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C O Pintado

Publications and source records attributed to C O Pintado.

11 recordsLinked to original sources
PubMed1999

A new epitope on sheep CD45R molecule detected by a monoclonal antibody.

This paper describes the production and characterization of a monoclonal antibody (mAb), Co-46D5, which recognizes a new epitope on the isoform of the homologous sheep leukocyte common antigen (LCA) or CD45. This nmAb was submitted to the 3rd workshop on ruminant leukocyte antigens and was assigned to a cluster reactive with B- and T-cells subsets. Co-46D recognizes a 220 kDa molecule on peripheral blood mononuclear cells (PBMC) and spleen cells but not on thymocytes. Flow cytometry (FCM) analysis shows that Co-46D5 reacted with 30% of PBMC and 50% of spleen cells and more than 95% of cells freshly isolated from lymphoid follicles of the ileal Peyer's patches (IPP) of young lambs. By immunohistochemistry, the antigen was detected mainly on B-cell areas of lymph nodes and spleen. It was also found on a subpopulation of medullar thymocytes. Based on these results, we assume that Co-46D5 recognizes a new epitope on the largest isoform of the sheep CD45 receptor, probably on the homologous to the human CD45RA isoform.

Animals↗
PubMed1996

1 alpha, 25-dihydroxyvitamin D3 (calcitriol) induces apoptosis in stimulated T cells through an IL-2 dependent mechanism.

The steroid hormone 1 alpha,25-dihydroxyvitamin D3 (calcitriol) has been shown to inhibit PHA-induced T-cell proliferation. In the present work we show that calcitriol caused a concentration-dependent decrease in the viability of PHA stimulated but not unstimulated T lymphocytes. Under microscopy, nonviable cells exhibit classic features of programmed cell death or apoptosis. In addition, the same concentration of calcitriol induces a blockage in the G1 phase of T cell cycle and decreased secretion of IL-2, which was correlated with the extent of apoptosis. Thus, addition of exogenous IL-2 reverted both the cell cycle block and the apoptotic cell death induced by calcitriol. This data indicates that calcitriol induced apoptosis in PHA-stimulated T cell, and suggests that this action is mediated through suppression of IL-2 secretion.

Animals↗
PubMed1996

Ruminant cluster WC13.

Five monoclonal antibodies (mAbs) belonged to preliminary cluster 27; however, only two mAbs, Buf13 (3W-506) and Co-3D1D4 (3W-202), were shown to detect the same surface antigen and belong to WC13. The other three mAbs, IVA120 (3W-323), IVA197 (3W-533) and IVA198 (3W-290), detected a 45 kDa molecule that could be fibrinogen (Mateo A., Perez de la Lastra, J., Moreno, A., Dusinsky, R., Bilka, F., Simon, M., Horovska, L., Naessens, J. and Llanes, D., 1996. Biochemical characterization of antigens detected with anti-platelet monoclonal antibodies. Vet. Immunol. Immunopathol., 52: 363-370; Perez de la Lastra, J.M., Mateo, Dusinsky, R., Bilka, Simon, M., Horovska, L. and Llanes, D., 1996. Two monoclonal antibodies from the platelet panel recognize sheep plasma fibronigen. Vet. Immunol. Immunopathol., 52:).

Animals↗
PubMed1996

A monoclonal antibody to ruminant fibrinogen produced through immunization with ovine peripheral blood leukocytes.

By immunizing BALB/c mice with peripheral blood leukocytes (PBL) we have obtained a monoclonal antibody (MAb) named Co.1C9D10, specific for the gamma chain of ruminant fibrinogen. This MAb immunoprecipitates a molecule of apparent molecular weight of 55/65 kDa under reducing conditions and of around 300 kDa under nonreducing conditions. Co.1C9D10 recognized the gamma chain of fibrinogen by immunoblotting techniques and blood vessel plasma from paraffin embedded tissues by immunocytological techniques. Flow cytometry analysis showed that fibrinogen appears adhered to monocytes and granulocytes being eliminated through EDTA treatment of the cells. This phenomenon explains why PBL used as immunogen was able to induce an MAb against fibrinogen.

Animals↗
PubMed1995

Characterisation of a membrane receptor on ruminants and equine platelets and peripheral blood leukocytes similar to the human integrin receptor glycoprotein IIb/IIIa (CD41/61).

This paper describes two anti-glycoprotein IIb/IIIa or CD41/61 murine monoclonal antibodies (Co.35E4 and Co.2oA1). The cellular distribution and apparent molecular weight of the antigen detected by these antibodies is consistent with their reaction with ruminant and equine glycoprotein IIb/IIIa. Biochemical analysis of the equine molecule using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) revealed bands of 24, 100 and 110 kDa under reducing conditions and 115 and 80 kDa under nonreducing conditions. Biochemical analysis of ruminant antigen revealed that the 24 kDa band did not appear owing to the absence of labelling with sulpho-NHS-biotin. Co.35E4 and Co.20A1 recognised two different Ca2+ complex independent epitopes. The glycoprotein IIb/IIIa was present on ruminant and equine granulocytes, monocytes and platelets. However, binding on granulocytes and monocytes was due to the adsorption of membrane platelet fragments.

Animals↗
PubMed1995

Homotypic aggregation of ovine leucocyte induced by anti-leucosialin (CD43) monoclonal antibodies.

Four monoclonal antibodies directed against ovine/bovine leucocyte antigens (Co.44B8, Co.11F10, Co.33B3 and Co.26F4) were produced and all recognized an antigen with an apparent molecular weight of 105 kDa under reducing conditions. This molecule was considered to be the ovine/bovine analogue of human, rat and mouse CD43 or leucosialin. This conclusion was based on (a) the cellular distribution of the antigen which was similar to that described in other species, (b) a decrease of apparent M(r) (150 kDa) after treatment with neuraminidase, and (c) production of cell aggregation by the four monoclonal antibodies and the influence of temperature and metabolic inhibitors on this phenomenon. Co.44B8, Co.11F10, Co.33B3 and Co.26F4 all recognized and immunoprecipitated the molecule after neuraminidase treatment of the cells. The data indicate an important function of CD43 as a mediator of cell aggregation for ruminant cells.

Animals↗
PubMed1995

A monoclonal antibody to an ovine gp130 molecule inhibits homotypic aggregation induced by anti-CD43 monoclonal antibodies of ruminant leukocytes.

A monoclonal antibody (mAb) Co.3E1D4 which recognized a molecule present on the surface of ovine peripheral blood granulocytes, monocytes, platelets and a small percentage of lymphocytes, was able to block leukocyte aggregation induced by mAbs specific for the leukosialin or CD43 molecule. Co.3E1D4 precipitated an antigen with apparent molecular weight of 130 kDa (under reducing and non-reducing conditions). Endoglycosidase F digestion of the molecule resulted in reduction in the apparent molecular weight. These data suggest that the antigen recognized by Co.3E1D4 may be homologous to the human CD31 or platelet endothelial cell adhesion molecule-1 (PECAM-1). Aggregation produced by other inducers such as PMA was not blocked showing that only some cell-cell interactions were mediated by the gp130 molecule.

Animals↗
PubMed1995

A monoclonal antibody to swine erythrocytes recognizes the B blood group on the major glycophorin.

Recently monoclonal antibodies (mAbs) to swine red blood cells have been described. One of them (1AC11) was specific for the major swine glycoprotein with a molecular weight of 45 kDa and another mAb, 2G2, recognized the Ba allele in the B system of swine blood groups. Immunoblotting experiments to characterize the mAb 2G2 indicated that it reacts with an antigen of 45 kDa, present on the aqueous phase, glycophorin fraction, of swine red blood cells with the Ba allele and does not react with BbBb homozygous cells. The antigen recognized by 2G2 has the same characteristics as the major glycophorin recognized by 1AC11, so we can conclude that the B system of the swine blood group is on the major glycophorin of swine erythrocyte membranes.

ABO Blood-Group System↗
PubMed1995

The beta chain of the GPIIb molecule on ruminant leukocytes and platelets is not labelled by the sulfo-NHS-biotin method.

Glycoprotein (Gp)IIb/IIIa molecules have been immunoprecipitated from platelets and leukocytes of cattle, goat, horse, human, sheep and swine using specific monoclonal antibodies. The sulfo-NHS-biotin (sulfosuccinimidobiotin) method used to label the proteins has been found unsuitable for labelling the beta chain of the ruminant GPIIb/IIIa molecule. The beta chain was present on ruminant leukocytes and platelets when immunoprecipitates were silver stained.

Animals↗
PubMed1995

Serologically defined lymphocyte alloantigens in Spanish sheep.

Using segregation and population analysis of serological data prepared in our laboratory, we have tentatively defined five OLA antigenic specificities: CO1.1, CO1.2, CO2.1 and CO2.2, whose genetic control would fit a model of two class I OLA loci (CO1.1 and CO1.2 first locus, CO2.1 and CO2.2 second locus, and CO3.1, that could represent a subtype of CO2.2. Alloantisera were obtained from Spanish Merino sheep by intrafamilial cross-immunization and from serum of primiparous and multiparous ewes. Screening of alloantisera for antilymphocyte reactivity was carried out by a two-step dye exclusion microcytotoxicity test against 216 animals belonging to different local breeds: Spanish Merino, Merino Landschaft, Manchega and Churra. Lymphocyte antigen specificities were characterized by cluster and correlation analysis, as well as family studies. Comparison of CO alloantisera with reference reagents from Scotland (CA reagents) showed an excellent correlation between CO1.1 and CA2, and CO2.1 and CA5. The reagents described can be used in various breeds, a characteristic important for their future applications.

Animals↗