Deletion of the Ptsn β isoform in mice does not alter peripheral blood leukocyte counts, population of peripheral lymphoid organs, or T cell integrin activation. (A) Generation of Ppp1r18β^−/− mice. Two sgRNAs targeting a site in exon1 that lies downstream of the initiator methionine for β-Ptsn (Met¹) and upstream of that for α-Ptsn (Met⁴²⁹), causing a 10-bp deletion that results in an early stop codon in β-Ptsn. (B)Ppp1r18β^−/− mice manifested loss of β-Ptsn isoform, but not α-Ptsn. Ptsn expression in splenocytes was assayed by immunoblotting using an antibody that reacts with the C-terminus of Ptsn and recognizes both α- and β-Ptsn isoforms. (C and D) Surface expression of α_L (CD11a), β₂ (CD18), α₄ (CD49d), β₁ (CD29), and β₇ integrins (C) or intracellular staining of RIAM (D) in splenocytes was measured by flow cytometry. Bar graphs represent mean ± SEM (n = 3 mice). Data are normalized to Ppp1r18β^+/+ samples = 1. Two-tailed t test; no significant differences were observed. (E)Ppp1r18β^−/− mice exhibit normal peripheral blood leukocyte counts. Mean ± SEM are plotted. Two-tailed t test; no significant differences were observed. (F) The number of T and B cells in MLN, PLN, and spleen (SPL) from WT or Ppp1r18β^−/− mice. Data are normalized to Ppp1r18β^+/+ samples = 100. Bar graphs represent mean ± SEM (n = 4 mice). Two-tailed t test; no significant differences were observed. (G and H) Deletion of Ppp1r18β^−/− does not impair T cell adhesion. CD4⁺ T cells were isolated from the spleen of WT or Ppp1r18β^−/− mice. Cell adhesion to immobilized ICAM-1 or VCAM-1 was assayed in flow conditions upon stimulation with SDF-1α. Rest, no stimulation. Bar graphs represent mean ± SEM (n = 6 mice). Two-tailed t test; no significant differences were observed. Source data are available for this figure: SourceData FS4.