First Author | Penkov D | Year | 2005 |
Journal | Mol Cell Biol | Volume | 25 |
Issue | 24 | Pages | 10768-81 |
PubMed ID | 16314502 | Mgi Jnum | J:103769 |
Mgi Id | MGI:3610703 | Doi | 10.1128/MCB.25.24.10768-10781.2005 |
Citation | Penkov D, et al. (2005) Involvement of Prep1 in the alphabeta T-cell receptor T-lymphocytic potential of hematopoietic precursors. Mol Cell Biol 25(24):10768-81 |
abstractText | Prep1 is a homeodomain transcription factor that acts by dimerizing with Pbx. Since Prep1 null embryos die at gastrulation, we studied Prep1(i/i) hypomorphic mice to study the physiological role of Prep1. A low percentage of homozygous Prep1(i/i) mice survived at birth, and their postnatal functions could be investigated. Reduced Prep1 expression caused an abnormal thymic T-cell development: increased CD4(-) CD8(-) double-negative thymocytes, decrease in alphabetaTCR(high) cells (cells with high levels of the alphabetaTau-cell receptor [alphabetaTCR]) and CD4(+) and CD8(+) single-positive (SP) thymocytes, and increase in gammadeltaTCR cells. Peripheral lymphoid organs of Prep1(i/i) mice contained fewer alphabetaTCR mature T cells and more gammadeltaTCR T cells than wild-type littermates. Moreover, Prep1(i/i) CD4(+) CD8(+) double-positive thymocytes underwent more apoptosis, and SP thymocytes proliferated less than control littermates. Mice that were lethally irradiated and then had Prep1(i/i) fetal liver cells transplanted showed the same defects as the Prep1(i/i) mice did. Among PBC family members, Pbx2 and very low levels of Pbx3 were observed in the thymi of wild-type mice. In Prep1(i/i) mice, the level of Pbx2 protein was profoundly decreased, while for Pbx3 no definitive conclusion could be reached. Therefore, the deficient postnatal T-lymphocytic potential of the Prep1 hematopoietic progenitors depends on the combined, not compensated, absence of Prep1 and at least Pbx2. |