PubMed Health⌕ Search

Biomedical subjects

D Carrière

Publications and source records attributed to D Carrière.

16 recordsLinked to original sources
PubMed1999

Whole blood capcellia CD4/CD8 immunoassay for enumeration of CD4+ and CD8+ peripheral T lymphocytes.

We evaluated the Whole Blood Capcellia(R) CD4/CD8, an immunoenzymatic method that provides absolute counts of CD4+ and CD8+ T cells in peripheral blood. The assay is based on the separation of T cells by use of an anti-CD2 magnetic bead suspension, followed by reaction of the CD4 or CD8 molecules with the corresponding monoclonal antibody coupled to peroxidase. CD4-positive monocytes were excluded from the assay. Freeze-dried magnetic bead-T-cell complexes were used as calibrators. Capcellia counts from HIV-1-infected patients were compared with those obtained by flow cytometry as the comparison method. The results by Capcellia correlated well with those by flow cytometric analysis: r2 = 0.95; P <0.001; (y = 0.96x - 22.1); Sy|x = 64 for CD4; r2 = 0.81; P <0.001; (y = 1.26x - 76.4); Sy|x = 139 for CD8; n = 76. The correlation between CD4+ T-cell counts determined by two trained experimenters was significant (r2 = 0.96). Our results indicate that this new ELISA technique for lymphocyte immunophenotyping is an efficient alternative to flow cytometry.

Antibodies, Monoclonal↗
PubMed1996

CD4 masking during human immunodeficiency virus type 1 infection, quantified on peripheral blood lymphocytes, is a potential marker of disease progression.

In human immunodeficiency virus type 1 (HIV-1)-infected adults, the proportion of gp120-free CD4 molecules on the surface of T lymphocytes was measured by double-epitope EIA and expressed as a CD epitope concentration ratio. In 51% of these patients (n=81), CD4 T cells showed a significant decrease (up to 100%) in the accessibility of the CD4 epitope in the D1 domain remained accessible. Of interest, a significant increase in the CD4 gp120 binding site concentration, without a change in T cell counts, was observed within 10 days after initiation of zidovudine treatment. Furthermore, CD4 masking by gp120 was associated with a poor clinical patient status. The assessment of the CD4 epitope concentration ratio is proposed as a surrogate marker of disease progression in HIV-1-infected patients.

Adult↗
PubMed1995

Expression of central and peripheral cannabinoid receptors in human immune tissues and leukocyte subpopulations.

Two proteins with seven transmembrane-spanning domains typical of guanosine-nucleotide-binding-protein-coupled receptors have been identified as cannabinoid receptors; the central cannabinoid receptor, CB1, and the peripheral cannabinoid receptor, CB2, initially described in rat brain and spleen, respectively. Here, we report the distribution patterns for both CB1 and CB2 transcripts in human immune cells and in several human tissues, as analysed using a highly sensitive and quantitative PCR-based method. CB1 was mainly expressed in the central nervous system and, to a lower extent, in several peripheral tissues such as adrenal gland, heart, lung, prostate, uterus, ovary, testis, bone marrow, thymus and tonsils. In contrast, the CB2 gene, which is not expressed in the brain, was particularly abundant in immune tissues, with an expression level 10-100-fold higher than that of CB1. Although CB2 mRNA was also detected in some other peripheral tissues, its level remained very low. In spleen and tonsils, the CB2 mRNA content was equivalent to that of CB1 mRNA in the central nervous system. Among the main human blood cell subpopulations, the distribution pattern of the CB2 mRNA displayed important variations. The rank order of CB2 mRNA levels in these cells was B-cells > natural killer cells >> monocytes > polymorphonuclear neutrophil cells > T8 cells > T4 cells. The same rank order was also established in human cell lines belonging to the myeloid, monocytic and lymphoid lineages. The prevailing expression of the CB2 gene in immune tissues was confirmed by Northern-blot analysis. In addition, the expression of the CB2 protein was demonstrated by an immunohistological analysis performed on tonsil sections using specific anti-(human CB2) IgG; this experiment showed that CB2 expression was restricted to B-lymphocyte-enriched areas of the mantle of secondary lymphoid follicles. These results suggest that (a) CB1 and CB2 can be considered as tissue-selective antigens of the central nervous system and immune system, respectively, and (b) cannabinoids may exert specific receptor-mediated actions on the immune system through the CB2 receptor.

Blotting, Northern↗
PubMed1995

A mouse monoclonal antibody specific for the V beta 5.3 chain of the human TcR recognizes a subgroup of the mouse TcR V beta 8.2 chains.

We have analyzed the reactivity of a mouse monoclonal antibody directed against the human T cell receptor for antigen (TCR). This antibody (111-427) of immunoglobulin G1 isotype has been produced in a BALB/c mouse immunized with HPB-ALL cells and normal human peripheral blood leukocytes. It reacts specifically with the HPB-ALL lymphoma and 2 to 7% of normal human blood lymphocytes, on which it has a mitogenic effect in vitro. We have shown that it immunoprecipitates the alpha beta TCR of HPB-ALL and that it is specific for the V beta 5.3 chain of the human TCR. In addition, we have observed that this antibody stains a minor fraction of T lymphocytes in different strains of mice. We have screened a number of murine T cell clones or hybridomas and have found that the T cell hybrid line DO.11.10.S4.4 is positive. We have been unable to immunoprecipitate reproducibly the molecule recognized by 111-427 after 125I cell surface labeling and cell lysis in NP-40 or digitonin, probably because of low-affinity binding. On Western blotting, 111-427 revealed one band that has an apparent molecular mass of 89 kDa in nonreducing conditions and disappears after reduction. Similar results were obtained in parallel with the F23.1 and F23.2 antibodies. Thus, this antibody appears to recognize an epitope present primarily on the V beta 8.2 chain of the mouse TCR. We have assayed its capacity to stimulate splenic T lymphocytes in vitro. We have observed that it is capable of triggering, to a minor degree in soluble form and very effectively when coupled to Sepharose beads, the proliferation of spleen T lymphocytes from mice chronically infected with the blood parasite Trypanosoma cruzi.

Amino Acid Sequence↗
PubMed1995

Functional epitope analysis of the human CD4 molecule: antibodies that inhibit human immunodeficiency virus type 1 gene expression bind to the immunoglobulin CDR3-like region of CD4.

We recently demonstrated that monoclonal antibody (MAb) 13B8-2, specific for the immunoglobulin (Ig) complementary determining region 3 (CDR3)-like region of the CD4 molecule, inhibits viral transcription in human immunodeficiency virus (HIV)-infected CEM cells and HIV type 1 (HIV-1) promoter activity. Here, we have studied the capacity of several MAb specific for the D1 domain of CD4, including anti-CDR2-like (Leu-3a and ST4) and anti-CDR3-like (13B8-2 and ST40) MAb, and for the D2 domain of CD4 (BL4) to inhibit both provirus transcription in HIV-1LAI-infected CEM cells and transcription of the chloramphenicol acetyltransferase (CAT) gene under control of the HIV-1 long terminal repeat in transiently transfected CEM cells. We found that HIV-1 promoter activity and provirus transcription are inhibited only by MAb that bind to the CDR3-like region in domain 1 of CD4. Moreover, we demonstrated that the Fab fragment of an anti-CDR3-like region-specific anti-CD4 MAb is a powerful inhibitor of HIV-1 promoter activity. These results have implications for understanding the role of the CDR3-like region in CD4 T-cell signaling, which controls provirus transcription.

Antibodies, Monoclonal↗
PubMed1992

Golgi vacuolization and immunotoxin enhancement by monensin and perhexiline depend on a serum protein. Implications for intracellular trafficking.

Vacuole formation around the Golgi and immunotoxin enhancement induced by low doses of the ionophore monensin were inhibited by 50% human plasma (final concentration), whereas the lysosomal pH increase remained unaffected. Immunotoxin enhancement by the Ca2+ antagonist perhexiline was also inhibited by plasma. The inhibiting factor was present in different species and highly concentration-dependent. After purification on DEAE- and CM-Sepharose it showed a heterogeneous distribution between 45 and 50 kDa, in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, an extreme isoelectric point near 3.5, and binding to wheat germ agglutinin-Sepharose. Maximum inhibition was found in the lower molecular mass fraction of 45 kDa. The 50-kDa fraction, although showing immunological identity reactions, remained almost inactive. The simultaneous inhibition of morphological alterations and the enhancement of immunotoxin activity by the highly enriched protein provides a first direct link between both events. Apart from a role of this serum glycoprotein on in vivo inhibition of immunotoxin enhancement, its ability to maintain normal intracellular trafficking in the presence of blocking agents, such as monensin and perhexiline, suggests a more fundamental role in the regulation of these mechanisms.

Biological Transport↗
PubMed1992

The effect of dietary sodium fluoride on internal organs, breast muscle, and bones in captive American kestrels (Falco sparverius).

In 1982, 29 7-day-old American kestrel (Falco sparverius) chicks from captive stock were randomly assigned to one of three dietary regimens: (1) 10 birds were fed daily with cockerel mash (0 ppm of F-: control birds); (2) 10 birds were fed daily with cockerel mash containing 1,120 ppm of F-; (3) 9 birds were fed daily with cockerel mash containing 2,240 ppm of F-. Growth of the kestrels was not significantly affected by NaF in their diet. No significant differences were found among the 3 groups for length of duodenum, jejunum and ileum. Rectum was longer as more fluoride was added to the diet. Weights of adrenals, brain, gizzard, spleen, heart, kidneys, liver, pancreas, and pectoral muscle were not significantly affected by treatment, although kidneys, spleen and adrenals tended to become lighter. Percent bone ash was significantly (P less than 0.05) increased, while bone breaking strength was significantly (P less than 0.05) decreased by treatment.

Animals↗
PubMed1990

Enhancement of ricin A chain immunotoxin activity by perhexiline on established and fresh leukemic cells.

In the perspective of increasing the clinical potential of ricin A chain immunotoxins (RTA-ITs), perhexiline (Pex) and four structural analogues (Pex 2, Pex 3, Pex 7, and Pex 11) were evaluated for their ability to enhance RTA-IT activity in vitro. Only perhexiline significantly enhanced the cytotoxic activity of anti-CD5 RTA-ITs, T101 and T101-F(ab')2, on CEM III cell line (30- to 2000-fold), and of anti-HLA-DR RTA-IT, HNC-241, on both RAJI cell line (greater than 100-fold) and two immortalized cell lines originating from patients suffering from B-cell chronic lymphocytic leukemia, EHEB and FS2 D5 (10-fold). On 16 consecutive fresh B-cell chronic lymphocytic leukemia cell samples, significant T101-F(ab')2 RTA-IT and HNC-241 RTA-IT enhancement was observed with perhexiline which was comparable to that of NH4Cl and monensin. Perhexiline almost completely blocked RTA-IT intracellular degradation and profoundly modified its routing. These observations were linked to perhexiline-induced lipidosis via inhibition of sphingomyelinase activity. In conclusion, since the concentrations used are relevant with the pharmacokinetics of this agent, perhexiline appears to be a promising agent for in vivo enhancement of ricin A chain immunotoxins.

Ammonium Chloride↗
PubMed1990

Stable expression and function of EBV/C3d receptor following genomic transfection into murine fibroblast L cells.

The Epstein-Barr virus (EBV) and the C3d component of complement bind to the same cell surface receptor (EBVR/CR2) which is part of the B lymphocyte differentiation antigen recognized by the monoclonal antibodies (mAb) of the cluster of differentiation 21 (CD21). To analyze EBV and C3d binding to this receptor, mouse fibroblasts were transfected with human genomic DNA and rare CD21-positive cells were selected and cloned by cell sorting. The presence of the human gene in host cell DNA as well as its transcription product were assayed with a cloned EBVR/CR2 cDNA by Southern and Northern blotting analysis, respectively. A glycoprotein of apparent molecular mass of 140 kDa, similar to that found in human B lymphocytes, was immunoprecipitated with anti-CD21 mAb and proved to be functional since both C3d and EBV bound efficiently and specifically to mouse cells expressing EBVR/CR2. However, no expression of EBV nuclear antigens, early antigens and viral capsid antigens was detected in cells exposed to EBV. This indicates that the presence of EBVR/CR2 is not sufficient to allow full infection of mouse fibroblasts.

Animals↗
PubMed1987

Influence of a diet of fluoride-fed cockerels on reproductive performance of captive American kestrels.

In 1982, twenty-four pairs of captive American kestrels (Falco sparverius) were forced to renest by removal of their first clutches 6 days after their completion. Immediately following, each of three groups of eight pairs was randomly assigned to one of three daily dietary regimes for 10 days: (1) three 1-day old cockerels with background levels of F(-) (62.4+/-51ppm, mean+/-SD) in their femurae, (2) two 10-day old cockerels with 4512+/-810ppm of F(-) in their femurae, (3) two 10-day old cockerels with 7690+/-417ppm of F(-) in their femurae. Fluoride levels in femurae of treated kestrels were significantly (P<0.0025) higher than those of control birds. Clutch sizes tended to be smaller as more fluoride was added to the diet, but not significantly so, due to an increase of the variance in the treatment group. Per cent fertility and per cent hatchability were not significantly affected by treatment. The fluoride content in eggshells in the fluoride-treated groups differed significantly from those of the control group (P<0.001).

Journal Article↗
PubMed1985

Endocytosis of an antibody ricin A-chain conjugate (immuno-A-toxin) adsorbed on colloidal gold. Effects of ammonium chloride and monensin.

An immunotoxin (IT) formed by a specific antibody coupled to the ricin A chain was adsorbed on colloidal gold particles (IT-Au). Binding and internalization of IT-Au in human lymphoblastic CEM cells were studied using electron microscopy. IT-Au showed specific cytotoxic activity toward the target cells. After 1 h at 4 degrees C, IT-Au were linked diffusely to the plasma membrane with 45% of the particles regrouped in clusters. Upon transfer to 37 degrees C, the particles carrying the ligand were regrouped more frequently and internalized into the cell by endocytosis through smooth microinvaginations or coated pits of the plasma membrane. After 15 min, IT-Au was observed in endocytic vacuoles, or receptosomes, in tubular structure near the Golgi apparatus and in lysosomes. Entry of IT-Au into lysosomes was rapid (around 50% of intracellular IT-Au particles after 30 min). NH4Cl or monensin, well-known potentiators of immunotoxin activity, when present in incubation medium, altered neither the processes nor the rate of IT-Au endocytosis. In the presence of either of these substances, IT-Au accumulated in the normal or often enlarged endocytic vacuoles, and entry into the lysosomes was slowed down (50% of particles after 2 h 15 min). We conclude that this intense slowing-down in the speed of IT-Au transportation into lysosomes and the functional modifications of these organelles help to explain the increased efficacy of immunotoxins in the presence of potentiators.

Adsorption↗
PubMed1983

[Immunotoxins].

Immunotoxins are conjugates between antibodies especially directed against cancer cells and a subunit of a powerful toxin. We used the A-chain of ricin. These conjugates are specifically cytotoxic when used at very low concentrations in vitro and can destroy more than 99.99% of clonogenic cells. The efficacy of immunotoxins was also demonstrated in vivo but is inferior to its in vitro potency. For this reason the first use of immunotoxins in man can be the cleaning up of bone marrow from leukemic cells in the near future.

Animals↗
PubMed1980

[Stereological analysis of normal Papio Papio liver parenchymal cells (author's transl)].

Stereological analysis of normal Papio Papio liver parenchymal cells has been performed according to the method of Weibel (1969). The study was carried out on liver samples collected from 3 males and 3 females. Sampling was done at three levels of magnification (X 250, X 5 000, X 15 000) without taking into consideration the lobular variations. The lobular stereological model included the hepatocyte, all the cellular organelles and the extra-hepatocytic space compartment. Surface and volume densities were determined; the results are given with respect to three reference units : 1 cm3 lobular tissue, 1 cm3 hepatocyte and 1 cm3 hepatocytic cytoplasm. The mean volume of the Baboon hepatocyte and its components were also measured. Statistical analysis of the results did not show wide individual variation in the population studied. The volume densities of the components were compared to those of rat, dog and man as determined by other investigators. The hepatocytes constitute 84,9% of the lobular volume, and the extra-hepatocytic space 15,1%. The mean individual volume of the hepatocyte is 6 470 micrometer3, which is higher than in rat and dog. The smooth endoplasmic reticulum has a much higher surface density (3,93 m2/cm3) than that of the rough endoplasmic reticulum (1,53 m2/cm3). The values obtained in the present study can be used as reference values in the evaluation of experimentally induced hepatic modifications in Baboon.

Animals↗
PubMed1978

[The mammary gland of the male rat: a histological, histochemical and ultramicroscopic study (author's transl)].

Results of a histological, histochemical and ultramicroscopic study of samples taken from the mammary glands of male Wistar, Sprague-Dawley and Long Evans untreated rats, aged about 8 weeks, are reported. Lobulo-alveolar epithelial formations were observed together with increased metabolic and secretory activity, more frequent in Wistar rats than in other strains. No visible morphological abnormality was noted in the genital tract or adenohypophysis. There was no sign of feminization. The same findings were observed in male Wistar and Sprague-Dawley rats given three different diets of which one was semi-synthetic. The possibility of an exogenous mammotropic dietary factor is therefore very improbable. Endogenous hormonal stimulation, especially consecutive increases in oestrogens and prolactin in the prepubertal period, is possibly the cause of development of mammary tissue. These results show that the mammary gland, in the normal male rat, is not inactive. It seems, therefore, that this organ is not a suitable model for the evaluation of experimental mammotropic effects.

Animals↗