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Biomedical subjects

S Slavin

Publications and source records attributed to S Slavin.

At least 109 records · Page 6Linked to original sources

Immunotherapy in conjunction with autologous and allogeneic blood or marrow transplantation in lymphoma.

Relapse is the major obstacle for successful transplantations in lymphoma. One of the ways to reduce relapse rates is to intensify immune-mediated effector mechanisms. Graft-versus-lymphoma may be achieved either by administration of cytokines or by allogeneic cell-mediated adoptive immunotherapy. The use of allogeneic non-myeloablative stem cell transplantation (SCT) is another option which may be applicable to all age groups. It remains to be seen whether non-myeloablative SCT will result in a lesser degree of relapse and higher disease-free survival in lymphoma patients.

Antilymphocyte Serum↗

Doctoring: University of California, Los Angeles.

The Doctoring curriculum at the University of California, Los Angeles, UCLA School of Medicine covers all four years of medical school. Its goal is to train physicians to give care that is compassionate, humanistic, high-quality, and evidence-based through a longitudinal, interdisciplinary curriculum with integration of learning experiences within and between years and with more emphasis on certain topics that had been previously neglected (e.g., advanced physical diagnosis, nutrition, public health, ethics). The curriculum operates alongside the traditional one, but strong attempts are made to link the two curricula. The authors describe the gradual introduction of the Doctoring curriculum, the sometimes formidable barriers that were encountered and in some cases still exist (e.g., some faculty and student resistance, need to find funds, faculty recruitment and retention). Active, interested faculty are essential, and intensive faculty development is needed. A detailed description of each year's courses and teaching approaches is given. Year one focuses on interpersonal communication, the medical interview, human development and behavior, and the role of the community in health care; year two, on clinical reasoning, physical diagnosis skills, population medicine, and ethics; year three, on clinical problem solving, health services, professionalization issues, and prevention; and year four (which is elective), on medical education and leadership. The methods of evaluating students, faculty, and the curriculum itself are described and assessed. The authors conclude with a review of plans, prospects, and ongoing problems.

Curriculum↗

Allogeneic cell-mediated and cytokine-activated immunotherapy for malignant lymphoma at the stage of minimal residual disease after autologous stem cell transplantation.

Immunocompetent donor-derived T lymphocytes play a crucial role in the elimination of residual leukemic cells post allogeneic bone marrow transplantation. Because this graft versus leukemia (GVL) effects is absent after autologous stem cell transplantation (ASCT), a high rate of relapse ensues. We introduced cell-mediated immunotherapy at the stage of minimal residual disease in lymphoma patients to help effect a GVL-like reaction by adoptive transfer of immunocompetent human leukocyte antigen-matched donor peripheral blood lymphocytes (PBL). Thirteen consecutive patients with high-risk lymphoma were treated with allogeneic cell therapy (AlloCT) after having undergone ASCT. In the absence of graft-versus-host disease, cell therapy-induced graft-versus-lymphoma reaction was amplified by human recombinant interleukin 2 (rIL-2) during 3 days to activate donor PBL in vivo, followed by infusion of in vitro rIL-2 activated donor lymphocytes combined with 3-day rIL-2 therapy. Nine of the patients underwent the treatment protocol well. In the four other patients, in whom the AlloCT resulted in marrow aplasia due to elimination of host hematopoietic cells, treatment with donor marrow cell infusion without further conditioning was performed. Adoptive cell therapy in the form of AlloCT may turn out to be an effective therapeutic modality for the treatment of resistant residual disease in lymphoma patients.

Adolescent↗

Continuous interleukin-2 infusion combined with cyclophosphamide- based combination chemotherapy in the treatment of hemato-oncological malignancies. Results of a phase I-II study.

The combination of a cyclophosphamide (CTX)-based chemotherapy regimen and interleukin-2 (IL-2) has been shown to provide synergistic effects against malignancy in animal models. We therefore conducted a phase I-II trial combining CTX-based combination chemotherapy or CTX alone with high-dose IL-2 in patients with advanced and refractory malignant disease. Fifteen patients with hemato-oncological malignancies (malignant lymphoma 8, multiple myeloma 3, solid tumor 2, leukemia 2) were enrolled in the study. Continuous high-dose IL-2 infusion was shown to be safely administered, starting as soon as recovery of white blood cell count. All patients developed rebound lymphocytosis 24-48 h after termination of IL-2 infusion. Although grade IV toxicity was observed in 5 patients (7 episodes), all side effects completely subsided. Triple chemotherapy (CTX, etoposide and Ara-C) seemed rather toxic (in this group of heavily treated patients) while CTX alone was well tolerated. Four out of 13 (31%) evaluable patients had partial response and another patient (7%) had stabilization of disease progression lasting 2-8 months. Our conclusion is that the combination of CTX and continuous infusion of IL-2 is feasible and should be investigated in patients with various malignant neoplasms.

Adult↗

Amelioration of diabetes in nonobese diabetic mice with advanced disease by linomide-induced immunoregulation combined with Reg protein treatment.

Oral linomide, (quinoline-3-carboxamide), has been shown to prevent autoimmune insulitis, islet destruction, and diabetes in NOD mice treated at an early stage of the disease, but confers only partial protection in animals with advanced disease. Reg protein, the gene product of a complementary DNA isolated from a regenerating rat islet library, has been previously shown to induce expansion of beta-cell mass in pancreatectomized rats. To determine the effect of treatment combining immunomodulation and Reg protein on advanced autoimmune diabetes, we treated female NOD mice with oral linomide and i.p. Reg protein injections. In 14-week-old animals with less severe disease (glucose tolerant), treatment with each agent alone resulted in amelioration of diabetes, as did treatment with Reg alone in 5-week-old prediabetic mice. In 14-week-old animals with more severe disease (glucose intolerant), only treatment with the combination of both agents, but not that with each separately, resulted in amelioration of diabetes. Our study suggests that treatment aimed at abrogation of autoimmunity combined with expansion of beta-cell mass constitutes a potential therapeutic approach for treatment of insulin-dependent diabetes mellitus.

Adjuvants, Immunologic↗

Allogeneic cell-mediated immunotherapy for breast cancer after autologous stem cell transplantation: a clinical pilot study.

Allogeneic cell therapy (allo-CT) is emerging as an effective treatment for patients relapsing after allogeneic bone marrow transplantation (BMT), indicating that tumor cells resisting chemoradiotherapy may still respond to immunocompetent allogeneic lymphocytes. We investigated possible graft-versus-tumor (GVT) effects in six patients with metastatic breast cancer that would be comparable to the graft-versus-leukemia (GVL) phenomenon occurring after allogeneic BMT in hematologic malignancies. The patients were cytoreduced with high-dose chemotherapy and autologous stem cell transplantation (ASCT), and were treated ambulatory with allo-CT consisting of adoptive transfer of HLA-matched donor peripheral blood lymphocytes (PBL) activated in vivo with human recombinant interleukin-2 (rIL-2). If no graft-versus-host disease (GVHD) developed, allo-CT was augmented with infusion of donor PBL, preactivated in vitro with rIL-2. Treatment was well tolerated, with low therapy-related toxicity in all patients. Two patients developed signs and symptoms compatible with GVHD grade I-II, one of whom shows no evidence of disease at more than 34 months out. In the remaining patients, progression-free survival following allo-CT ranged between 7 and 13 months. Allogeneic cell-mediated, cytokine-activated immunotherapy might be utilized for induction of GVT in metastatic breast cancer. A search for techniques to boost chimerism without severe GVHD is indicated.

Adult↗

Enhanced lymphoid cell recovery after bone marrow transplantation: correlation with the presence of costimulatory antibodies in serum.

We describe a patient with T cell deficiency who underwent bone marrow transplantation (BMT) from an HLA-identical brother. The patient's white blood cell count recovered with exceptional rapidity post-BMT: after 7 to 9 days it rose sharply to 98x10(9) cells/L, 76% of which were mononuclear leukocytes. It then decreased, and a second peak was observed 250 days post-BMT. Lymphocytes from both peaks displayed a phenotype of mature T cells together with characteristics of a constitutively activated state; that is, they 1) exhibited high levels of tyrosine-phosphorylated T cell receptor (TCR) zeta chain, 2) spontaneously secreted IL-2, 3) expressed activation specific cell surface markers, and 4) were unresponsive to in vitro stimuli. The increased cell counts in both peaks correlated with the presence of anti-lymphocytic antibodies in the patient's serum, which reacted with peripheral blood lymphocytes (PBLs) both from the donor and from unrelated individuals. These antibodies were present before BMT and reappeared post-BMT. Variable number tandem repeats analysis revealed that the patient's PBLs were chimeras for up to 2 years post-BMT. This finding could explain the newly synthesized post-BMT anti-lymphocytic antibodies and the appearance of the second WBC peak during that period. The patient's anti-lymphocytic antibodies displayed costimulatory activity, enhancing the in vitro proliferation of normal T cells suboptimally activated via the TCR. The unique characteristics of these antibodies could explain the enhanced T cell recovery observed post-BMT as well as the constitutive activation state of these cells. Furthermore, such antibodies may eventually facilitate development of a therapeutic method for inducing enhanced post-BMT recovery.

Adolescent↗

Cytokine gene transduction into non-immunogeneic murine tumor cells.

The effect of cytokine transduction on the tumorigenicity and immunogenicity of murine non-immunogeneic mammary carcinoma (4T1), acute myeloid leukemia (mAML) and partially immunogenic B-cell leukemia (BCL1) has been evaluated in syngeneic strains of mice. Transduction by retroviral vectors containing the genes for GM-CSF, IL-2 or IFN-gamma did not lead to a marked antitumor effect in 4T1 mammary tumor or BCL1. A reduced local tumor size was observed in mice inoculated with 4T1 cells transduced with both GM-CSF and IL-2 genes followed by an in vitro exposure to recombinant IFN-gamma, but survival was not prolonged. Tumorigenicity of mAML cells transduced with the gene coding for IFN-gamma was significantly reduced as manifested by prolonged survival of mice in comparison with animals inoculated with non-transduced mAML cells. Transduction by each of the aforementioned cytokines did not affect the immunogenicity of these tumor model cells. The results suggest that genetic modification of spontaneous and non-immunogenic experimental tumor models does not necessarily support direct utilization of cytokine gene therapy for clinical application. More effective methods have yet to be established in order to achieve an antitumor effect in spontaneous non-immunogenic malignancies.

Animals↗

Immunotherapy with recombinant human interleukin-2 and recombinant interferon-alpha in lymphoma patients postautologous marrow or stem cell transplantation.

Immune-mediated effects appear to play a major role in controlling minimal residual disease (MRD). We, therefore, investigated the role of recombinant human interleukin-2 (rIL-2) given concomitantly with interferon-alpha (IFN-alpha) in malignant lymphoma (ML) patients with responding disease following autologous bone marrow or blood stem cell transplantation (ABSCT). Fifty-six patients were included in this investigation. Thirty-two patients had non-Hodgkin's lymphoma (NHL) and 24 patients had Hodgkin's disease (HD). Sixty-one patients (NHL 36, HD 25) served as historical controls. Patients from both groups had similar demographic characteristics, the same stage of disease at presentation, status of disease at transplantation, conditioning regimens, and type of transplant. rIL-2 and IFN-alpha were self-administered in two cycles beginning 2.5 to 10.5 months (median, 4 months) posttransplant and separated by a 4-week interval. Each cycle consisted of IFN-alpha subcutaneously (SC) 3 x 10(6) U/d x 5 d/wk combined with rIL-2 SC 3 to 6 IU/m2/d x 5 d/wk for 4 weeks. The incidence of survival and disease-free survival (DFS) was significantly higher in the group under investigation than in the historical controls (P < .01). Of 56 patients with ML treated with IFN-alpha + rIL-2, 45 patients are DFS (80.4%) after a follow-up of 7 to 78 months (median, 34 months), whereas in the historical controls, 32 of 61 (52.5%) patients are disease free, in a follow-up of 4 to 84 months (median, 23 months) posttransplant (P < .01). Our preliminary results are encouraging and suggest that home administered immunotherapy with IFN-alpha and rIL-2 is relatively well tolerated and may intensify remission in ML patients with MRD following ABSCT.

Adolescent↗

Permanent and specific transplantation tolerance induced by a nonmyeloablative treatment to a wide variety of allogeneic tissues: I. Induction of tolerance by a short course of total lymphoid irradiation and selective elimination of the donor-specific host lymphocytes.

The long-term success of organ transplantation is limited by complications resulting from consistent nonspecific immunosuppression. Induction of stable, donor-specific tolerance remains the main goal of transplantation immunology. In this article, a new, nonmyeloablative method is described for induction of transplantation tolerance to fully mismatched bone marrow cells (BMC), bone marrow stromal precursors, heart muscle, and skin allografts. The method is based on pretransplant conditioning with no postgraft immunosuppression, and consists of a short course (six daily fractions of 200 cGy) of total lymphoid irradiation (sTLI), followed by selective elimination of donor-specific alloreactive cells of the host escaping low-dose sTLI. Donor-specific alloreactive cells were activated by intravenous inoculation with a high dose of donor BMC (3 x 10(7) cells) 1 day after sTLI, and eliminated by a single intraperitoneal dose (200 mg/kg) of cyclophosphamide given 1 day after cell transfer. Infusion of a low number of T cell-depleted BMC (3 x 10(6) cells) after tolerogenic preconditioning converted recipients to stable mixed chimeras free of graft-versus-host disease. The same treatment provided long-lasting acceptance of heterotopically transplanted allografts of the heart muscle and of the stromal precursors to the hematopoietic microenvironment. This treatment also led to acceptance and life-long survival of full-thickness donor skin allografts. However, skin allografts survived only in mice that received donor T cell-depleted BMC after cyclophosphamide and had 20-50% donor cells in the blood. Our results suggest that after sTLI, additional selective clonal deletion of residual host cells induces a state of long-lasting specific tolerance to a wide variety of donor-derived tissues.

Animals↗

Induction of graft vs. tumor effect in a murine model of mammary adenocarcinoma.

We have attempted to induce immune-mediated graft-vs.-tumor (GVT) effects against solid tumors, using a murine model of mammary adenocarcinoma derived from BALB/c(H-2d) mice. A cell line (4Tl) isolated from this tumor model was highly tumorigenic in syngeneic (BALB/c) or haplo-identical (BALB/c x C57B1/6)F1 mice (F1), was only partially tumorigenic in an H-2d congenic strain of mice (DBA/2) and was non-tumorigenic in a major histocompatible (MHC)-unrelated (H-2b) strain of mice (C57B1/6). 4Tl cells express class I MHC antigens and adhesion molecules but do not express MHC class II antigens or B7-1 co-stimulatory molecules. Female BALB/c (H-2d) or F1 (H-2d/b) mice were reconstituted with male bone marrow (BM) cells derived from minor histocompatible (MiHC)-mismatched DBA (H-2d) donors or with MHC-mismatched C57B1/6 (H-2b) BM cells, respectively, 24 hr following lethal total body irradiation. Recipient mice carrying MiHC- or MHC-mismatched donor cells were inoculated with 4Tl cells 2-3 months following BM reconstitution. Chimeras reconstituted with allogeneic donor cells that were MiHC- or MHC-incompatible with tumor cells were able to down-regulate the development of the primary tumor expressing host-ype MHC alloantigens. Tumor size in BM chimeras across MiHC or MHC antigens was significantly smaller than tumor size observed in normal BALB/c or F1 controls. The GVT effect might be of help in improving immunotherapy for solid tumors in humans.

Adenocarcinoma↗

Interleukin-7-enhanced cytotoxic T lymphocyte activity after viral infection in marrow transplanted mice.

Lethally irradiated BALB/c mice were reconstituted by syngeneic bone marrow transplantation (BMT), and injected with recombinant interleukin 7 (rIL-7), recombinant interleukin 2 (rIL-2), or saline 10 days post-transplantation. Intranasal infection with A/PR8/34 influenza virus 2 weeks after BMT was associated with the highest survival rate in the rIL-7 treated group. The protective mechanism elicited by rIL-7, as manifested by very low virus titers in the lung, involves T and B cell functions. High hemagglutinin inhibition antibody levels were observed on days 7 and 12 post-challenge in the rIL-7 mice. Moreover, the anti-influenza cytotoxic T lymphocyte activity was induced primarily by rIL-7, leaving the effect of rIL-2 on the same level as that of the control. Thus, rIL-7 promotes both T cell-mediated function and B cell production during the immunodeficient state after BMT. This cytokine may prove a potential immunotherapeutic modality in BMT recipients.

Animals↗

A fludarabine-based protocol for bone marrow transplantation in Fanconi's anemia.

Allogeneic bone marrow transplantation (BMT) is an effective therapy for Fanconi's anemia (FA). However, mortality and transplant-related complications are usually high due to increased sensitivity to the alkylating agents and radiation commonly used for pre-transplant conditioning. Fludarabine monophosphate is a purine analogue that has been proven effective as a conditioning agent for chronic lymphocytic leukemia patients. We report a child with FA in leukemic transformation with thrombocytopenia and 20% myeloblasts who underwent successful BMT following conditioning with fludarabine/ATG/cyclophosphamide. The regimen was well tolerated, no transplant-related complications were observed, and engraftment was rapid. The child is currently 10 months post-BMT, in excellent clinical condition with a normal blood count, 100% chimerism and no sign of graft-versus-host disease (GVHD). We suggest that this fludarabine-based regimen may be effective in the conditioning of standard, as well as transforming, FA patients for BMT.

Antineoplastic Agents↗

Immunomodulatory effects of linomide in animals immunized with immunopathogenic retinal antigens: dissociation between different immune functions.

Linomide (LS-2616, quinoline-3-carboxamide) has been reported to exert a diverse range of effects on the immune system. On one hand, this drug was found to stimulate the immune system and to enhance activities such as DTH or allograft rejection. On the other hand, linomide was shown to inhibit the induction of experimental autoimmune encephalomyelitis and myasthenia gravis, as well as the development of diabetes in non-obese diabetic (NOD) mice. Here we report the effects of linomide in animals immunized with uveitogenic retinal antigens. Treatment with linomide completely inhibited the development of experimental autoimmune uveoretinitis (EAU) in mice immunized with interphotoreceptor retinoid-binding protein and markedly suppressed EAU in rats immunized with S-antigen (S-Ag). In addition, linomide-treated rats exhibited reduced antibody production and lymphocyte proliferative response to S-Ag. In contrast to these suppressive activities, linomide treatment did not affect the development of adoptively transferred EAU in rats and moderately enhanced the DTH reactions to S-Ag in immunized rats in which EAU and other immune responses to this antigen were suppressed.

Adjuvants, Immunologic↗

Activated long-term peripheral blood cultures as preparation for adoptive alloreactive cell therapy in cancer patients.

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.

CD28 Antigens↗