[Influence of mesenchymal stromal cells on B-cell line growth and immunoglobulin synthesis].

A number of publications contain contradictory data about influence of mesenchymal stromal cells (MSC) on B-lymphocyte growth, differentiation and production of immunoglobulins (Ig). The aim of the study was to investigate the influence of MSC derived from adipose tissue of healthy donors and cancer patients on the proliferation and Ig synthesis of lymphoblastoid cell line Namalva and myeloma cell line U266. Co-cultivation of Namalva cells with MSC stimulated their proliferation, decreased the doubling time and the minimal effective seeding dose and therefore made cloning of these lymphoblastoid cells possible. The presence of MSC supported the survival and proliferation of Namalva cells cultivated in growth factor deficient medium. MSC also stimulated proliferation of U266 myeloma cells. Both MSC derived from adipose tissue from the healthy donors and from patients with breast cancer effectively stimulated B-cell lines proliferation. Presence of MSC in mixed cultures had no influence on the production of IgM or IgE by Namalva or U266 cells respectively. Co-cultivation of Namalva or U266 with MSC resulted in the formation of close intercellular contacts between cells of both types.

[Monoclonal antibodies against human secretory component: epitope specificity and utility for immunoanalysis].

AIM: To develop and characterize by immunochemical methods the panel of monoclonal antibodies (MAbs) recognizing different antigenic determinants ofhuman secretory component (SC) molecule. MATERIALS AND METHODS: sIgA and SC were obtained from colostrum by combination of ion-exchange chromatography and gel filtration. Recombinant SC was expressed in Escherichia coli cells transformed by construction that contained fragment of gene coding extracellular domain of receptor for polymeric Ig. MAbs were produced and studied using hybridoma technologies and different methods of immunoenzyme analysis respectively. RESULTS: Panel comprising 10 MAbs against human SC of which 4 types of antibodies recognize cryptic epitopes of free SC and other 6 types recognize epitopes exposed both on SC and sIgA. MAbs panel contains antibodies interacting with conformational and linear epitopes of antigen. Three from obtained MAbs bind to SC epitopes which structure is determined by presence of carbohydrate residues in the molecule of antigen. Immunometric systems were developed which allow to differentially detect free SC and sIgA. CONCLUSION: Developed and characterized MAbs panel recognizing different epitopes of SC molecule opens new opportunities for laboratory and basic research of human secretory immunity.

[Distribution of alleles of DRB, DQB and DQA loci of major histocompatibility complex in healthy donors of Saint Peterburg]. / Osobennosti raspredeleniia allelei lokusov DRB, DQB i DQA glavnogo kompleksa gistosovmestimosti u zdorovykh donorov Sankt-Peterburga.

The distribution of alleles of DRB, DQB and DQA loci was investigated in 118 healthy donors from St. Petersburg. Said alleles were identified by the restriction fragment length polymorphism method using DRB, DQB and DQA probes after TaqI digestion and Southern blotting. The frequencies of said alleles were compared with those of a cohort of healthy donors living in Germany. A significantly higher frequency of DRB-17-2 was identified in the Russian donors, as compared with the German counterparts. Also, the Russian donors revealed a decrease in the frequency of DQB-1 (P = 0.01) and an increase in that of DQB-X allele (P = 0.05). An analysis of DRB, DQB and DQA locus a alleles adhesion in a sample of donors from St. Petersburg showed it to agree, in a large proportion of cases, with the literature data. A parallel study of immunological specificity of DR antigen was undertaken to compare the results of genetic and serologic typing; errors in DR specificity identification were found to have been made in 17.0%.

[Effect of antilymphocyte globulin on growth and erythroid differentiation of K-562 cells]. / Vliianie antilimfotsitarnogo globulina na rost i éritroidnuiu differentsirovku kletok linii K-562.

The influence of antilymphocytic globulin (ALG) on the proliferative activity and erythroid differentiation of erythromyeloid K-562 cells was studied. It has been established that ALG produces a dose-dependent inhibiting effect (20-150 micrograms of ALG/ml) on the proliferative activity of K-562 cells and induces erythroid differentiation of these cells that does not depend on the concentration of ALG used in the test. Pretreatment of K-562 cells with ALG increases their sensitivity to the following growth-inhibiting action of cytosine-arabinoside.

[Changes in the functional properties of NK-cells and the cytostatic activity of granulocytes in acute leukemia patients]. / Izmenenie funktsional'nykh svoistv NK-kletok i tsitostaticheskoi aktivnosti granulotsitov u bol'nykh ostrym leikozom.

Effector activity of natural killers (NK) was studied, and functional state of NK and granulocytes was evaluated in 23 normal subjects and 28 acute leukemia patients (12 of them being in clinico-hematological remission up to 2 years). In acute leukemia significant disorders are observed in the system of nonspecific antitumor defence that is evidenced by a drastic decrease of NK activity due to changes in the functional properties of NK--their capacity for producing conjugates and blast cell lysis, low sensitivity to exogenous interferon, and lowered spontaneous cytostatic of granulocytes.

[Functional changes in the natural killer cells of patients with acute leukemia]. / Funktsional'nye izmeneniia estestvennykh killernykh kletok u bol'nykh ostrym leikozom.

The results of study of NKC activity (51Cr release assay, conjugate-forming and lytic activity) in healthy persons and patients with acute leukemia (AL) in active phase and in remission are presented. It has been shown that the depression of the NKC activity in acute phase of AL (6 times as low as in norm) and in remission (3 times as low as in norm) depended upon disturbances of the processes of conjugate formation, lytic and recycling activity. Correlation has been found between percentage of lytic conjugates and that of cytotoxicity. The increase of NKC activity in remission seemed to be due to tendency to normalization of functional state of NK-cells (conjugate-forming and recycling activity).

[Cytostatic activity of granulocytes in patients with acute leukemia]. / Izuchenie tsitostaticheskoi aktivnosti granulotsitov u bol'nykh ostrym leikozom.

The in vitro spontaneous cytostatic activity of peripheral blood granulocytes against human tumour cell of erythromyeloid line K-562 has been studied in healthy persons and in patients with acute leukemia. It has been found that with the target cell K-562: granulocyte ratio of 1:20, the normal granulocytes inhibit the K-562 cell growth by 44.3 +/- 3.1% at 37 degrees C within 42 h; in patients with acute leukemia in the acute phase of the disease the cytostatic activity is greatly lowered, while in remission up to two years it increases, however, without reaching the normal values. In remissions of more than three years, this physiological function of granulocytes is normalized.

[Activity of natural killers in acute leukemia in children]. / Aktivnost' estestvennykh killerov pri ostrom leikoze u detei.

Natural killer (NK) activity was studied in healthy children, (16) and those with acute leukemia at different phases of the disease (63). Patients' age ranged 3-11 years. NK activity was measured by release of 51Cr from the labelled K 562 target cells. A sharp decrease in NK activity was found in the acute phase, irrespective of the morphologic pattern of acute leukemia, the degree of blastosis and therapy. 75% of patients achieving remission revealed a decreased NK activity within the first 24 months, while in 25% it was normal. At 3 years and later, the majority of responders showed normal NK activity.

[Enzymes of purine nucleotide catabolism in lymphocytes in normal states and in chronic lymphoid leukemia]. / Fermenty katabolicheskikh prevrashchenii purinovykh nukleotidov limfotsitov v norme i pri khronicheskom limfoleikoze.

Activities of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) as well as their ratio in chronic lymphocytic leukemia (CLL) were found to be several times lower as compared with normal cells and to depend upon the duration and severity of leukemic process. Ratio of ADA and PNP activities in CLL was inverted as compared with those of normal cells; 5'-nucleotidase activity varied within all the stages of the disease from zero values to supernormals. There was a correlation between beneficial effects of treatment of the CLL patients and an increase in ADA and PNP activities in their peripheral lymphocytes.

[Metabolism of nucleotides and RNA in leukocytes in chronic myeloleukosis]. / Obmen nukleotidov i RNK v leikotsitakh pri khronicheskom mieloleikoze.

Biosynthesis of purine and pyrimidine nucleotides was distinctly increased in leukocytes of patients with chronic myeloid leukosis, involving mainly the reutilization of preformed nitrogenous bases and nucleosides. An increase in the rate of 14C-orotate and 3H-uridine incorporation into the pyrimidine pool of myeloid leukosis cells correlated with stimulation of uridine kinase and orotidine monophosphate pyrophosphorylase, catalyzing biosynthesis of pyrimidine nucleotides in the reutilization pathway and de novo, respectively. The system of adenosine deaminase, providing the high rate of adenosine incorporation into the nucleotide pool, was apparently responsible mainly for the rate of reutilization synthesis of purine nucleotides in normal and leukemic leukocytes. Synthesis of RNA in leukocytes of patients with chronic myeloleukemia was increased mainly due to consumption of nucleotides formed via the reutilization pathway.