Regulation of lymphokine expression in T cell activation. I. Rapid loss of interleukin‐specific RNA after removal of the stimulating signal

Swoboda, Rolf; Bormmhardt, Ursula; Schimpl, Anneliese

doi:10.1002/eji.1830210716

Cited by 16 publications

(6 citation statements)

References 30 publications

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“…the primary T cell growth factor IL-2, and up-regulation of CD25. In our experiments, there is an apparent discrepancy between the effective activation of UCB naive CD4 ϩ cells after TCR engagement alone and the low amount of IL-2 secreted at 24 h. A significant earlier IL-2 production may not have been detected in our experiments, but this is improbable, as the peak of IL-2 gene expression in most activatory systems is ϳ24 h. Presumably, the low concentration of IL-2 detected at 24 h by anti-CD3-stimulated UCB-CD4 ϩ CD45RA ϩ cells rapidly disappeared as a result of autocrine consumption during posterior proliferation [41].…”

Section: Discussionmentioning

confidence: 57%

Distinctive response of naïve lymphocytes from cord blood to primary activation via TCR

Cantó

Rodríguez-Sánchez

Vidal

2003

Journal of Leukocyte Biology

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Umbilical cord blood (UCB) is now being considered an alternative to bone marrow for restoring hematopoiesis after myeloablative therapy. The lower risk of acute and chronic graft-versus-host disease in patients who received UCB cells seems related to the nature of UCB-T cells. Phenotypically, UCB-CD3+ cells are mostly naive (CD45RA+) and represent a transitional population between thymocytes and adult T cells. We examined the immune reactivity of highly purified, negatively selected CD4+CD45RA+ cells by mimicking activation via T cell receptor (TCR). All experiments included the extensively characterized adult peripheral blood (APB) cells as reference. On the contrary to APB, naive UCB-CD4+ cells were able to proliferate with anti-CD3 stimulation alone. With addition of interleukin (IL)-2 or costimulatory signal, both populations reached similar proliferation. Forty-eight hours after anti-CD3 stimulation, CD4+CD45RA+ from UCB, but not APB, showed characteristic blastic morphology and significant expression of CD25 on the surface. A low concentration of IL-2 was detected at 24 h by anti-CD3-stimulated UCB CD4+CD45RA+, which rapidly disappeared. By 72 h after activation, CD4+CD45RA+ UCB cells showed extensive apoptosis, whereas CD4+CD45RA+ APB cells showed low levels of apoptosis. Using RNase protection assay, we observed that CD95L levels were significantly higher in naive CD4+ cells from UCB than from APB after activation. However, neutralizing Fas-Fc protein was unable to inhibit anti-CD3-induced apoptosis, suggesting that this was a CD95-independent mechanism. These results indicate that UCB-CD4+CD45RA+ cells are able to start proliferating as a result of early IL-2 production after TCR engagement alone, but probably, as a result of the consumption of this IL-2, they undergo cell death.

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Section: Discussionmentioning

confidence: 57%

Distinctive response of naïve lymphocytes from cord blood to primary activation via TCR

Cantó

Rodríguez-Sánchez

Vidal

2003

Journal of Leukocyte Biology

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“…Furthermore, it validates in vitro experiments demonstrating that the kinetics of cytokine production and CD40-1igand expression can be superimposed (7). The observation that during the entire experimental period antigen-specific AFC and gp39 § cells were found in close proximity, in addition to in vitro experiments which showed that extended contact (more than 48 h) is required for maximal proliferative responses (58) or cytokine production (59), suggests that T-B conjugates may persist for several days in vivo. Fig.…”

Section: Discussionmentioning

confidence: 84%

In vivo CD40-gp39 interactions are essential for thymus-dependent humoral immunity. I. In vivo expression of CD40 ligand, cytokines, and antibody production delineates sites of cognate T-B cell interactions.

Eertwegh¹,

Noelle²,

Roy³

et al. 1993

The Journal of Experimental Medicine

235

115

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SummaryT-B cell interactions have a central role in the development of antibody responses. Upon activation, T helper (Th) cells express the ligand for CD40, gp39, which is essential for Th cell-dependent B cell activation. The cytokines produced by activated Th cells have a regulatory role in B cell differentiation. In this study, we investigated, using immunohistochemical techniques, the in vivo time course and localization of gp39 expression and cytokine production in relation to the specific antibody production. Both the immunization with keyhole limpet hemocyanin (KLH), a thymus-dependent (TD) antigen, and trinitrophenyl (TNP)-FicoU, a thymus-independent type 2 (TI-2) antigen, induced Th cells to express gp39. The expression of gp39 was restricted to Th cells in the outer periarteriolar lymphocyte sheaths (outer-PALS) and around the terminal arterioles (TA). Incidentally, gp39 + Th cells were found in the corona of follicles, whereas gp39 + cells were never found in the germinal centers or marginal zones of the spleen. Maximum frequencies of gp39 + cells were observed 3 and 4 d after primary and secondary immunization with KLH. After injection of TNP-Ficoll, a marked increase in gp39 + cells was observed, confirming previous observations that activated T cells are involved in TI-2 antibody responses. Analysis of the in vivo cytokine production revealed that interleukin 2 (IL-2)-, IL-4-and interferon 3/ (IFN-q0-producing cells (IFN-q/-PC) developed according to similar kinetics as observed for gp39 + cells. IL-2-PC and IL-4-PC were present in higher frequencies as were IFN-3/-PC in the immune response against TNP-KLH. Double staining experiments revealed gp39 + Th cells producing IL-2, IL-4, or IFN-% suggesting that these cells were involved in both the initial activation as well as the differentiation process of B cells into antibody-forming cells. Dual immunohistochemical analysis revealed gp39 + T cells and cytokine-PC in close proximity to antigen-specific, antibody-forming B cells. In conclusion, this study shows that in vivo gp39 is expressed on activated Th cells after immunization with TD and TI-2 antigens. Furthermore, the time course and compartmentalization of gp39 + expression, cytokine production and antibody formation after immunization suggest that cognate T-B cell interactions and T cell-regnlated B cell differentiation occur in the outer-PALS and around the TA of the spleen.

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“…It has been previously shown that upon stimulus removal and restimulation, IL-2 gene transcription occurs with faster kinetics (30,31). It is possible that the faster kinetics of transcription following A, Generation of a standard curve to show the correlation between Ct (threshold cycle) and input DNA.…”

Section: Chromatin Remodeling Occurs With Altered Kinetics In Restimumentioning

confidence: 99%

Chromatin Remodeling, Measured by a Novel Real-Time Polymerase Chain Reaction Assay, Across the Proximal Promoter Region of the IL-2 Gene

Rao¹,

Procko²,

Shannon³

2001

The Journal of Immunology

183

222

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The structure of chromatin and its remodeling following activation are important aspects of the control of inducible gene transcription. The IL-2 gene is induced in a cell specific-manner in T cells following an antigenic stimulus. We show, using a novel real-time PCR assay, that significant chromatin remodeling of the IL-2 proximal promoter region occurred upon stimulation of both the murine EL-4 T cell line and primary CD4+ T cells. Chromatin remodeling appears to be limited to the first 300 bp of the proximal promoter region as measured by micrococcal nuclease and restriction enzyme accessibility. Time course studies indicated that chromatin remodeling was observed at 1.5 h postinduction and was maintained for up to 16 h. The remodeling is reversible upon removal of the stimulus. The region immediately upstream from the transcription start site, however, remains accessible for up to 16 h. Upon restimulation, remodeling occurs much more rapidly, consistent with a more rapid rise in IL-2 mRNA levels. Using a number of pharmacological inhibitors we show that remodeling is dependent on the presence of specific transcription factors, but not on the modification of histones. The development of this novel chromatin accessibility assay based on real-time PCR has allowed rapid, sensitive, and quantitative measurements on the IL-2 gene following cellular activation in both T cell lines and primary cells.

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Regulation of lymphokine expression in T cell activation. I. Rapid loss of interleukin‐specific RNA after removal of the stimulating signal

Cited by 16 publications

References 30 publications

Distinctive response of naïve lymphocytes from cord blood to primary activation via TCR

Distinctive response of naïve lymphocytes from cord blood to primary activation via TCR

In vivo CD40-gp39 interactions are essential for thymus-dependent humoral immunity. I. In vivo expression of CD40 ligand, cytokines, and antibody production delineates sites of cognate T-B cell interactions.

Chromatin Remodeling, Measured by a Novel Real-Time Polymerase Chain Reaction Assay, Across the Proximal Promoter Region of the IL-2 Gene

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