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Antigen-specific precursor frequency impacts T cell proliferation, differentiation, and requirement for costimulation.

Ford ML, Koehn BH, Wagener ME, Jiang W, Gangappa S, Pearson TC, Larsen CP - J. Exp. Med. (2007)

Bottom Line: Using an adoptive transfer system to incrementally raise the precursor frequency of antigen-specific CD8(+) T cells, we found that donor-reactive T cells primed at low frequency exhibited increased cellular division, decreased development of multifunctional effector activity, and an increased requirement for CD28- and CD154-mediated costimulation relative to those primed at high frequency.The results demonstrated that recipients with low CD4(+) and CD8(+) donor-reactive T cell frequencies exhibited long-term skin graft survival upon CD28/CD154 blockade, whereas simultaneously raising the frequency of CD4(+) T cells to approximately 0.5% and CD8(+) T cells to approximately 5% precipitated graft rejection despite CD28/CD154 blockade.These results demonstrate a critical role for initial precursor frequency in determining the CD8(+) T cell requirement for CD28- and CD154-mediated costimulatory signals during graft rejection.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery and Emory Transplant Center, Emory University, Atlanta, GA 30322, USA.

ABSTRACT
After a brief period of antigenic stimulation, T cells become committed to a program of autonomous expansion and differentiation. We investigated the role of antigen-specific T cell precursor frequency as a possible cell-extrinsic factor impacting T cell programming in a model of allogeneic tissue transplantation. Using an adoptive transfer system to incrementally raise the precursor frequency of antigen-specific CD8(+) T cells, we found that donor-reactive T cells primed at low frequency exhibited increased cellular division, decreased development of multifunctional effector activity, and an increased requirement for CD28- and CD154-mediated costimulation relative to those primed at high frequency. The results demonstrated that recipients with low CD4(+) and CD8(+) donor-reactive T cell frequencies exhibited long-term skin graft survival upon CD28/CD154 blockade, whereas simultaneously raising the frequency of CD4(+) T cells to approximately 0.5% and CD8(+) T cells to approximately 5% precipitated graft rejection despite CD28/CD154 blockade. Antigenic rechallenge of equal numbers of cells stimulated at high or low frequency revealed that cells retained an imprint of the frequency at which they were primed. These results demonstrate a critical role for initial precursor frequency in determining the CD8(+) T cell requirement for CD28- and CD154-mediated costimulatory signals during graft rejection.

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Decreased OT-I T cell expansion in the presence of CTLA-4 Ig/anti-CD154 after priming at low, but not high, antigen-specific precursor frequency. 106 or 107 OT-I T cells (along with 106 OT-II cells) were adoptively transferred into naive B6 recipients that then received an mOVA skin graft. (A) Results showed that mice receiving a low frequency (106) of OT-I T cells were protected from rejection by CTLA-4 Ig/anti-CD154, whereas mice receiving a high frequency (107) rapidly rejected their grafts (P < 0.001). (B) Analysis of the percentage of Thy1.1+ CD8+ T cells in the DLN revealed that costimulation blockade inhibited the expansion/accumulation of OT-I T cells in mice responding from low frequency, whereas the expansion/accumulation of OT-I cells responding from high frequency was not as potently affected. (C) Absolute numbers of OT-I T cells isolated from the DLN showed a convergence at the peak of expansion at day 10 in both the low and high frequency untreated groups as well as the CTLA-4 Ig/anti-CD154–treated high frequency group. In contrast, the low frequency, CTLA-4 Ig/anti-CD154–treated group exhibited minimal expansion of OT-I T cell numbers. These data are representative examples of four independent experiments, with two to three mice per group, per time point, per experiment.
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fig3: Decreased OT-I T cell expansion in the presence of CTLA-4 Ig/anti-CD154 after priming at low, but not high, antigen-specific precursor frequency. 106 or 107 OT-I T cells (along with 106 OT-II cells) were adoptively transferred into naive B6 recipients that then received an mOVA skin graft. (A) Results showed that mice receiving a low frequency (106) of OT-I T cells were protected from rejection by CTLA-4 Ig/anti-CD154, whereas mice receiving a high frequency (107) rapidly rejected their grafts (P < 0.001). (B) Analysis of the percentage of Thy1.1+ CD8+ T cells in the DLN revealed that costimulation blockade inhibited the expansion/accumulation of OT-I T cells in mice responding from low frequency, whereas the expansion/accumulation of OT-I cells responding from high frequency was not as potently affected. (C) Absolute numbers of OT-I T cells isolated from the DLN showed a convergence at the peak of expansion at day 10 in both the low and high frequency untreated groups as well as the CTLA-4 Ig/anti-CD154–treated high frequency group. In contrast, the low frequency, CTLA-4 Ig/anti-CD154–treated group exhibited minimal expansion of OT-I T cell numbers. These data are representative examples of four independent experiments, with two to three mice per group, per time point, per experiment.

Mentions: Given the finding that a high precursor frequency of CD8+ T cells was critically important in the generation of costimulation blockade-resistant rejection, we sought to define the effects of altered CD8+ T cell precursor frequency on the programmed expansion and differentiation of donor-specific T cells in the presence of costimulation blockade. Two groups of B6 mice with varying precursor frequencies of donor-specific CD8+ T cells were prepared by transferring 106 or 107 OT-I T cells. Both groups also received a fixed dose of 106 OT-II CD4+ T cells, an mOVA skin graft, and CTLA-4 Ig/anti-CD154. Again, we observed that the initial CD8 precursor frequency had a profound impact on graft survival after treatment with costimulation blockade. Mice that received 106 OT-II cells and 106 OT-I T cells accepted an mOVA skin graft for >150 d after treatment with costimulation blockade, whereas mice that received 106 OT-II cells and 107 OT-I T cells showed rapid and consistent costimulation blockade-resistant rejection resulting in graft rejection with an MST of 17 d (P < 0.001) (Fig. 3 A). Clinical rejection was confirmed by immunohistochemical analysis of the donor skin tissue, which revealed Thy1.1+ infiltration at day 14 after transplant in CTLA-4 Ig/anti-CD154–treated mice possessing a high but not low frequency of OT-I/OT-II T cells (Fig. S1, available at http://www.jem.org/cgi/content/full/jem.20062319/DC1).


Antigen-specific precursor frequency impacts T cell proliferation, differentiation, and requirement for costimulation.

Ford ML, Koehn BH, Wagener ME, Jiang W, Gangappa S, Pearson TC, Larsen CP - J. Exp. Med. (2007)

Decreased OT-I T cell expansion in the presence of CTLA-4 Ig/anti-CD154 after priming at low, but not high, antigen-specific precursor frequency. 106 or 107 OT-I T cells (along with 106 OT-II cells) were adoptively transferred into naive B6 recipients that then received an mOVA skin graft. (A) Results showed that mice receiving a low frequency (106) of OT-I T cells were protected from rejection by CTLA-4 Ig/anti-CD154, whereas mice receiving a high frequency (107) rapidly rejected their grafts (P < 0.001). (B) Analysis of the percentage of Thy1.1+ CD8+ T cells in the DLN revealed that costimulation blockade inhibited the expansion/accumulation of OT-I T cells in mice responding from low frequency, whereas the expansion/accumulation of OT-I cells responding from high frequency was not as potently affected. (C) Absolute numbers of OT-I T cells isolated from the DLN showed a convergence at the peak of expansion at day 10 in both the low and high frequency untreated groups as well as the CTLA-4 Ig/anti-CD154–treated high frequency group. In contrast, the low frequency, CTLA-4 Ig/anti-CD154–treated group exhibited minimal expansion of OT-I T cell numbers. These data are representative examples of four independent experiments, with two to three mice per group, per time point, per experiment.
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Related In: Results  -  Collection

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fig3: Decreased OT-I T cell expansion in the presence of CTLA-4 Ig/anti-CD154 after priming at low, but not high, antigen-specific precursor frequency. 106 or 107 OT-I T cells (along with 106 OT-II cells) were adoptively transferred into naive B6 recipients that then received an mOVA skin graft. (A) Results showed that mice receiving a low frequency (106) of OT-I T cells were protected from rejection by CTLA-4 Ig/anti-CD154, whereas mice receiving a high frequency (107) rapidly rejected their grafts (P < 0.001). (B) Analysis of the percentage of Thy1.1+ CD8+ T cells in the DLN revealed that costimulation blockade inhibited the expansion/accumulation of OT-I T cells in mice responding from low frequency, whereas the expansion/accumulation of OT-I cells responding from high frequency was not as potently affected. (C) Absolute numbers of OT-I T cells isolated from the DLN showed a convergence at the peak of expansion at day 10 in both the low and high frequency untreated groups as well as the CTLA-4 Ig/anti-CD154–treated high frequency group. In contrast, the low frequency, CTLA-4 Ig/anti-CD154–treated group exhibited minimal expansion of OT-I T cell numbers. These data are representative examples of four independent experiments, with two to three mice per group, per time point, per experiment.
Mentions: Given the finding that a high precursor frequency of CD8+ T cells was critically important in the generation of costimulation blockade-resistant rejection, we sought to define the effects of altered CD8+ T cell precursor frequency on the programmed expansion and differentiation of donor-specific T cells in the presence of costimulation blockade. Two groups of B6 mice with varying precursor frequencies of donor-specific CD8+ T cells were prepared by transferring 106 or 107 OT-I T cells. Both groups also received a fixed dose of 106 OT-II CD4+ T cells, an mOVA skin graft, and CTLA-4 Ig/anti-CD154. Again, we observed that the initial CD8 precursor frequency had a profound impact on graft survival after treatment with costimulation blockade. Mice that received 106 OT-II cells and 106 OT-I T cells accepted an mOVA skin graft for >150 d after treatment with costimulation blockade, whereas mice that received 106 OT-II cells and 107 OT-I T cells showed rapid and consistent costimulation blockade-resistant rejection resulting in graft rejection with an MST of 17 d (P < 0.001) (Fig. 3 A). Clinical rejection was confirmed by immunohistochemical analysis of the donor skin tissue, which revealed Thy1.1+ infiltration at day 14 after transplant in CTLA-4 Ig/anti-CD154–treated mice possessing a high but not low frequency of OT-I/OT-II T cells (Fig. S1, available at http://www.jem.org/cgi/content/full/jem.20062319/DC1).

Bottom Line: Using an adoptive transfer system to incrementally raise the precursor frequency of antigen-specific CD8(+) T cells, we found that donor-reactive T cells primed at low frequency exhibited increased cellular division, decreased development of multifunctional effector activity, and an increased requirement for CD28- and CD154-mediated costimulation relative to those primed at high frequency.The results demonstrated that recipients with low CD4(+) and CD8(+) donor-reactive T cell frequencies exhibited long-term skin graft survival upon CD28/CD154 blockade, whereas simultaneously raising the frequency of CD4(+) T cells to approximately 0.5% and CD8(+) T cells to approximately 5% precipitated graft rejection despite CD28/CD154 blockade.These results demonstrate a critical role for initial precursor frequency in determining the CD8(+) T cell requirement for CD28- and CD154-mediated costimulatory signals during graft rejection.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery and Emory Transplant Center, Emory University, Atlanta, GA 30322, USA.

ABSTRACT
After a brief period of antigenic stimulation, T cells become committed to a program of autonomous expansion and differentiation. We investigated the role of antigen-specific T cell precursor frequency as a possible cell-extrinsic factor impacting T cell programming in a model of allogeneic tissue transplantation. Using an adoptive transfer system to incrementally raise the precursor frequency of antigen-specific CD8(+) T cells, we found that donor-reactive T cells primed at low frequency exhibited increased cellular division, decreased development of multifunctional effector activity, and an increased requirement for CD28- and CD154-mediated costimulation relative to those primed at high frequency. The results demonstrated that recipients with low CD4(+) and CD8(+) donor-reactive T cell frequencies exhibited long-term skin graft survival upon CD28/CD154 blockade, whereas simultaneously raising the frequency of CD4(+) T cells to approximately 0.5% and CD8(+) T cells to approximately 5% precipitated graft rejection despite CD28/CD154 blockade. Antigenic rechallenge of equal numbers of cells stimulated at high or low frequency revealed that cells retained an imprint of the frequency at which they were primed. These results demonstrate a critical role for initial precursor frequency in determining the CD8(+) T cell requirement for CD28- and CD154-mediated costimulatory signals during graft rejection.

Show MeSH
Related in: MedlinePlus