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Biomedical subjects

E Vilmer

Publications and source records attributed to E Vilmer.

At least 127 records · Page 7Linked to original sources
PubMed1990

Lack of permissivity of human monoclonal CD4+ lymphocytes to HIV.

Although knowledge has accumulated about GP110-CD4 interaction, viral penetration into human CD4+ lymphocytes remains unclear, in spite of the fact that all studies on HIV infection were performed on cell-transformed lineages, or on human polyclonal CD4+ cells. In order to investigate this viral entrance into susceptible cells, we studied the permissivity of 13 human monoclonal CD4+ lymphocytes by means of reverse transcriptase (RT) assay and immunocapture. We demonstrated a differential susceptibility to HIV of these CD4+ clones. In a second experiment, HIV infection was studied: (1) sequentially by RT assay and P24 immunocapture on several clones; (2) by cocultivation of infected clones with umbilical cord lymphocytes. These experiments suggested existence of permissive and "nonpermissive" CD4+ monoclonal lymphocytes. Slot blot, then PCR, revealed that proviral DNA sequences were detectable in all clones, but were present at lower levels in nonpermissive clones.

Antibodies, Monoclonal↗
PubMed1989

Unusually high frequencies of HIV-specific cytotoxic T lymphocytes in humans.

CTL specific for the HIV belong to the CD8 subset of T lymphocytes, and their activity is restricted by class I HLA transplantation Ag. In this report, HIV-specific CTL and their precursor cells were quantified by limiting dilution analysis. CTL were recovered from the lungs, lymph nodes, and blood of asymptomatic seropositive carriers and of patients with AIDS. HIV was found to be very immunogenic. High frequencies of both HIV-specific CTL and CTL precursor cells were detected in infected individuals. These CTL killed autologous HIV-infected macrophages and T4 lymphoblasts. They also killed doubly transfected P815-A2-env-LAV mouse tumor cells, which express the human HLA-A2 gene and the HIV-1 env gene. In the longitudinal studies of two HIV-infected patients, CTL and CTL precursor cell frequencies decreased as the clinical and immunologic status of the patients deteriorated. Most surprisingly, PBL from seronegative donors also responded to HIV stimulation in vitro and generated large numbers of HLA-restricted, HIV-specific CTL.

Animals↗
PubMed1989

Incidence, severity, and prevention of infections in chronic granulomatous disease.

We retrospectively analyzed the frequency and nature of infections occurring in 48 patients with chronic granulomatous disease. The long-term use of trimethoprim-sulfamethoxazole and ketoconazole as a preventive therapy for infections has also been evaluated. Lymphadenitis, lung infections, dermatitis, enteral infections, and hepatic abscesses were the most frequent infections. Staphylococcus aureus, Salmonella, and Aspergillus were the main microorganisms encountered. Twelve patients died: five from lung aspergillosis, three from hepatic abscesses, two from pneumonopathy of unknown origin, one from salmonellosis, and one from another probable infection that could not be proved. The actuarial survival rate was 50% at 10 years of age, with a prolonged plateau thereafter. There was no difference in survival rates between patients with X-linked and those with autosomal recessive chronic granulomatous disease. The 8-year actuarial survival rate was significantly higher for patients born in 1978 or afterward than for patients born before 1978 (92.9% vs 70.5%). A retrospective analysis of the occurrence of bacterial and fungal infections in patients who received trimethoprim-sulfamethoxazole and ketoconazole as infection prophylaxis indicated that the former was effective against bacterial infections but that ketoconazole provided no protection against Aspergillus infections.

Adolescent↗
PubMed1988

Immune recognition of AIDS virus antigens by human and murine cytotoxic T lymphocytes.

The CTL response to HIV was analyzed in humans and in mice. By using a novel and strictly autologous lymphocyte culture system, human CTL lines were established with PBL from seropositive asymptomatic donors and from patients suffering from AIDS or presenting AIDS-related complex. CTL from HLA-A2 donors recognize and kill murine P815 mastocytoma cells doubly transfected with the human HLA-A2 gene and the HIV env gene; they also kill HLA-compatible human macrophages infected with HIV. CTL specific for the HIV env Ag were also generated in BALB/c mice by immunization with syngeneic murine cells transfected with the HIV env gene. Human and murine HIV-immune CTL populations belong to the CD8 subset of T lymphocytes and are restricted by class I HLA or H-2 transplantation Ag, respectively, in the recognition of HIV env Ag. The two different experimental systems presented here can be used to study CD8 lymphocyte immunity against HIV. The murine model of CTL immunity offers the additional advantage of avoiding the manipulation of infectious virus isolates.

Animals↗
PubMed1988

Expression of the T cell gamma gene by a functionally defined human T cell clone. Characterization at DNA, RNA, and cell membrane level.

In the present study we describe one CD2+CD3+ clone termed DS6 which expressed neither CD4 nor CD8 differentiation antigens and failed to react with WT31, a monoclonal antibody directed against the T cell antigen receptor alpha/beta heterodimer. This clone was isolated from peripheral blood T lymphocytes of a patient with a prolonged immunodeficiency after allogeneic bone marrow transplantation. Normal-sized T cell gamma gene transcripts were detected in DS6 by northern analysis, whereas no mature beta or alpha chain mRNA were found. The rearrangement of TCR beta chain genes and T cell gamma genes was analysed. While in DS6, TCR beta chain genes remain in germinal configuration, and a unique pattern of monoallelic T cell gamma gene rearrangement was observed. The rearrangement involves the recently described V gamma 5 segment and the J gamma 1 joining segment, which is located upstream of the C gamma 1 constant region. To determine the molecular structure present on DS6, an immunoprecipitation was performed with monoclonal anti-CD3 antibody and a rabbit antiserum raised against gamma protein. We have observed, in association with the CD3 complex, a 90 kDa structure which under reducing conditions resolves into three subunits of 45, 40 and 37 kDa. We demonstrated that the rabbit anti-gamma serum only immunoprecipitates the two lower bands. The upper band corresponds to a presently undefined T cell receptor chain. Next, we showed the non major histocompatibility complex (MHC)-restricted cytolytic activity exhibited by these CD3+CD4-CD8- cloned T cells and inhibition of the natural killer (NK)-like activity by the anti-CD3 monoclonal antibody. The triggering of CD2 or CD3 molecules increased IL-2 receptor expression on DS6 but failed to induce cell proliferation. This contrasts with recent results obtained with gamma-expressing T cell clones and illustrates the functional heterogeneity of the cells bearing the second T cell receptor.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1988

Predominant expression of circulating CD3+ lymphocytes bearing gamma T cell receptor in a prolonged immunodeficiency after allogeneic bone marrow transplantation.

The cell surface expression of alpha:beta heterodimer was studied using WT31 monoclonal antibody, in peripheral blood lymphocytes (PBL) from a patient who developed a prolonged immunodeficiency after allogeneic bone marrow transplantation. This patient, grafted for chronic myelogenous leukemia, received T cell depleted bone marrow from her HLA, A, B, D matched sibling. The late occurrence of opportunistic infection, led us to analyze the phenotype of patient PBL. 70% of PBL were CD3+ and 29% WT31+, indicating that the majority of CD3+ PBL did not express the alpha:beta heterodimer. Transcription of the genes encoding the alpha, beta, and gamma chains was assessed in cell lines derived from PBL, by Northern blot analysis. We showed that the CD3+ WT31- subset expressed a truncated, beta mRNA (1.0 kb) and also truncated alpha transcript (1.4 kb). To determine the CD3-associated structure on CD3+ WT31- cell line, immunoprecipitation assays were performed using monoclonal anti-CD3 and an hetero antiserum against gamma peptides. These CD3+ WT31- cells expressed a disulfide linked dimer, composed of products of gamma gene (37 kD, 40 kD) and of undefined delta chain (45 kD). Functional analyses were performed in PBL before and after sorting with WT31 and anti-CD3 antibody. These circulating CD3+ WT31- cells were unable to proliferate when triggered with anti-T3 beads and they seemed to mediate a suppressor activity on CD3+ WT31+ cells.

Adult↗
PubMed1988

Prominent expansion of circulating lymphocytes bearing gamma T-cell receptors, with preferential expression of variable gamma genes after allogeneic bone marrow transplantation.

The presence of two distinct T-cell receptors (TCR) alpha/beta dimers or gamma/delta dimers, was systematically analyzed in peripheral blood lymphocytes form 26 recipients of allogeneic bone marrow transplants for leukemia. When using monoclonal antibody WT31, which recognizes a common epitope on the alpha/beta heterodimer, the expansion of peripheral CD3+, WT31- cells to 40% of the PBLSs was detected in two patients. In patient 2, the presence of circulating TCR gamma-bearing cells was directly demonstrated with monoclonal antibody Ti gamma A directed against the V gamma 9 J gamma p gene products. From CD3, WT31- clones derived from patients 1 and 2, sequential immunoprecipitations were performed with anti-CD3 and anti-C gamma to determine the CD3-associated structure. Molecular weights of gamma subunits were different in both patients, thus indicating structural heterogeneity. The ability of TCR gamma clones to proliferate when stimulated with anti-CD3 beads was observed for clones from patient 2, whereas this response required exogenous interleukin-2 for clones from patient 1. We have already shown that the TCR gamma cells from patient 1 might have played a role in the immunodeficient state. Similar conclusions cannot be drawn from patient 2. Southern blot analysis of total PBL gamma cell lines and clones indicated that this major circulating subset of TCR gamma cells retained a TCR beta gene in germline configuration and preferentially expressed a single V gamma gene, V gamma 5 for patient 1 and V gamma 9 for patient 2.

Antibodies, Monoclonal↗
PubMed1988

[T lymphocyte receptors after allogenic bone marrow transplantation].

Following allogeneic bone marrow transplantation, prominent expansion of peripheral T cells (40%) bearing gamma T cell receptor was observed in some patients. Biochemical, functional and molecular analyses were performed to characterize this T cell receptor and to understand its role in the immunodeficient state after transplantation.

Antibodies, Monoclonal↗
PubMed1987

Clinical and immunological restoration in patients with AIDS after marrow transplantation, using lymphocyte transfusions from the marrow donor.

The diagnosis of transfusion-associated acquired immunodeficiency syndrome (AIDS) was made in 2 patients who developed delayed opportunistic infections and severe cytopenias--56 months for the former (patient 1) and 22 months for the latter, (patient 2) following bone marrow transplantation (BMT) for aplastic anemia. In the third case, grafting for acute leukemia (patient 3) (HIV) infection was probably responsible for the failure of hematological and immunological reconstitution 8 months after allogeneic BMT. Each patient received 6 lymphocyte transfusions from the marrow donor for 3 weeks, combined with a 3-month course of low-dose recombinant alpha interferon. This treatment was followed by recombinant gamma interferon for 3 months. We showed that these 3 patients could resume a normal life for 9 months, at least, and that hematological restoration was observed. Our treatment succeeded in correcting the defect of proliferative response to Candida and the impairment of gamma interferon generation for 4 months in one patient and for more than 12 months in the other two recipients. Nevertheless T4 lymphocyte levels increased only slightly and HIV can still be isolated from the patients' blood. At the time of writing, patients 1 and 3 remain in good health with a partial immunological restoration while patient 2 has died of neurological impairment 2 years after the AIDS diagnosis. Although we cannot generalize this successful therapeutic approach to all patients with AIDS, the results may provide an interesting model of the potential effect of lymphocyte transfusions and the role of interferon therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1987

[Allogenic bone marrow grafts in chronic myeloid leukemia].

Between August 1979 and April 1986, we treated 70 patients with chronic myeloid leukemia by supralethal chemoradiotherapy followed by bone marrow transplantation (BMT) from HLA identical sibling donors (65 patients) or from identical twins (5 patients). All patients were splenectomized before BMT. To prevent graft versus host disease Cyclosporin alone or associated with Methotrexate was given; in addition 13 patients received a T cell depleted marrow. All patients showed engraftment. Of the 5 patients treated by syngenic BMT, 2 patients relapsed but all are alive in remission, 2 of them after a successful second BMT. Of the 36 patients treated by allogeneic BMT in the chronic phase, 20 are alive in unmaintained remission after a median follow-up of 24 months (range 6 to 58). No patients have relapsed. The actuarial survival at 2 years was 60%. Of the 29 patients with more advanced disease, 19 have survived with the actuarial survival at 2 years 50%. We conclude that the probability of cure after BMT is very high, especially if BMT is performed while the patient remains in the chronic phase. Only 3 patients grafted in accelerated or blast phase died with relapse. The main cause of death was interstitial pneumonitis (15 patients) and 10 patients died from other transplant-related complications.

Adolescent↗
PubMed1986

A study of 25 patients with chronic granulomatous disease: a new classification by correlating respiratory burst, cytochrome b, and flavoprotein.

Twenty-five patients suffering from chronic granulomatous disease (CGD) and their families were investigated. Defects in the superoxide generating system were characterized at the level of the heme-containing cytochrome b and of the FAD-containing flavoprotein, both localized in the plasma membrane of granulocytes. It was confirmed that in most of the typical cases (18 of 22), the complete inability of superoxide generation was associated with the absence of detectable cytochrome b. Mothers but not fathers of such male patients were characterized by a diminished content of cytochrome b, confirming that the affected gene is localized on the X chromosome. In contrast, the granulocytes of four other typical patients (two female and two male) contained normal amounts of cytochrome b, whereas oxidative activity was absent. Since no abnormality of oxidative activity as well as of cytochrome b was found in granulocytes of the mothers and fathers of these patients, an autosomal recessive mode of inheritance of the disease is probable. The flavoprotein deficiency found in the granulocytes of four male patients was always associated with an absence of detectable cytochrome b. This could indicate a structural relationship between flavoprotein and cytochrome b (e.g., a flavocytochrome). Three further patients with mild X-linked CGD contrasted with the patients with severe or classic X-linked disease; the oxidative activity of their phagocytes was diminished but not absent, and the cytochrome b present, albeit in small amounts.

Adolescent↗
PubMed1986

HLA-haploidentical bone marrow transplantation for severe combined immunodeficiency using E rosette fractionation and cyclosporine.

Eight patients with severe combined immunodeficiency received bone marrow cells from their HLA haplotype-identical fathers after bone marrow T cell depletion by rosetting with neuraminidase-treated sheep red cells. Because the method led to the infusion of a small percentage of T lymphocytes (0.1% to 0.3%), cyclosporin was given by continuous intravenous infusion for two months in order to prevent the occurrence of graft-v-host disease (GVHD). Three patients who did have residual nonfunctional T lymphocytes received busulfan and cyclophosphamide before transplantation. Engraftment was observed in seven patients, and severe GVHD was not seen. Two patients died early after the bone marrow transplantation because of prior infections, and a third died at day 90 from a B cell lymphoproliferative syndrome. The five other patients are doing well. Stable engraftment has been achieved with reconstitution of cell-mediated immunity in 5/5 and humoral immunity in 4/5 patients.

Adenosine Deaminase↗
PubMed1986

Bone marrow transplantation for chronic granulocytic leukemia.

Thirty-seven patients with chronic granulocytic leukemia have been treated with supralethal chemoradiotherapy followed by transplantation of bone marrow from HLA-identical donors. All patients showed engraftment, and the Philadelphia chromosome (PH1) disappeared in each case. Four patients had syngeneic grafts before blast crisis and are still alive; 2 are in remission not maintained by therapy, and 2 others are receiving chemotherapy after having relapsed in the chronic phase. Thirty-three patients had allogeneic grafts; only 2 received the grafts during blast crisis, and neither is a long-term survivor. Of the 13 patients who had grafts in the accelerated phase, 6 died of complications related to the transplantation, and 1 died after a myeloblastic relapse. Thus 6 patients are in unmaintained remission with a median follow-up of 13 months. Eighteen patients received grafts in the chronic phase. All 10 survivors are in unmaintained remission with a median follow-up of 14 months; in this group, no patient has relapsed. The granulocytic hyperplasia of the chronic phase can be more effectively ablated than established blastic leukemia. The mortality rate of transplant-related complications must be weighted against the typical rate of progression of chronic granulocytic leukemia. Although a longer follow-up period is needed for full evaluation, bone marrow transplantation may now be offered to patients in the chronic phase in an attempt to achieve long-term survival or cure of more than one-half of these patients.

Adolescent↗