Identification of the target cells in human B lymphocytes for transformation by Epstein-Barr virus.
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Adult↗
Biomedical subjects
T Abo
Publications and source records attributed to T Abo.
Target cells for interferon production in human leukocytes stimulated by sendai virus.
Whole leukocytes, mononuclear cells, polymorphonuclear cells (PMN), MONOCYTES, PURIFIED LYMPHOCYTES, AND T (rosette-forming cells, RFC) and non-T (nonrosette-forming cells, nonRFC) lymphocytes isolated from the human peripheral blood were stimulated by Sendai virus, respectively, and examined for interferon production in their culture fluids. High levels of interferon were produced by mononuclear cells, but not by PMN. Removal of monocytes from the mononuclear cell population did not affect at all the levels of interferon produced, although it strongly suppressed interferon induction by polyinosinic-polycytidylic acid (poly IC) and mitogenic response to phytohemagglutinin (PHA) of the lymphocytes. Purified monocytes and T lymphocytes were unresponsive to the virus. In contrast, a population of purified non-T lymphocytes produced high levels of interferon. Addition of monocytes to the interferon-producing non-T lymphocytes did not affect the levels of interferon produced. No detectable levels of interferon were produced in the mixture of T lymphocytes and monocytes. It is concluded that non-T lymphocytes may be a major target for interferon induction of human leukocytes by Sendai virus.
Cell Separation↗
Exposure by phospholipase A of receptors for sheep erythrocytes on human B cells.
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Animals↗
Studies of surface immunoglobulins on human B lymphocytes. II. Characterization of a population of lymphocytes lacking surface immunoglobulins but carrying Fc receptor (SIg-Fc+ cell).
Surface markers and organ distributions of B lymphocytes bearing surface immunoglobulins (SIg B) and lymphocytes lacking SIg but carrying Fc receptors (SIg-Fc+), and the variations of both the cell populations in the autoimmune diseases were studied. Peripheral blood lymphocytes contained approximately 9% SIg B and 22% SIg-Fc+ cells. Both the populations of SIg B and SIg-Fc+ cells were included in the cells that formed no E-rosettes. When previously treated with neuraminidase, however, the SIg-Fc+ cells formed E-rosettes, whereas SIg B showed no ability to form rosettes. C receptors as detected by human complement were found in the large portions of SIg B but in a minority of the SIg-Fc+ cell population. The tissues that contained the highest concentrations of SIg B and SIg-Fc+ cells were the spleen and peripheral blood, respectively. In the patients with an autoimmune disease in active stages SIg B cells in the peripheral blood markedly increased and, reversed, SIg-Fc+ cells decreased; in contrast, in remission of the diseases SIg B cells dropped down and SIg-Fc+ increased up to their normal levels. A possible relationship between the SIg B and SIg-Fc+ cells in regard to the differentiation of B lymphocytes was presemed.
Animals↗
Heterogeneity of human T lymphocytes to bind sheep erythrocytes and mitogenic responses of their subpopulations.
Heterogeneity of human T lymphocytes was examined by the rosette formation of sheep red blood cells (E-rosette) in two different reaction media: fetal calf serum (FCS) and gelatin Veronal buffer (GVB). Nearly all the T lymphocytes could form rosettes in FCS at 1 degrees C (FCS-R) independently of the incubation time. In contrast, rosette formation in GVB (GVB-R) was apparently dependent upon the incubation time and could not be used in the enumeration of the total T cells even after long incubation. Among the possible subpopulations, a fraction (T1) that could form GVB-R as well as FCS-R, and the other fraction (T2) that could form only FCS-R were partially purified by rosette formation and by density gradient on a Ficoll-Isopaque layer. In contrast to the T cell-depleted fraction (B) which formed EAC rosettes in a majority of cells and E rosettes in a few cells, only a small portion of cells from both the T1 and T2 fractions could form EAC-rosettes. T1 cells possessed high responses to PHA as estimated by the counts of 3H-TdR incorporation as well as the stimulation indices. In contrast, T2 cells possessed a lower responsiveness to the mitogen, and B fraction cells could not respond at all. These results suggested that a positive correlation exists between the ability of E rosette formation and responsiveness to PHA in the T cell subpopulations. Preliminary experiments also suggested that percentages of T1 cells highly responsive to PHA may decrease and, therefore, those of T2 cells less responsive to the mitogen may increase in the T cell population of the patients with some immunodeficiencies.
Adolescent↗
Studies of surface immunoglobulins on human B lymphocytes. I. Dissociation of cell-bound immunoglobulins with acid pH or at 37 degrees C.
Lymphocyte preparations isolated from the human peripheral blood were exposed to different acid pH or incubated at 37 degrees C and the presence of immunoglobulin (Ig) on the cell surface was examined by immunofluorescence (IF) tests. Subsequently, such treated cells were incubated in the autologous serum or in the purified IgG, IgA or IgM proteins and their ability to bind each class of Ig was examined. The results showed that IgG molecules dissociated from large proportions of IgG-positive cells upon exposure to pH 4 at 1 degrees C for 1 min or upon incubation at 37 degrees C for 20 min. The cells from which IgG had been dissociated could again combine with IgG, whereupon the number of positive cells increased, being restored to the number of equivalent to or higher than those before acid or 37 degrees C treatment. These results indicated that the treatment could elute the cell-bound IgG present on the cell and that the receptor sites were not degraded by the treatment and could combine with IgG. These cell-bound IgG were observed not only on the monocytes, but also on the small lymphocytes. It was also found that certain proportions of mononuclear cells carried the cell-bound IgA that could be dissociated with acid pH or 37 degrees C. No cell-bound IgM was observed on any mononuclear cells. Microscopic observations before and after acid or 37 degrees C treatment revealed that the staining distribution of the cell-bound IgG and IgA on the cell was granular, appearing as a discontinuous fluorescence ring and forming multiple aggregates but no typical polar caps on warming. In contrast, IgG, IgA, and IgM stable to acid or 37 degrees C treatment were found on the lymphocytes but not on the monocytes, and their staining distribution was uniformaly diffuse, appearing as a continuous ring and forming a typical cap on warming. Exposure of the cells to pH 4 or 37 degrees C could also elute the cell-bound IgG passively adsorbed to the human lymphoid cells in a culture, but did not affect the intrinsic S.Ig on the lymphoid cells in a culture or on the lymphoma cells. These results indicate that the exposure of the cells to acid pH or to 37 degrees C may enable us to detect unfailingly S.Ig lymphocytes by removing the cell-bound IgG and IgA present on the monocytes and/or lymphocytes. Thus, an average value of approximately 10% was obtained for the S.Ig lymphocyte in the lymphocyte preparations from 11 healthy individuals. In addition, the results provided the evidence that, even in normal peripheral blood lymphocytes, there may be a population of B lymphocytes which lack the S.Ig but carry the cell-bound Ig.
Acetates↗