Thymus-dependent increase in number of T cells in parathymic lymph nodes induced by the biscoclaurine alkaloid, cepharanthine.

In mice treated with cepharanthine (Cepha), a biscoclaurine alkaloid, the number of T cells was increased in the parathymic lymph nodes (PtLNs) which are considered to be the specialized lymph nodes in local differentiation of T cells. Such PtLN cells exhibited augmented proliferative responses to T cell mitogens and exogenous interleukin 2 (IL 2) and showed a great ability to produce IL2, which suggests an increase in mature T cells in the PtLN. However, such increases in the number of T cells and in the mitogen response were not observed in adult thymectomized mice. A low level of plasma prostaglandin E2 (PGE2) was observed in Cepha-treated mice. Replenishment of the PGE2 in such mice with exogenous PGE2 prevented the increase in T cells in the PtLN. These results suggest that the migration of mature T cells from the thymus to PtLN is increased by Cepha and that Cepha is able to regulate their traffic by a prostaglandin-mediated system.