Interleukin 2 promotes growth and cytolytic activity in human T3+4-8- thymocytes (original) (raw)
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European Journal of Immunology, 1989
T cell activation induced via the CD3-T cell receptor (TcR) complex, or by triggering of polyclonal antigen-independent pathways, involves both interleukin 2 (IL 2) production and IL 2 receptor (IL 2R) expression and results in T cell proliferation. To assess the potential role of the IL 2 pathway in T cell development, growth and activation requirements of intrathymic T cell precursors were analyzed and correlated with the expression of IL 2R. In contrast to CD3-TcR+ (either CD4' or CD8') mature thymic cells, CD3-TcR-CD1-4-8-early prothymocytes constitutively expressed IL 2R and displayed IL 2-mediated proliferation, which was inhibited by anti-IL 2R monoclonal antibodies (mAb). Moreover, prothymocytes developed spontaneous proliferation in the absence of exogenous IL 2, which was also abrogated by blocking of IL 2R with specific mAb. The possibility that both IL 2 production and IL 2R expression are autonomously activated early in T cell development, before acquisition of the CD3-TcR complex, led us to study the implication of alternative pathways of activation at this ontogenic stage. Triggering of the CD2 pathway with mAb against two different epitopes of the molecule (D66 and 9.6/Tlll) induced proliferation of CD3-TcR-prothymocytes in the absence of exogenous IL 2, while proliferation of CD3-TcR' mature thymocytes required IL 2 supplementation. These data suggest that polyclonal activation of the IL 2 pathway may be selectively operative at early stages of T cell development, being involved in the growth and differentiation of intrathymic T cell precursors.
Proliferation of phenotypically immature human thymocytes with and without interleukin 2 receptors
Journal of immunology (Baltimore, Md. : 1950), 1986
Previous studies have indicated that the human thymus is composed of several discrete compartments. Cortical thymocytes are reactive with the monoclonal antibody anti-T6, whereas most medullary cells, unreactive with anti-T6, stain brightly with anti-T3, which defines mature T cell populations. Only a minor thymocyte population lacks both T3 and T6 but expresses T11 antigens. Within the thymus, several proliferating lymphoblasts are present. In addition a distinct subset shows the capacity to proliferate in response to mitogens. By continuous Percoll density gradient centrifugation, we have obtained a cell fraction comprising the vast majority of cells able to proliferate spontaneously or after PHA stimulation. By a panning procedure performed with anti-T3 and anti-T6 antibodies, three phenotypically distinct thymocyte subsets were separated from this fraction, and their functional capabilities were tested. The spontaneous proliferating activity was found to be mainly attributable t...
European Journal of Immunology, 1989
Unite INSERM U 25, UA 122 CNRS' , H6pital Necker and Unit6 d'hnmunobiologie', Institut Pasteur, Paris Interleukin 2 receptor expression and interleukin 2 production in exponentially growing T cells: major differences between in vivo and in vitro proliferating T lymphocytes* In the present study we have assessed the growth requirements for in vivo proliferating mature T cells. For that purpose we have selected experimental approaches which allow the study of exponential growth in vivo of a major fraction of T cells, and make it possible to obtain large numbers of T cells in cycle. Two types of growing T cell populations were used: peripheral T lymphocytes, proliferating exponentially after transfer into syngeneic athymic nude mice, and activated T cells in lymph nodes of normal mice draining the site of oxazolone administration. The results obtained show that mature T cell growth in vivo is not accompanied by expression of high-affinity interleukin 2 (IL2) receptor in the majority of activated cells, is not abrogated by in vivo administration of anti-IL2 receptor antibodies or enhanced by the in vivo injection of recombinant IL2, and that in vivo growing T cells do not produce detectable amounts of IL2, as evaluated functionally by limiting dilution assays or the presence of IL2 mRNA, detected by Northern blots or in situ hybridization. The presented data thus indicate that the rules known to apply to T cell activation and proliferation in vitro differ from those used by in vivo growing T lymphocytes, at least in the two systems studied. Abbreviations: (r)IL2: (Recombinant) interleukin 2 IL 2R: IL2 receptor LN: Lymph node(s) LD: Limiting dilution Con A: Concanavalin A mAb: Monoclonal antibody(ies) BrdUrd: 5-Bromo-2deoxyuridine sIg: Surface immunoglobulin 0 VCH Verlagsgesellschaft mbH, D-6940 Weinheim, 1989
Immunobiology, 1982
The antigenic requirements for stimulating the production of interleukin 2 (ILZ) and the growth of IL2 producing T cells was evaluated using antigen-(Keyhole limpet hemocyanin) specific Fl T helper cell lines. The results demonstrate that both the induction and growth of these cells requires specific antigen and antigen-presenting cells of the correct I-A type. Evidence is presented that argues that soluble macrophage derived factors released as a result of T cell-macrophage interaction are insufficient, even in the presence of antigen, to promote growth of IL2 producing cells. We thus conclude that the direct interaction of IL2 producing cells with an antigen presenting cell is obligatory for activation and growth. These results suggest that T cell proliferation, and as a consequence the magnitude of T cell mediated immune responses, is limited by the availability of «appropriately» presented antigen to IL2 producing T cells. The requirement for antigen presenting cells in antigen-driven responses is in contrast with mitogen-induced T cell activation, in which soluble factors can substitute for the accessory cells.
International Immunology, 1992
Early murine fetal thymocytes express functional, high affinity IL-2 receptors as determined by: (i) the presence of IL-2R 0 chain (p75) mRNA; (II) IL-2 (10 U/ml) induced cell proliferation/cellular maturation in lobe submersion cultures (LSC). Under the Influence of IL-2, early thymocytes differentiate In vitro into more mature, early single positive CD4~CD8+ followed In vivo by double positive CD4+CD8+ and single positive CD4 + CD8"T and CD4CD8 + thymocytes. Specific Intoxication of high affinity IL-2R positive thymocytes by recombinant lnterleukin-2-diphtheria toxin-related fusion protein (DAB 4W -IL-2) results In transient, dose dependent blockade of In vivo and In vitro thymocyte maturation. DABug-IL-2 Induced effects upon In vivo maturation are reversible within 2 weeks after cessation of drug administration. Taken together, these results demonstrate the expression of functional, high affinity IL-2 receptors on early thymocytes. Elimination of high affinity IL-2 receptor positive thymocytes with DAB 466 -IL-2 results in transient blockade of T cell maturation. Since DAB^-IL^ Is now In clinical trial, it Is reassuring to note that It does not permanently disrupt thymlc maturation.
Proceedings of the National Academy of Sciences, 1986
In vivo, immunocompetent T lymphocytes are only detected late in ontogeny, among mature thymocytes expressing either T4 (L3T4 in mouse) or T8 (Lyt-2) surface glycoproteins. We have previously shown, however, that there are functional precursors among T3+4-6-8human thymocytes in vivo. Here we report on the in vitro differentiation of prothymocytes into T3+4-6-8and mature T cells. T11+3-4-6-8prothymocytes (0.5% of total thymocytes, >98% pure) were obtained after treatment of thymocytes with OKT3 (T3), OKT4A (T4), Nal/34 (T6), and B9.4 (T8) monoclonal antibodies plus complement. During culture, the prothymocyte precursors acquire first T3 and then either T4 or T8, but not T6. The largest subpopulation in the thymus, T4+6+8+ cells, are not detected among the in vitro T-cell precursors. During culture, the precursors acquire cytolytic activity as soon as they express either the T3+4-6-8or the mature (T3+4+8or T3+4-8+) phenotypes. We suggest that T3+4-6-8cells are a productive, transitional stage in T-lymphocyte development.
Activation of CD 4-, CD 8- thymocytes with IL 4 vs IL 1 + IL 2
The Journal of Immunology
Thymocytes from C57BL/6 mice were highly purified to obtain the CD 4-, CD 8- subpopulation which constitutes only 5% of all thymocytes. Substantial proliferation was induced in vitro with either IL-1 + IL-2 or with IL-4 in the presence of PMA. IL-1 and IL-2 synergized in inducing proliferation of these purified CD 4-, CD 8- thymocytes whereas neither synergized with IL-4. In order to determine whether stimulation with IL-1 + IL-2 acted via IL-4 or vice versa, cultures were treated reciprocally with affinity-purified anti-IL-2 or anti-IL-4 antibodies. Cultures with IL-4 were inhibited by anti-IL-4 but were unaffected by anti-IL-2. The CD 4-, CD 8- thymocytes cultured with IL-1 + IL-2 + anti-IL-2 were inhibited to baseline IL-1 stimulation. At low concentrations of IL-1 (1 U/ml) and IL-2 (100 U/ml), anti-IL-4 had no effect, whereas at higher levels of IL-1 (2 U/ml IL-1), and 100 or 200 U/ml IL-2, anti-IL-4 significantly reduced DNA synthesis. This result suggests that at higher concen...
Responsiveness of fetal and adult CD4-, CD8- thymocytes to T cell activation
The Journal of Immunology
Day-14 fetal CD4-, CD8- thymocytes showed a greater proliferative response to PMA + IL-4 than did adult double-negative thymocytes. In contrast, adult double-negative thymocytes were more responsive to PMA + IL-1 + IL-2 or to IL-1 + IL-2 alone. The adult double-negative thymocytes showed significantly greater proliferation than fetal thymocytes after stimulation via anti-CD3 or anti-Thy-1 in the presence or absence of interleukins (IL-1 + IL-2 or IL-4). Adult CD4-, CD8- thymocytes also exhibited greater calcium mobilization following anti-CD3 stimulation IL-2-dependent activation with anti-Thy-1 or IL-1 + IL-2 in the absence of PMA resulted in marked expansion of CD 3+, F23.1+, CD4-, CD8- thymocytes, a population absent in fetal thymocytes but constituting 4% of pre-cultured CD4-, CD8- adult thymocytes. IL-4 + PMA failed to expand this CD 3+ population. It is hypothesized that before expression of functional TCR, T cell development may be more dependent on activation pathways not us...
Cellular Immunology, 1985
In this study, we demonstrate that an IL-2-dependent T-cell clone (HT-2) can be grown in a serum-free medium (HBlO I) with defined additives at rates comparable to those which can be obtained in serum-containing medium. Further, we show that cells cultured in the serumfree medium in the absence of IL-2 arrest growth in the G, portion of the cell cycle, and that these arrested cells can be stimulated to reenter the cell cycle upon the addition of IL-2 to the culture medium. Growth of these cells in the absence of serum requires the presence of IL-2 as well as other hormones and growth factors and 2-mercaptoethanol. HT-2 cells have been grown continuously in the serum-free medium for periods of up to 1 month. 0 1985 Academic press. Inc.