title: Early growth response gene-2 (Egr-2) regulates the development of B and T cells.
abstract: BACKGROUND
  Understanding of how transcription factors are involved in lymphocyte development still remains a challenge. It has been shown that Egr-2 deficiency results in impaired NKT cell development and defective positive selection of T cells. Here we investigated the development of T, B and NKT cells in Egr-2 transgenic mice and the roles in the regulation of distinct stages of B and T cell development.
  
  
  RESULTS
  The expression of Egr1, 2 and 3 were analysed at different stages of T and B cell development by RT-PCT and results showed that the expression was strictly regulated at different stages. Forced expression of Egr-2 in CD2(+) lymphocytes resulted in a severe reduction of CD4(+)CD8(+) (DP) cells in thymus and pro-B cells in bone marrow, which was associated with reduced expression of Notch1 in ISP thymocytes and Pax5 in pro-B cells, suggesting that retraction of Egr-2 at the ISP and pro-B cell stages is important for the activation of lineage differentiation programs. In contrast to reduction of DP and pro-B cells, Egr-2 enhanced the maturation of DP cells into single positive (SP) T and NKT cells in thymus, and immature B cells into mature B cells in bone marrow.
  
  
  CONCLUSIONS
  Our results demonstrate that Egr-2 expressed in restricted stages of lymphocyte development plays a dynamic, but similar role for the development of T, NKT and B cells.
authors.affiliation: Department of Biosciences, Brunel University, Uxbridge, London, United Kingdom. su-ling.li@brunel.ac.uk
authors.forename: Suling
authors.initials: S
authors.lastname: Li
authors.forename: Alistair L J
authors.initials: AL
authors.lastname: Symonds
authors.forename: Bo
authors.initials: B
authors.lastname: Zhu
authors.forename: Mengya
authors.initials: M
authors.lastname: Liu
authors.forename: Meera V
authors.initials: MV
authors.lastname: Raymond
authors.forename: Tizong
authors.initials: T
authors.lastname: Miao
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
mesh_terms: D000818:Animals; D017209:Apoptosis; D001402:B-Lymphocytes / Q000166:cytology* / Q000378:metabolism; D001483:Base Sequence; D017931:DNA Primers; D051767:Early Growth Response Protein 2 / Q000235:genetics / Q000502:physiology*; D005434:Flow Cytometry; D020287:In Situ Nick-End Labeling; D051379:Mice; D008822:Mice, Transgenic; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1 / Q000378:metabolism; D051881:Receptor, Notch1 / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology* / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000378:metabolism
chemical_list: D017931:DNA Primers; D051767:Early Growth Response Protein 2; C497327:Egr2 protein, mouse; C497762:Notch1 protein, mouse; C539818:Nr4a1 protein, mouse; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D051881:Receptor, Notch1