Human fetal and tumor alpha-fetoproteins differ in conformationally dependent epitope variants expression.

Expression of two conformationally dependent epitopes (cdes) designated as cdeD and cde106 of human alpha-fetoprotein (hAFP) was studied in hAFP of fetal and tumor origin. This was done by immunoaffinity electrochromatography on nitrocellulose membrane and by ELISA. Using anti-cdeD and anti-cde106 monoclonal antibodies (MoAbs), the relationship between the cde-positive and cde-negative hAFP fractions was evaluated in 75 samples with the above techniques.

Conformational variants of human alpha-fetoprotein.

The immunological heterogeneity of human alpha-fetoprotein (AFP) was demonstrated using immunoaffinity electrochromatography on monoclonal antibodies (MoAbs) to 3 non-cross-reacting epitopes of this protein. At least 4 subfractions expressing different epitopes were found in the native AFP. These subfractions demonstrated molecular weights similar to the major component of the original AFP.

Epitope mapping of human alpha-fetoprotein.

Thirty monoclonal antibodies (MoAbs) to human alpha-fetoprotein (AFP) were compared with one another by two methods: Immunoaffinity electrochromatography or additive ELISA. The first method permitted to analyse the epitopes of native AFP in solution [Abelev et al., Immunol Lett 1994;40:133-138] while the other approach also detects the epitopes of conformationally modified (partly denatured) AFP fixed on the plastic [Yazova et al.

Inducible protein in rat hepatomas with expression alternative to alpha-fetoprotein.

The rat hepatoma cell line McA RH7777 was cloned into alpha-fetoprotein-producing (AFP+) and non-producing (AFP-) sublines. A monoclonal antibody (MAb A2/3) reacting with an antigen (Ag A2/3) present only in AFP- clones or AFP- cells in mixed clones was obtained. Ag A2/3 was absent from the liver of embryonic, fetal, newborn and adult rats, but it was present in gastric and intestinal mucosa of adult rats.

Monoclonal antibodies against human tetranectin, epitope characterization and use in immunohistochemistry.

Two IgG2a/kappa- and three IgG1/kappa monoclonal antibodies (MAbs) were produced against human tetranectin (TN): this is the first report of stable hybridomas producing MAbs against TN. All the MAbs reacted with non-conformational epitopes located within amino acid residues 50-181 of the primary sequence. In relative epitope mapping with enzyme immunoassay and isotachophoresis the five MAbs defined two independent epitope groups.

Biliary glycoprotein 1 expression during embryogenesis: correlation with events of epithelial differentiation, mesenchymal-epithelial interactions, absorption, and myogenesis.

Biliary glycoprotein (Bgp1), a carcinoembryonic antigen-related family member of the immunoglobulin superfamily, is involved in normal and neoplastic events. Analysis of Bgp1 expression throughout post-implantation mouse embryogenesis using reverse transcription-polymerase chain reactions, immunostaining with anti-Bgp1 monoclonal antibodies, and in situ hybridization with specific Bgp1 cDNA fragments revealed that Bgp1 may be involved in a number of specific embryonic processes. Immunoblot analysis of Bgp1 deletion mutant proteins indicated that distinguishable epitopes of the molecule were preferentially identified by the three Bgp1 antibodies used in this study.

Human alpha-fetoprotein epitopes as revealed by monoclonal antibodies.

The epitope specificity of 12 anti-human alpha-fetoprotein monoclonal antibodies (Mabs) was estimated in an enzyme-linked immunosorbent assay (ELISA). A combination of two different approaches: (i) Mabs binding to heterologous alpha-fetoprotein (AFP); and (ii) cooperative Mabs binding to human AFP (hAFP) when tested in pair mixtures; was used. This double-approach methodology was found to be more reliable for the definition of Mab specificities than either method alone.

The antigen of bile canaliculi of the mouse hepatocyte: identification and ultrastructural localization.

The AgB10 antigen of bile canaliculi of the mouse hepatocyte was identified using monoclonal antibodies. The Mr value of 116000 for AgB10 was measured by immunoblotting. The tissue localization of AgB10 was studied by light and electron microscopy using the immunoperoxidase technique.

Performance of multistep immunochemical reactions by counterflow isotachophoresis on nitrocellulose membranes--II. Epitope analysis of monoclonal antibodies.

The method for comparison of epitope specificity of different monoclonal antibodies to one antigen, using a panel of monoclonal antibodies to mouse and human alpha-fetoprotein is described. The method used exploits the special properties of electroendosmotic flow in nitrocellulose membranes under the conditions of anionic isotachophoresis. Electroendosmosis allows successive transfer of several immunoreagents to the dots of monoclonals previously bound to the nitrocellulose membrane.

Mixed precipitation in gel: a new method of identification and characterization of monoclonal antibodies.

A mixed precipitation in the gel (MPG) technique is suggested for detection and characterization of monoclonal antibodies (MAbs). The MPG is based on the formation of a mixed precipitate composed of an antigen, the corresponding MAb and precipitating polyclonal antiserum. MAb incorporated into the precipitate is revealed by Fab'-peroxidase conjugate added to polyclonal antiserum.

Termination of natural tolerance to alpha-foetoprotein in rats: study of cell-mediated immunity in the macrophage migration inhibition test.

Immunization of rats with mouse alpha-foetoprotein has been earlier shown to induce the antibody response to self AFP or rats. In this work a single injection of AFPm resulted in termination of natural tolerance of effector T-cells to AFPr, as shown by the macrophage migration inhibition test using peritoneal exudate cells from immunized animals. A significant reaction was elicited by both AFPm and AFPr in the course of primary, secondary and third immunization with AFPm.