Naslov
Variations in thymocyte susceptibility to clonal deletion during ontogeny: implications for neonatal tolerance

Autori
Zacharchuk, Charles M ; Merćep, Mladen ; June, Carl H ; Weissman, Allan M ; Ashwell, Jonathan D

Izvornik
Journal of immunology (0022-1767) 147 (1991); 460-465

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
apoptosis ; tolerance ; T cells ; thymocyte ; activation

Sažetak
Activation of immature thymocytes via the TCR results in programmed cell death and clonal deletion. We have examined thymocytes from mice of different ages and observed that, whereas TCR- mediated signaling caused deletion of thymocytes from newborn and 3-week-old mice, it failed to delete thymocytes from mice of 1 week of age. This could not be attributedt o differences in cell surface TCR expression, TCR- mediated phosphoinositide hydrolysis or Ca2+ mobilization, or total cellular levels of TCR zeta- and eta- chains. Moreover, thymocytes of all ages were equally susceptible to corticosteroid- and Ca2+ ionophore-induced programmed cell death. These data are consistent with the notion that fetal and neonatal thymocytes represent a relatively synchronous wave of cells passing through phases in which they are susceptible and then resistant to TCR- induced programmed cell death. They also support the notion that the classical phenomenon of neonatal tolerance is due to clonal deletion and that the inability of allogeneic cells to tolerize mice at 1 week of age is because the thymocytes are refractory to TCR-alphabeta- mediated clonal deletion.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Temeljne medicinske znanosti

POVEZANOST RADA