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Restricted clonal expression of IL-2 by naive T cells reflects differential dynamic interactions with dendritic cells.

Hurez V, Saparov A, Tousson A, Fuller MJ, Kubo T, Oliver J, Weaver BT, Weaver CT - J. Exp. Med. (2003)

Bottom Line: T cells destined to produce IL-2 required prolonged interactions with DCs, whereas most T cells established only transient interactions with DCs and were activated, but did not express IL-2.Extended conjugation of T cells with DCs was not always sufficient to initiate IL-2 expression.Thus, there is intrinsic variability in clonal T cell populations that restricts IL-2 commitment, and prolonged engagement with mature DCs is necessary, but not sufficient, for IL-2 gene transcription.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, University of Alabama at Birmingham, AL 35294, USA.

ABSTRACT
Limited frequencies of T cells express IL-2 in primary antigenic responses, despite activation marker expression and proliferation by most clonal members. To define the basis for restricted IL-2 expression, a videomicroscopic system and IL-2 reporter transgenic model were used to characterize dendritic cell (DC)-T cell interactions. T cells destined to produce IL-2 required prolonged interactions with DCs, whereas most T cells established only transient interactions with DCs and were activated, but did not express IL-2. Extended conjugation of T cells with DCs was not always sufficient to initiate IL-2 expression. Thus, there is intrinsic variability in clonal T cell populations that restricts IL-2 commitment, and prolonged engagement with mature DCs is necessary, but not sufficient, for IL-2 gene transcription.

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Time-lapse videomicroscopy of DO11.IL-2P/GFP Tg T cells and DCs interaction with or without OVAp. (a) Naive CD4 T cells were isolated from DO11.IL-2P/GFP mice and cultured with DC hybrid cells and OVAp as described in Materials and Methods, and were imaged sequentially at 0.5-min intervals by phase-contrast microscopy for a total of for 10 h. The GFP fluorescent signal was collected at 30-min intervals and has been digitally superimposed over the transmitted light images. A green arrow identifies a T cell that ultimately expressed GFP; the red arrow identifies a cell that remained GFP− (localized under the GFP+ cell at 8 and 9 h), despite intimate contact with a DC shared with a GFP+ cell. (b) Representative images of a T cell–DC conjugate in the absence of OVAp. Same experimental condition as in a. Red arrow identifies the only T cell that established a prolonged interaction with a DC. No GPF signal was detected during the 10-h incubation.
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fig4: Time-lapse videomicroscopy of DO11.IL-2P/GFP Tg T cells and DCs interaction with or without OVAp. (a) Naive CD4 T cells were isolated from DO11.IL-2P/GFP mice and cultured with DC hybrid cells and OVAp as described in Materials and Methods, and were imaged sequentially at 0.5-min intervals by phase-contrast microscopy for a total of for 10 h. The GFP fluorescent signal was collected at 30-min intervals and has been digitally superimposed over the transmitted light images. A green arrow identifies a T cell that ultimately expressed GFP; the red arrow identifies a cell that remained GFP− (localized under the GFP+ cell at 8 and 9 h), despite intimate contact with a DC shared with a GFP+ cell. (b) Representative images of a T cell–DC conjugate in the absence of OVAp. Same experimental condition as in a. Red arrow identifies the only T cell that established a prolonged interaction with a DC. No GPF signal was detected during the 10-h incubation.

Mentions: To further characterize the kinetic interactions between T cells and DCs, prolonged videomicroscopic imaging of DC–T cell interactions was performed. For these studies, the V-2 DC hybrid line was used because it provided easier morphological discrimination from T cells, although comparable results were obtained with either splenic or BM-derived DCs (unpublished data). As shown in Fig. 4 a, and in time-lapse videos (Videos 1–3 and 5, available at http://www.jem.org/cgi/content/full/jem.20022230/DC1), individual T cells and DCs could be continuously tracked throughout a 9–12-h culture period, and the expression of IL-2/GFP by individual T cells could be visualized. Under conditions of antigenic stimulation, two general subpopulations of T cells could be defined: a highly motile population that generally engaged in only intermittent, transient (<15 min) contact with DCs before detaching, moving away, and often sequentially contacting other DCs transiently; and a population of T cells that were stably conjugated to a DC for prolonged periods (>4 h). Within the population of T cells that formed long-term conjugates (LTCs), a fraction expressed detectable GFP as early as 3–4 h after contact, whereas another fraction of LTC never expressed GFP during the period of observation (10–12 h). In the absence of antigen, far fewer DC–T cell conjugates formed and GFP expression was not induced (Fig. 4 B and Video 4, available at http://www.jem.org/cgi/content/full/jem.20022230/DC1).


Restricted clonal expression of IL-2 by naive T cells reflects differential dynamic interactions with dendritic cells.

Hurez V, Saparov A, Tousson A, Fuller MJ, Kubo T, Oliver J, Weaver BT, Weaver CT - J. Exp. Med. (2003)

Time-lapse videomicroscopy of DO11.IL-2P/GFP Tg T cells and DCs interaction with or without OVAp. (a) Naive CD4 T cells were isolated from DO11.IL-2P/GFP mice and cultured with DC hybrid cells and OVAp as described in Materials and Methods, and were imaged sequentially at 0.5-min intervals by phase-contrast microscopy for a total of for 10 h. The GFP fluorescent signal was collected at 30-min intervals and has been digitally superimposed over the transmitted light images. A green arrow identifies a T cell that ultimately expressed GFP; the red arrow identifies a cell that remained GFP− (localized under the GFP+ cell at 8 and 9 h), despite intimate contact with a DC shared with a GFP+ cell. (b) Representative images of a T cell–DC conjugate in the absence of OVAp. Same experimental condition as in a. Red arrow identifies the only T cell that established a prolonged interaction with a DC. No GPF signal was detected during the 10-h incubation.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2196090&req=5

fig4: Time-lapse videomicroscopy of DO11.IL-2P/GFP Tg T cells and DCs interaction with or without OVAp. (a) Naive CD4 T cells were isolated from DO11.IL-2P/GFP mice and cultured with DC hybrid cells and OVAp as described in Materials and Methods, and were imaged sequentially at 0.5-min intervals by phase-contrast microscopy for a total of for 10 h. The GFP fluorescent signal was collected at 30-min intervals and has been digitally superimposed over the transmitted light images. A green arrow identifies a T cell that ultimately expressed GFP; the red arrow identifies a cell that remained GFP− (localized under the GFP+ cell at 8 and 9 h), despite intimate contact with a DC shared with a GFP+ cell. (b) Representative images of a T cell–DC conjugate in the absence of OVAp. Same experimental condition as in a. Red arrow identifies the only T cell that established a prolonged interaction with a DC. No GPF signal was detected during the 10-h incubation.
Mentions: To further characterize the kinetic interactions between T cells and DCs, prolonged videomicroscopic imaging of DC–T cell interactions was performed. For these studies, the V-2 DC hybrid line was used because it provided easier morphological discrimination from T cells, although comparable results were obtained with either splenic or BM-derived DCs (unpublished data). As shown in Fig. 4 a, and in time-lapse videos (Videos 1–3 and 5, available at http://www.jem.org/cgi/content/full/jem.20022230/DC1), individual T cells and DCs could be continuously tracked throughout a 9–12-h culture period, and the expression of IL-2/GFP by individual T cells could be visualized. Under conditions of antigenic stimulation, two general subpopulations of T cells could be defined: a highly motile population that generally engaged in only intermittent, transient (<15 min) contact with DCs before detaching, moving away, and often sequentially contacting other DCs transiently; and a population of T cells that were stably conjugated to a DC for prolonged periods (>4 h). Within the population of T cells that formed long-term conjugates (LTCs), a fraction expressed detectable GFP as early as 3–4 h after contact, whereas another fraction of LTC never expressed GFP during the period of observation (10–12 h). In the absence of antigen, far fewer DC–T cell conjugates formed and GFP expression was not induced (Fig. 4 B and Video 4, available at http://www.jem.org/cgi/content/full/jem.20022230/DC1).

Bottom Line: T cells destined to produce IL-2 required prolonged interactions with DCs, whereas most T cells established only transient interactions with DCs and were activated, but did not express IL-2.Extended conjugation of T cells with DCs was not always sufficient to initiate IL-2 expression.Thus, there is intrinsic variability in clonal T cell populations that restricts IL-2 commitment, and prolonged engagement with mature DCs is necessary, but not sufficient, for IL-2 gene transcription.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, University of Alabama at Birmingham, AL 35294, USA.

ABSTRACT
Limited frequencies of T cells express IL-2 in primary antigenic responses, despite activation marker expression and proliferation by most clonal members. To define the basis for restricted IL-2 expression, a videomicroscopic system and IL-2 reporter transgenic model were used to characterize dendritic cell (DC)-T cell interactions. T cells destined to produce IL-2 required prolonged interactions with DCs, whereas most T cells established only transient interactions with DCs and were activated, but did not express IL-2. Extended conjugation of T cells with DCs was not always sufficient to initiate IL-2 expression. Thus, there is intrinsic variability in clonal T cell populations that restricts IL-2 commitment, and prolonged engagement with mature DCs is necessary, but not sufficient, for IL-2 gene transcription.

Show MeSH
Related in: MedlinePlus