Regulation of T cell homeostasis during fetal and early postnatal life.
Before parturition the fetal lamb develops a large pool of long-lived recirculating T cells which provides a large population of naive T cells with a diverse TcR repertoire. After birth and concomitant with exposure to environment antigens, fetal T cells are rapidly replaced by short-lived cells formed postnatally. The majority of thymic emigrants homing to spleen in postnatal lambs are short-lived, in contrast to emigrants targeting lymph nodes where a population appears to be long-lived. The lifespan of thymic emigrants in the fetus is unknown as in the relative importance of antigen-driven processes versus developmental programming in regulating T cell homeostasis in early postnatal life.
Cunningham
C P
CP
Laboratory for Foetal and Neonatal Immunology, The University of Melbourne, Parkville, Vic., Australia.
Cahill
R N
RN
Washington
E A
EA
Holder
J E
JE
Twohig
J P
JP
Kimpton
W G
WG
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D005260:Female; D005333:Fetus / Q000276:immunology*; D006706:Homeostasis / Q000276:immunology*; D008198:Lymph Nodes / Q000196:embryology / Q000276:immunology; D011247:Pregnancy; D012756:Sheep / Q000196:embryology / Q000276:immunology*; D013154:Spleen / Q000196:embryology / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000196:embryology / Q000276:immunology