ADAM8 is expressed in thymic stromal cells and thymocytes.

<p>Relative ADAM8 RNA levels as determined by qrtPCR in (A) total thymic tissue, thymic hematopoietic cells (CD45⁺, EpCAM⁻), epithelial cells (CD45⁻, EpCAM⁺), endothelial cells (CD45⁻, EpCAM⁻, CD31⁺) and other non-epithelial stromal cells (EpCAM⁻, CD45⁻, CD31⁻), (B) thymic T cell subsets and (C) TEC. FACS sorted cells (>95% purity) were analyzed for ADAM8 RNA expression using the reference gene HPRT. ADAM8 RNA values are expressed relative to HPRT expression. Data are presented as mean values and error bars as SEM. Data are from at least two independent experiments (n≥3). (D–G) Reporter gene (β-galactosidase) expression in ADAM8^−/− thymic sections detected by immunofluorescence. Thymic sections were stained with antibodies directed against β-galactosidase to reveal potential ADAM8 expression and (D) β5t marking cTEC, (E) MTS10 marking mTEC, (F) ER-TR7 marking fibroblasts and (G) KT-3 marking T cells. Scales bar 50 µm. Data are from at least four independent experiments (n≥4).</p

Similar usage of Vα and VβTCR chains in wt and ADAM8^−/− CD4 lymphocytes.

<p>Frequencies of CD3⁺ CD4⁺ lymph node cells expressing indicated subfamilies of Vα or Vβ TCR chains determined by flow cytometry. Data are representative of two independent experiments with n≥4 age- and gender-matched mice per group in each experiment. Data are presented as mean values and error bars as SEM.</p

ADAM8^−/− thymocytes have increased proliferation and reduced apoptosis rates.

<p>(A) Frequencies of Ki-67^hi cells in DN, DP^lo and DP^hi subsets of wt and ADAM8^−/− thymi. (B) Frequency of Caspase-3⁺ thymocytes in wt and ADAM8^−/− thymi. Data are representative of two independent experiments with n≥4 age- and gender-matched mice per group in each experiment. Data are presented as mean values and error bars as SEM. *, p<0.05, **, p<0.01.</p

ADAM8^−/− thymi have an increased mass and a reduced cortex/medulla ratio associated with a relative increase in mTEC.

<p>(A) Weight and (B) total numbers of thymocytes thymi from age- and gender-matched wt and ADAM^−/− mice (n = 8). (C) Cortex/medulla ratios examined on Hematoxylin/Eosin stained 20 µm sections of wt and ADAM8^−/− thymi (each 6 sections of 6 wt or ADAM^−/− thymi). Frequencies of (D) cTEC (Ly51^hi, UEA-1^lo) and (E) mTEC (Ly51^lo, UEA-1^hi) in CD45⁻, EpCAM⁺ thymic epithelial fraction of thymic suspensions obtained by collagenase/dispase treatment. Data are representative of two independent experiments with at least four mice per group. Data are presented as mean values and error bars as SEM. *, p<0.05, **, p<0.01, *** p<0.001.</p