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Biomedical subjects

L Thiry

Publications and source records attributed to L Thiry.

At least 19 recordsLinked to original sources
PubMed1992

Lethal oxidative damage to human immunodeficiency virus by human recombinant myeloperoxidase.

Human recombinant myeloperoxidase was evaluated in a cell-free system for its inactivation properties on the replication of human immunodeficiency virus, HTLV-IIIB. In the presence of a hydrogen peroxide generating system (glucose and glucose oxidase) and sodium thiocyanate, the recombinant enzyme inhibited virus-induced syncytium formation and viral replication without causing any cytopathic effects on SupT1 reporter cells. In addition, U937 monocytoid cells, chronically infected with HIV1, were exposed to recombinant myeloperoxidase (10 U/ml) and monitored during 48 h for the accumulation of intracellular p24 viral antigen. Under these conditions, the recombinant enzyme significantly reduced intracellular viral replication without affecting cell viability.

Cell Line↗
PubMed1990

Inhibition of HIV infectivity by lactoperoxidase-produced hypothiocyanite.

HIV aliquots, from a supernatant of ARV-4 cell line, were mixed with an equal volume of a OSCN.generating glucose-glucose oxidase + thiocyanate-lacteroperoxidase solution, and then pre-incubated at 37 degrees C for periods of 30 secs to one hour. These mixtures were then inoculated into cultures of phytohaemagglutinin-stimulated lymphocytes. Viral growth was monitored with an ELISA quantitating the specific p24 protein either in the culture cells or in the supernatant. In control experiments, the virus produced both intra- and extra-cellular p24. In the controls, concentration of p24 per 10(6) lymphocytes grew rapidly. By contrast, HIV that was pretreated with the OSCN generating system for 30 sec., produced very little p24, and no detectable amount of this protein could be found after 2 min. pre-treatment.

Antiviral Agents↗
PubMed1987

Absence of antibodies to HIV-2/HTLV-4 in six central African nations.

We studied 1508 individuals from Zaire, Burundi, Tanzania, Zambia, Kenya, and Cameroon for antibodies to HIV-2/HTLV-4. AIDS, ARC, other disease or tumor patients and healthy people were sampled from 1984-1986. By radioimmunoprecipitation and SDS/PAGE analysis and/or Western blot we failed to find any samples with specific antibodies to HIV-2/HTLV-4 indicative of infection. In contrast, 363 of these 1508 individuals demonstrated antibodies to HIV-1/HTLV-3B by the same serologic assays. HIV-2/HTLV-4 infection appears to be quite rare in Central Africa. AIDS and related syndromes in this study were exclusively correlated with HIV-1 infection. Studies in West Africa have shown high rates of infection with HIV-2/HTLV-4 where cases of AIDS are still relatively uncommon. These results indicate that HIV-2/HTLV-4 has a distinct geographic distribution from that of HIV-1 in Africa. Further studies are necessary to better define the pathogenicity and natural history of this distinct new virus, HIV-2/HTLV-4.

Antibodies, Viral↗
PubMed1986

Glycosylation inhibitors block the expression of LAV/HTLV-III (HIV) glycoproteins.

The glycosylation inhibitors 2-deoxy-D-glucose (2-dGlc) and, to a lesser extent, beta-hydroxynorvaline blocked the formation of syncytia in HIV (LAV/HTLV-III)-infected cells. Using monospecific polyclonal antibodies against recombinant envelope proteins gp110 and gp41 or monoclonal antibodies against env gp110, we could demonstrate a marked reduction in the immunoreactivity of these antigens in HIV-infected cells exposed to the glycosylation inhibitors. There was concomitant accumulation of core proteins p15 and p24, as shown by a solid phase radio-immunoassay, and a decreased oligosaccharide synthesis of env proteins, as monitored by the incorporation of [6-3H]GlcNAc. The reverse transcriptase was not affected by the compounds. Glycosylation inhibitors may be considered for the chemotherapy of AIDS or AIDS-related complex, or chemoprophylaxis of HIV-positive individuals.

Deoxy Sugars↗
PubMed1986

Markers of HTLV-III in patients with end stage renal failure treated by haemodialysis.

Patients and members of staff from a haemodialysis unit were tested for markers of infection with human T cell lymphotropic virus type III (HTLV-III), the virus associated with the acquired immune deficiency syndrome (AIDS). An enzyme linked immunosorbent assay showed eight of 100 patients to have antibodies to HTLV-III. In five of these patients past or present infection with HTLV-III was confirmed by Western blot analysis or detection of HTLV-III antigens in lymphocyte cultures, or both. Investigation of other risk factors for AIDS showed that the putative source of HTLV-III was unrelated to dialysis in two patients whereas blood transfusion was the most likely cause of contamination in the others. No member of staff gave a positive result in the enzyme linked immunosorbent assay. Nosocomial transmission of HTLV-III seems unlikely if precautions similar to those recommended for the control of hepatitis B infection are applied.

Acquired Immunodeficiency Syndrome↗
PubMed1986

LAV/HTLV-III infection in children of African origin: experience in Belgium.

From December 1982 to June 1985, we diagnosed LAV/HTLV-III infection in 16 children of African origin living in Belgium or referred to one of the hospitals participating in this study. Diagnosis was proven in seven of them by isolation of virus of the LAV/HTLV-III group. In the nine others, LAV/HTLV-III infection was highly probable because of the presence of antibodies against the virus (seven subjects) or clinical and immunological evidence of immune deficiency associated with a parental history of LAV/HTLV-III infection (two subjects). Five of these children had a severe illness starting in the first months of life (range 20 days--4 months) and died within 4 months (range 19 days--10 months). Eight children presented later in life (mean age 35 months, range 2-66 months) with a milder and more chronic disease characterized by the presence of generalized lymphadenopathy (6/8), hepatomegaly (5/8), splenomegaly (5/8), interstitial pulmonary infiltration (4/8), parotid swelling (3/8), CSF lymphocytosis (3/5), diarrhoea without pathogen isolated (1/8) and fever (1/8). At least one of the parents of each child was of African origin. At the time of birth of their child two mothers and one father had an AIDS-related complex. After a mean period of 34 months (range 3-87 months) five fathers and six mothers had a symptomatic LAV/HTLV-III infection (AIDS or AIDS-related complex).

Acquired Immunodeficiency Syndrome↗
PubMed1985

Bovine leukemia virus-related antigens in lymphocyte cultures infected with AIDS-associated viruses.

An earlier finding that lymphocytes from African patients with the acquired immune deficiency syndrome (AIDS) react with rabbit antiserum to purified antigens of bovine leukemia virus (BLV) prompted a study of the possible cross-reactions between a BLV-infected ovine cell line and human lymphocytes inoculated with a strain of lymphadenopathy syndrome-associated virus (LAV). A solid-phase radioimmunoassay was used to detect antigenic markers of the retroviruses. Crude extracts from short-term cultures of lymphocytes infected with LAV bound rabbit antisera to the LAV glycoprotein gp13 (molecular weight 13,000) and the BLV proteins p24 and gp51, but did not bind antibodies to the p24 of human T-cell leukemia virus type I (HTLV-I). Antiserum to LAV gp13 reacted with an ovine cell line producing BLV but also weakly with virus-free ovine cells. Lymphocyte cultures from four African patients with AIDS expressed BLV-related antigens within 6 to 10 days of culture, at the moment when particle-bound reverse transcriptase was produced. BLV-related antigens were induced in lymphocyte cultures from healthy individuals by addition of filtered supernatant or irradiated cells of the original culture. The antisera to BLV used in this study may prove useful for the detection of AIDS-associated viruses in short-term cultures of lymphocytes from AIDS patients or their contacts.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Human syncytiotrophoblast membrane proteins defined using a heterologous antiserum.

Detergent extracts of human trophoblast plasma membranes (TrPM) and of other fetal tissues from the same conceptus were prepared and the proteins separated by use of isoelectric focusing. A major band of isoelectric point (pI) 4.1 was present in TrPM together with minor bands of (pI) 4.9, 5.9, 7.3, 7.8 and 7.9. These bands were absent from non-trophoblastic fetal tissues. The pI 4.1 protein reacted with an 125I-labelled IgG fraction of a heterologous antiserum raised against TrPM and was found to have an apparent molecular weight of 100,000. This protein did not appear to be placental alkaline phosphatase, SP1, transferrin or human chorionic gonadotrophin. Many neoplastic cell lines tested also revealed a major protein band of pI 4.1 but it has not been established that this was the same protein as found in the TrPM preparations.

Antigens, Surface↗
PubMed1984

Study of the expression of a glycoprotein of retroviral origin in the plasma of patients with hematologic disorders and in the plasma of normal individuals.

A 74,000 molecular weight glycoprotein was purified from the plasma of a patient with chronic myelogenous leukemia in blast crisis. Monoclonal antibodies were produced in the mouse and used to characterize this protein. It was shown to contain p15E antigenic determinants and portions of a reverse transcriptase. The level of this protein was found to be elevated in leukemic patients with high white blood cell counts and also in some patients with other hematopoietic disorders as compared to the level measured in normal individuals. The level of the protein was strongly reduced in acute leukemia patients after intense chemotherapy treatment. We tentatively conclude that this protein is of endogenous retroviral origin and perhaps regulates hematopoietic tissues.

Acute Disease↗
PubMed1983

Cell receptors for baboon endogenous virus recognized by monoclonal antibodies.

Hybridomas from mice immunized with baboon endogenous virus (BaEV) from A204(M7) cells produced several antiviral monoclonal antibodies and, in addition, antibodies D-12 and E-4, which appeared to be virus specific because they reacted with BaEV but not with Mason-Pfizer virus or RD-114 virus. However, they also bound to human virus-free cells, and they did not recognize BaEV from bat or canine host cells. Cell membrane targets for these antibodies comigrated with an 18,000-dalton protein, which may contain specific determinants of BaEV receptors since antibody masking of these cell sites prevented BaEV but not Mason-Pfizer virus or RD-114 virus adsorption. However, RD-114 virus interfered with BaEV adsorption. Thus, the two viral receptors must be adjacent, but the antibody D-12 and E-4 targets are not within the active site of RD-114 virus receptor. Conversely, cell coating with BaEV from bat or canine hosts inhibited antibody D-12 binding. Noncultivated human lymphocytes and cells from fetal organs bound much less antibody D-12 than did cells from established cell lines, with a correlation between amounts of antibody D-12 acceptor sites and BaEV receptors. Thus, in vivo, BaEV infection of human cells may be inefficient. In vitro, antibody D-12 treatment of chronically infected A204(M7) cells caused intracellular accumulation of viral proteins and decreased virus release, with no such effect on RD-114 virus-producing cells. Canine cells bound antibody D-12 only if coated with BaEV from A204(M7) cells, indicating that the human determinant coadsorbed with the virions to animal cells. Possibly, determinants of cell receptors participate in BaEV maturation and become associated with the virions.

Adsorption↗