Long-term retention of mature NK1.1+ NKT cells in the thymus.
The NKT cell pool in the thymus contains immature (NK1.1(-)) and mature (NK1.1(+)) subsets that represent distinct linear stages of a linear developmental pathway. An unexplained paradox is why immature NK1.1(-) NKT cells are mainly exported to the periphery instead of the more mature and more abundant NK1.1(+) NKT cells. In this study we have determined that mature NK1.1(+) NKT cells are retained by the thymus to form an extremely long-lived resident population capable of rapid and prolonged production of IFN-gamma and IL-4. The retention of mature NKT cells provides an explanation for why the periphery is mainly seeded by immature NK1.1(-) cells despite mature NK1.1(+) NKT cells being more abundant in the thymus. This is the first study to identify a mature T cell subset retained within the thymus and is additional evidence of the distinct developmental pathways of mainstream T cells and NKT cells.
Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia. berzins@unimelb.edu.au
Stuart P
SP
Berzins
Finlay W
FW
McNab
Claerwen M
CM
Jones
Mark J
MJ
Smyth
Dale I
DI
Godfrey
D000375:Aging / Q000276:immunology; D000818:Animals; D002454:Cell Differentiation; D016207:Cytokines / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D050378:T-Lymphocytes, Regulatory / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology* / Q000276:immunology* / Q000637:transplantation; D013997:Time Factors
D016207:Cytokines