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L Lagneaux

Publications and source records attributed to L Lagneaux.

29 records · Page 2Linked to original sources
PubMed1991

Prevention of CMV-induced myelosuppression by anti-CMV antibodies: an in vitro model.

Pathogenesis of cytomegalovirus (CMV)-induced myelosuppression is not clearly understood and could be related to a direct toxic effect on the marrow progenitors and/or an alteration of the marrow environment. Myeloid progenitors (granulocyte-macrophage colony-forming units, CFU-GM) were not affected by incubation with increasing titers of CMV (10-10(5) plaque-forming units [pfu]/ml) during 2-6 h. By contrast, using the blast colony-forming cell (Bl-CFC) assay, we confirmed that CMV induced myelosuppression through an alteration of the marrow-derived stromal layer. Using this experimental model, we compared the capacity of nonspecific human immunoglobulins (IgG), specific polyclonal anti-CMV IgG, and a human monoclonal anti-CMV IgG to prevent the myelosuppressive effect of 10(4) pfu/ml of CMV. Specific anti-CMV IgG (polyclonal or monoclonal) at the concentration of 10 micrograms/ml were able to prevent the CMV-induced myelosuppressive effect, whereas nonspecific human IgG was not effective in this model. Our results suggest that 1) CMV-induced myelosuppression is related to an alteration of the marrow microenvironment, 2) specific monoclonal and polyclonal anti-CMV IgG prevent this myelosuppressive effect in vitro, and 3) human monoclonal anti-CMV IgG could be useful in vivo in the immunoprophylaxis of CMV infections.

Antibodies, Monoclonal↗
PubMed1990

Production of human monoclonal IgG antibodies reacting with cytomegalovirus (CMV).

A human monoclonal antibody (MoAb) reacting with cytomegalovirus (CMV) has been produced using somatic cell hybridization between Epstein-Barr virus (EBV) infected B lymphocytes and a human-mouse heteromyeloma cell line (SHM-D33). The hybrids were selected in HAT medium containing 5 x 10(-7) ouabain. The median level of Ig production was 5 (0.1-20) micrograms/10(6) cells/day. One selected hybridoma (IB-8E9H5) has been maintained in continuous culture for more than 30 months with a stable IgG2, lambda production. Molecular hybridization using EBV-specific probes demonstrate that our hybrids have lost the IR-1 EBV sequence during fusion. Unexpectedly, these blotting experiments revealed the presence of multiple EBNA-1 sequences dispersed among the genomic DNA of the SHM-D33 cell line. Screening for anti-CMV specificity was performed by ELISA and confirmed by immunofluorescence staining. Thus far, three CMV reference strains and 14 local strains are stained by the MoAb as early as 3 h after CMV infection of human fibroblasts, apparently through the recognition of a nuclear viral antigen of 67 kDa. In conclusion, this technique permits (a) the removal of the EBV genome contained in the lymphoblastoid parental cell line and (b) the production of human anti-CMV MoAb with potential applications in the prevention of life threatening CMV infections.

Antibodies, Monoclonal↗
PubMed1990

Inhibitory effects of potent inhibitors of human immunodeficiency virus and cytomegalovirus on the growth of human granulocyte-macrophage progenitor cells in vitro.

Phosphonoformate, ganciclovir, zidovudine and the novel acyclic nucleotide analogues (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine [(S)-HPMPA] and (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine [(S)-HPMPC] were evaluated for their inhibitory effect on colony forming unit formation by human granulocyte-macrophage progenitor cells (obtained from 11 healthy volunteers) in vitro. The 50% inhibitory dose of zidovudine, (S)-HPMPA, (S)-HPMPC, ganciclovir and phosphonoformate were 10.61, 16.55, 80.88, 41.02 and 668.64 microM, respectively, when the median-effect principle was applied. The bone marrow toxicity of zidovudine used at a low concentration (3.74 microM) was significantly decreased if the drug was combined with (S)-HPMPA, (S)-HPMPC or ganciclovir. If used at higher concentrations (74.90 microM), zidovudine showed increased myelotoxicity in the presence of (S)-HPMPA and ganciclovir, but not (S)-HPMPC.

Adenine↗
PubMed1990

Influence of recombinant alpha and gamma interferons on the in vitro proliferation of myeloid and leukemic progenitors.

We have compared the effect of alpha 2-C and gamma recombinant interferons (rIFNs) on normal myeloid progenitors (N-CFU-GM), chronic myeloid leukemia (CML) progenitors (CML-CFU-GM) and leukemic progenitors (L-CFU) of acute non-lymphoblastic leukemia (ANLL) patients. Within 14 days of continuous exposure in culture, a dose-dependent inhibition of CFU-GM was seen for most normal subjects. Resistance to rIFNs was frequent in leukemic patients and even more in acute leukemia than in CML. Stimulation of clonogenic cell growth was seen for a minority of leukemic patients. When only the sensitive cases were considered, no difference in sensitivity was noticed between normal, CML and ANLL patients. A good correlation was observed between the activity or the lack of activity of alpha and gamma rIFNs.

Bone Marrow↗
PubMed1989

Comparison of in vitro inhibition of etoposide (VP16) on leukemic and normal myeloid, erythroid clonogenic cells.

We have compared in various clonogenic assays the in vitro sensitivity to etoposide (VP16) of 1) human leukemic precursors (leukemia colony-forming units; L-CFU), 2) normal erythroid progenitors (erythroid burst-forming units; BFU-E, and 3) normal committed myeloid progenitors (granulocyte-macrophage colony-forming units; CFU-GM and more primitive hemopoietic precursors (PPC) that adhere to cultured marrow stromal cells. Bone marrow samples were obtained from 15 normal subjects and 16 leukemic patients: 9 in the acute phase of acute nonlymphoblastic leukemia (ANLL) and 7 in complete remission. VP16 was tested at concentrations ranging from 10(-8) to 10(-3) M. The median recoveries at 10(-3) M VP16 were respectively 0%, 0.5%, 0%, and 0% for leukemic progenitors, CFU-GM from leukemic patients in complete remission, normal CFU-GM, and BFU-E, and 23% for PPC. This indicates that CFU-GM, BFU-E, and L-CFU are highly sensitive to VP16, whereas PPC, more primitive myeloid precursors, are spared. These results suggest that VP16 may be used as an "ex vivo" purging agent for autologous bone marrow.

Cell Survival↗
PubMed1988

Elevation of IgE-binding factors in serum of patients with B cell-derived chronic lymphocytic leukemia.

One hundred nineteen sera from patients with various lymphoproliferative diseases and normal sera were tested by a solid-phase radioimmunoassay (RIA) for their content in IgE-binding factor (IgE-BF), a soluble glycoprotein binding to IgE and derived from low-affinity IgE receptors (Fc epsilon R). Fc epsilon R, recently identified as CD23, are known to be expressed on the surface of B cells at the intermediate stage of differentiation. The results indicate that in all cases of chronic lymphocytic leukemia (CLL) tested (n = 40), IgE-BF levels (45 to 8,656 U/mL) were 3-fold to 500-fold higher than in 24 controls (15.5 +/- 2 U/mL). With a few exceptions, serum IgE-BF levels could differentiate patients with CLL from those with other leukemias or lymphomas. In vitro studies indicated that B lymphocytes isolated from CLL patients produced 8 to 50 times more IgE-BF than did normal B cells (P less than 0.001). IgE-BF level was correlated with the Rai stage of the disease (P = 0.002) and the lymphocyte count (P = 0.041). IgE-BF was purified to homogeneity from one CLL serum sample by a combination of affinity chromatography and reverse-phase high-performance liquid chromatography (HPLC). this IgE-BF proved identical to IgE-BF isolated from the culture supernatant of RPMI 8866 cells, a B lymphoblastoid cell line bearing Fc epsilon R and secreting IgE-BF. Indeed, the two molecules had the same mol wt (25 to 27 kd), the same isoelectric point, and the same tryptic map. We suggest that determination of serum IgE-BF might prove useful for clinical monitoring of CLL.

B-Lymphocytes↗
PubMedDate not supplied

Growth factors and DLI in adult haploidentical transplant: a three-step pilot study towards patient and disease status adjusted management.

Haploidentical transplant is now established as a procedure of choice for patients who lack a compatible donor. However, they are still referred too late, heavily pretreated, at very advanced stages. We initiated a three-step phase I study trying improve transplant-related mortality, relapse rate, and immunity: G-CSF + DLI, GM-CSF + DLI, patient- and disease-adapted strategy. Thirty-three consecutive leukemia patients, aged 18-55, were investigated (20 very poor risk, 11 poor risk, and 2 better risk). GvH type NK alloreactivity was chosen when possible (18/33) and balanced across the three groups. In the first nine patients, G-CSF was used and escalated prophylactic DLI started at month 1. Thus, G-CSF and 1-3 DLI (10(4) CD3/kg) is safe. It results in faster CD4 recovery and a low rate of infections. However, it was insufficient to induce a GVL effect. In the next 12 patients, GM-CSF was used plus 1 DLI (10(4) CD3/kg) at day 30 unless aGVHD (3 patients). The comparison between the two first groups can be summarized as follows: G-CSF + DLI: TRM at day 100: 0, RR: 6/9, severe aGVHD: 0. GM-CSF + 1 DLI group: RR: 1/12, TRM at day 100: 3, aGVHD > 1: 9/12, price to pay: GVHD resulting in five deaths in total. Step 3 (13 patients) consists of a patient-adapted strategy: no more aspecific DLI (selected anti-CMV and aspergillus DLI planned in all patients); in myeloid disorders with NK alloreactivity: no GF. In the other cases, GM-CSF (at a reduced total dose of 500 mug) is given the follow-up of these 13 patients, although promising is currently short (median 5 months). Overall, TRM at day 100 is 3/29, reflecting the good tolerance of the conditioning in a heavily pretreated population (median age: 43). NRR mortality (8/26) at 1 year is greater in the GM-CSF + DLI group, reflecting the impact of severe aGVHD. We conclude that the third strategy might improve the outcome without exposing patients to unnecessary severe GVHD.

Adolescent↗
PubMedDate not supplied

The aspirin metabolite salicylate inhibits breast cancer cells growth and their synthesis of the osteolytic cytokines interleukins-6 and -11.

Some epidemiological studies have suggested that aspirin could be a chemopreventive agent against breast cancer. We tested the effects of the aspirin metabolite salicylate (SA) on four (Hs578T, MCF-7, MDA-MB-231, and T-47D) breast cancer cell (BCC) lines in vitro. Two features were studied: the proliferation of BCC and their production of the osteolytic cytokines interleukins-6 (IL-6) and -11 (IL-11) since BCC frequently metastasize to bone and induce tumor-induced osteolysis. SA, from 0.5 to 5 mM, caused BCC growth inhibition by up to 70% (IC50 range 2.54 to 4.28 mM). At high concentrations, the drug induced apoptosis only (MDA-MB-231), or both apoptosis and primary necrosis (MCF-7). SA, as well as indomethacin (INDO), reduced the synthesis of IL-6 and -11, at both the protein and mRNA levels, in the two cell lines producing these cytokines (MDA-MB-231 and Hs578T). This latter effect seemed to be mediated by PGE2 since SA and INDO reduced PGE2 levels in MDA-MB-231 and Hs578T cells, PGE2 was not detected in MCF-7 and T-47D cells and exogenous PGE2 increased IL-6 and -11 expression by MDA-MB-231 cells. Collectively, our results suggest that SA could reduce the growth of breast tumors and inhibit to some extent the ability of BCC to induce osteoclast recruitment and osteolysis. These data indicate the need for further epidemiological and experimental studies.

Breast Neoplasms↗