Cell cycle arrest effects of large-dose FTY720 on lymphocytes in mouse skin transplantation models.

To probe into the mechanism of immunosuppression of FTY720, the authors study the cell cycle arrest effects of large-dose FTY720 on lymphocytes in mouse skin transplantation models and the expression of cell cycle–related factors in cell cycle regulation system in mouse skin allograft models using flow cytometry, Immunohistochemical staining, and reverse transcriptase–polymerase chain reaction (RT-PCR). FTY720 could prolong survival days of graft in mouse skin transplantation models obviously (p < 0.01). In thymus gland and lymph node, compared with the control group, cell percentage in G0-G1 increases and cell percentage in G2-M and S decreases in the treated group (p < 0.01). Expression of P16 increases and expression of cyclin D1 decreases in the treated group (p < 0.05). In thymus gland, it is shown by semiquantitative RT-PCR that the quantity of mRNA of P16 increases in the treated group (p < 0.01), and the quantity of mRNA of cyclin D1 decreases in the treated group (p < 0.01). FTY720 is a kind of e...