Gold is a T cell polyclonal activator in BN and LEW rats but favors IL-4 expression only in autoimmune prone BN rats

Concanavalin A, a nonspecific polyclonal activator of T lymphocytes, activates Lyl and Ly23 subclasses to the same degree. After activation, the Ly23 subclass, but not the Lyl subclass, has the following properties: (a) Suppression of the antibody response to sheep erythrocytes (SRBC) in vitro. (b) Production of a soluble factor that suppresses the anti-SRBC response in vitro. (c) Suppression of the generation of cell-mediated cytotoxicity to H-2 target cells in vitro. Con A-activated cells of the Lyl subclass, but not the Ly23 subclass, express helper function in the anti-SRBC response in vitro. Because the intact Con A-stimulated T-cell population contains both cell types, these cells do not exert detectable helper effects in an anti-SRBC system in vitro, because the helper effect of Lyl cells is masked by the suppressor effect of the Ly23 cells. Each function is revealed by eliminating one or the other population with the relevant Ly antiserum. The resting T-cell population, before activation by Con A, also contains already programmed Lyl and Ly23 cells with similar helper and suppressor potentials, respectively. This is revealed by experiments with Ly subclasses which have been separated from the resting T-cell population and then stimulated by Con A. Thus helper and suppressor functions, as expressed in these systems, are manifestations of separate T-cell-differentiative pathways and do not depend upon stimulation of the cells by antigen.

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T-cell regulation of murine IgA synthesis.

Journal of Experimental Medicine ◽

10.1084/jem.149.3.632 ◽

1979 ◽

Vol 149 (3) ◽

pp. 632-643 ◽

Cited By ~ 178

Author(s):

C O Elson ◽

J A Heck ◽

W Strober

Keyword(s):

T Cells ◽

T Cell ◽

Cell Activity ◽

Lymphoid Cells ◽

Lymphoid Tissues ◽

Activated T Cells ◽

Peripheral Lymph ◽

Polyclonal Activator ◽

Helper Activity ◽

High Level

In studies reported here, the polyclonal activator lipopolysaccharide was used to stimulate the synthesis and secretion of IgM, IgA, and IgG in cultures of mouse lymphoid cells. The total immunoglobulin of each class which resulted was measured by specific double-antibody radioimmunoassays. The effect of Con A-activated T cells from various tissues on such immunoglobulin synthesis was then assessed. Variations in regulatory T-cell activity among the various lymphoid tissues for IgA but not for IgM or IgG was observed. In particular, Peyer's patches T cells were found to contain a high level of IgA T-cell helper activity compared to that of spleen or peripheral lymph node. The independent variation of T-cell regulatory activity for IgA as compared to that for IgM and IgG among the different tissues is most consistent with there being a separate subset of T cells specifically regulating IgA. The significance of these findings for the understanding of the secretory immune system is discussed.

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Immunopotentiation of the humoral response by liposomes: Effect of a T cell polyclonal activator

Cellular Immunology ◽

10.1016/0008-8749(88)90234-1 ◽

1988 ◽

Vol 116 (2) ◽

pp. 320-330 ◽

Cited By ~ 14

Author(s):

Hélène-Marie Thérien ◽

Eliane Shahum

Keyword(s):

T Cell ◽

Humoral Response ◽

Polyclonal Activator

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Electron microscope study of the secretory activity of epithelial cells in embryonic thymus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010015945x ◽

1990 ◽

Vol 48 (3) ◽

pp. 382-383

Author(s):

H. Alasam

Keyword(s):

Cell Differentiation ◽

T Cell ◽

Epithelial Cells ◽

Electron Density ◽

Secretory Activity ◽

T Cell Differentiation ◽

High Electron ◽

Transmission Electron ◽

Medullary Epithelial Cells ◽

Thymic Factor

The possibility that intrathymic T-cell differentiation involves stem cell-lymphoid interactions in embryos led us to study the ultrastructure of epithelial cell in normal embryonic thymus. Studies in adult thymus showed that it produces several peptides that induce T-cell differentiation. Several of them have been chemically characterized, such as thymosin α 1, thymopoietin, thymic humoral factor or the serum thymic factor. It was suggested that most of these factors are secreted by populations of A and B-epithelial cells.Embryonic materials were obtained from inbred matings of Swiss Albino mice. Thymuses were disected from embryos 17 days old and prepared for transmission electron microscopy. Our studies showed that embryonic thymus at this stage contains undifferentiated and differentiated epithelial cells, large lymphoblasts, medium and few small lymphocytes (Fig. 5). No differences were found between cortical and medullary epithelial cells, in contrast to the findings of Van Vliet et al,. Epithelial cells were mostly of the A-type with low electron density in both cytoplasm and nucleus. However few B-type with high electron density were also found (Fig. 7).

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