Mitogen-activated lymphocytes of normals and glioma patients produce factors with anti-glioblastoma activity in vitro

Intermittent cyclophosphamide and prednisone treatment of polyneuropathy associated with monoclonal gammopathy of undetermined significance

In an open prospective study, we analyzed the effect of cyclophosphamide (300 mg/m2 body surface daily for 4 days) combined with prednisone (40 mg/m2 body surface daily for 5 days) at 4-week intervals during 6 months in 16 patients with polyneuropathy associated with monoclonal gammopathy of undetermined significance (MGUS). Eleven patients had an IgM-MGUS and five an IgG-MGUS. During a follow-up period of 3 years, eight patients had improvement and six patients stabilized, based on quantitative neurologic examination, the Rankin disability scale, and electrophysiologic studies. These 14 patients had neuropathy with demyelinating and axonal features. One patient with a purely axonal neuropathy had deterioration despite therapy. One other patients developed severe leukopenia as side effect of cyclophosphamide, necessitating withdrawal of treatment. A difference in response was not present in patient with IgM- or IgG-MGUS, nor in patients with or without autoantibodies against myelin-associated glycoprotein. Nine patients had a bone marrow biopsy before and 1 year after treatment. In eight patients, the monoclonal lymphoid IgM or plasma cell IgG infiltration decreased, while in four the monoclonality disappeared after treatment. In the patient who had neurologic deterioration, repeated bone marrow biopsy showed deposits of amyloid. In conclusion, short-term treatment with intermittent cyclophosphamide and prednisone may have a long-term favorable effect in patients with demyelinating polyneuropathy associated with MGUS.

Systemic chemotherapy combined with local adoptive immunotherapy cures rats bearing 9L gliosarcoma

Survival of Fischer rats bearing 9L gliosarcoma in the brain was measured to determine the efficacy of 1) systemically administered chemotherapy with local adoptive immunotherapy (chemo-adoptive immunotherapy) or 2) systemically administered chemo-immunotherapy. Winn assays, where tumor instillation coincided with the start of treatment, and one-week established tumor assays were conducted. Survival of chemo-adoptive immunotherapy treated groups given intraperitoneal cyclophosphamide and intracranial lymphokine activated killer cells and recombinant Interleukin-2 was significantly extended when compared to sham treated control groups, to groups given chemotherapy with intraperitoneal cyclophosphamide, and to groups treated by local adoptive immunotherapy with intracranial lymphokine activated killer cells and Interleukin-2. The killer cells were generated from spleens of donor rats that either had or had not been given cyclophosphamide 24 h earlier. Long-term survivors (9/39), sacrificed at day 70, were obtained only in the chemo-adoptive immunotherapy treated groups; 7/39 had no histologic evidence of tumor and had focal sterile abscesses at the site of killer cell instillation. Average group weight plotted over time showed that there was acceptable toxicity with chemo-adoptive immunotherapy; the toxicity was identical to that obtained with systemic cyclophosphamide treatment. In contrast, survival of chemo-immunotherapy treated groups given systemic cyclophosphamide and Interleukin-2 was not significantly extended from groups which were sham treated or treated only with systemic Interleukin-2. Rapid decline of average group weight plotted over time and early deaths following chemo-immunotherapy treatment indicated that the regimen was toxic. The effect of cyclophosphamide administration on the splenocytes of donor rats and the LAK cells generated from them was determined by in vitro studies analyzing cell number, viability, phenotypic expression and cytotoxicity against 9L tumor. In the treatment of this intracranial neoplasm, the beneficial effects of cyclophosphamide were determined to occur in situ in the tumor-bearing host. No benefit resulted from cyclophosphamide treatment of donor rats that supplied splenocytes for LAK cell production.

Inflammatory leukocytes associated with increased immunosuppression by glioblastoma

In order to determine the in vivo immune response in glioblastoma, monoclonal and polyclonal antibodies specific for inflammatory leukocytes and immunoregulatory products were utilized to stain tissue from four surgical specimens. The more activated the inflammatory cells, the more activated the tumors appeared to be. In the tumor with the largest infiltration (Case 3), inflammatory cells were stained for interferon-gamma, interleukin-2, interleukin-1 beta, lymphotoxin, tumor necrosis factor-alpha, and transforming growth factor-beta. The tumor cells also expressed interleukin-1 beta, interleukin-6, transforming growth factor-beta, tumor necrosis factor-alpha, and prostaglandin E. In contrast, in the tumor with the least inflammatory response (Case 1), the tumor cells did not express any cytokines. Expression of cytokines by glioma cells was modest in the two cases with modest inflammatory responses. Cellular inflammation, primarily consisting of T cells and macrophages with few or no B cells or natural killer cells, was two- to 15-fold greater outside the tumor than within. In contrast to leukocytes outside the tumor, which were activated and expressing class II major histocompatibility antigens, leukocytes within the tumor parenchyma or at the tumor's edge were negative for these antigens. In the four specimens studied here, the tumor cells themselves were also negative for class II major histocompatibility antigens. These findings, although preliminary, suggest that inflammatory cells within gliomas are inactivated and that glioma cells may increase the expression of immunosuppressive cytokines in response to an increased lymphocyte infiltrate. This observation, if corroborated by more extensive studies, may help to explain the failure of immune treatments in glioblastoma multiforme.

Interleukin-2-activated lymphocytes from brain tumor patients. A comparison of two preparations generated in vitro

Two preparations of human recombinant interleukin-2 (rIL-2)-activated lymphocytes from patients harboring malignant brain tumors were characterized as autologous-stimulated lymphocytes (ASL) and lymphokine-activated killer (LAK) cells. ASL were generated from Ficoll-Paque-isolated, nonadherent, defibrinated peripheral blood lymphocytes (PBL) that were stimulated overnight with phytohemagglutinin (PHA) and cultured with rIL-2 (100 U/ml) for 10 days. LAK cells were produced by culturing all PBL in rIL-2 (500 U/ml) for 4 days. In 4-hour chromium release assays, LAK cells showed greater cytotoxicity than ASL against natural killer (NK)-sensitive and NK-resistant tumor cell lines; by 18 hours, the effectiveness of ASL equaled that of LAK cells. By electron microscopic study, PBL, LAK cells, and ASL showed differences. The helper/inducer to suppressor/cytotoxic ratio (T4+/T8+) of PBL, LAK cells, and ASL was 1.1:1, 1.0:1, and 0.4:1, respectively. ASL, when compared with PBL or LAK cells, have a significantly higher percentage of MO1+/DR+ and T8+/9.3+ subpopulations. ASL and LAK cells, used for the therapy of gliomas, are distinct.

Leukoregulin inhibits the growth of human glioblastoma in vitro

Growth of cultured human glioblastoma cells was profoundly inhibited by concentrated lymphokines prepared from mitogen-activated blood mononuclear cells of normal donors. Cloning efficiency of glioma cells and their absolute number were decreased as well. Partially purified leukoregulin, free of lymphotoxin, tumor necrosis factor and gamma-interferon, similarly suppressed DNA synthesis and clonogenicity. The decrease in absolute numbers of tumor target cells indicated that leukoregulin was directly cytolytic as well as cytostatic for human glioblastoma cells. Our data indicate that leukoregulin is at least one of the factors produced by activated lymphocytes which inhibits the proliferation of human glioblastoma in vitro.