Characterization of human thymocyte behavior in situ (111.46)

• Published in: The Journal of immunology (1950) 2012-05, Vol.188 (1_Supplement), p.111-111.46
• Main Authors: Melichar, Heather, Halkias, Joanna, Ross, Jenny, Taylor, Kayleigh, Yen, Bonnie, Robey, Ellen
• Format: Article
• Language: English
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.188.Supp.111.46

Thymocyte development occurs through the coordinated movement of developmental intermediates to defined anatomical locations within the thymus during which thymocytes sample surrounding cells and the microenvironment for signals to promote differentiation. The development of an experimental model in which purified, labeled cell populations migrate into a 3-dimensional living thymic slice gives us the first opportunity to visualize and monitor the behavior of human thymic subsets in situ. Double negative (DN) progenitors and CD4+CD8+ double positive (DP) human thymic subsets primarily localize to the cortex, whereas CD4+ and CD8+ single positive (SP) subsets localize appropriately to the medulla. In many respects, the migration of human thymic subsets mirror that of their murine counterparts: immature DP and DN cells move randomly with slow motility rates, DP cells migrate slower than DN, and both SP populations are fast and exhibit some directional movement presumably toward the medulla. These similarities between human and mouse thymocyte motility occur despite significant differences in the development and microenvironment of the thymus between the species. We are also examining cross-talk between mouse and human factors as well as the sensitivity of human thymic subsets to chemokine signals. The suitability of the thymic slice model to study human thymocyte development is a powerful system to study and manipulate processes that are otherwise inaccessible to researchers.