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At least 19 recordsLinked to original sources
PubMed1992

Study of the effect of lithium on lymphokine-activated killer cell activity and its antitumor growth.

The in vitro effect of lithium on lymphokine-activated killer cell (LAK) activity and its in vivo antitumor growth were observed. LAK activity was enhanced when LiCl was added during LAK cell induction, and this enhancement was observed both in human peripheral blood mononuclear cell and in mouse splenocytes used as LAK precursors. Cholera toxin, which can increase intracellular levels of cAMP, decreased LAK cell activity. However, lithium partially reversed this inhibitory effect, indicating that lithium increased LAK cell activity by decreasing cAMP levels. D-Sphingosine, an inhibitor of protein kinase C, and EGTA, a calcium chelator, both inhibited the LAK cell activity. However, their inhibitory effects could not be reversed by lithium because lithium was added in the culture in combination with one of these inhibitors during LAK cell induction. By using slot blot analysis, the effect of lithium on the expression of tumor necrosis factor-alpha mRNA of LAK cells was analyzed. Lithium increased the level of tumor necrosis factor-alpha mRNA when both lithium and interleukin 2 were added to induce LAK cells. The in vivo antitumor effect of lithium has also been studied. Using a mouse melanoma experimental model, the effect of lithium on tumor growth was also observed. Both lithium alone and interleukin 2/LAK had an antitumor effect, whereas the treatment of interleukin 2/LAK in combination with lithium had the strongest inhibitory effect on tumor growth, since this treatment resulted in reduction of tumor size and prolongation of survival in tumor-bearing mice. Therefore, it is hopeful that lithium can be used as a new immunomodulator for cancer immunotherapy and immune diseases.

Animals↗
PubMed1992

Potentiated lymphokine-activated killer cell activity generated by low-dose interleukin-2 and mismatched double-stranded RNA.

Lymphokine-activated killer (LAK) cell activity was measured in human peripheral blood mononuclear cells (PBMC) treated in vitro for 3 days with recombinant interleukin-2 (rIL-2) and mismatched double-stranded RNA (dsRNA). Lytic activity was measured utilizing K562 (NK-sensitive) and 786-0 (NK-resistant) target cells. PBMC cultured with rIL-2 (10-1000 BRMP U/ml) alone showed concentration-dependent lytic activity against the 786-0 target cells, while cells cultured in unsupplemented medium or medium supplemented with mismatched dsRNA (200 micrograms/ml) alone could not lyse the 786-0 targets. The combination of mismatched dsRNA with suboptimal concentrations of rIL-2 (10-30 U/ml) showed enhancement of both natural killer (NK) and LAK cell activities. The uptake of [3H]thymidine by treated effector cells was dependent on time and rIL-2 concentration and was not increased in the cells treated with low-dose rIL-2/mismatched dsRNA, compared to those treated with low-dose rIL-2 or mismatched dsRNA alone. Similarly, changes in the expression of CD3, CD4, CD8, CD57, CD16 and CD25 cell surface antigens were independent or rIL-2 concentration and not altered by the presence of mismatched dsRNA. These results indicate that mismatched dsRNA can potentiate rIL-2-induced LAK cell activity by increasing the functional activity per cell, rather than by increasing the number of activated cells.

Cytotoxicity, Immunologic↗
PubMed1979

Rheumatoid synovial lymphocytes lack concanavalin-A-activated suppressor cell activity.

Synovial lymphocytes eluted by enzyme treatment from eleven patients with rheumatoid arthritis (RA) were investigated for the presence of concanavalin A (Con A)-activated suppressor cell activity as compared with that of peripheral blood lymphocytes of twenty normal donors. In addition, two patients with psoriatic arthritis and juvenile rheumatoid arthritis (JRA) were also investigated. Synovial lymphocytes from the eleven RA patients showed a mean augmentation of 28 +/- 13.30, and thus clearly lacked suppressor activity, whereas the mean suppression in the lymphocytes from the twenty normal donors was 13 +/- 14.40. Synovial lymphocytes from one patient with JRA and one with psoriatic arthritis showed a normal suppressor activity.

Arthritis, Juvenile↗
PubMedDate not supplied

Effect of choriocarcinoma supernatant on natural killer and lymphokine-activated killer cell activity.

The effect of JEG-3 choriocarcinoma supernatant on human natural killer cell and lymphokine-activated killer cell activity was investigated. Choriocarcinoma supernatants from JEG-3 cell lines were obtained at the time of their optimal growth. K562 erythroblastoid cells were used as target cells for natural killer and lymphokine-activated killer cell mediated lysis in a 51Cr release assay. The choriocarcinoma supernatants had a significant dose-dependent suppressive effect on natural killer and lymphokine-activated killer cell activity. This suppression was more expressed at high effector: target cell ratios. Therefore, choriocarcinoma supernatants appear to have potent inhibitory effects on many aspects of cellular immunity, although, additional studies should be performed to further characterize and identify immunoregulatory molecule(s) in choriocarcinoma supernatants.

Choriocarcinoma↗
PubMed1979

Use of a human plaque-forming cell assay to study peripheral blood bursa-equivalent cell activation and excessive suppressor cell activity in humoral immunodeficiency.

A plaque assay that detects human mononuclear blood cells producing immunoglobulin (Ig)M antibody to sheep erythrocytes was investigated for its usefulness in studying B-cell activation and regulation in 24 patients with humoral immunodeficiency. Cells from 3 of 15 patients with common variable agammaglobulinemia produced some plaques (range 40--160/10(6) cells; normal range 80--1240/10(6)), but those from the other 12, from all 7 with x-linked agammaglobulinemia and from the 2 with x-linked immunodeficiency with hyper-IgM failed to produce any detectable plaques. In co-cultures of patient and normal cells a very good correlation was seen between results of the plaque assay and an IgM biosynthesis assay in detecting excessive suppressor cell activity. Cells from 7 of 15 common variable agammaglobulinemics, from 3 of 7 x-linked agammaglobulinemics, and from both patients with hyper-IgM caused significant suppression of IgM biosynthesis and(or) plaque formation by normal cells. The observations in the last two groups and discordance for excess suppressor activity in identical twins with common variable agammaglobulinemia suggest that the activity develops secondarily to whatever their primary defects may be. Culturing non-T cells from common variable agammaglobulinemics exhibiting excessive suppressor cell activity with normal T cells resulted in plaque formation in four of five patients so studied; in all five the suppressor activity was found in the T-cell population. The availability of a plaque assay for the study of blood cells from immunodeficient patients provides a new probe to examine the cellular nature of such defects.

Adolescent↗
PubMed1992

Ability of tolerized Th1 and Th2 clones to stimulate B cell activation and cell cycle progression.

Tolerant and nontolerant murine Th1 and Th2 clones, specific for human gamma-globulin (HGG), were compared for their ability to promote cell cycle entry and progression by B cells in vitro. When stimulated with HGG, nontolerant Th1 and Th2 clones induced similar increases in B cell membrane MHC class II levels--a phenomenon associated with early B cell activation. Nontolerant Th1 and Th2 clones also induced B cell DNA synthesis, an event associated with subsequent G1 phase traversal, although Th2 cells were more efficient than Th1 cells in stimulating this activity. Exposure of Th clones to tolerogen in the form of HGG-pulsed chemically fixed APC inhibited the ability of Th1 clones, but not Th2 clones to promote polyclonal B cell DNA synthesis in HGG-stimulated secondary cultures. However, Th1 clones exposed to tolerogen did not lose their ability to increase the expression of MHC class II molecules on B cells in these cultures. These results indicate that tolerance induction does not inhibit the ability of Th1 clones promote B cell cycle progression. In contrast, exposure of Th2 cells to tolerogen does not inhibit significantly the ability of these cells to stimulate B cell cycle entry or progression.

Animals↗
PubMed1992

Detection of regulatory factors of lymphokine-activated killer cell activity in head and neck cancer patients treated with interleukin-2 and interferon alpha.

Interleukin-2 (IL-2) and interferon-alpha (INF-alpha) are biologic modifiers that have met with limited clinical success in the treatment of human malignancies. We conducted a phase 2 trial of IL-2-IFN-alpha in patients with advanced or unresectable squamous cell carcinoma of the upper aerodigestive tract. Two patients were analyzed sequentially for serum induction phase-blocking factors of lymphokine-activated killer (LAK) cell activity in their therapy. Serum also modulated LAK activity independent of autologous or allogeneic effector cells. Significantly inhibitory serum samples were stable in multiple freezings and thawings. Heat-treating the inhibitory serum, at 56 degrees C for 30 minutes, only partially removed the serum inhibitory capacity. Sequential analysis of p55 and p75, subunits of IL-2 receptors, showed that absence of effector cell lytic activity was associated with markedly decreased fluorescence of the IL-2Rp75 subunit only. No significant alteration of the IL-2Rp55 subunit occurred with therapy. These studies support the theory that lymphocyte and multiple serum factors, developing during IL-2-IFN-alpha therapy, regulate the induction of in vitro LAK activity. Further understanding of these factors may lead to improvements in biologic modifier therapy.

Aged↗
PubMed1979

Con-A-activated T cells secrete factors with polyclonal B-cell-activating properties.

Concanavalin A induced polyclonal antibody synthesis in normal spleen cells in vitro. Optimal responses were obtained by Con A concentrations lower than those optimal for induction of DNA synthesis. T cells, but not macrophages, were necessary for the effect. Spleen cells from nude mice were not activated, whereas cells from the LPS non-responder stain C3H/HeJ were activated to polyclonal antibody synthesis by Con A. Supernatants from Con A activated spleen cells could by themselves induce polyclonal antibody synthesis in untreated spleen cell cultures, even when Con A had been removed by absorption with Sephadex G-50 and when alpha-methyl-mannoside was present in the secondary cultures. T cells produced the active supernatants, which were competent to induce polyclonal antibody synthesis, but not DNA synthesis, in both H-2-incompatible and compatible strains. When the supernants were absorbed with erythrocyte antigens, they specifically induced an enhanced response, in secondary cultures, to the antigen used for absorption. Possible mechanisms of this specific effect are discussed.

Animals↗
PubMed1992

Augmentation of human lymphokine-activated killer cell activity in splenic lymphocytes by the combination of low-dose interleukin 2 plus interleukin 3.

The effect of interleukin 3 (IL-3) on lymphokine-activated killer cell (LAK) generation in splenic lymphocytes was examined in patients with gastric cancer or idiopathic thrombocytopenic purpura (ITP). IL-3 alone did not induce any significant LAK activity from splenic lymphocytes. However, IL-3 addition to the culture with low-dose IL-2 significantly augmented the activity of LAK cells. Spleen cells precultured with IL-3 for 2 days and then added to IL-2 became more potent LAK cells than the spleen cells cultured with the same doses of IL-3 plus IL-2. Phenotypic analysis using flow cytometry demonstrated that IL-2 alone increased in cells expressing CD2+, -11+, and -16+ cells, whereas IL-3 plus IL-2 induced the expansion of CD3+ and CD8+ cells in addition to CD2+, -11+, and -16+ cells. These results suggest that IL-3 plus IL-2 phenotypically induces not only natural killer-like LAK cells (CD2+, -11+, and -16+) but T cell-like LAK cells (CD3+ and -8+). We are now investigating the characteristics of immature T cell populations in the spleen responsive to IL-3 using T-cell receptor antibody.

Antigens, CD↗
PubMedDate not supplied

Role of human blood monocytes in up-regulation of lymphokine (interleukin-2)-activated killer cell activity with cisplatin and FK-565.

The role of cisplatin (CP) and FK-565 in monocyte-mediated up-regulation of lymphokine-activated killer (LAK) cell induction by interleukin-2 (IL-2) was examined. Treatment of peripheral-blood mononuclear cells (PBMC) with CP or FK-565 in the presence of IL-2 resulted in a significant increase in LAK activity against NK-resistant Raji cells, as assessed by the 4-hour 51Cr release assay, depending on the dose of CP, FK-565 and IL-2. Up-regulation of IL-2-induced LAK activity by CP/FK-565 was significantly higher in whole PBMC as compared to PBMC depleted of monocytes. Addition of different numbers of monocytes to cultures of lymphocytes plus IL-2 along with CP or FK-565 resulted in a significant up-regulation of LAK activity depending on the number of monocytes added. Pretreatment of monocytes for 2 h with CP or FK-565 before addition of lymphocytes plus IL-2 resulted in significant up-regulation of LAK activity as compared to untreated monocytes. Culture supernatant of CP- or FK-565-treated monocytes also significantly up-regulated IL-2-induced LAK activity of lymphocytes. The results of the present investigation suggest that up-regulation of LAK activity by CP and FK-565 in human PBMC is monocyte-mediated. Further, our data demonstrate that tumor necrosis factor and IL-1 play an important role in the up-regulation of LAK activity by monocytes that have been pretreated with FK-565 or CP. These results indicate that CP and FK-565 may be useful in modulating the immune response during treatment of neoplasia with IL-2 and LAK therapies.

Adjuvants, Immunologic↗
PubMed1992

Lymphokine-activated killer cell and natural killer cell activities in patients with systemic sclerosis.

OBJECTIVE: To determine the ability of T lymphocytes and natural killer (NK) cells from patients with systemic sclerosis (SSc) to respond to cytokines and to generate immune effector cells. METHODS: The numbers and percentages of peripheral blood T and NK cells were examined by 2-color flow cytometry, and NK and lymphokine-activated killer (LAK) cell function were measured in 4-hour 51Cr-release assays, in 34 patients with SSc. The patients were categorized into 3 subgroups: 10 had diffuse cutaneous disease of less than or equal to 3 years disease duration, 11 had diffuse cutaneous SSc of greater than 3 years duration, and 13 had limited cutaneous disease. RESULTS: Baseline and activated NK and T cell numbers and NK activity were normal in SSc patients. However, mean LAK activity was significantly depressed in all SSc subgroups. CONCLUSION: Decreased LAK cell function, despite normal numbers of circulating T and NK cells, indicates that SSc patients have poor ability to produce effector cells in response to interleukin-2.

Adult↗
PubMed1992

T cell activation and T cell receptor variable region gene usage in measles.

T cell activation and T cell receptor variable (V) regions were studied with monoclonal antibodies in peripheral blood lymphocytes from 22 patients with measles. Increased (greater than 5%) activated T cells (HLA-DR+ CD3+ cells) were noted in 14 of the 22 patients. Elevations of V beta 5+ and V beta 8+ T cells were observed in two and four patients, respectively, and appeared to be associated with T cell activation. The duration of fever was significantly prolonged in those with increased (greater than 10%) activated T cells (p less than 0.01). These results suggest that T cell activation and the preferential expansion of V beta 8+ and V beta 5+ T cells are associated with the pathogenic process of measles.

Adolescent↗
PubMedDate not supplied

Susceptibility of human leukemia to allogeneic and autologous lymphokine-activated killer cell activity: analysis of 252 samples.

The present study investigated the susceptibility of human leukemia cells to allogeneic lymphocytes with lymphokine-activated killer (LAK) activity from normal donors and autologous LAK activity from patients in complete remission. LAK activity was generated from peripheral-blood mononuclear cells cultured for 6 days with 1,000 U/ml recombinant interleukin-2 (IL-2). Cytotoxicity was evaluated using a standard 4-hour chromium release assay. Susceptibility of leukemic cells to LAK was defined on the basis of the mean Cr release in 52 samples of normal bone marrow cells. Using allogeneic LAK, we examined leukemic cells from bone marrow or peripheral blood of 252 patients [102 with acute myeloid leukemia (AML), 99 with acute lymphoblastic leukemia (ALL), 13 with chronic myelogenous leukemia in blast crisis (CML-BC) and 38 with chronic leukemias of various types]. A significant lysis could be detected in 62% of all leukemias tested (in 68% of AML, 60% ALL, 92% CML-BC, 39% chronic leukemias). The mean chromium release (effector-to-target cell ratio 50:1) was 28.8 +/- 13.5% for LAK-sensitive leukemias versus 5.2 +/- 3.2% for resistant leukemias. We observed a distinct susceptibility of various leukemia subtypes. LAK cytotoxicity against autologous leukemia cells was examined in 40 leukemia patients in complete remission (24 AML, 16 ALL). 63% of the patients developed a significant cytotoxicity against their autologous leukemia cells. Regarding mean Cr releases, the efficiency of allogeneic LAK activity of normal donors did not differ significantly from that of autologous LAK activity of patients in complete remission against the same leukemic target cells. Analysis of our data revealed that examinations with allogeneic LAK activity make it possible to predict whether patients will develop significant in vitro killing of their autologous leukemia cells during complete remission. These results may be of particular importance in determining which patients could benefit from immunologic therapy modalities and in scheduling immunotherapy. Further clinical studies are necessary to ascertain the clinical significance of therapeutic approaches with IL-2 or adoptive cellular immunotherapy combined with IL-2 for treatment of human leukemia.

Acute Disease↗
PubMed1992

Up-regulation of IL-2 induced lymphokine activated killer cell activity by cisplatin and FK-565: involvement of calcium ion.

As reported earlier, the IL-2 induced lymphokine activated killer (LAK) activity is significantly up-regulated in the presence of cisplatin/FK-565. Based on these observations, we have investigated whether calcium is involved in the generation of LAK activity by IL-2 alone or along with CP/FK-565. We have shown that treatment of PBMC with IL-2 for four days caused an increase in intracellular free calcium and in ATP levels, which were further significantly enhanced when LAK cells were generated in the presence of CP/FK-565. Depletion of calcium resulted in decreased cytotoxic activity. Addition of tumor cells to LAK cells, generated in the presence of IL-2 alone or along with CP/FK-565 caused an instant rise in intracellular free calcium which was significantly decreased when an increase in intracellular free calcium was observed in calcium-free, EGTA-containing buffer. These data suggest that calcium is required for the activation and manifestation of lytic activity by LAK cells. Further, we observed that the increase in intracellular free calcium is not associated with the blastogenic response of peripheral blood mononuclear cells in response to treatment of IL-2 alone or together with CP/FK-565.

Adenosine Triphosphate↗
PubMed1992

In vitro and in vivo suppression of interleukin-2-activated killer cell activity by chimeric proteins between interleukin-2 and Pseudomonas exotoxin.

The biological effects of IL-2 are mediated through high (complex of alpha and beta chain) or intermediate (beta chain) affinity IL-2 receptors. Previously, chimeric proteins composed of IL-2 and Pseudomonas exotoxin (IL-2-PE) were shown to be specifically cytotoxic to cells bearing IL-2 receptors. It has also been shown that IL-2-PE chimeric proteins can abrogate T cell-mediated immune response in vitro. In the current study, we have investigated the effects of IL-2-PE on LAK activity both in vivo and in vitro. We administered either IL-2-PE40 (comprised of IL-2 and 40-kDa portion of PE) or IL-2-PE66 (comprised of IL-2 and 66-kDa molecule of PE) to normal C57BL/6 mice for 3 or 8 days and LAK activity was assessed in various organs of mice. We found that IL-2-PE40 generated LAK activity in various compartments of mice and the level of activity was slightly lower than that observed with an equivalent amount of recombinant (r) IL-2 alone. However, IL-2-PE66 failed to generate LAK activity which would have been induced due to an equivalent concentration of rIL-2. IL-2-PE66 also did not induce LAK activity from the splenocytes during in vitro culture while IL-2-PE40 generated good LAK activity. An equivalent amount of IL-2 also generated potent LAK activity. The suppression of LAK activity by IL-2-PE66 was also evident in cells preactivated with IL-2; however, this inhibition was partial. The suppressive activity of IL-2-PE66 was shown to be mediated through IL-2 receptor interactions as excess amounts of rIL-2 were able to abrogate its effect. Both IL-2 toxins were equivalently cytotoxic to IL-2 receptor-bearing HUT 102 cells and both were able to compete from high and intermediate affinity IL-2 receptors. Taken together, our data indicate that IL-2-PE66 is highly cytotoxic to LAK cells while IL-2-PE40 is less cytotoxic. Thus, data from our study and from other published reports indicate that IL-2-PE66 is more potent immunosuppressive agent than IL-2-PE40.

ADP Ribose Transferases↗
PubMed1976

Mast cell activation and tissue cell proliferation.

The effect of mast cell activation and degranulation on the proliferation in the intact mesentery was studied in Sprague-Dawley rats. Mast cell activation was achieved by a single intraperitoneal injection of Compound 48/80. The proliferation was studied using three independent methods for estimation of cell production and DNA synthesis: 1. the mitotic index, 2. the relative number of cells having a DNA content in the S and G2 regions, by Feulgen photometric measurement in individual cells, and 3. the specific DNA activity, employing a method which combines a liquid scintillation technique after an intravenous injection of 3H-thymidine and Feulgen photometric determination of the DNA content per membrane preparation. It was found that the proliferation of the normal mesenchymal cells adjacent to the activated and degranulated mast cells in the mesentery was significantly increased within 24 and 32 h, the maximum increase being more than 20-fold compared to untreated controls. The results suggest that the common type of mast cell may have a pathophysiological function related to stimulation of local cell proliferation.

Animals↗