RESUMEN

The authors review current data on the production and characterization of anti-D monoclonal antibodies. The main methods for establishment of anti-D antibody secreting cell lines are considered: EBV-transformation of B lymphocytes from immune donor and hybridization with malignant human or murine cell lines. Serologic and immunological properties of anti-D monoclonal reagents for blood group Rh-typing as well as feasibility of using anti-D monoclonal antibodies as a modality against hemolytic disease of the newborn are discussed.

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

Four IgG1 monoclonal antibodies (MoAbs) to the Rh antigen D, produced by stable Epstein-Barr virus transformed B-lymphoblastoid cell lines were assessed in different serological tests. Their suitability in blood group typing was shown in antiglobulin, enzyme or albumin methods. The specificity and activity of MoAbs was tested with a panel of red cells of various Rh-phenotypes. The supernatants of all four lines showed anti-D specificity and ability to react with Du red cells. Mean level of MoAbs concentration was near 10 micrograms/ml. These human anti-D MoAbs proved to be useful D-typing diagnostic reagents.

Asunto(s)

RESUMEN

The authors suggest a simple sensitive technique for enzyme immunoassay (EIA) of ABH antigens in saliva and semen. A two-staged dot blot solid-phase EIA on nitrocellulose membranes was employed with anti-ABH monoclonal antibodies obtained in immunization of mice with human red cells. 4-chloro-1-naphthol substrate solution was used to visualize the peroxidase label. The results of analysis of salivary and spermatic samples obtained from donors of various groups evidence that this EIA variant may be useful in forensic medicine.

Asunto(s)

Asunto(s)

RESUMEN

The attempt of retroviral transfer of the bacterial Neor gene into stromal precursor cells able to transfer haemopoietic microenvironment and to long-term support of haemopoiesis in vitro and in vivo was made. The existence of marker gene in stromal cells was established by the method of polymerase chain reaction. The transduced stromal precursor cells create normal haemopoietic microenvironment. The data obtained would be important for the further investigation of proliferation and differentiation of stromal precursor cells.

Asunto(s)

RESUMEN

Fine epitope specificity of ten monoclonal antibodies (MA) agglutinating red blood cells B was studied. Three methods were used: 1) inhibition of MA binding to natural antigen by synthetic oligosaccharides (OS) and their polyacrylamide conjugates, 2) direct MA binding to a series of synthetic OS-polyacrylamide conjugates differing in carbohydrate epitope density, 3) direct MA binding to the affinity sorbents. It is shown that all antibodies studied prefer trisaccharide B determinant Gal alpha 1-3(Fuc alpha 1-2) Gal independently of their ability to discriminate serological subgroups of B erythrocytes (B, Bweak, B3). The correlation of the MAs epitope specificity with their ability to agglutinate red blood cells B subgroups is discussed. Of an interest is that MAs which are able to agglutinate any B subgroups also bing the synthetic tetrasaccharide Gal alpha 1-3(Fuc alpha 1-2)Gal beta 1-3GalNAc, a B type 3 determinant.

Asunto(s)

RESUMEN

The effect of introduction by means of electroporation of protogene ras into cells of antibody-producing hybridoma was studied. Doubling time (TD) of transduced subclones, in which H-ras gene was expressed, proved to be 1.8-fold shorter as compared to the parent line. Other characteristics of the hybridoma (cloning efficiency, antibody production in vitro, the time of ascitic fluid appearance in mice and antibody titer in vivo) were not changed. Addition of 12-0-tetradecanoylphorbol acetate to the culture did not alter the growth parameters of H-ras transduced subclones.

Asunto(s)

RESUMEN

Human B-lymphoblastoid cell lines producing specific anti-D antibodies against Rh0(D) antigen have been established by EBV-transformation. The strong influence of the donor's immune status (serum titer of anti-D antibodies, intravenous booster injection prior to bleeding) is shown. The cell lines cloned by limiting dilution continuously produce anti-D antibodies in culture for 7 months or longer which is sufficient to support large-scale production of anti-D antibodies based on the cultivation of cryopreserved cells. Anti-D IgGl monoclonal antibodies obtained react with Rh-positive and Du cells but not with Rh-negative cells in serological tests. These human monoclonal antibodies could be useful in the prevention of Rh hemolytic disease of newborns.

Asunto(s)

RESUMEN

The protocol of Epstein-Barr virus (EBV)-induced transformation of B-lymphocytes from reripheral blood of normal humans has been described. The requirements for mononuclear EBV-infection and for selection, cultivation, and cloning of EBV-transformed cell lines have been investigated. Successful establishment of stable human immunoglobulin-producing cell lines from lymphocytes of immunized donors could be achieved following the protocol presented.

Asunto(s)

RESUMEN

Cells responsible for repopulation of irradiated longterm cultures of murine bone marrow and capable of generating CFUs for at least 4-5 weeks after seeding referred here to as primitive hemopoietic stem cells (P-HSC) were assayed by limiting dilution analysis. During development of mice P-HSC can be detected for the first time in the liver of 12-13-day-old embryos and their number is about 10 per organ. At day 17-18 of gestation the number of P-HSC increases ten-fold; however, we could not detect the proliferation of these cells using the technique of hydroxyurea suicide. In the adult mouse P-HSC content is about 100 precursors per femur and their concentration is one P-HSC per 1-2 x 10(5) bone marrow cells. P-HSC content in the spleen is 0.5 per 10(6) cells. In vivo treatment with 5-fluorouracil or hydroxyurea (six injections every 6 h) does not alter significantly the number of P-HSC, although either treatment kills about 99% of CFUs. Several months after reconstitution of lethally irradiated mice with a "small" inoculum of bone marrow cells (0.20-0.35 x 10(6)) the number of bone marrow P-HSC was reduced as compared to that in animals reconstituted by injection of a "large" cell dose (20-35 x 10(6)). These data suggest that P-HSC have limited proliferative potential and are incapable of self-maintenance.

Asunto(s)

RESUMEN

Fine epitope specificity of three anti-A monoclonal antibodies (MA) 1H410, 3F9, and 44F9 was studied by: 1) direct MA binding to synthetic oligosaccharides (OS) linked to polyacrylamide matrix, and 2) inhibition of MA binding to natural antigen by synthetic OS and their polyacrylamide conjugates. It has been established that the antigen binding site of MA 1H10 is specific for tetrasaccharide A (type 3), whereas MAs 3F9 and 44F9 recognize trisaccharide A, the contribution of alpha-L-fucosyl residue being insignificant in the case of 44F9 binding. The correlation of the MAs epitope specificity with their ability to agglutinate red blood cells of A1 and weak A subgroups is discussed.

Asunto(s)

RESUMEN

A new category of primitive hemopoietic stem cells determined in murine bone marrow long-term culture (CFU-BMLTC) is described. The novel precursors give rise to hemopoietic colonies corresponding to "cobble stone" areas observed on the adherent cellular layer. The linear relationship between the colony number and the dose of bone marrow cells explanted in the culture has been discovered. Radiosensitivity of the new type of hemopoietic precursors in the bone marrow of adult mice is characterized by D0-1.28 Gy. CFU-BMLTC were also identified in 13-day mouse fetal liver. In contrast to CFUs the precursors described are less sensitive to extensive in vivo treatment with hydroxyurea. The data obtained have permitted the authors to make a conclusion on a higher status of CFU-BMLTC as compared to CFUs in the hemopoietic stem cell hierarchy.

Asunto(s)

RESUMEN

The principles of obtaining monoclonal antibodies against D-antigen of the rhesus system are overviewed. The lines secreting anti-D antibodies are characterized. The strategies for selecting the anti-D producers secreting the antibodies are substantiated, which are useful for developing rhesus-typing diagnostics and preparations to prevent Rh-sensitization.

Asunto(s)

RESUMEN

A complex of experimental original laboratory findings is presented to demonstrate a restricted proliferative potential of stem hemopoietic cells. Development of new methodologies to study primitive stem hemopoietic cells, i. e. the cells that are responsible for maintenance of continuous blood formation, allowed for confirming their existence, assessing their content in the hemopoietic tissue, determining the time and site of their embryonic origin, and for showing their limited capacity for regeneration. The obtained evidence is important for the understanding the mechanisms governing hemopoiesis.

Asunto(s)

RESUMEN

In this article serologic characteristics of monoclonal antibodies with anti-N specificity is given. Antibodies are directed to homologous sequence of N-form of A glycophorine (group-specific N-antigen) and B glycophorine, expressed both on N- and on M-erythrocytes. Higher titre and avidity of monoclonal antibodies with anti-N specificity in relation to erythrocytes with N-phenotype make it possible to detect N-antigen in material subjected to expert evaluation.

Asunto(s)

RESUMEN

An absolute number of the primitive stem cells (PSC) providing for prolonged maintenance of hemopoiesis in culture was measured with the aid of the limiting dilution method. The number of the PSC was determined according to the magnitude of the "zero" class cultures, i. e. of the cultures in which CFUs could not be demonstrated after 5-8 weeks. The fitness of the method can be proved by the presence of the linear relations between the number of the explanted stem cells and the number of the PSC as well as by the passage of the regression curve through the origin of coordinates. The data on the content of the PSC functioning in vivo and in vitro turned out similar, amounting to about 100 cells per mouse femur.

Asunto(s)

RESUMEN

Serologic description of murine monoclonal antibodies (H-86/44 and H-86/50) which are capable to detect a membrane-connected form of human H antigen is given. The antibodies are notable for ability (H-86/44) to be absorbed by salivary H substance of ABH secretors i.e. to detect a soluble form of H antigen. Highly specific, highly active and standard anti-H reagents may be produced on the basis of the anti-H monoclonal antibodies obtained.

Asunto(s)

Asunto(s)