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E V Sidorova

Publications and source records attributed to E V Sidorova.

At least 19 recordsLinked to original sources

Role of different B-cell subsets in the specific and polyclonal immune response to T-independent antigens type 2.

Role of different B-cell subsets in the immune response to T-independent antigen type 2 (TI-2) was studied. BALB/c and C57BL/6 mice were immunized by polyvinylpyrrolidon (PVP), and the numbers of antibody- and Ig-forming cells (AFC and IFC, respectively) were determined by ELISPOT method. The number of cells producing non-specific Ig (nIFC) was calculated as the difference between the number of IFC and AFC; the number of nIFC induced by PVP was calculated as the difference between the number of nIFC in immune and control splenocytes. Immunization by PVP induced not only the AFC appearance, but also the increase in the number of the antigen-induced nIFC. The treatment of splenocytes by anti-CD5 antibodies and guinea pig complement reduced the increase in the numbers of newly formed AFC and nIFC to approximately 40% of control level. It means that CD5+ cells play an important role not only in the specific, but also in polyclonal immune response to non-self TI-2. To be sure that the decrease of AFC and nIFC numbers is due to depletion for CD5+ B-cells, but not CD5+ T-cells, splenocytes were separated to B-1 and B-2 subsets, and the numbers of AFC, IFC and nIFC were determined in each B-cell subpopulation separately. The overwhelming majority of newly formed AFC and nIFC was detected in B-1 subset. The numbers of AFC and nIFC in B-1 compartment was approximately 10-fold greater than in B-2 cells. A close parallelism between AFC and nIFC formation was observed. It is concluded that specific and polyclonal immune response to non-self TI-2-PVP-depends mainly on CD5+ B-1 subset.

Animals↗

Role of different lymphocyte subpopulations in the formation of non-specific immunoglobulins induced by antigen injection.

The formation of antibody and non-specific immunoglobulin under the influence of T-dependent (TD) and type 2 T-independent (TI-2) antigens in mice of two congenic strains CBA (Lyb5-, Lyb5+) and CBA/N (Lyb5-) was studied. TD antigens induced in mice of both strains not only the appearance of antibody-forming cells (AFC), but also a great increase in the number of cells producing non-specific immunoglobulins (nIFC). TI-2 antigens induced the AFC and antigen-dependent nIFC formation in CBA mice only. It is concluded that during immune response to TI-2 antigens not only the AFC appearance but the increase in nIFC formation (polyclonal activation) is due mainly to the mature Lyb5+ B cells.

Animals↗

A new approach to obtain Lyb5-specific antiserum.

A new approach to obtain antiserum specific for Lyb5.2 allotype, was developed. Mice of DBA/2 inbred strain, bearing Lyb5.1 allotype, were made unresponsive to cellular antigens of Lyb5-CBA/N mice by specific tolerance induction. These tolerant recipients were further immunized with suspensions of splenocytes from CBA mice which contain Lyb5.2 + B lymphocytes. Thus obtained Lyb5.2-specific antiserum was cytotoxic for 25-30% of CBA or BALB/c (both Lyb5.2 + allotype) but not for CBA/N spleen cells. When splenocytes of BALB/c mice preimmunized with polyvinylpyrrolidone (T-independent type 2 antigen) were treated with this antiserum, 50% decrease in numbers of antibody-forming and antigen-induced non-specific immunoglobulin-forming cells was documented. We conclude that, during humoral immune response to T-independent type 2 antigen, not only antibody-forming cells but also non-specific immunoglobulin-forming cells are recruited from the Lyb5 + B cell pool.

Animals↗

Role of antigen-binding B lymphocytes in the formation of antigen-dependent nonspecific immunoglobulin-forming cells.

A role for antigen-binding B cells in the induction of antigen-dependent B cells producing antigen-nonspecific immunoglobulins (nIFC) is analyzed. An in vitro immune response system was used; sheep red blood cells were employed as the antigen. It is shown that cocultivation of antigen-binding B cells with resting naive splenocytes in the presence of homologous antigen resulted not only in an increase in the number of antibody-forming cells (AFC), but also in a sharp increase in nIFC. Cocultivation of G0 splenocytes with primed B cells depleted for antigen-binding cells did not affect AFC induction, and only slightly augmented the number of nIFC. It is suggested that some of the nIFC appearing after antigenic stimulation arise from resting B lymphocytes in response (direct or indirect) to nonspecific B-cell factor(s).

Animals↗

[The hemodynamic support of physical loading in patients with mitral valve prolapse].

Bicycle ergometry and echocardiographic studies were carried out in 29 patients aged 17-29 years with first revealed mitral valve prolapse (MVP) without any signs of mitral regurgitation. According to bicycle ergometry, the patients manifested changes in hemodynamics pointing to dysfunction of the cardiovascular system. Echocardiography discovered a reduction of the mass and a rise of the rate of contraction of the circular fibers of the left ventricle, evidence of the myocardial genesis of the hemodynamic changes. Comparison of the findings of bicycle ergometry and echocardiography allowed a conclusion about the necessity of the follow-up of patients with MVP in spite of the high level of threshold load and the lack of the clinical signs of heart failure.

Adolescent↗

[Immunosuppression induced by respiratory viruses (influenza virus, adenovirus) in mice].

The influence of respiratory viruses (adenovirus, influenza virus) on humoral immune response to heterologous T-dependent and T-independent antigens was studied. It was shown that inoculation of mice by the influenza virus (A/PR8/34-A/PR/8) 3 days before sheep red blood cells administration led to the inhibition of antibody forming cell (AFC) and immunoglobulin, forming cell (IFC) increase on 69% and 59% respectively. Adenovirus type 6 induced the similar suppression of AFC and IFC formation. Thus, viruses induced immuno-suppression, which was polyclonal. It was also shown that virus of one strain (type) could inhibit immune response to another strain (type) of virus. The immune response to T-independent antigen was not suppressed. The virus-induced immunosuppression was dependent on: 1) the infectivity of respiratory viruses, 2) the route of virus and heterologous antigen injection, and 3) the interval between the viruses and antigen inoculation.

Adenoviridae↗

[Monoclonal antibodies to ceruloplasmin and their use for immunoenzyme assay of this protein].

The hybridoma technology was used to produce monoclonal antibodies to human ceruloplasmin. The antibodies were found to be related to Ig G1. Using these monoclonal antibodies for PAP-ELISA of ceruloplasmin, it was possible to determine 10(-11) M of the protein. Monoclonal antibodies coupled to CNBr-Sepharose were used for the rapid one-stage purification of ceruloplasmin from human placental serum. Ceruloplasmin obtained by this method contained no type 2 copper normally detected in protein preparations by conventional methods.

Animals↗

[The dynamics of Treponema-specific blood immunoglobulins in early forms of syphilis].

The study has involved 73 patients with syphilis, 31 female and 42 male ones, aged 18-42. Four of these suffered from primary seronegative, 14 from primary seropositive, 21 from secondary fresh, 22 from secondary recurrent, and 12 from early latent seropositive syphilis. Peripheral blood sera were under study. Treponema-specific antibodies of the IgM and IgG classes were titered by enzyme immunoassay. The detected changes in Treponema-specific immunoglobulinemia are in good correlation with clinical staged pattern of syphilis and antiinfectious immunity status.

Adolescent↗

Preparation of Hybridomas producing monoclonal antibodies against human interferon.

To prepare hybridomas secreting monoclonal antibodies (MoAb) against human alpha-interferon (alpha-IFN), BALB/c mice were immunized with IFN produced in Namalwa cells. Native alpha-IFN, as well as partially purified or on cellulose adsorbed alpha-IFN preparations were used for immunization. Seven hybridomas continuously secreting IgG against human alpha-IFN were prepared by fusion of splenocytes from immunized donors with the mouse myeloma cells. MoAb reacted in ELISA as well as in neutralization test with human lymphoblastoid, leukocytic and recombinant alpha-IFN.

Animals↗

[Relation of the formation of producers of antigen-dependent nonspecific immunoglobulins to the dose of T-dependent and T-independent antigens].

The dependence of the production of antibody-forming cells (AFC) and non-specific immunoglobulin-forming cells (nIFC) on the doses of T-dependent (sheep red blood cells, SRBC) and T-independent (polyvinylpyrrolidone, PVP and pneumococcal polysaccharide SSS III) antigens was investigated. The immunization of BALB/c mice with immunogenic or subimmunogenic doses of SRBC and PVP induced a marked increase in the number of antigen-dependent nIFC. In contrast, the injection of any SSS III doses did not influence the amount of nIFC, although a specific immune response to SSS III was quite obvious. Thus, two T-independent antigens, type II, differ in their ability to induce non-specific immune reactions. The experiments on simultaneous administration of monoclonal anti-Thy-1.2 antibodies and PVP or SSS III to mice have demonstrated that these differences were not related to T-suppressor activity. The possible role of T helpers in the immune response to T-independent antigens is discussed.

Animals↗

[Role of G0- and G1-splenocytes and antigen-binding lymphocytes in the production of antigen-dependent nonspecific immunoglobulins].

Immunization of irradiated and syngeneic splenocyte-treated CBA mice with bovine red blood cells stimulated the formation of both antigen-producing cells (APC) and antigen-dependent nonspecific immunoglobulin-producing cells (NIGPC). The injection of G0-cell-enriched, instead of normal, splenocytes (together with bovine RBC) to irradiated mice reduced by half the production of antigen-dependent NIGPC. Thus, it is evident, that some of them are formed from preexisting blast cells (G1). An additional removal of antigen-binding cells (ABC) from G0 lymphocyte population produced a still greater reduction in NIGPC formation (the increment was 92.3% lower than in the control). It is concluded that antigen-dependent NIGPC are formed both due to specific antigen-stimulation of G0 cells aid to nonspecific stimulation of blast cells with factors produced by antigen-stimulated T-cells.

Animals↗

Inhibition of cells producing antigen-dependent non-specific immunoglobulins by isologous anti-erythrocyte immunoglobulins.

Mice injected with isologous cellulose-conjugated immunoglobulins containing antibodies to sheep red blood cells develop a specific unresponsiveness to the homologous antigen. It was shown that such animals demonstrate a sharp decrease not only in the number of antibody-forming cells but also in the number of cells secreting antigen-dependent non-specific immunoglobulins. The suppression of both processes is antigen-specific. It is suggested that the reduced appearance of cells forming antigen-dependent non-specific immunoglobulins is due to suppression either of hypothetic inductors or precursors of these cells, which resemble the precursors of antibody producers in their idiotypes. The presence of the common precursors of antibody- and antigen-dependent non-specific immunoglobulin-forming cells is an alternative possibility.

Animals↗

Studies on lipopolysaccharide-induced polyclonal B cell activity in mice tolerized by sheep red blood cells and cyclophosphamide.

The polyclonal immune response was induced in untreated mice and mice treated with cyclophosphamide by the administration of lipopolysaccharide from E. coli or S. marcescens. The number of cells forming antibodies to sheep red blood cells and to trinitrophenyl, and of cells producing immunoglobulins increased. The administration of LPS to mice pretreated with SRBC and CY (tolerant mice) considerably reduced the number of anti-SRBC AFC in comparison with the controls. The tolerogenic treatment did not change the number of anti-TNP AFC and IPC. Analogous results were obtained in genetically athymic (nude) mice and in B mice (thymectomized, lethally irradiated and reconstituted with embryonic liver cells). The results suggest that a deletion or a temporary inactivation of a fraction of the antigen-specific B cells occurs in tolerant mice. This inactivation cannot be explained by the absence of expression of surface immunoglobulins on B cells nor by the activity of suppressor T cells.

Animals↗

[Suppression of the formation of cells secreting antibodies and antigen-dependent nonspecific immunoglobulins in mice receiving isologous antierythrocyte immunoglobulins].

Mice injected with syngeneic cellulose-conjugated immunoglobulins (Ig) containing antibodies to sheep red blood cells (SRBC) develop a specific non-responsiveness to SRBC. Such animals demonstrate a sharp decrease not only in the formation of anti-SRBC antibody producers but also of the cells secreting antigen-dependent nonspecific Ig. The inhibition of both these processes is antigen-specific. It is suggested that inhibition of the cells forming antigen-dependent nonspecific Ig is due to suppression of either hypothetic inductors or precursors of these cells expressing an idiotype spectrum similar to that of anti-SRBC antibody producers.

Animals↗

[Role of antigen-binding cells in the formation of producers of antibodies and antigen-dependent nonspecific immunoglobulins].

The role of antigen-binding cells in the formation of antigen-dependent nonspecific immunoglobulin producers in the Mishell-Dutton system was investigated. It was shown that the main part of antigen-dependent nonspecific immunoglobulin producers arise from the cells bearing antigen-specific receptors (as well as antibody producers). The nature of antigen-specific receptors of the precursors of antibody-forming and antigen-dependent nonspecific immunoglobulin-forming cells is discussed.

Animals↗