Evaluation of quantitative parameters of the interaction of antibody-bearing liposomes with target antigens

The model system for the analysis of targeted liposomes is proposed--the layer of protein antigen adsorbed on polystyrene wells. Antibodies were treated with palmitoyl chloride and liposomes were produced by the cholate dialysis method in the presence of the modified protein (7 X 10(-4) mol protein/mol lipid). Affinity of antibody-bearing liposomes to the antigen on the surface of Multiwell plates was studied, and apparent dissociation constant value was estimated: KD was in the range 1.5 to 5 X 10(-9) M liposomes. Sequential transfers of liposomes in antigen-coated plates revealed that the high-affinity fraction of liposomes is adsorbed first. The bound fraction has 1.7-times-higher protein content. For effective in vivo targeting it would be necessary to have high-affinity liposomes and a high concentration of the target antigen.     

Immunochemical detection with rabbit polyclonal and mouse monoclonal antibodies of different pools of phytochrome from etiolated and green Avena shoots

While two monoclonal antibodies directed to phytochrome from etiolated oat (Avena sativa L.) shoots can precipitate up to about 30% of the photoreversible phytochrome isolated from green oat shoots, most precipitate little or none at all. These results are consistent with a report by J.G. Tokuhisa and P.H. Quail (1983, Plant Physiol. 72, Suppl., 85), according to which polyclonal rabbit antibodies directed to phytochrome from etiolated oat shoots bind only a small fraction of the phytochrome obtained from green oat shoots. The immunoprecipitation data reported here indicate that essentially all phytochrome isolated from green oat shoots is distinct from that obtained from etiolated oat shoots. The data indicate further that phytochrome from green oat shoots might itself be composed of two or more immunochemically distinct populations, each of which is distinct from phytochrome from etiolated shoots. Phytochrome isolated from light-grown, but norflurazon-bleached oat shoots is like that isolated from green oat shoots. When light-grown, green oat seedlings are kept in darkness for 48 h, however, much, if not all, of the phytochrome that reaccumulates is like that from etiolated oat shoots. Neither modification during purification from green oat shoots of phytochrome like that from etiolated oat shoots, nor non-specific interference by substances in extracts of green oat shoots, can explain the inability of antibodies to recognize phytochrome isolated from green oat shoots. Immunopurified polyclonal rabbit antibodies to phytochrome from etiolated pea (Pisum sativum L.). shoots precipitate more than 95% of the photoreversible phytochrome obtained from etiolated pea shoots, while no more than 75% of the pigment is precipitated when phytochrome is isolated from green pea shoots. These data indicate in preliminary fashion that an immunochemically unique pool of phytochrome might also be present in extracts of green pea shoots.Abbreviation ELISA enzyme-linked immunosorbent assay - mU milliunit - Pfr far-red-absorbing form of phytochrome - Pr red-absorbing form of phytochrome     

A novel immunoassay with direct relevance to protection against organophosphate poisoning

Antiparaoxon immune sera were employed in a new immunoassay based on competition between acetylcholinesterase and antibodies for the binding ofparaoxon. Unlike radioimmunoassay, the new assay described herein can be extended to predict the feasibility of antibodies to confer in vivo protection of acetylcholinesterase against organophosphate poisoning. The toxicity of paraoxon was reduced in mice which were pre-injected with the immune sera.     

A broad spectrum monoclonal antibody to alpha-tubulin does not recognize all protozoan tubulins

Summary Monoclonal antibodies able to recognize single antigenic determinants are a powerful tool for the study of immunological heterogeneity of antigens. In this paper we have used a monoclonal antibody against the -subunit of pig brain tubulin (TU-01) to investigate the immunoreactivity of tubulins from mammals, avians, amphibia, echinodermata, plathelmints, slime moulds and protozoa. Immunoreactivity was detected using immunoblotting and indirect immunofluorescence of isolated cells. Our results show that the antigenic determinant recognized by the TU-01 antibody is present in all metazoan tubulin tested and among the eukaryotic microorganisms only in the flagellateTrichomonas vaginalis. Indirect immunofluorescence also reveals that not allTrichomonas microtubules are stained by TU-01 antibody indicating the presence of different tubulins within a single cell. This results are consistent with the multitubulin hypothesis (Fulton andSimpson 1976).     

Diversity in the immune system: “Preconceived ideas” or ideas preconceived?

Two concepts of the evolution and regulation of expression of the combining site repertoire of the immune system, are compared. One view is based on the Associative Recognition Theory as formulated by the author and the other is based on the Idiotype Network Idea as conceived by Jerne. The two concepts are analyzed from the point of view of their logic, internal consistency and factual support.     

Immunofluorescence staining of thin-filament sections not participating in actomyosin crossbridges: Studies by use of a monoclonal antibody specific to actin

Summary Monoclonal antibodies (mcab) were produced in vitro by fusing mouse X63-Ag8.653 plasmacytoma cells with spleen cells from a Balb/c mouse immunized with primary cultures of chick skeletal muscle (pmcc). After cloning on agar, stable clones were obtained, the antibodies of which stain specifically the I-band of myofibrils in the immunofluorescence (IF) procedure. For further characterization of these mcab their affinities to muscle proteins were tested by immunoblotting and by enzyme-linked immunosorbent assay (ELISA). Mcab specific for actin were revealed by these criteria. One of the anti-actin antibodies, mcab 647, reveals a variety of IF-staining patterns on myofibrils. On rest-length myofibrils the I-band is labeled only. However, at sarcomere lengths below 2 m, where the thin filaments meet in the middle of the A-band and form a region of double overlap, an additional fluorescent band appears in this position. The fluorescence intensity of this band is increased significantly in shorter sarcomeres. Finally, when the I-band has disappeared at a sarcomere length of 1.5 m, fluorescence is located exclusively in the middle of the A-band. These IF-staining patterns suggest that only those sections of the thin filament are stained that do not participate in actomyosin crossbridges.     

马立克氏病毒单克隆抗体的研究

获得了4株分泌马立克氏病毒(MDV)特异性单克隆抗体(McAb)的杂交瘤细胞:4BS10对MDV所有毒株呈阳性反应;4CN8 对MDV血清1,3型毒株发生反应;2BN90和4CN24只对MDV血清1型毒株有阳性反应。3个McAb属IgG1,1个为IgG2b,均不中和MDV,免疫扩散试验也无沉淀线。对禽白血病毒(ALV)无交叉反应。 以2BN90和辣根过氧化物酶、异硫氰酸荧光素的结合物进行直接酶联免疫吸附试验和直接荧光抗体试验,均获得成功。抗体滴度前者为1/51,200,后者为1/640。对ALV无交叉反应。     

Induction of autolysis of staphylococci by the basic peptide antibiotics Pep 5 and nisin and their influence on the activity of autolytic enzymes

Pep 5 and nisin are cationic bactericidal peptides which were shown to induce autolysis in Staphylococcus cohnii 22. In contrast to nisin, Pep 5 induced lysis could be stimulated in the presence of glucose. Addition of lipoteichoic acids (LTA) (d-alanine:phosphorus=0.475:1) inhibited all effects of Pep 5 on susceptible cells in a molar ratio LTA:Pep 5 of 10:1. Treatment of S. cohnii 22 with Pep 5 or nisin for 20 min and subsequent washing with 2.5 M NaCl released autolysin activity. Crude preparations of the hydrolyzing enzymes produced free amino groups as well as polysaccharide fragments from the murein backbone, suggesting the presence of a muramidase or glucosamidase, and endopeptidase or amidase. Both enzyme activities were inhibited by lipoteichoic acid; they could be fully reactivated by addition of Pep 5 in sufficient concentrations. The velocity of hydrolysis was not influenced by nisin, whereas it was doubled in presence of Pep 5. The results are discussed in view of a possible mechanism of induction of lysis by Pep 5 and nisin.Abbreviations A.U. arbitrary unit - CCCP carbonylcyanide-m-chlorophenyl hydrazone - DNase deoxyribonuclease - CYG casein yeast extract glucose - IT initial turbidity - LTA lipoteichoic acid - RNase ribonuclease - TSB Tryptone Soy Broth     

抗人肺癌细胞单克隆抗体的制备及其特性的研究

用人肺鳞癌细胞LTEP-78细胞系免疫Blab/c小鼠获得3株抗人肺癌细胞的单克隆抗体杂交瘤系。其中BLTI-01株经六次克隆化培养,体外传代8个月以上。BLTI-01与白细胞抗原及血型抗原基本上无交叉反应;与骨髓细胞无交叉反应;与癌胚抗原和胎甲球蛋白不相关;与肺鳞癌、肺腺癌细胞系及部分其它肿瘤细胞呈阳性反应。     

抗胃癌细胞系单克隆抗体PD4的初步研究

以胃癌细胞系MGC803免疫Balb/c小鼠,取其脾细胞与小鼠骨髓瘤细胞NS-1融合。经选择培养、筛选及克隆化,获得恒定地分泌抗胃癌细胞系单克隆抗体(MoAb)的杂交瘤细胞系PD4。MoAb PD4与3/4胃癌细胞系有强结合反应,与4/4肺癌细胞系有弱结合反应,但与淋巴细胞、ABO红细胞、骨髓细胞、二倍体成纤维细胞及经检测的其他肿瘤细胞均无反应。PD4抗原主要表达于靶细胞的膜上,不耐热,为分子量40kD的蛋白性抗原。该抗原与HLA抗原系统,血型抗原系统无关,亦不同于其他作者所报告的其他胃癌相关抗原。