[Study of the antigenic structure of human immunoglobulin lambda-chain using monoclonal antibodies]. / Issledovanie antigennoi struktury lambda-tsepei immunoglobulinov cheloveka s pomoshch'iu monoklonal'nykh antitel.

Nine monoclonals against human Ig lambda chains were produced, 4 antibodies react with C-domain, 5--with V-domain of the lambda chain. Anti-C lambda domain antibodies recognize not less than 3 epitopes and one of them is expressed only on the isolated chain. Anti-V lambda antibodies bind both isolated lambda chain and intact IgG, IgM, IgA. Four epitopes are expressed by few lambda Bence Jones proteins of the III subgroup, the immunogen possessing the same isotype. The 4 mentioned epitopes represent private idiotypic determinants. The epitope 3E10 is characteristic of 50% Bence Jones proteins of the II and III V lambda-subgroups thus representing a common idiotypic determinant. Using anti-V lambda antibodies germ line variability of V lambda III proteins was analysed and the similarity of antigenic structure of normal and myeloma human Ig lambda chains was demonstrated.

[Immunoenzyme test system with monoclonal antibodies to human IgG4 in the determination of allergen-specific antibodies in pollinosis]. / Immunofermentnaia test-sistema s monoklonal'nymi antitelami k IgG4 cheloveka dlia vyiavleniia allergenspetsificheskikh antitel pri pollinoze.

ELISA for determination of allergen-specific IgG4 antibodies was developed with the help of monoclonal anti-IgG4 antibodies obtained by classic hybridoma technique. Subclass specificity of antibodies were studied in sera of 108 patients suffering from pollinosis. Antibodies of this isotype were found in the majority of patients with tree pollen allergy but not in patients with grass pollen allergy. The level of IgG4 antibodies correlated with the severity of the disease but not with the intensity of skin tests. Specific hyposensitization resulted in significant increase of IgG4 antibody level in patients with tree pollen allergy. Determination of IgG4 antibodies is proved to be useful to reveal tree pollen allergy and to monitor hyposensitization therapy.

[Antigenic determinants of the constant region of human immunoglobin kappa-chain detected by monoclonal antibodies]. / Antigennye determinanty postoiannogo domena kappa-tsepei immunoglobulinov cheloveka, vyiavliaemye s pomoshch'iu monoklonal'nykh antitel.

Ten different monoclonal antibody (monAB) preparations reacting with human IgL chains of the kappa type have been obtained. Nine of the monAB interacted with the kappa-chain C domain, whereas only one monAB reacted with the V domain. It has been determined that monAB against the C domain react with three different epitopes. One epitope is expressed on intact Ig molecules as well as on isolated kappa-chains, whereas the other two epitopes are found only on isolated kappa-chains. The expression of these epitopes in 40 different myeloma kappa-chain preparations belonging to four various subgroups was studied. The level of this C domain epitope expression has been shown to depend on the variable subgroups of kappa-chains indicating a close association between V and C domains. This association leads to the alteration of antigenic activity of some C domain epitopes. The alterations are thought to be local because, as a rule, they involve only one of the three epitopes.

A new approach to studies of cell-antibody interactions using fluorescent lipid probes.

The interaction of poly- and monoclonal antibodies against the L-chain of human Ig with Burkitt lymphoma EB-3 cells was studied using a fluorescent lipid probe, anthrylvinyl-labelled sphingomyelin, incorporated into the cell plasma membrane. Binding of the antibodies to Ig receptors on the surface was shown to induce changes in the fluorescence polarization of the probe. The high sensitivity of the method allows one to detect less than 100 antibody molecules per cell. The possibility of using cells or liposomes carrying antigens and fluorescent lipids for the determination of antibodies in solution is discussed.

[Selective cytotoxicity of antibody-ricin-A-chain conjugate for human tumor B cells. II. Comparison of activity of immunotoxins conjugated with poly- and monoclonal antibodies]. / Izbiratel'naia tsitotoksichnost' kon''iugata antitelo-A-tsep' ritsina dlia opukholevykh B-kletok cheloveka. II. Sravnenie aktivnosti immunotoksinov, poluchennykh na osnove poli- i monoklonal'nykh antitel.

The A-chain of a plant toxin ricin has been coupled to poly- and monoclonal antibodies specific to the L-chains of human IgG. The inhibitory effect of the conjugates has been compared with the ability of the antibodies to bind to target cells. Cytotoxicity of the conjugates has been monitored following incorporation of 14C-leucine radioactivity into Burkitt lymphoma cells with surface Ig. The 50% inhibition of protein synthesis is observed 18 h after treatment of cells with immunotoxins, when the concentration of the conjugates with poly- and monoclonal antibodies is 1.2.10(-9) M and 0.7.10(-9) M, respectively. The data take into account that only part of the polyclonal antibodies molecules is able to react with target cells. The control conjugates containing either monoclonal antibodies that do not react with the lymphoma cells surface L-chains or nonimmune serum IgG proved to have no effect on target cells even at the level of 10(-7) M. The immunotoxins with poly- and monoclonal antibodies produce almost the same kinetics of protein synthesis inhibition, when incubated with lymphoma cells for 60 min. However, a 30 min treatment reveals a considerably higher cytotoxicity of the conjugate with monoclonal antibodies.

Cell biology of human IgM-producing hybridomas derived from a fusion of human spleen lymphocytes with mouse myeloma cells.

Hybrids were derived from the fusion of mouse myeloma cells with human spleen cells from a patient with active idiopathic thrombocytopenia. Of 288 initially seeded cultures, 186 were found to produce human Ig. The growth and Ig production rates, cloning efficiencies using different feeder layers and the karyotype were determined for 9 clones that stably produced human monoclonal IgM (2-100 micrograms/ml) for at least 9 months. All cells of the Ig-producing hybridoma clones were positive for cytoplasmic-Ig, whereas only 20-65% of cells expressed surface Ig (mu and chains). Human monoclonal antibodies in mass cultures were derived in serum-free PRMI 1640 medium. Two clones produced human IgM (nearly 2 mg/ml) in the ascitic fluid of nude mice. Feeder cells of peritoneal macrophages from Balb/c mice enabled more efficient recloning of human x mouse hybrids than did thymocytes. Nearly all subclones derived from 2 clones were found to produce the same monoclonal antibodies as the parental lines. Information on the individual parameters of a hybridoma cell line may be helpful in the large-scale production of human monoclonal antibodies.

[Selective interaction of immunoglobulin polypeptide chains. Quantitative evaluation of the idiotypic and antigen binding activity of reassociated immunoglobulin molecules]. / Izbiratel'noe vzaimodeistvie polipeptidnykh tsepei immunoglobilinov.Kolichestvennaia otsenka idiotipicheskoi i antigensviazyvaiushchei aktivnosti reassotsiirovannykh molekul immunoglobulinov.

We have analysed reassociated Ig molecules, containing heavy (H) or light (L) chains of Ig-B2 monoclonal antibody with human fibronectin binding activity and L of H chains of normal mouse serum immunoglobulin (Ig-NM). Examination of Ig-B2 idiotype expression in reassociated Ig indicated that 0.4% L-NM and 0.8% H-NM were able to restore Ig-B2 idiotype. The analysis of antigen binding capacity of reassociated Ig demonstrated, that only 4% H-NM created antigen binding site in complex with L-B2. We have determined the leading role of L-chain in creation of idiotype and binding site of Ig-B2. Selectivity of interaction between H and L chains is discussed. The results indicate, that not more than 4-6% of random H--L combinations produce functional Ig.

[Allelic exclusion in hybridomas. I. Isolation and properties of a hybrid clone producing two allelic variants of light chain immunoglobulins in the rat]. / Allel'noe iskliuchenie v gibridomakh. I. Poluchenie i svoistva gibridomnogo klona, produtsiruiushchego dva allel'nykh varianta legkikh tsepei immunoglobulinov krysy.

Expression of RI-1a and RI-1b allelic genes controlling the production of rat lg kappa L-chains by hybridoma cells in vitro was studied. By fusing mouse myeloma cells with RI-1a/RI-1b heterozygous rat splenocytes the unique cloned hybrid cell line secreting both allelic variants has been established. This line may have appeared because cell hybridization made it possible to fix the rare case of correct rearrangement of the kappa chain gene segments on both homologous chromosomes.

[Antigenic markers of variable region of mouse myeloma MOPC 21 light chain]. / Antigennye markery variabel'noi oblasti legkoi tsepi mielomnogo immunoglobulina myshi MOPC 21.

Monospecific antibodies against V-region of the L-chain of the mouse myeloma protein MOPC21 (VK 15 group) were obtained and used for preparation of antibody-immunoadsorbents. By means of the immunoadsorbents the content of normal immunoglobulins with antigenic markers of VK 15 group in the serum of mouse strains BALB/c, CBA and C57BL/6 was determined. The least quantity of the proteins determined by this method was estimated to be 1.4%. If each of K-chains of the variable groups is represented equally in the population of normal immunoglobulins, the number of VK groups and respectively germ-line VK genes should be not less than 70.