Figure 1.

The FcRγ transgene restores T cell development in ζKO mice. (a) The FcRγ replaces ζ in allowing normal development in thymus. Thymuses were removed from various types of mice. Their cellularities were as follows: ζKO, 30 ± 12 × 10⁶; FcRγTG ζKO, 110 ± 21 × 10⁶; and ζ⁺, 140 ± 18 × 10⁶. Thymocytes were stained with fluorescein isothiocyanante–anti-CD8, phycoerythrin–anti-CD4, and biotin–anti-TCR plus cychrome–streptavidin. (b) Double-positive thymocytes from FcRγTG ζKO mice express nearly normal levels of TCR, but these levels are reduced on SP thymocytes, particularly the CD4⁺ SP thymocytes. (c) Mature peripheral T cells in FcRγTG⁺ ζKO mice express TCR at lower levels than those of thymocytes and mature T cells in ζ⁺ mice.