FIGURE 1.

Generation and phenotypic characterization of CD5ΔCK2BD mice. A, Targeting strategy to generate the Cd5^{Δck2bd/Δck2bd} knock-in mouse. The targeting construct was generated with a region of Cd5 gene containing exons 6-10 retrieved from the BAC clone RP24-424J1 (C57BL/6). Nucleotides encoding the four amino acids necessary for binding of CK2 with CD5 (S458-S461) in exon 10 (*) of the mouse Cd5 gene were deleted in the targeting construct and founder chimeras were developed using Bruce-4 targeted embryonic stem cells. The Neo selection cassette was deleted by breeding with C57BL/6.E2a-Cre mice to generate the Cd5^{Δck2bd/Δck2bd} Cre-deleted mouse. The 5′ probe used for screening embryonic stem cells based on the insertion of a novel BamH1 site (boxed) is represented in the 5′ Arm A that was used to retrieve the Cd5 gene from the BAC clone. B, PCR-based screening strategy for knock-in mice. Photomicrograph of an agarose gel showing PCR product from tail DNA of Cd5^{Δck2bd/Δck2bd}, Cd5^wt/wt, and Cd5^Δck2bd/wt mice amplified with specific forward (5′-atggactcccacgaagtgctg-3′) and reverse (5′-cttgtagaggatggtgcca-3′) primers targeting the 5′ region of exon 9 and the 3′ region of the lox-P site. C, CD5 expression levels on T-cell subsets in the thymus and lymph node of 6-8 week old CD5WT (red), CD5KO (green) andCD5ΔCK2BD (blue) male mice. D, Frequencies of CD4⁺ and CD8⁺ lymphocytes in the thymus, lymph node, and spleen of 7-8 week old CD5WT, CD5KO and CD5ΔCK2BD male mice. Numbers represent the average percentage of cells is each gate ±SEM. Arrows point to the CD4^loCD8^lo thymocytes. Data is representative from one mouse of 6-9 mice per group. DN, double negative. DP, double positive. SP, single positive.