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Biomedical subjects

H Kristofová

Publications and source records attributed to H Kristofová.

At least 19 recordsLinked to original sources

Monoclonal antibodies suitable for plum pox virus determination.

Monoclonal antibodies (MAbs) to plum pox virus (PPV) were obtained after immunization of BALB/c mice with purified PPV-W isolate. Spleen cells from a mouse showing a high serum titer were used for fusion with Sp2/0-Ag14 myeloma cells. Culture supernatants were screened for specific antibody production against PPV-W isolate using indirect ELISA. A total of six stable hybridoma lines producing MAbs of IgG class were obtained. All four PPV isolates tested (W, A, D and M) can be distinguished by these MAbs. Two highly efficient antibodies were chosen for practical purposes, and their applicability in PPV diagnostics has been studied since 1989 in parallel with polyclonal antibodies and commercial kits (Boehringer, Bioreba). The experiments have proven comparable sensitivity with a detection limit ranging between 10 and 50 ng of virus per ml sample. In routine diagnostics of plums, peaches and apricots our MAbs ranked at least as high as the commercial kits.

Animals↗

A monoclonal antibody applicable for determination of C-peptide of human proinsulin by RIA.

BALB/c, (BALB/c x B10.A)F1 and (BALB/c x B10)F1 hybrid mice were immunized with C-peptide of human proinsulin. The (BALB/c x B10.A)F1 hybrids were the best responders and yielded 3 hybridomas secreting specific monoclonal antibodies. One of them, C-PEP-01, bound the C-peptide with high affinity (Kas = 1.1 x 10(9) l/mol), cross-reacted fully with human proinsulin but not with insulin, glucagon or somatostatin and apparently recognized the regions of C-peptide comprising amino acid residues 8-13 and 25-31. A RIA system could be set up employing this monoclonal antibody suitable for estimation of C-peptide concentrations in a diagnostically useful range (1-50 ng/ml).

Amino Acid Sequence↗

Monoclonal antibodies against human leucocyte antigens. IV. Antibodies against subunits of the LFA-1 (CD11a/CD18) leucocyte-adhesion glycoprotein.

Six monoclonal antibodies were prepared that recognize a broadly expressed antigen composed of noncovalently associated 95 kDa and 180 kDa subunits. Antibodies MEM-25, MEM-83 and MEM-95 are shown to react with a determinant(s) present on the isolated larger subunit identified as the CD11a glycoprotein, MEM-48 reacts with the isolated smaller subunit which is identical to the CD18 glycoprotein. Antibodies MEM-30 and MEM-94 recognize probably a determinant in the CD11a/CD18 complex (i.e., LFA-1 antigen) dependent on association of the constituent chains. Cytotoxic activity of NK cells in inhibited by antibodies MEM-25, MEM-95 and less strongly by MEM-30 and MEM-94.

Animals↗

Characterization of a broadly expressed human leucocyte surface antigen MEM-43 anchored in membrane through phosphatidylinositol.

A monoclonal antibody MEM-43 was prepared, which recognizes an antigen expressed on all peripheral blood leucocytes, on erythrocytes and several cell lines, but is absent from U937, Nalm-6, Daudi and Raji cell lines. The antigen isolated by immunoaffinity chromatography from several cell lines is an 18,000-25,000 mol. wt glycoprotein. An apparently identical antigen isolated from erythrocytes binds to several lectins and has a 14,000 mol. wt polypeptide backbone, modified by an endoglycosidase F-sensitive carbohydrate moiety. The epitope recognized is reduction-sensitive. The sequence of N-terminal 17 amino acid residues was determined; five out of six N-terminal amino acids are identical to those found at the N-terminus of the mouse lymphocyte surface antigen Ly-6C. The antigen is completely released from the cell surface after treatment with phosphatidylinositol-specific phospholipase C.

Amino Acid Sequence↗

Monoclonal antibodies against human leucocyte antigens. III. Antibodies against CD45R, CD6, CD44 and two newly described broadly expressed glycoproteins MEM-53 and MEM-102.

Monoclonal antibodies against several human leucocyte cell surface antigens were prepared and characterized: (1) MEM-56, MEM-93, MEM-66, and MEM-104 against the CD45R antigen (220 kDa and 205 kDa mol. wt. forms of the leucocyte common antigen CD45 expressed on B-lymphocytes, myeloid cells and a subpopulation of T-lymphocytes); (2) MEM-98 and MEM-100 against the T-lymphocyte antigen CD6 (mol. wt. 100 kDa); (3) MEM-85 against the broadly expressed antigen CD44 (mol. wt. 85 kDa) which was recently shown by us to be identical with the lymphocyte homing receptor; (4) MEM-53 against a newly described broadly expressed antigen of 35-40 kDa mol. wt. and (5) MEM-102 against another newly described glycoprotein of 40 kDa mol. wt. anchored in membrane through a phosphatidylinositol moiety.

Animals↗

Monoclonal antibodies against human alpha-fetoprotein. Exploitation of an unusual calcium-dependent interaction with the antigen for analytical and preparative purposes.

Seven murine hybridomas were established producing IgG1 monoclonal antibodies (mAbs) against three different epitopes of human alpha-fetoprotein (alpha FP). The interaction of two of these mAbs (AFP-01 and AFP-02) with the antigen was strongly inhibited by calcium-chelating agents. The mAb AFP-11 could be used for estimation of alpha FP by RIA in the concentration range of 5-100 ng/ml. Several combinations of the mAbs could be used in a two-site sandwich-ELISA for similar purposes. Immunoaffinity chromatography on a column of immobilized mAb AFP-01 permitted the purification of alpha FP.

Animals↗

Monoclonal antibodies reacting with gliadin as tools for assessing antigenic structure responsible for exacerbation of celiac disease.

Monoclonal antibodies reactive with gliadin were prepared by fusion of spleen cells isolated from gliadin-immunized BALB/c mice with myeloma cells. The reactivity of mAbs with different preparations of gliadin and their enzymatic digest were measured using ELISA method. The mAb produced by GL 1 clone was shown to react preferentially with alpha-gliadin and its enzymatic digest.

Antibodies, Monoclonal↗

Characterization of a 95 kDa human leucocyte sialoglycoprotein: its identity with CD43, gpL115, leukosialin and sialophorin.

A monoclonal antibody, MEM-59, was prepared, which recognizes a heavily sialylated glycoprotein antigen expressed on most human leucocytes, the apparent molecular mass of which is strongly dependent on the concentration of polyacrylamide gel used for SDS-PAGE. The antigen isolated on immobilized MEM-59 reacted in Western blotting with mAbs described previously by others as recognizing antigens of similar properties. These experiments indicate that the molecules called CD43, gpL115 (sialophorin) or leukosialin are identical and different from a 75-85-kDa glycoprotein of similarly broad tissue distribution (CDw44). Most of the anti-CD43 mAbs recognize sialic acid-dependent epitopes. None of the anti-CD43 mAbs tested stimulated proliferation of peripheral blood leucocytes in vitro.

Antibodies, Monoclonal↗

Monoclonal antibodies against human leucocyte antigens. II. Antibodies against CD45 (T200), CD3 (T3), CD43, CD10 (CALLA), transferrin receptor (T9), a novel broadly expressed 18-kDa antigen (MEM-43) and a novel antigen of restricted expression (MEM-74).

The specificities of several monoclonal antibodies described by us earlier were determined more exactly: (1) antibodies MEM-31 and MEM-32 are directed against CD8 and CD5 T cell antigens, respectively: (2) MEM-15 and MEM-18 react with the CD14 monocyte antigen; (3) MEM-28 recognizes the CD45 pan-leucocyte antigen. Several new monoclonal antibodies are described: (4) MEM-55 and MEM-58, reactive with subsets of CD45-related molecules; (5) MEM-43, recognizing a broadly expressed 18-kDa glycoprotein; (6) MEM-57, reacting with the CD3 antigen complex: (7) MEM-59 recognizing the CD43 leucocyte antigen; (8) MEM-74, which reacts with an unidentified antigen strongly expressed on several cell lines and many leukaemic cells but absent from most resting leucocytes; (9) MEM-75, directed against transferrin receptor, and (10) MEM-78, recognizing CD10 (CALLA) antigen.

Antibodies, Monoclonal↗

Biochemical characterization of a soluble form of the 53-kDa monocyte surface antigen.

Two monoclonal antibodies, MEM-15 and MEM-18, were prepared which recognize a monocyte 53-kDa antigen. A soluble form of this antigen was found in most normal sera and in urine of some nephrotic patients. Milligram amounts of this glycoprotein were isolated by immunoaffinity chromatography from urine and used for quantitative amino acid and carbohydrate analysis and N-terminal amino acid sequencing. The reactivity of the isolated antigen with several previously described monoclonal antibodies indicates that it is the antigen previously called MY-4 or MY-23. A significant homology exists between the sequenced N-terminal portion of the antigen and sequences found in the kinase-related transforming protein src and in the precursor of epidermal growth factor.

Amino Acid Sequence↗

Characterization of seven new monoclonal antibodies against human DR, DR + DP and DQ1 + DQ3 antigens.

Seven murine monoclonal antibodies were prepared that react with human class II antigens. Four of them (HL-39, MEM-12, MEM-24G, and MEM-32B: react with a monomorphic determinant dependent on association of heavy and light chains of DR antigens, two others (HL-38 and HL-40) recognize a monomorphic determinant localized on the light chains of DR and DP antigens. The antibody HL-37 is directed against a determinant present on DQ1 and DQ3, but not DQ2 molecules; at least in the case of DQ1, the epitope recognized is located on the light chain.

Animals↗

Monoclonal antibodies against human leucocyte antigens. I. Antibodies against beta-2-microglobulin, immunoglobulin kappa light chains, HLA-DR-like antigens, T8 antigen, T1 antigen, a monocyte antigen, and a pan-leucocyte antigen.

Monoclonal antibodies against several human leucocyte cell surface antigens were prepared and characterized: B2M-02, a non-cytotoxic antibody against beta-2-microglobulin; MEM-09 and MEM-40, against immunoglobulin kappa-type light chains; MEM-12, MEM-24G and MEM-32B, all against a monomorphic determinant in MHC class II antigens, presumably HLA-DR, dependent on the association of alpha and beta chains; MEM-15 and MEM-18, against a monocyte antigen of 55 kDa; MEM-28, against a 200 kDa antigen expressed on all leucocytes; MEM-31, against the T8 antigen of the cytotoxic/suppressor T-lymphocyte subpopulation; MEM-32, against the T1 antigen of T lymphocytes.

Animals↗

Two-step freezing of hybridoma cells in 96-well microculture plates.

Stabile hybridoma cells, colonies of hybridoma cells 14 days after fusion of immune spleen and myeloma cells, myeloma cells and fibroblasts cultured in 96-well microculture plates were frozen by the method of two-step freezing. The culture medium was aspirated, and 50 microliter of the medium containing a cryoprotectant (5% dimethyl sulphoxide) was added for 10 min at room temperature. The plates were put into microtene bags, placed at -25 degrees C in a freezer for 30 min and then stored at -100 degrees C in liquid nitrogen vapour. Plates with cells were thawed rapidly in a 50 degree C water bath. After thawing the hybrid cells were viable and continued to produce the specific antibody.

Animals↗

Murine hybridoma monoclonal antibodies against insulin: cross-reactivity with insulins of three species and blocking of insulin binding to its receptor.

Six hybridoma cell lines secreting monoclonal antibodies against pig insulin and cross-reacting with human and bovine insulins were obtained. Five of these monoclonal antibodies were IgG1, kappa, one IgG2b, kappa; their pI values were in the range of pH 6.3-7.4 and dissociation constants of the insulin-antibody complexes were 0.3-2 X 10(-8) mol/l, as determined by an immunoradiometric inhibition assay. All of these antibodies reacted with sterically closely related determinants and blocked the binding of 125I-pig insulin to the receptor on human MOLT-4 cell line.

Animals↗