Lymphoid organ development and cell migration.

As we travel into a new century, confronted with new infectious diseases and bioweapon threats, with surgeons continuing to push the boundaries of what is transplantable, and with gene therapists working on ways to remedy a myriad of genetic diseases, the need for improved methods to augment and suppress immune function is paramount. The recent discovery that a novel immunosuppressant works by blocking lymphocyte egress from lymphoid organs provides a compelling example of how improved understanding of lymphoid organ function will contribute to future drug development and human health. This volume brings together reviews from leaders in the field of thymus and secondary lymphoid organ biology, including discussions on the roles of transcriptional regulators Foxn1, retinoid-related orphan receptor gamma and nuclear factor-kappaB in lymphoid organ development, the function of lymphotoxin and other cytokines in lymphoid tissue organization, the guidance activity of chemokines in a multitude of immune cell-positioning events, the mechanism of action of the immunosuppressant FTY720, and the application of two-photon laser scanning microscopy to reveal the dynamic behavior of lymphoid cells in the depths of these essential tissues.