BMT was given lymphoblastoid human alpha-IFN after a third relapse. Further donor lymphocyte infusions were followed by repeated courses of 30 days treatment with a low dosage of IL-2 subcutaneously, alternately with alpha-IFN. This treatment resulted in a hematologic and cytogenetic remission. He also developed a limited degree of chronic GVHD. At the latest follow-up at 20 months after the third course of lymphocyte infusions he is in continuous hematologic and cytogenetic remission. Furthermore, a qualitative PCR analysis for the bcr/abl translocation is negative.
 ...
PMID:Lymphoblastoid human interferon and low dose IL-2 combined with donor lymphocyte infusion as therapy of a third relapse of CML--a case report. 883 27

There is good evidence that T lymphocytes play an important role in the graft-versus-leukemia (GVL) effect following allogeneic bone marrow transplantation (BMT) for hematologic malignancies. However, the role of natural killer (NK) cells in GVL is less clear. To further investigate a possible association of NK cells with GVL we studied 15 patients undergoing BMT for chronic myeloid leukemia (CML), correlating T-cell (CD4+ and CD8+) and NK-cell (CD16+ 56+) recovery with relapse and graft-versus-host disease (GVHD). Patients were studied on three occasions up to 9 months after BMT, for lymphocyte surface phenotype and for spontaneous and IL-2-stimulated (LAK cell) cytotoxic function. Circulating CD8+ and NK but not CD4+ cell numbers were significantly lower in five patients who relapsed compared with those remaining in remission after BMT (mean 0.03 vs 0.32 x 10(9)/l, p = 0.002 for CD8+ cells: mean 0.03 vs 0.11 x 10(9)/l, p = 0.002 for NK cells). There was no correlation of CD4+. CD8+, or NK cell numbers and development of grade-II or more acute GVHD. Spontaneous NK cytotoxic function rose to within the normal range in the first month after BMT. LAK function remained low during the study period. These results link NK cell recovery more closely with a GVL than with a GVH effect.
 ...
PMID:Association of natural killer cell immune recovery with a graft-versus-leukemia effect independent of graft-versus-host disease following allogeneic bone marrow transplantation. 903 7

Liver infiltrating lymphocytes (LIL) were isolated from HCV-positive (+) and HCV-negative (-) end-stage livers. Phenotypic analysis and functional studies using proliferative and lymphocytotoxic assays were performed with the isolated LIL. Two CD3+ lymphocyte populations were found in LIL using FITC anti-CD3 monoclonal antibodies (mAb). One was a bright fluorescence intensity population (as in PBL), and the other dim. We calculated the number of FITC-anti-CD3 mAbs bound per lymphocyte on PBL and LIL and found 80,040 +/- 4628 and 39,615 +/- 3932, respectively. Therefore, HCV+ and HCV- patient PBL contained approximately twice the number of CD3 molecules per cell than patient CD3+ LIL. LIL also contained approximately a threefold higher concentration of TCR alpha beta +, CD4-CD8-, and CD56,16 (NK) cells than the patient PBL. Thus, a major subset of LIL is phenotypically similar to mouse NK1.1+ "intermediate" T cells. LIL freshly isolated from HCV+ livers exhibited weak CTL activity against EBV- or Con A-transformed lymphoblast targets infected with vaccinia-HCV recombinant virus (rHCV) or primary hepatocyte cultured cells. However, after in vitro coculture of LIL with rHCV, these cells developed a strong cytotoxicity for the above targets. In contrast, LIL from HCV- livers were not cytotoxic against the same targets. Histochemical studies (in situ) demonstrated that these hepatocytes express CD95, and stains demonstrated apoptosis. The HCV+ hepatocytes also express class I MHC molecules and ICAM-1. The addition of mAb specific for these adhesion molecules inhibited CML activity. Short-term cultured hepatocytes (targets) from HCV+ and HCV- patients produced low levels of cytokines IL-1 beta, IL-2, IL-6, TNF alpha, and IFN-gamma but a high level of IL-8. It is speculated that LIL expressing reduced numbers of CD3 molecules may even function as immune regulators as proposed for intermediate T cells in mice.
 ...
PMID:The immune reactivity role of HCV-induced liver infiltrating lymphocytes in hepatocellular damage. 908 90

We investigated the role of endogenous or exogenous nitric oxide (NO) on human lymphocyte function. We used sodium nitroprusside, nitroglycerine, S-nitroso-N-acetylpenicillamine, sodium nitrite and S-nitroso-L-glutathione as NO-generating compounds. All agents were used at doses that do not produce direct cytotoxicity as measured by trypan blue exclusion as well as chromium-51 release assay. The immune responses examined were peripheral blood lymphocytes (PBL) proliferation and IL-2 production after activation with OKT3 and PHA; allogeneic mediated proliferation and cell mediated cytotoxicity (CML) in MLR; IgG and IgM production after PBL activation with Con-A; proliferation and expression of IFN-gamma and IL-4 mRNA after activation of allogeneic CD4+T cell clones. Cytokine mRNA expression was measured by reverse transcriptase PCR. Our results show that proliferating lymphocytes do not produce a detectable amount of NO as measured by the Griess reaction. In separate experiments, the addition of NG-monomethyl-L-arginine (L-NMMA) did not affect lymphocyte proliferation. Sodium nitroprusside and nitroglycerine exerted a dose dependent antimitogenic effect, inhibited cytokine production and expression, CML generation and antibody production. DNA gel electrophoresis showed no evidence for enhanced programmed cell death. The antimitogenic effect could not be blocked by the NO scavengers, hemoglobin or methylene blue. In contrast, the other nitric oxide generating compounds did not inhibit lymphocyte mitogenesis. The results suggest that human lymphocytes do not produce appreciable amounts of NO to affect lymphocyte mitogenesis. Sodium nitroprusside and nitroglycerine have a potent but nonspecific immunoinhibitory effect on human lymphocyte function by a mechanism other than NO production. In addition, pharmacological levels of NO do not inhibit human lymphocyte mitogenesis.
 ...
PMID:Analysis of the in vitro effect of exogenous nitric oxide on human lymphocytes. 920 99

Chronic myelogenous leukemia (CML) is a lethal disease of the hematopoietic stem cell. Bone marrow transplantation has highlighted the importance of allogeneic disparity in maintaining remissions in CML. However, it has been unclear whether the immune effect against CML is mediated by T cells, natural killer cells (NK) or a combination of both. We have previously demonstrated that autologous activated NK are capable of selectively lysing malignant CML progenitors while sparing benign progenitors. NK effectors may play an important role in CML since NK lytic function, clonogenic frequency and proliferative capacity decrease as CML progresses from chronic phase to advanced phase and blast crisis. Incubation of CML NK with IL-2 is capable of restoring cytolytic activity to normal levels. We hypothesize that activated NK represent a potential therapy against CML to maintain remissions in a minimal residual disease setting induced by autologous transplantation. Clinical trials are in progress to test whether IL-2 based immunotherapy and activated cell infusions play a therapeutic role in CML.
 ...
PMID:The role of autologous natural killer cells in chronic myelogenous leukemia. 947 21


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