[HIV envelope proteins are bound by human epidermal Langerhans cells by a binding site which differs from the site on the CD4 molecule, and are internalized by receptor endocytosis].

Langerhans cells (LC) are epidermal dendritic cells which express several surface antigens among them the CD4 antigens. We investigated the fate of HIV envelope glycoproteins (gp 120 and gp 160) incubated with healthy human trypsinized LC in suspension. After trypsin treatment only the epitope for OKT4 appeared to be resistant.

Characterization of polyoma virus early proteins expressed from vaccinia virus recombinants.

We previously reported that live recombinant vaccinia viruses (VV) encoding either the large T (LT) or middle T (MT) antigens of polyoma virus (PyV) were able to induce rejection of tumors caused by PyV-transformed cells [Lathe et al., Nature 326 (1987) 878-880]. Here we present evidence that PyV early proteins expressed by the recombinants retain the biochemical characteristics of their authentic counterparts despite the cytopathic effect of VV infection.

Loss of CD4 membrane expression and CD4 mRNA during acute human immunodeficiency virus replication.

Using mAbs and genomic probe to the CD4 molecule, the HIV receptor, we demonstrated that HIV replication induces the disappearance of its functional receptor from the cell surface by two distinct mechanisms. First, after being expressed onto the cell surface, HIV envelope gp110 will complex CD4, efficiently masking the CD4 epitope used by the virus to bind its receptor. This phenomenon occurs on the surface of each infected cell and is not due to the release of soluble gp110; infection with recombinant HIV/vaccinia viruses expressing a mutated HIV env gene designed to prevent gp110 release from the cell surface induces a similar gp/CD4 complexes formation.

HIV-specific T lymphocyte immunity in mice immunized with a recombinant vaccinia virus.

Infection by the human immunodeficiency virus (HIV) induces T cell immunity in humans, chimpanzees and macaques. The protective value of this immune response is not clear. We have consequently developed a murine experimental system to study HIV-specific CD4 and CD8 T lymphocyte immunity in vitro and in vivo.

Alpha-smooth muscle actin is transiently expressed in embryonic rat cardiac and skeletal muscles.

Actin isoform expression may change during development, and in certain physiological, experimental and pathological situations. It is accepted that during sarcomeric (skeletal and cardiac) muscle development, the alpha-skeletal and alpha-cardiac isoforms of actin accumulate rapidly at the onset of muscle fibre formation, while there is a rapid fall in the expression of nonmuscle (beta and gamma) actin isoforms. Here we show that, before birth, both skeletal and myocardial cells express significant amounts of alpha-smooth muscle actin mRNA and protein.

First field trial of fox vaccination against rabies using a vaccinia-rabies recombinant virus.

A field trial of fox vaccination against rabies using a vaccinia-rabies recombinant virus was carried out in Belgium on October 24, 1987. Each vaccine capsule contained a suspension of 10(8) TCID50 of the recombinant virus and was introduced into a chicken head. Each chicken head contained 150 mg of tetracycline as a marker of uptake.

Development of animal recombinant DNA vaccine and its efficacy in foxes.

Rabies is prevalent in most parts of the world. An extensive reservoir of the disease is present in the population of wild animals. The fox in particular is a major vector of the disease in North America and Europe.

Use of recombinant vaccinia-rabies virus for oral vaccination of fox cubs (Vulpes vulpes, L) against rabies.

Thirteen fox cubs were orally administered 10(7.2) plaque-forming units of live vaccinia-rabies glycoprotein recombinant virus. On Day 28 post-vaccination, all but 1 cub had produced rabies virus antibodies.

Improved antigenicity of the HIV env protein by cleavage site removal.

The HIV env glycoprotein mediates virus infection and cell fusion through an interaction with the CD4 molecule present at the surface of T4+ lymphocytes. Although env presents a major antigenic target, vaccinia recombinants expressing env elicit low titres of anti-env antibody (Kieny et al., Bio/Technology, 4, 790-795, 1986).

Recombinant polyoma--vaccinia viruses: T antigen expression vectors and anti-tumor immunization agents.

Live vaccinia virus recombinants expressing viral antigens have recently been developed as effective anti-viral vaccines. We have examined the possibility of extending this approach to specific anti-tumor immunity, using tumors induced by the polyoma virus (PyV) as a model system. Three recombinant vaccinia viruses, separately encoding the three early proteins of the polyoma virus (large, middle and small tumor (T) antigens) were constructed.

Isotypic restriction of the antibody response to human immunodeficiency virus.

HIV-infected individuals progress toward AIDS despite the early elicitation of a specific immune response. Analysis of the isotypic distribution of HIV-specific antibodies appears of special interest for two reasons: first, isotypic diversity is partly under the control of antigen-specific T-helper cells, the very cells infected by HIV; second, isotype determines antibody functions, effector (neutralization, antibody-dependent complement, or cell-mediated cytotoxicity) as well as blocking functions. We have investigated by Western blot analysis the isotypic profile of the antibody response to HIV structural proteins (env, gag, pol) and to the nonstructural protein F (3' orf), which is absent from the virion and might primarily target infected cells.

The crooked neck dwarf muscular dysgenesis in fowl is due to a selective alteration of the somitic myogenic cell line.

Muscular dysgenesis in trunk and limb regions of the crooked neck dwarf (cn/cn) fowl is characterized by a complete disorganization of the muscles, starting at 7.5 days of incubation and resulting, at the end of the incubation period, in a profound muscular atrophy. It has previously been attributed to progressively extending defects of the myotubes.

Muscular dysgenesis in fowl: ultrastructural study of skeletal muscles in the crooked neck dwarf (cn/cn) mutant.

In vivo evolutive aspects of muscular dysgenesis were studied in normal and crooked neck dwarf (cn/cn) 7.5- to 20-day chick embryos. Wing, leg and breast muscles were processed for electron microscopy.

[Experience with antirabies vaccination of foxes using the oral route coordinated among several European countries and perspectives on the use of recombinant vaccinia-rabies virus].

Campaigns of fox vaccination against rabies were carried out in Belgium, grand-duchy of Luxembourg and France in September 1986, June and September 1987. The SAD B19 attenuated strain of rabies virus, contained in baits (Tübingen baits) was used as vaccine. Baits were distributed at a range density of 11 to 15 baits per km2.

Origin and development of avian skeletal musculature.

Experimental studies have shown that the myogenic stem cells in birds migrate from the somite into the lateral plate mesoderm, where they later differentiate into muscle cells. Muscles being made up of myocytes and connective tissue cells, the interactions between these two types of cells of different embryological origins have been considered during the development of the musculature. In particular, our purpose was to focus on the genesis of the spatial organization of the musculature; we have taken advantage in this field of research of an embryological muscular dysgenesis in which the muscles lose their patterning.

HIV F/3' orf encodes a phosphorylated GTP-binding protein resembling an oncogene product.

Apart from the retroviral gag, pol and env the HIV genome contains the F (3' orf) gene which encodes a polypeptide of 206 amino acids which is myristylated at the N-terminal and whose function is unknown. We have expressed the F gene in Escherichia coli and from a recombinant vaccinia virus, VVTGfHIV. The F-protein produced in VVTGfHIV-infected mammalian cells is myristilated, and is phosphorylated by protein kinase C at a residue close to the N-terminus like pp60-src (ref.

Attempt to produce a chick/mouse heteroclass musculature.

Heteroclass chick/mouse chimaeras were prepared by transplanting somitic presumptive myogenic cells or limb bud myoblasts from donor mouse embryos into chick hosts, to replace (1) previously extirpated brachial somitic mesoderm or (2) experimentally deleted limb premuscular masses. Since mouse and chick cells can be distinguished by differential staining affinities, this parameter was used to verify the viability of the implant and to assess its fate. Our analyses showed that transplanted mouse somitic myogenic stem cells or limb bud myoblasts did not participate in the host brachial musculature, whatever the experimental conditions.

Tumour prevention and rejection with recombinant vaccinia.

Tumour-specific antigens (TSA; ref. 1) have been exploited in the diagnosis and imaging of human cancer and anti-TSA antibodies have therapeutic potential. Vaccination with TSA or anti-idiotypic (TSA) antibodies has also been used to control tumour growth in model systems.

Oral vaccination of the fox against rabies using a live recombinant vaccinia virus.

Rabies, a viral disease affecting all warm-blooded animals, is prevalent in most parts of the world, where it propagates amongst wild animals, particularly the fox and dog. The public health and economic consequences of infection in man and livestock are well known. Attempts to control the disease by vaccinating wild carnivores with inactivated or attenuated rabies virus remain controversial, and we have instead evaluated here the potential of a recombinant vaccinia virus to protect foxes against the disease.

On the non-equivalence of skeletal muscle satellite cells and embryonic myoblasts.

Postnatal satellite cells, isolated from normal or previously denervated skeletal muscles of juvenile quails, were tested as to their capacity to participate in embryonic muscle ontogeny. They were grafted into 2-day chick embryo hosts, in place of a piece of brachial somitic mesoderm. Satellite cell implants were prepared from pellets either of freshly isolated cells or of cells precultured in vitro under proliferative conditions.

Expression of rabies virus glycoprotein from a recombinant vaccinia virus.

Rabies is one of the oldest diseases know to man, but its successful control has remained elusive. Although effective vaccines of tissue culture origin against rabies do exist, such preparations are expensive. Live vaccinia virus (VV) recombinants expressing influenza or hepatitis B antigens have recently been used to immunize against these diseases.

Immunofluorescent localization of extracellular matrix components during muscle morphogenesis. II. In chick embryos with hereditary muscular dysgenesis (cn/cn).

The immunofluorescent distribution of types I and III collagen, fibronectin, and laminin during muscle morphogenesis of the crooked neck dwarf mutant chick embryo differs from that of the normal chick. The drastic difference is related to the inability of the mutant embryo to maintain a harmonious muscle pattern. The first sign of the defect is the disaggregation of type I collagen fibers of the tendons and the disorganization of the intermuscular spaces.

Protection from rabies by a vaccinia virus recombinant containing the rabies virus glycoprotein gene.

Inoculation of rabbits and mice with a vaccinia-rabies glycoprotein recombinant (V-RG) virus resulted in rapid induction of high concentrations of rabies virus-neutralizing antibodies and protection from severe intracerebral challenge with several strains of rabies virus. Protection from virus challenge also was achieved against the rabies-related Duvenhage virus but not against the Mokola virus. Effective immunization by V-RG depended on the expression of a rabies glycoprotein that registered proline rather than leucine as the eighth amino acid from its NH2 terminus (V-RGpro8).