Limits...
Polyclonal Recipient nTregs Are Superior to Donor or Third-Party Tregs in the Induction of Transplantation Tolerance.

Pilat N, Klaus C, Hock K, Baranyi U, Unger L, Mahr B, Farkas AM, Wrba F, Wekerle T - J Immunol Res (2015)

Bottom Line: Treg therapy is limited by the availability of cells as large-scale expansion is time-consuming and associated with the risk of contamination with effector cells.Here we show that CD4(+)CD25(+) in vitro activated nTregs are superior to TGFβ induced iTregs in promoting the induction of chimerism and tolerance.Moreover, we show that only recipient Tregs, but not donor or third-party Tregs, had a beneficial effect on BM engraftment at the tested doses.

View Article: PubMed Central - PubMed

Affiliation: Section of Transplantation Immunology, Department of Surgery, Medical University of Vienna, 1090 Vienna, Austria.

ABSTRACT
Induction of donor-specific tolerance is still considered as the "Holy Grail" in transplantation medicine. The mixed chimerism approach is virtually the only tolerance approach that was successfully translated into the clinical setting. We have previously reported successful induction of chimerism and tolerance using cell therapy with recipient T regulatory cells (Tregs) to avoid cytotoxic recipient treatment. Treg therapy is limited by the availability of cells as large-scale expansion is time-consuming and associated with the risk of contamination with effector cells. Using a costimulation-blockade based bone marrow (BM) transplantation (BMT) model with Treg therapy instead of cytoreductive recipient treatment we aimed to determine the most potent Treg population for clinical translation. Here we show that CD4(+)CD25(+) in vitro activated nTregs are superior to TGFβ induced iTregs in promoting the induction of chimerism and tolerance. Therapy with nTregs (but not iTregs) led to multilineage chimerism and donor-specific tolerance in mice receiving as few as 0.5 × 10(6) cells. Moreover, we show that only recipient Tregs, but not donor or third-party Tregs, had a beneficial effect on BM engraftment at the tested doses. Thus, recipient-type nTregs significantly improve chimerism and tolerance and might be the most potent Treg population for translation into the clinical setting.

No MeSH data available.


Recipient but not donor and third-party Tregs prevent BM rejection. Groups of B6 mice were grafted with 15–20 × 106 Balb/c BM cells under the cover of costimulation blockade (anti-CD154, CTLA4Ig) and rapamycin (○ no Tregs; control n = 5) and were additionally treated with 3 × 106 nTregs of recipient (■  n = 4), donor (◆  n = 4), or third-party (∆  n = 3) origin. Donor (H-2Dd+) chimerism among leukocytes of T cell (CD4+ and CD8+), B cell (B220+), and the myeloid (Mac1+) lineage was assessed by flow cytometry of peripheral blood at multiple time points and is shown as mean percent (error bars indicate standard deviation). ∗∗p < 0.005, ∗p < 0.05 (Student's t-test for recipient Tregs versus each other group).
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4530277&req=5

fig4: Recipient but not donor and third-party Tregs prevent BM rejection. Groups of B6 mice were grafted with 15–20 × 106 Balb/c BM cells under the cover of costimulation blockade (anti-CD154, CTLA4Ig) and rapamycin (○ no Tregs; control n = 5) and were additionally treated with 3 × 106 nTregs of recipient (■  n = 4), donor (◆  n = 4), or third-party (∆  n = 3) origin. Donor (H-2Dd+) chimerism among leukocytes of T cell (CD4+ and CD8+), B cell (B220+), and the myeloid (Mac1+) lineage was assessed by flow cytometry of peripheral blood at multiple time points and is shown as mean percent (error bars indicate standard deviation). ∗∗p < 0.005, ∗p < 0.05 (Student's t-test for recipient Tregs versus each other group).

Mentions: The limited availability of Tregs from a single individual could constitute a major barrier to the implementation of Treg cell-based therapy in the clinical setting. Third-party derived Tregs could be a promising alternative, as they can be prepared and expanded in advance and stored until use. Therefore, we tested the potency of different Tregs sourced to induce chimerism and allograft tolerance. In vitro activated nTregs from recipient, donor, or third-party strain were used at a dose of 3 × 106 cells in combination with the Treg BMT protocol [10]. Whereas recipient Tregs again potently induce hematopoietic chimerism, donor and third-party Treg therapy failed to prevent BM rejection. Chimerism in recipient Treg treated mice was permanent and of multilineage nature in all recipients, whereas recipients of donor or third-party Tregs (and controls without Treg treatment) failed to develop multilineage chimerism (p < 0.05 for most time points) (Figure 4). Donor Treg treatment led to transient chimerism in one recipient; however, chimerism was restricted to the B cell and myeloid lineages and became undetectable after 4 months after BMT.


Polyclonal Recipient nTregs Are Superior to Donor or Third-Party Tregs in the Induction of Transplantation Tolerance.

Pilat N, Klaus C, Hock K, Baranyi U, Unger L, Mahr B, Farkas AM, Wrba F, Wekerle T - J Immunol Res (2015)

Recipient but not donor and third-party Tregs prevent BM rejection. Groups of B6 mice were grafted with 15–20 × 106 Balb/c BM cells under the cover of costimulation blockade (anti-CD154, CTLA4Ig) and rapamycin (○ no Tregs; control n = 5) and were additionally treated with 3 × 106 nTregs of recipient (■  n = 4), donor (◆  n = 4), or third-party (∆  n = 3) origin. Donor (H-2Dd+) chimerism among leukocytes of T cell (CD4+ and CD8+), B cell (B220+), and the myeloid (Mac1+) lineage was assessed by flow cytometry of peripheral blood at multiple time points and is shown as mean percent (error bars indicate standard deviation). ∗∗p < 0.005, ∗p < 0.05 (Student's t-test for recipient Tregs versus each other group).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4530277&req=5

fig4: Recipient but not donor and third-party Tregs prevent BM rejection. Groups of B6 mice were grafted with 15–20 × 106 Balb/c BM cells under the cover of costimulation blockade (anti-CD154, CTLA4Ig) and rapamycin (○ no Tregs; control n = 5) and were additionally treated with 3 × 106 nTregs of recipient (■  n = 4), donor (◆  n = 4), or third-party (∆  n = 3) origin. Donor (H-2Dd+) chimerism among leukocytes of T cell (CD4+ and CD8+), B cell (B220+), and the myeloid (Mac1+) lineage was assessed by flow cytometry of peripheral blood at multiple time points and is shown as mean percent (error bars indicate standard deviation). ∗∗p < 0.005, ∗p < 0.05 (Student's t-test for recipient Tregs versus each other group).
Mentions: The limited availability of Tregs from a single individual could constitute a major barrier to the implementation of Treg cell-based therapy in the clinical setting. Third-party derived Tregs could be a promising alternative, as they can be prepared and expanded in advance and stored until use. Therefore, we tested the potency of different Tregs sourced to induce chimerism and allograft tolerance. In vitro activated nTregs from recipient, donor, or third-party strain were used at a dose of 3 × 106 cells in combination with the Treg BMT protocol [10]. Whereas recipient Tregs again potently induce hematopoietic chimerism, donor and third-party Treg therapy failed to prevent BM rejection. Chimerism in recipient Treg treated mice was permanent and of multilineage nature in all recipients, whereas recipients of donor or third-party Tregs (and controls without Treg treatment) failed to develop multilineage chimerism (p < 0.05 for most time points) (Figure 4). Donor Treg treatment led to transient chimerism in one recipient; however, chimerism was restricted to the B cell and myeloid lineages and became undetectable after 4 months after BMT.

Bottom Line: Treg therapy is limited by the availability of cells as large-scale expansion is time-consuming and associated with the risk of contamination with effector cells.Here we show that CD4(+)CD25(+) in vitro activated nTregs are superior to TGFβ induced iTregs in promoting the induction of chimerism and tolerance.Moreover, we show that only recipient Tregs, but not donor or third-party Tregs, had a beneficial effect on BM engraftment at the tested doses.

View Article: PubMed Central - PubMed

Affiliation: Section of Transplantation Immunology, Department of Surgery, Medical University of Vienna, 1090 Vienna, Austria.

ABSTRACT
Induction of donor-specific tolerance is still considered as the "Holy Grail" in transplantation medicine. The mixed chimerism approach is virtually the only tolerance approach that was successfully translated into the clinical setting. We have previously reported successful induction of chimerism and tolerance using cell therapy with recipient T regulatory cells (Tregs) to avoid cytotoxic recipient treatment. Treg therapy is limited by the availability of cells as large-scale expansion is time-consuming and associated with the risk of contamination with effector cells. Using a costimulation-blockade based bone marrow (BM) transplantation (BMT) model with Treg therapy instead of cytoreductive recipient treatment we aimed to determine the most potent Treg population for clinical translation. Here we show that CD4(+)CD25(+) in vitro activated nTregs are superior to TGFβ induced iTregs in promoting the induction of chimerism and tolerance. Therapy with nTregs (but not iTregs) led to multilineage chimerism and donor-specific tolerance in mice receiving as few as 0.5 × 10(6) cells. Moreover, we show that only recipient Tregs, but not donor or third-party Tregs, had a beneficial effect on BM engraftment at the tested doses. Thus, recipient-type nTregs significantly improve chimerism and tolerance and might be the most potent Treg population for translation into the clinical setting.

No MeSH data available.