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Biomedical subjects

Y Irlin

Publications and source records attributed to Y Irlin.

7 recordsLinked to original sources
PubMed1997

Monitoring of effector and target cell stimulation during conjugation by fluorescence polarization.

The aim of the present study was to trace early intracellular changes induced in effector and target cells during their conjugation. This was performed by monitoring the intracellular fluorescein fluorescence polarization (IFFP), using the Cellscan apparatus. This apparatus permits the repetitive spectroscopic measurement of individual selected live cells within a population of many cells, while the location of each cell is known and preserved during the various cell manipulations and/or their suspending medium. Both natural killer (NK) and lymphocyte activated killer (LAK) cells were used as effector cells, while NK-sensitive K562 and NK-resistant Daudi cell lines were used as targets. In this study kinetic IFFP measurements were carried out for a period of approximately 4 h following cell attachment. Within minutes following effector-target conjugation, transient reduction of IFFP was observed consecutively, first in the effector and then in the target cells. A continuous reduction of IFFP occurring only in target cells was also found 50 min following conjugation. No reduction in IFFP was observed using NK- and LAK-resistant target cells. Good correlation was found between early stages of conjugation, as assessed by IFFP, and cytolytic efficiency as assessed by 51chromium release assay. When NK-resistant and LAK-resistant target cells were used, no reduction of IFFP was observed.

Cell Communication↗
PubMed1997

Infection of K562 cells with influenza A virus increases their susceptibility to natural killer lysis.

Natural killer (NK) cells play a role in the natural immunity against tumor cells. In the present study, we demonstrate that infection of the NK-sensitive tumor cell line K562 with influenza A virus caused a substantial increase in lysis of up to sevenfold when compared to noninfected cells. Similar to NK cells, IL-2-activated killer cells exhibited higher lytic activity against virus-infected K562 cells. This effect of the virus correlated with the increase in the expression of intracellular adhesion molecule-1 (ICAM-1) on K562 cells. Changes in the susceptibility to NK lysis were accompanied by alterations, within minutes, in the cytoskeleton as detected by intracellular fluorescein fluorescence polarization measured on the Cellscan, a static cytometer. The possible role of iCAM-1 and the cytoskeleton in the cytotoxic response of NK cells is discussed.

Cytotoxicity, Immunologic↗
PubMed1992

Thy-1 antigen-mediated adhesion of mouse lymphoid cells to stromal cells of haemopoietic origin.

Thy-1 antigen is one of the widespread cell surface antigens. The antigen is expressed in the cells of a wide variety of different tissues and species and its pattern varies considerably during development and among species. Although the Thy-1 is one of the members of Ig-superfamily its function(s) remain unknown. Here we show that monoclonal antibodies to mouse Thy-1.2 antigen prevent adhesion of Thy-1.2-positive mouse T-leukemic cells 127 to monolayers of two mouse bone marrow stromal cell lines (14F1.1 and MBA-15). The same antibodies do not prevent adhesion of cell 127 to monolayers of two other mouse bone marrow stromal cell lines (MBA-2.1 and MBA-1.1.1) and to a wide spectrum of different normal and tumor mouse cell lines. A characteristic of the cell line 14F1.1 is the ability to support growth of mouse haemopoietic stem-cells. This data suggest that cells of stromal lines 14F1.1 and MBA-15 contain on their surface a specific ligand for the Thy-1 molecule. Cell-cell interaction via this ligand and the molecule on the cell surface may be an important step for development of certain lineages of cells.

Animals↗
PubMed1990

Nonspecific immunopotentiators and pregnancy loss: complete Freund adjuvant reverses high fetal resorption rate in CBA x DBA/2 mouse combination.

CBA/J female mice mated with DBA/2J males show a high incidence of fetal resorptions. This paper presents data demonstrating that nonspecific immunopotentiation by complete Freund adjuvant (CFA) reversed pregnancy loss in CBA/J mothers. Immunization of more than 70 CBA/J females mated with DBA/2J males with CFA reduced the incidence of fetal resorption from 27.3 +/- 1.9 to 7.9 +/- 1.5%. The injection of Thymus Humoral Factor known to be a potent T cell stimulator did not reduce the number of fetal resorptions. The route of CFA distribution was found to be important--only foot pad injections were effective in fetal protection, whereas i.p. treatment did not reduce fetal resorptions. Fetal protection could be transferred by splenocytes of CFA-injected CBA/J mothers (9.6 +/- 5.0% fetal resorptions). Sera from treated CBA/J mice could not cause such an effect (17.6 +/- 4.6 vs. 21.3 +/- 6.1 in control animals). Thus, stimulation of the maternal immune system by nonspecific immunopotentiators can improve reproductive performance of this mouse combination which has an increased rate of pregnancy loss. Possible mechanisms of this fetal protection are discussed.

Animals↗
PubMed1989

Immunopotentiation and pregnancy loss.

To test the hypothesis that immunopotentiation of the maternal immune system is beneficial for the developing embryo, we examined (1) the effect of specific preimmunization with paternal leucocytes in women and BALB/c splenocytes in CBA/J x DBA/2J mice (which show increased % fetal resorption) and (2) the influence of non-specific potentiators such as complete Freund's adjuvant and thymus humoral factor on the abortion rate in CBA/J mothers. Subsequent pregnancy was successful in 76% of habitually aborting women after immunization with paternal leucocytes. Immunization of CBA/J mice with complete Freund's adjuvant (2 foot-pad injections) decreased the resorption rate (11.3% vs 34.9% without treatment). The effect was followed by a slight decrease of the L3H4-positive lymphocyte subpopulation in the spleen but not in the draining lymph nodes, as measured by flow cytometry analysis. The amount of Lyt-2 positive lymphocytes was not changed as a result of treatment. Thymus humoral factor did not influence the abortion rate in CBA/J females mated with DBA/2J male mice. Our results show that non-specific stimulation of the maternal immune system by complete Freund's adjuvant can improve reproductive success in allogeneic mice with increased pregnancy loss. The exact mechanism of this improvement is still unclear but it seems that systemic cellular mechanisms are not responsible for the effect.

Abortion, Habitual↗
PubMedDate not supplied

Immune features in complete Freund adjuvant-treated CBA/J mouse model.

Immunostimulation with complete Freund adjuvant (CFA) reverses the tendency to fetal loss in the CBA/J x DBA/2J mouse. First attempts to understand the mechanisms underlying this effect were to evaluate phenotypic and functional changes in the lymphocytic cell population after immunopotentiation. We demonstrated that treatment with CFA leads to diminished responses of maternal splenocytes towards paternal alloantigens and this low response cannot be improved with exogenous interleukin-2. Lymphocytes derived from spleen, para-aortic draining lymph nodes and placenta significantly suppress maternal response to paternal antigens. The effect of low fetal resorption rate is followed by marked elevation of asialo GM-1 and HNK-1-positive cells but not followed by any change of the L3T4 or Lyt-2-positive lymphocyte population in either the spleen or in draining lymph nodes. L3T4 and Lyt-2-positive cells have not been found in the placenta. An important feature was marked elevation of Mac-1-positive cells in the placentas of CFA-treated animals. The relevance of these findings to CFA-induced fetal protection is still under investigation.

Animals↗