Figure 2.

Negative selection is absent or attenuated in the neonatal thymus. (a) FCM histogram analysis for Vγ2 expression in adult (top row) and neonatal (day 2, bottom row) thymus from Tg^b/d (left) and Tg^d/d (right) mice. Data shown represent 1 of 3 independent experiments. (b) Tg^b/d Vγ2⁺ but not Tg^b/d Vγ2^– neonatal thymocytes can give rise to Vγ2⁺ IEL. Flow cytometry–sorted Tg^b/d Vγ2⁺ (3 × 10⁵) and Vγ2^– (10⁶) neonatal thymocytes were injected into TL^b+ athymic C57BL/6 mice. Six weeks later, IEL of injected athymic mice were examined for the presence of graft-derived (H-2^d+) Tg Vγ2⁺ IEL. Data shown represent 1 of 3 independent experiments.