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.

Interactions between the human monocytic leukaemia THP-1 cell line and Old and New World species of Leishmania.

The human promyelocytic THP-1 cell line has been found to support the growth of Leishmania parasites. THP-1 cells, differentiated with retinoic acid, cease replication while remaining in suspension. 72 +/- 8% of THP-1 cells became infected after inoculation with promastigotes of several Old and New World Leishmania species. The resulting amastigotes (19 +/- 5 per infected cell) were easy to harvest, capable of reinfecting cultures of normal human cells and, in the case of L. major and L. infantum, caused specific lesions in BALB/c mice. This culture system should facilitate biochemical and immunological studies on amastigotes and be of use in screening anti-parasite drugs.

Effects of serotonin and melanin on in vitro HIV-1 infection.

In this article, we describe the effect of indoleamines: serotonin (5-HT) and synthetic soluble melanin, on the multiplication of HIV-1 in T4 lymphocytic cell lines. The results show that viral production is increased when infected CEM-11 cells are incubated with 5-HT (10(-7) M and 10(-8) M) for 72 hours, whereas at higher doses (10(-3) M and 10(-4) M), there is an inhibition of viral multiplication. As well, when infected CEM cells were cultured in the presence of 5-HT at 10(-4) M, during 15 days, virus production, syncytia formation and cytolytic effect were drastically inhibited. Melanin also inhibits HIV-1 cytopathic effect on MT-2 cells, without cell toxicity, at concentrations of 0.2-10 micrograms/ml. Syncytium formation and cell lysis were also blocked by melanin at concentrations of 0.1 to 10 micrograms/ml, when uninfected MT-2 cells were mixed with HIV-1 chronically infected CEM-11 cells.

Immunization of dogs with a Leishmania infantum-derived vaccine.

A partially-purified extract of Leishmania infantum has been administered to healthy dogs. Post-immunization sera were found to neutralize the infectivity of L. infantum and to abate the development of L. major. Muramyl dipeptide and one of its derivates, murabutide, were the best adjuvants.

The molecular cloning and sequence of the common marmoset interferon-gamma (MaIFN-gamma) gene.

A DNA fragment covering marmoset interferon gamma (MaIFN-gamma) was cloned from the DNA of peripheral blood leucocytes, sequenced and compared to its human IFN-gamma counterpart. The two nucleotide sequences were found to be highly homologous (90.3%). The position of the exons are directly comparable with those of the human IFN-gamma gene and follows the pattern of structural conservation found elsewhere. The present work makes available recombinant MaIFN-gamma for animal experiments.

Immunological evaluation of cell-mediated and humoral immunity in Thai patients with cerebral and non cerebral Plasmodium falciparum malaria: II. Evolution of serum levels of immunoglobulins, antimalarial antibodies, complement fractions and alpha interferon.

In Thai patients with Plasmodium falciparum malaria, IgG and IgM values were elevated, whereas IgA levels were within normal ranges. No association of Ig values with parasitaemia was noted. IFA-IgM antibody levels were lower in cerebral malaria (CM) than in the non cerebral malaria (NCM) group. IFA-IgG antibodies were present in all patients. The mean C3 and C4 values were similar among patients from the CM and NCM groups. Interferon like activity was detected in all CM and NCM patients, and no correlation was found with either antimalarial antibodies, complement or parasitaemia.

[Effect of human interferon on viral production in a cell line chronically infected by a type D retrovirus (Mason-Pfizer virus)]. / Effet de l'interféron humain sur la production virale d'une lignée cellulaire chroniquement infectée par un rétrovirus de type D.

Human interferon specifically inhibits the viral multiplication in a human cell line infected by a type D retrovirus, the Mason-Pfizer virus (MPV). This inhibition is less important than for type C viruses.

Biochemical characterization of simian foamy virus type i.

Simian syncitium-forming ("foamy") virus type I (SFV1) was characterized biochemically. RNA was extracted from purified virus either with 0.1 per cent SDS or by the standard phenol-chloroform method. By both techniques a main component of 65-70S was found. Denaturation of the 65-70S RNA by heat resulted in a shift of the sedimentation coefficient mainly to a 30-35S component. Electrophoresis on a composite polyacrylamide gel demonstrated the existence of three minor RNA's: 8S, 5S and 4S respectively. PAGE-SDS analysis of disrupted purified virions enabled the separate migration of five viral proteins and the identification of two main proteins: a 30 kd polypeptide and a 70 kd polypeptide.

Study of a human heteroploid cell line cryptically infected by a murine oncornavirus.

This report concerns the establishment of a human cell line cryptically infected by a murine leukemia virus (MuLV). This cell line, named J112, is characterized by the presence of genetic viral information in a majority of cells as demonstrated by immunological and virological methods, and by the absence of detectable viral activity in the supernatant culture fluids. Nevertheless, electron microscopy demonstrated the presence of a small number of particles which have the morphology of immature type C particles. We discuss the importance of this experimental model in relationship with non-producing (NP) infections of human cells by oncogenic retroviruses.

[Production of circulating interferon in human malaria]. / Production d'interféron circulant au cours du paludisme humain.

The presence of an interferon-like activity inhibiting the cytopathic effect of vesicular stomatitis virus was studied in 216 sera from 100 patients with P. falciparum (67 cases), P. vivax (16), P. ovale (13), P. malariae (4) infections. 87% of patients were found positive on one or more occasions. The prevalence of interferon-like activity was similar in all 4 species. Titers varied between 20 to 320 U/ml and were found to be higher in Europeans experiencing a primary attack of malaria (mean = 72 U/ml) than in subjects from hyperendemic areas of West Africa (mean = 37 U/ml). In patients followed-up either a delayed positivity or an increase of interferon-like activity was found in 60% of cases. High titers were observed up to the 3rd month. The viral inhibitory activity met all criteria for defining interferon. Seroneutralization assays using anti-alpha and anti-gamma interferon antibodies showed in 5 patients that human malaria was associated with the presence of a gamma interferon.

Circulating interferon in cytomegalovirus infected bone-marrow-transplant recipients and in infants with congenital cytomegalovirus disease.

In a study concerning five CMV-infected bone-marrow-transplant recipients, five congenital CMV diseases and appropriate controls, presence of high levels of circulating interferon (IFN) was demonstrated exclusively during the course of CMV disease. This interferon was predominantly "immune" or gamma interferon (gamma-IFN). These results suggest that during CMV disease the interferon compartment of the immune response is modified.

Effect of human interferon on type D retroviruses multiplication in chronically infected cell lines.

A study was made on the effect of human interferon (HuIFN) on the synthesis and release of type D viruses (MPMV and SMRV) by chronically infected human lines. Interferon at concentrations of 50 IU/ml lead to an inhibition of the extracellular virus production by about 50%-80% as measured by virus-associated reverse transcriptase activity, by metabolic labeling of the virus with (3H) uridine or (3H) amino acids, or by electron microscopy counting of particles. The profiles of intracellular viral proteins, as visualized by radioimmunoprecipitation and electrophoresis, were not different in control or IFN-treated cells and the yield of intracellular protein p27 stayed unchanged or was slightly increased. Electron microscopy of thin sections taken from the control and IFN-treated cells revealed no difference in any subcellular structures including that of the viruses. However, electron microscopic examination of IFN-treated cells showed an increased number of either budding particles and intracytoplasmic precursors (two- to five-fold) or mature virus particles (four- to ten-fold) on the cell surface of the IFN-treated cells. These results indicate that IFN inhibits further developments of MPMV and SMRV replication as was described for type C and B retroviruses.

Characterization of RNase H activity associated with reverse transcriptase in simian foamy virus type 1.

Spumavirinae or foamy viruses have been shown to have a characteristic RNA-dependent DNA polymerase activity. We demonstrate here the existence of an RNase H activity that copurifies with the 81-kilodalton monomeric polypeptide, which carries the RNA-dependent DNA polymerase activity of simian foamy virus type 1. RNase H degrades RNA hybrid substrates; however, it does not solubilize single-stranded RNAs. Inactivation assays with heat, high levels of bivalent cations, ethidium bromide, and sodium fluoride suggest that the RNase H catalytic site could be topologically independent from the DNA polymerase catalytic site.

Reverse transcriptase from simian foamy virus serotype 1: purification and characterization.

Chromatography on heparin-Sepharose, known for its affinity for nucleotide-binding polypeptides, was used to purify the viral RNA-dependent DNA polymerase (reverse transcriptase) from the core polypeptides of simian foamy virus type 1. This procedure allowed the recovery of highly purified enzyme with a high specific activity. The average molecular weight of this monomeric enzyme is 81,000 and is thus comparable to that found for other known primate retroviruses. Reverse transcriptase activity of simian foamy virus type 1 requires a ribonucleotide template as a primer or otherwise a DNA with 3'-OH ends. Other optimal conditions of activity are reviewed. Heat inactivation studies led to the concept of an enzyme with two loci, one specific for the substrate and the other for the template-primer.

Isolation and characterization of a new simian foamy virus serotype from lymphocytes of a Papio cynocephalus baboon.

A new type of syncytium-forming (foamy) virus was isolated from peripheral lymphocytes of a Papio cynocephalus baboon after cocultivation with a rhesus monkey cell line. The isolate was characterized by cytopathogenic effect, host range, electron microscopy, reverse transcriptase activity and physical and chemical properties. Seroneutralization tests indicate that the new isolate is antigenically distinct from the other nine known simian foamy virus serotypes.

Effect of levamisole on interferon production by PHA-stimulated human leukocyte cultures.

Mononuclear leukocytes of 10 normal blood donors were cultured in vitro and treated with phytohemagglutinin (PHA-P) and/or levamisole. Interferon-like activity was investigated in the supernatant fluids of the cultures, using VSV as challenge virus. In most of the cases the PHA-stimulated interferon-like activity was slightly but significantly enhanced by levamisole. The antiviral activity produced in the supernatant fluids was characterized as interferon since it was trypsin sensitive, species specific and inhibited by specific antiserum. This interferon has the characteristic sensitivity to PH2 of immune interferon.

Studies on in vitro interferon induction capacity and interferon sensitivity of simian foamy viruses.

We demonstrate that Simian Foamy viruses (SFV) types 1, 2, 4 and 10 do not induce Interferon (IFN) production in mouse and primate (simian and human) cell lines, but that their cytopathogenic effect is blocked by this viral inhibitor. The mechanisms of action of IFN seems to be different from that of other Retroviridae. No trapping of virions appears in treated cells examined by ectron microscopy. Moreover, neither precursor nor mature virus particles were observed in infected cultures submitted to IFN treatment.

Circulating interferon in cytomegalovirus infected bone-marrow-transplant recipients and in infants with congenital cytomegalovirus disease.

In a study concerning five CMV-infected bone-marrow-transplant recipients, five congenital CMV diseases and appropriate controls, presence of high levels of circulating interferon (IFN) was demonstrated exclusively during the course of CMV disease. This interferon was predominantly "immune" or gamma interferon (gamma-IFN). These results suggest that during CMV disease the interferon compartment of the immune response is modified.

Effect of interferon on chronic infection of human cells by xenotropic type-C viruses.

Different preparations of human interferon inhibit virus production in human cells chronically infected by a variety of type-C xenotropic viruses. Some of these viruses have been incriminated in the development of leukemia in primates. The characteristics of blocking of viral multiplication are similar to those described for the effect of mouse interferon on ecotropic viruses. The amount of free virus in culture supernatants is strongly decreased while intracellular protein p30 stays unchanged or is slightly increased. On the other hand, the inhibitory effect is reversible. The withdrawal of interferon results in a rapid increase in virus production as detectable in supernatant fluids. In the light of these results it is suggested that human interferon might be useful in the treatment of some blood malignancies suspected of being related to infection with xenotropic type-C viruses.