Editors' ChoiceApoptosis

Survival in Developing Immune Systems

STKE  04 Jul 2000:
Vol. 2000, Issue 39, pp. tw8
DOI: 10.1126/stke.2000.39.tw8

Proper development of the immune system requires complicated controls of the development of thymocytes and selection of functional T cells through positive and negative selection. Sun et al. examined the role of the retinoic acid receptor-related orphan receptor (RORγ) in development of the mouse immune system. Their studies of animals that lacked RORγ indicate that RORγ enhances survival of thymocytes by promoting the expression of the anti-apoptotic protein Bcl-xL. The knockout animals lacked lymph nodes and Peyer's patches, apparently because of failed development of the CD4+ progenitor cells required for normal development of these structures. The authors propose that regulation of RORγ signals might modulate expression of Bcl-xL and thus control "death by neglect" of thymocytes that fail to interact productively with peptide-MHC complexes.

Sun, Z., Unutmaz, D., Zou, Y.-R., Sunshine, M.J., Pierani, A., Brenner-Morton, S., Mebius, R.E., and Littman, D.R. (2000) Requirement for ROR in thymocyte survival and lymphoid organ development. Science 288: 2369-2373. [Abstract] [Full Text]