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- Document 0404
- DOCN M9610404
- TI Intermediate steps in thymic positive selection. Generation of CD4-8+ T
- cells in culture from CD4+8+, CD4int8+, and CD4+8int thymocytes with
- up-regulated levels of TCR-CD3.
- DT 9601
- AU Kydd R; Lundberg K; Vremec D; Harris AW; Shortman K; Walter and Eliza
- Hall Institute of Medical Research, Melbourne,; Victoria, Australia.
- SO J Immunol. 1995 Oct 15;155(8):3806-14. Unique Identifier : AIDSLINE
- MED/96003419
- AB Minor thymus subpopulations representing possible intermediates in
- thymic positive selection were isolated by cell sorting from bcl-2
- transgenic mice, and cultured 1 to 4 days in simple medium to assess
- their ability to spontaneously develop the surface phenotype of mature T
- cells. Recovery of cells was in the 60 to 80% range, and no cell
- proliferation occurred. Only cells originally expressing high, near
- mature T cell levels of CD3 developed further in culture by
- down-regulation of CD4 or CD8. The main mature cell product was CD4-8+,
- regardless of whether the starting phenotype of the CD3high
- intermediates was CD4+8+, CD4int8+, or CD4+8int; only an intermediate
- subpopulation expressing the highest levels of CD4 (CD4high8int)
- produced a dominance of CD4+8- mature progeny. Partial down-regulation
- of CD8 was therefore not a good indicator of CD4+ T lineage commitment.
- These and previous results indicate that maturation to the CD8+ T
- lineage involves a rapid up-regulation of the TCR-CD3 complex, but a
- relatively slow down-regulation of CD4; it may also involve a partial,
- transient reduction in surface CD8. In contrast, maturation to the CD4+
- T lineage involves a relatively rapid down-regulation of CD8, with
- maintenance of high levels of CD4. There appears to be a marked
- asymmetry in the developmental steps leading from CD4+8+ thymocytes to
- the CD8+ or to the CD4+ T cell lineage.
- DE Animal Cell Differentiation CD4-CD8 Ratio CD4-Positive
- T-Lymphocytes/*IMMUNOLOGY CD8-Positive T-Lymphocytes/*IMMUNOLOGY
- Lymphocyte Transformation Mice Mice, Inbred C57BL Mice, Transgenic
- Proto-Oncogene Proteins/GENETICS Receptor-CD3 Complex, Antigen,
- T-Cell/*METABOLISM Support, Non-U.S. Gov't T-Lymphocyte
- Subsets/*IMMUNOLOGY Thymus Gland/CYTOLOGY Up-Regulation
- (Physiology)/*IMMUNOLOGY JOURNAL ARTICLE
-
- SOURCE: National Library of Medicine. NOTICE: This material may be
- protected by Copyright Law (Title 17, U.S.Code).
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-