Biomedical subjects

A R De Fougerolles

Publications and source records attributed to A R De Fougerolles.

4 recordsLinked to original sources

PubMed1994

Intercellular adhesion molecules (ICAM)-1 ICAM-2 and ICAM-3 function as counter-receptors for lymphocyte function-associated molecule 1 in human immunodeficiency virus-mediated syncytia formation.

It has been previously demonstrated that lymphocyte function-associated molecule 1 (LFA-1) plays a major role in human immunodeficiency virus (HIV)-mediated syncytia formation. In the present study we investigated the involvement of intercellular adhesion molecule-1 (ICAM-1), ICAM-2 and ICAM-3 in the process. The ability of monoclonal antibodies (mAb) directed against ICAM-1, ICAM-2 and ICAM-3 to block syncytia was analyzed either in phytohemagglutinin (PHA)-activated lymphocytes infected in vitro with primary or laboratory strains of HIV or by coculturing a T cell line stably expressing HIV envelope with PHA-activated lymphocytes. Complete inhibition of syncytia formation was observed only by the simultaneous addition to the cell cultures of all (i.e. anti-ICAM-1, anti-ICAM-2 and anti-ICAM-3) mAb. These results indicate that the interaction between LFA-1 and ICAM is a critical step in HIV-mediated syncytia formation, and that ICAM-1, ICAM-2 and ICAM-3 are the receptor molecules for the LFA-1-dependent syncytia formation.

Antibodies, Monoclonal↗

PubMed1994

Evaluation of the role of exogenous pathogens on the incidence of embryo loss during early pregnancy in mice.

The mating of CBA/j female mice (H2k) by DBA/2j male mice (H2d) typically results in an elevated incidence of spontaneous embryo loss thus providing an ideal genetically controlled laboratory model for the study of the factors causing early embryo loss during pregnancy. There is now considerable data on the cells and factors involved in fetal resorption but little is known about the events which activate this process. While the activation of the maternal response to the fetal implant could have endogenous or genetic origins, a role for exogenous factors including microbial pathogens could also be involved. In order to investigate these possibilities, the reproductive success of CBA/j female x DBA/2j male matings in a conventional animal care facility were compared with matings in a specific pathogen free (SPF) animal facility. All animals housed under these conditions were routinely screened by immunoassay and culture, for the presence of a number of viral and bacterial pathogens of mice. The incidence of spontaneous embryo loss in specific pathogen free CBA female mice mated by DBA and other male strains was found to be virtually identical to that of CBA female mice infected with multiple viral pathogens and housed under otherwise identical conditions (non-SPF). However, the numbers of implantation per pregnancy was significantly greater in an SPF facility. Therefore, exposure of mating mice to exogenous viral and bacterial pathogens did not appear to alter the overall incidence of spontaneous embryo resorption. It was concluded that the immunomodulatory effects of infection by common murine pathogens neither augmented nor reduced post-implantation embryo losses.

Abortion, Veterinary↗

PubMed1993

CDw50 and ICAM-3: two names for the same molecule.

CDw50 differentiation antigen is a molecule broadly expressed on hematopoetic cells but not on other cells. Previous experiments showed that CDw50 monoclonal antibodies (mAb) inhibited primary mixed lymphocyte culture (MLC). To understand the function of CDw50 better, we purified it and obtained peptide sequence. At the same time, intercellular adhesion molecule (ICAM)-3, the third ligand of lymphocyte function-associated molecule 1, was described by mAb and subsequent cDNA cloning. Immunochemical, functional, and protein sequencing studies show that ICAM-3 and CDw50 are the same glycoprotein, a 120-kDa surface molecule with presumably an important role in the immune responses.

Amino Acid Sequence↗

PubMed1992

Isolation, characterization, and expression of mouse ICAM-2 complementary and genomic DNA.

Intercellular adhesion molecule-2 (ICAM-2), a cell surface glycoprotein, is a second counter-receptor for lymphocyte function-associated Ag-1 (LFA-1). We report here the isolation and characterization of the cDNA and the gene that encode murine ICAM-2 (Accession numbers X65493 and X65490, respectively). The deduced sequence of the cDNA has 60% amino acid identity with its human counterpart and has the same expression pattern in cells and tissues. Furthermore, COS cells transfected with mouse ICAM-2 complementary and genomic DNA bind to purified human LFA-1, demonstrating the conservation of the function of ICAM-2 as a ligand for LFA-1 and conservation across species of sequences that are critical for binding to human LFA-1. COS cells transfected with the ICAM-2 cDNA do not react with mAb PA3, previously suggested to define ICAM-2 in the mouse. The mouse ICAM-2 gene was isolated and its structural organization determined. The gene is present in a single copy in the mouse genome and contains four exons spanning about 5.0 kb of DNA. The exon/intron architecture correlates to the structural domains of the protein and resembles that of other Ig superfamily members. The gene for ICAM-2, which is constitutively expressed in endothelial cells, has several conserved sequence motifs in its promoter region, including a direct repeat, and lacks transcription factor-binding sites present in the ICAM-1 gene, which is inducible in endothelial cells.

Amino Acid Sequence↗