Figure 2

Deletion of FSP1⁺ cells dramatically altered thymus structure and cell composition.

(A) Representative photographs of thymus organs in TK⁻ and TK⁺ transgenic mice with and without GCV treatment for 18 days were shown. (B) Thymus weight and total cell numbers of thymocytes in TK⁻ and TK⁺ mice with GCV treatment were summarized. (C) Thymic sections from GCV treated TK⁻ and TK⁺ mice were stained with FSP1 to determine the ablating efficiency (upper). The H&E and CK5/CK8 staining of thymic sections showed decreased area of thymic medullary region in TK⁺ mice than in TK⁻ mice after GCV treatment (middle and lower). (D) Representative FACS analysis of CD45⁻EpCAM⁺ TECs, MHCII^high and MHCII^low TECs in the isolated thymic cells was shown. The cell number of TECs in TK⁺ mice was less than in TK⁻ mice after GCV treatment. (E) The percentage and the total cell number of MHCII^high and MHCII^low TECs in GCV-treated TK⁻ and TK⁺ mice were summarized. Representative FACS profiles (F) and the percentage and total cell number (G) of mTECs and cTECs in CD45⁻EpCAM⁺ cells in GCV-treated TK⁻ and TK⁺ mice were shown. Phenotypic characterization (H) and the percentages (I) of MHCII⁺, CD80⁺ and Aire⁺ mTECs in the gated thymic CD45⁻ or CD45⁻EpCAM⁺ cells of TK⁻ and TK⁺ mice with GCV treatment. (J) The total cell numbers of CD45⁻EpCAM⁺UEA-1⁺MHCII^high, CD45⁻EpCAM⁺UEA-1⁺CD80^high, CD45⁻EpCAM⁺UEA-1⁺CD80^low and CD45⁻EpCAM⁺UEA-1⁺Aire⁺ cells in GCV-treated TK⁻ and TK⁺ mice. Representative results are shown from one of three independent experiments performed. Data were shown as mean ± SD (N = 5). *P < 0.05, **P < 0.01, ***P < 0.001 compared with TK⁻ mice.