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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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Quantitative analysis of the movements of the different T cell subpopulations imaged by time-lapse videomicroscopy. (A) The total conjugation time with DCs over the 10-h incubation period of 50 Motile GFP−, 9 LTC GFP−, and 15 GFP+ cells is plotted as follows: Motile GFP−, blue squares; LTC GFP−, yellow squares; and GFP+, green circles. The horizontal bars indicate the average conjugation time of the GFP− and GFP+ populations. (B) Average velocity. The average velocity of individual T cells analyzed in A over the 10-h incubation period is represented as follows: Motile GFP+, blue squares; LTC GFP−, yellow squares; and GFP+, green circles. The horizontal bars indicate the mean velocity of the GFP− and GFP+ populations. (C) Variation over time in average velocity of the CD4 T cells in each subpopulation. The instantaneous velocity of individual T cells analyzed in A was measured every minute for 10 h. Average velocity for Motile GFP− (blue line), LTC GFP− (yellow line), and GFP+ (green line) T cells was calculated and plotted over time. (D) Cell number distribution over time. The total cell numbers from the entire microscopic field (20×) of a representative experiment were counted every hour for 10 h. The cells were classified in three subpopulations: Motile GFP− (blue), LTC GFP− (yellow), and GFP+ (green).
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fig6: Quantitative analysis of the movements of the different T cell subpopulations imaged by time-lapse videomicroscopy. (A) The total conjugation time with DCs over the 10-h incubation period of 50 Motile GFP−, 9 LTC GFP−, and 15 GFP+ cells is plotted as follows: Motile GFP−, blue squares; LTC GFP−, yellow squares; and GFP+, green circles. The horizontal bars indicate the average conjugation time of the GFP− and GFP+ populations. (B) Average velocity. The average velocity of individual T cells analyzed in A over the 10-h incubation period is represented as follows: Motile GFP+, blue squares; LTC GFP−, yellow squares; and GFP+, green circles. The horizontal bars indicate the mean velocity of the GFP− and GFP+ populations. (C) Variation over time in average velocity of the CD4 T cells in each subpopulation. The instantaneous velocity of individual T cells analyzed in A was measured every minute for 10 h. Average velocity for Motile GFP− (blue line), LTC GFP− (yellow line), and GFP+ (green line) T cells was calculated and plotted over time. (D) Cell number distribution over time. The total cell numbers from the entire microscopic field (20×) of a representative experiment were counted every hour for 10 h. The cells were classified in three subpopulations: Motile GFP− (blue), LTC GFP− (yellow), and GFP+ (green).

Mentions: Analysis of the average velocity and total DC–T cell conjugation times of GFP+ and GFP− subpopulations confirmed the visual impressions from time-lapse videos (Fig. 6 A). The GFP− population stayed in contact with a DC for 102 ± 23 min on average with a majority of the GFP− cells that either did not interact with a DC at all, or did so very briefly (<15 min). In contrast, the GFP+ population remained firmly attached to DCs 554 ± 19 min on average, with 77% of the cells staying in intimate contact with one or, rarely, two DCs during the entire experiment (∼10 h). The striking difference in conjugation time was correlated with a significant difference (P < 0.01) in average velocity between the GFP− and GFP+ population (3.2 ± 0.2 and 0.6 ± 0.07 μm/min, respectively) (Fig. 6, B and C), even though the velocity measurement does not distinguish between the intrinsic motility of isolated T cells and the motility of DCs, to which T cells were attached.


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)

Quantitative analysis of the movements of the different T cell subpopulations imaged by time-lapse videomicroscopy. (A) The total conjugation time with DCs over the 10-h incubation period of 50 Motile GFP−, 9 LTC GFP−, and 15 GFP+ cells is plotted as follows: Motile GFP−, blue squares; LTC GFP−, yellow squares; and GFP+, green circles. The horizontal bars indicate the average conjugation time of the GFP− and GFP+ populations. (B) Average velocity. The average velocity of individual T cells analyzed in A over the 10-h incubation period is represented as follows: Motile GFP+, blue squares; LTC GFP−, yellow squares; and GFP+, green circles. The horizontal bars indicate the mean velocity of the GFP− and GFP+ populations. (C) Variation over time in average velocity of the CD4 T cells in each subpopulation. The instantaneous velocity of individual T cells analyzed in A was measured every minute for 10 h. Average velocity for Motile GFP− (blue line), LTC GFP− (yellow line), and GFP+ (green line) T cells was calculated and plotted over time. (D) Cell number distribution over time. The total cell numbers from the entire microscopic field (20×) of a representative experiment were counted every hour for 10 h. The cells were classified in three subpopulations: Motile GFP− (blue), LTC GFP− (yellow), and GFP+ (green).
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Related In: Results  -  Collection

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fig6: Quantitative analysis of the movements of the different T cell subpopulations imaged by time-lapse videomicroscopy. (A) The total conjugation time with DCs over the 10-h incubation period of 50 Motile GFP−, 9 LTC GFP−, and 15 GFP+ cells is plotted as follows: Motile GFP−, blue squares; LTC GFP−, yellow squares; and GFP+, green circles. The horizontal bars indicate the average conjugation time of the GFP− and GFP+ populations. (B) Average velocity. The average velocity of individual T cells analyzed in A over the 10-h incubation period is represented as follows: Motile GFP+, blue squares; LTC GFP−, yellow squares; and GFP+, green circles. The horizontal bars indicate the mean velocity of the GFP− and GFP+ populations. (C) Variation over time in average velocity of the CD4 T cells in each subpopulation. The instantaneous velocity of individual T cells analyzed in A was measured every minute for 10 h. Average velocity for Motile GFP− (blue line), LTC GFP− (yellow line), and GFP+ (green line) T cells was calculated and plotted over time. (D) Cell number distribution over time. The total cell numbers from the entire microscopic field (20×) of a representative experiment were counted every hour for 10 h. The cells were classified in three subpopulations: Motile GFP− (blue), LTC GFP− (yellow), and GFP+ (green).
Mentions: Analysis of the average velocity and total DC–T cell conjugation times of GFP+ and GFP− subpopulations confirmed the visual impressions from time-lapse videos (Fig. 6 A). The GFP− population stayed in contact with a DC for 102 ± 23 min on average with a majority of the GFP− cells that either did not interact with a DC at all, or did so very briefly (<15 min). In contrast, the GFP+ population remained firmly attached to DCs 554 ± 19 min on average, with 77% of the cells staying in intimate contact with one or, rarely, two DCs during the entire experiment (∼10 h). The striking difference in conjugation time was correlated with a significant difference (P < 0.01) in average velocity between the GFP− and GFP+ population (3.2 ± 0.2 and 0.6 ± 0.07 μm/min, respectively) (Fig. 6, B and C), even though the velocity measurement does not distinguish between the intrinsic motility of isolated T cells and the motility of DCs, to which T cells were attached.

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