INTERMEDIATE STEPS IN THYMIC POSITIVE SELECTION - GENERATION OF CD4(-)8(+) T-CELLS IN CULTURE FROM CD4(+)8(+), CD4(INT)8(+), AND CD4(+)8(INT) THYMOCYTES WITH UP-REGULATED LEVELS OF TCR-CD3
- Author(s)
- KYDD, R; LUNDBERG, K; Vremec, D; Harris, AW; Shortman, K;
- Details
- Publication Year 1995-10-15,Volume 155,Issue #8,Page 3806-3814
- Journal Title
- JOURNAL OF IMMUNOLOGY
- Publication Type
- Journal Article
- Abstract
- 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 CD3(high) intermediates was CD4(+)8(+), CD4(int)8(+), or CD4(+)8(int); only an intermediate subpopulation expressing the highest levels of CD4 (CD4(high)8(int)) 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.
- Publisher
- AMER ASSOC IMMUNOLOGISTS
- Keywords
- BCL-2
- Terms of Use/Rights Notice
- Refer to copyright notice on published article.
Creation Date: 1995-10-15 12:00:00