摘要:

The use of monoclonal antibodies forin vivotherapeutic approaches depends largely on their specificity. During the characterization of ricin A-chain-murine monoclonal antibody conjugates we found that the binding specificity of a monoclonal antibody raised against human ovarian carcinoma (MOv2) seemed altered. Therefore, the binding reactivity of the unmodified antibody (MOv2), the conjugation intermediate (MOv2-PDP) and the conjugate (MOv2-A chain) was titrated by solid-phase radioimmunoassay on 11 human tumor cell lines belonging to seven different histotypes. The three reagents bound with the two reference cell lines (SW626:ovary carcinoma and HT-29:colon carcinoma). The MOv2-PDP and the Mov2-A chain also reacted with seven other cell lines which were unreactive with the unmodified MOv2. In addition MOv2-PDP exhibited reactivity on all normal cells tested (peripheral blood lymphocytes and skin fibroblasts). To elucidate the significance of these findings the following experiments were performed: cross inhibitions between the unmodified and modified monoclonal antibodies; comparative absorption tests with different cell lines; and immunoblotting analysis of the target antigens. The results suggest that after chemical modification with SPDP the monoclonal antibody MOv2 increases its binding activity, so that even a low number of antigenic sites can be detected. This study underlines the need to redefine the specificity of a conjugate before considering therapeutic applications.

ISSN:0272-457X    

DOI:10.1089/hyb.1986.5.1

年代:1986

数据来源: MAL

摘要:

Monoclonal antibodies against ricin toxin were produced and some of their properties investigated. Antibodies 196 C12 and 197 C7 raised against A-chain reacted with a CnBr fragment probably comprised between amino acid 254 and 262. Antibodies 193 A9, 196 A3, and 191 B7 recognized a 6-7 kD CnBr peptide. A second set of antibodies was raised against whole inactivated ricin. Most of them bound in a solid phase radioimmunobinding assay only to ricin and few had a low activity against purified A-chain. Different effects were noted on toxin action in cultured leukemic cells. If cells were preincubated with ricin followed by antibodies, MAb 207 E5 and 216 B3 had a strong enhancing effect on toxin action. If antibodies and toxin were mixed and then added to sensitive cells, antibody 207 E5 gave a strong protection while 216 B3 maintained its enhancing activity. The effect of antibody 216 B3 was further investigated by quantitative cloning experiments which showed that toxin had a fivefold enhancement in its activity by a preincubation with this antibody. Binding of fluorescinated ricin to leukemic target cells was inhibited by a preincubation with antibody 207 E5 while antibody 216 B3 had no effect.

ISSN:0272-457X    

DOI:10.1089/hyb.1986.5.9

年代:1986

数据来源: MAL

摘要:

Human B-lymphocytes were fused with the human lymphoblastoid B-cell line WI-L2-729 HF2. Hybridoma frequencies were in the range of 10-5when the mononuclear cells were (a) prestimulated with pokeweed mitogen (PWM), (b) fused with polyethyleneglycol (PEG), and (c) selected in a hypoxanthine-azaserin (HAza) containing medium. To generate monoclonal antibodies (MAb) specific for tetanus toxin (TToxin) human spleen cells were precultured with PWM plus tetanus toxoid (TToxoid) in two separate fusions. Two hybridomas were selected based on high binding activity using an enzyme-linked immunosorbent assay (ELISA) for TToxoid. Both hybridomas, cloned twice and designated anti-TT1 and anti-TT2, exhibited a near tetraploid karyotype and showed stable production of antibody (0.15 μg/ml) over several months.Using ELISA for fragments of TToxin and the immunoblotting technique, the two IgG1monoclonal antibodies were found to bind to the heavy chain portion of the B-fragment (anti-TT1) and on the C-fragment (anti-TT2) of the toxin. When tested in an ELISA with TToxin the combination of anti-TT1 and anti-TT2 showed higher binding activity than either reagent alone. In anin vivoneutralization assay mice were completely protected against TToxin by the combination of the two antibodies while either antibody alone resulted only in a delay of death of the mice. These findings demonstrate that a cocktail of appropriate human monoclonal antibodies can be far superior to a single reagent when used in a therapeutic setting

ISSN:0272-457X    

DOI:10.1089/hyb.1986.5.21

年代:1986

数据来源: MAL

摘要:

The stable mouse X human hybridomas were established by cell fusion of a mouse myeloma cell line, a P3-X63-Ag8-653 (P3-653) subclone, with human peripheral blood mononuclear cells (PBMs) from normal volunteers for production of human monoclonal antibody against a predefined, clinically important antigen of viral origin, hepatitis-B surface (HBs) antigen. For successful mouse X human fusions, it was extremely important to preselect volunteers and to sensitize their PBMs by usingin vitrosensitization. The resulting mouse X human hybridomas have continuously secreted a relatively high amount of human monoclonal antibodies to HBs antigen over nine months without cloning.

ISSN:0272-457X    

DOI:10.1089/hyb.1986.5.33

年代:1986

数据来源: MAL

摘要:

Spleen lymphocytes obtained from mice immunized withTrichomonas vaginalisATCC 30001 were fused with P3-X63-Ag8-653 mouse myeloma in order to produce hybridomasecreting antibodies againstT. vaginalisassociated antigens. Six hybridoma cloned cell lines were established; three produced IgG1, two produced IgG2a, and one produced IgM monoclonal antibody. These six monoclonal antibodies showed binding to seven isolated strains ofT. vaginalisbut did not bind toGiardia lamblia. Three of those monoclonal antibodies did not bind toTritrichomonas foetus. These anti-trichomonal monoclonal antibodies should prove to be of great value as diagnostic and research reagents.

ISSN:0272-457X    

DOI:10.1089/hyb.1986.5.43

年代:1986

数据来源: MAL

ISSN:0272-457X    

DOI:10.1089/hyb.1986.5.53

年代:1986

数据来源: MAL

ISSN:0272-457X    

DOI:10.1089/hyb.1986.5.54

年代:1986

数据来源: MAL

ISSN:0272-457X    

DOI:10.1089/hyb.1986.5.57

年代:1986

数据来源: MAL

ISSN:0272-457X    

DOI:10.1089/hyb.1986.5.91

年代:1986

数据来源: MAL