Immunological parameters were evaluated in patients treated with cytokine-mediated immunotherapy (CMI) consisting of low doses of recombinant human interferon alpha 2a (rIFN alpha) and recombinant human interleukin-2 (rIL-2) administered either concomitantly or sequentially by subcutaneous self-injections in an outpatient setting. Twenty-six patients with hematological malignancies and 2 metastatic melanoma patients in a progressive stage were enrolled in this clinical trial. Of the 26 patients, 24 were at a stage of minimal residual disease, including 14 patients who had received autologous bone marrow transplantation (ABMT) 2-5 months previously, 7 chronic myelogenous leukemia (CML) and 3 acute myeloid leukemia (AML) patients. Two patients (1 CML and 1 mult. myeloma) were treated at a stage of progressive disease. Non-MHC-restricted cytotoxicity directed against natural-killer(NK)-resistant (Daudi) and NK-sensitive (K562) target cells was assessed before, during and after CMI, either in fresh peripheral blood samples (spontaneous activity) or after in vitro rIL-2 activation (induced activity). Spontaneous killing activity was low prior to treatment, but increased upon termination of treatment in 10/15 evaluated cycels. rIL-2-activated cytotoxicity in vitro was markedly elevated in 8/12 and 6/8 patients after one and two cycles, respectively, of sequential treatment, as well as in 3/8 CML and 5/6 patients after one and two cycles, respectively, of concomitant treatment. Activation of the T cell mitogenic response was demonstrated in 6/9 patients after concomitant CMI, while no such effect was observed throughout a sequential treatment in lymphoma and leukemia patients after ABMT. Although a direct correlation between immune stimulation and the in vivo antitumor response cannot yet be determined, our clinical observations support a beneficial therapeutic effect in a substantial number of patients. These results indicated that the ambulatory CMI protocol of rIL-2 and rIFN alpha could stimulate the host defense immune system and may be helpful in mediating the in vivo antitumor response in patients with minimal residual disease.
Donor-derived CD4+ T cells may play a role in the development of graft-versus-host disease (GVHD) and graft-versus-leukemia reaction after allogeneic bone marrow transplantation (BMT). Therefore, we evaluated the effect of CD4+ T-cell depletion on GVHD and graft-versus-leukemia reaction after HLA-matched BMT. CD4 depletion was performed using anti-CD4 monoclonal antibodies and immunomagnetic beads, initially in small-scale experiments on bone marrow and granulocyte colony-stimulating factor-mobilized peripheral blood apheresis products. The result was elimination of the CD4+ T cells from both sources (0% and 2+/-1.4% CD4+ cells, respectively). Subsequently, we used this technique for large-scale negative selection of CD4+ T cells from bone marrow grafts of four consenting leukemic patients in relapse (ALL-3, ANLL-1) (M-3, F-1). The large-scale CD4+ T-cell depletion resulted in >98% (n=4) elimination of CD4+ cells. The resulting population included 17.7+/-4.6% CD3+ T cells, 8.9+/-2.5% CD8+ T cells, 0.1+/-0.1% CD16+ natural killer cells, and 2.3+/-3.2% CD34+ hematopoietic progenitor cells. Patients were transplanted with 2.84+/-1.31 x 10(8) viable cells/kg. They received cyclosporine starting on day -1 as GVHD prophylaxis. Engraftment was fast with a white blood cell count of >1 x 10(9)/L on day 13.2+/-0.5, an absolute neutrophil count of >0.5 x 10(9)/L on day 13.8+/-0.5, and a platelet count of >25 x 10(9)/L on day 26.5+/-6.8. Immunological reconstitution was normal, and peripheral blood phenotyping 3 weeks after BMT disclosed 49.0+/-5.0% CD3, 14.3+/-12.4% CD4, and 59.5+/-7.8% CD8 T cells in addition to 17.0+/-3.0% CD16+ and 9.0+/-3.0% CD56 natural killer cells. Three out of four patients developed very early grade IV GVHD beginning on day 12 (10-13) and died 2-4 months after BMT. One patient is alive and well with a follow-up of 36 months. We conclude that selective CD4 T-cell depletion does not prevent GVHD.
Different modes of in vitro activation of peripheral blood mononuclear cells (PBMC) were compared for their effect on long-term propagation. PBMC cultures were activated by short exposures to the mitogen phytohemagglutinin (PHA) and the CD3 complex, with or without secondary signals provided by ligands of CD28 costimulatory molecules. Activation and long-term cultures were carried out in the presence of recombinant interleukin-2 (rIL-2). Addition of supernatant derived from IL-2-activated PBMC improved culture cell yield. Cumulative fold expansions ranged between 10(3) and 10(5) within 21 days. The highest cell yield was found after PHA activation. Fewer cells were obtained after activation with a combination of CD3 and CD28, and even fewer were obtained after CD3 activation alone. An increase in CD8+ and CD56+ cells, without change in CD4+ cells, was found in activated cultures when compared with fresh PBMC. Non-MHC-restricted cytotoxic activity was documented in all activated cultures. Cytotoxic activity per culture was highest in PHA-activated PBMC because of the high cell yield on the day of harvest. Successful in vitro expansion of PBMC might be helpful for gene transfer into T lymphocytes, as well as for the induction of an antitumor response, particularly for prevention and treatment of relapse of hematologic malignancies following allogeneic or autologous bone marrow transplantation.
Although allogenenic stem cell transplantation may provide a cure for a growing number of patients with hematologic malignancies and several metastatic solid tumors, several problems remain to be solved. In routine medical practice transplant can be offered for patients with a matched donor available whereas the large majority of patients in need have no matched donor available. Although alloreactive lymphocytes may eliminate residual malignant cells, such an effect is accompanied by acute and chronic GVHD which may be hazardous even in recipients with perfectly matched allografts, and prohibitive in recipients treated with haploidentically mismatched allografts. On the other hand immunotherapy with intentionally mismatched allografts could provide a much more effective tool for eradication of tumor cells resistant to chemotherapy. We have pioneered a new approach for treatment of patients with resistant hematological malignancies (AML/MDS 5; ALL 1; Biphenotype 2; NHL 3; HD 1) using matched siblings (n=4), matched unrelated donor (n=1) or haploidentically mismatched donors (n=7). Prevention of rejection of mismatched allografts was accomplished by combination of fludarabine and deletion of donor reactive host lymphocytes by infusion of donor mononuclear blood cells and elimination of alloreactive lymphocytes susceptible to high-dose cyclosphosphamide (60mg/kgx3) one day later. Prevention of GVHD following infusion of G-CSF mobilized, haploidentically mismatched blood stem cells was accomplished using Miltenyi’s immunomagentic beads coupled with anti-AC133 (n=6) or using anti-CD3 (n=1). No other anti-GVHD prophylaxis was used. Following transplantation, patients were treated with rIL-2 activated donor peripheral blood lymphocytes activated for 4 days at 37°C in 5% C02 in air incubator with rIL-2 6,000 IU/ml. T cell depletion was accomplished either by positive selection of CD56+ (n=10) or negative selection of CD3 (n=2) for optimal induction of graft vs leukemia (GVL) effects by mismatched and fully activated NK cells. One patient with resistant leukemia became disease free for 8 months but died of resistant aspergilosis which was evident prior to transplantation. Five out of 12 patients with intractable and fully resistant leukemia are alive with no GVHD and no evidence of disease 1–18 (median 13) months post transplantation. Based on our ongoing preliminary study we conclude that patients with resistant hematological malignancies may benefit from cell therapy mediated by rIL-2 activated donor lymphocytes, and most likely from intentionally mismatched haploidentical allografts following elimination of host anti-donor alloreactive lymphocytes and prevention of GVHD by positively or negatively selected stem cells, followed by immunotherapy with rIL-2 activated CD3 depleted NK cells. Intentionally mismatched rIL-2 activated NK cells represents a safe approach for elimination of residual tumor cells, aiming for induction of GVL while avoiding GVHD.
Linomide (quinoline-3-carboxamide), a well tolerated, orally administered compound was recently shown to be effective in the prevention and treatment of several autoimmune diseases in experimental animal models. We have investigated its effect on specific humoral immune responses directed to T-cell-dependent soluble or particulate antigens and to a T cell-independent antigen in several mouse strains. Linomide administered after antigen priming did not affect primary and secondary antibody responses directed to T-cell particulate antigens (SRBC) or soluble antigens given with or without complete Freund's Adjuvant (CFA). Linomide treatment given prior to antigen priming did not affect the antibody response to a soluble antigen (TNP-KLH) given with an adjuvant. In contrast, dose-dependent down regulation of primary antibody responses was observed when T cell-dependent (BSA-dextran) or T-cell-independent (TNP-Ficoll) antigens were administered in an immunogenic form without adjuvant after starting Linomide treatment. The primary anti-SRBC antibody response was also suppressed by high dose Linomide given prior to immunization although normal secondary responses were retained. It is worth noting that no immunosuppressive effects on antibody responses were found at low dose ranges which effectively reversed T cell dependent autoimmune manifestation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.