- 作者: Hong-Wen Huang; Yun-Jung Chiang; Shuen-Iu Hung; Chung-Leung Li; Jeffrey Jong-Young Yen
- 作者服務機構: 1 Institute of Biomedical Sciences, Academia S璯ica, No. 128, Sec.2, Yen-Jiou-Yuan Rd., Taipei, 11529, Taiwan; ; 2 Genotyping Center, Genomics Research Center, Academia S璯ica, Taipei, 11529, Taiwan; ; 3 Stem Cell Program, Institute of Cellular & Organismic Biology/Genomics Research Center, Academia S璯ica, Taipei, 11529, Taiwan
- 中文摘要: --
- 英文摘要: Homeostasis of the hematopoietic system is tightly regulated by an array of cytokines that control proliferation, differentiation and apoptosis of various cell lineages. To identify genes that are essential for hematopoietic homeostasis, we screened C57BL/6 mice that had been genome-wide mutagenized by N-ethyl-N-nitrosourea (ENU) to produce altered blood cell composition. We identified a mutant mouse line with a drastic reduction in the number of T and B cell lineages in lymphatic tissues and peripheral blood, as well as severe atrophy of the thymus and lymph nodes. Genotyping with a genome-wide single nucleotide polymorphism (SNP) marker set mapped the mutant phenotype to chromosome 3A and subsequent direct DNA sequencing revealed a G-to-A point mutation in the splicing donor site of the third exon of the candidate gene for IL-7, a lymphocyte survival cytokine. Such mutation resulted in skipping of exon 3 and production of an internally truncated IL-7 (△E3-1L7). Furthermore, using recombinant proteins produced in a baculoviral system, we demonstrated that △E3-IL7 had no detectable anti-apoptotic activity even at a dose that was 30 times more than that required for a wild-type protein to manifest a full activity in a naive T cell survival assay. Our data suggest that this mutant mouse line provides an alternative animal model for the study of severe combined immunodeficiency (SCID) syndrome in humans.
- 中文關鍵字: --
- 英文關鍵字: IL-7, ENU mutagenesis, phenotype screening, lymphopenia