T-cell homeostasis is regulated by several molecules; among these, interleukin (IL)-7 plays an essential role in the survival and homeostatic proliferation of peripheral naive T cells. In a previous study, we investigated whether human mesenchymal stromal cells (MSCs) could be engineered with the IL-7 gene to produce functional level of this cytokine. In the present study, we analyzed the impact of different quantities of IL-7 produced by MSCs on the survival and proliferation of a negative immunoselected naive (CD3/CD45RA) T-cell population. Co-cultivation of peripheral naive T cells with MSCs producing low (16 pg/mL) or high (1000 pg/mL) IL-7 levels or in the presence of exogenous IL-7 (0.01 ng/mL and 100 ng/mL) maintained the CD3/CD45RA naive T-cell phenotype. Chemokine receptor CCR7 expression was also maintained among this T-cell population. Naive T-cell molecular characteristics were maintained as assessed by the V spectratyping complexity score, which showed the maintenance of a broad T-cell repertoire. No Th1 or Th2 differentiation was observed, as assessed by interferon- or IL-4 accumulation. In contrast, only MSCs producing high amounts of IL-7 caused increased activation (CD25 31.2% 12% vs 10% 3.5%; P < .05), proliferation (CD71 17.87% vs 9.3%3, P < .05), apoptosis (assessed by annexin V: 18.6% 5% vs 14.9% 2.6%; P > .05), and the phase S cell cycle (15% vs 6.9%, P > .05). Exogenous IL-7 exhibited no significant effect. In conclusion, we demonstrated that IL-7 produced by MSCs has a dose-independent effect on naive T-cell survival while exerting a dose-dependent effect on activation/proliferation. Due to the continuous production of IL-7 by engineered cells, our system is more efficacious than exogenous IL-7
Interleukin-7-engineered mesenchymal cells: in vitro effects on naive T-cell population.
SPORTOLETTI, PAOLO;DEL PAPA, BEATRICE;DE IOANNI, Maria;BELL, ALAIN SYLVIN;FETTUCCIARI, Katia;FALZETTI, Franca;MARTELLI, Massimo Fabrizio;TABILIO, Antonio;DI IANNI, Mauro
2006
Abstract
T-cell homeostasis is regulated by several molecules; among these, interleukin (IL)-7 plays an essential role in the survival and homeostatic proliferation of peripheral naive T cells. In a previous study, we investigated whether human mesenchymal stromal cells (MSCs) could be engineered with the IL-7 gene to produce functional level of this cytokine. In the present study, we analyzed the impact of different quantities of IL-7 produced by MSCs on the survival and proliferation of a negative immunoselected naive (CD3/CD45RA) T-cell population. Co-cultivation of peripheral naive T cells with MSCs producing low (16 pg/mL) or high (1000 pg/mL) IL-7 levels or in the presence of exogenous IL-7 (0.01 ng/mL and 100 ng/mL) maintained the CD3/CD45RA naive T-cell phenotype. Chemokine receptor CCR7 expression was also maintained among this T-cell population. Naive T-cell molecular characteristics were maintained as assessed by the V spectratyping complexity score, which showed the maintenance of a broad T-cell repertoire. No Th1 or Th2 differentiation was observed, as assessed by interferon- or IL-4 accumulation. In contrast, only MSCs producing high amounts of IL-7 caused increased activation (CD25 31.2% 12% vs 10% 3.5%; P < .05), proliferation (CD71 17.87% vs 9.3%3, P < .05), apoptosis (assessed by annexin V: 18.6% 5% vs 14.9% 2.6%; P > .05), and the phase S cell cycle (15% vs 6.9%, P > .05). Exogenous IL-7 exhibited no significant effect. In conclusion, we demonstrated that IL-7 produced by MSCs has a dose-independent effect on naive T-cell survival while exerting a dose-dependent effect on activation/proliferation. Due to the continuous production of IL-7 by engineered cells, our system is more efficacious than exogenous IL-7I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
