Defects in thymocyte differentiation and thymocyte-stromal interactions in the trisomy 16 mouse.
We have examined fetal thymic development in the trisomy 16 (Ts16) mouse, which is considered to be a model for human trisomy 21, or Down Syndrome. The Ts16 thymus contains 10 to 20% of the number of lymphocytes found in a normal thymus at a comparable stage. Expression of thymocyte differentiation markers (Thy-1, CD5, CD8, CD4, CD3, and HSA) is severely affected in Ts16 fetuses aged 14-18 gestational days. When thymuses from 14-day Ts16 mice were cultured in vitro, these markers eventually reached levels of expression comparable to those seen in normal thymuses in culture. On the other hand, expression of CD44 appears to be unaffected in Ts16 thymuses in vivo, but declines in vitro relative to normal thymuses. Reconstitution of depleted thymic stroma with thymocytes showed evidence of defects in both developmental compartments.
Ewart
J L
JL
Department of Biology, Goddard Laboratories, University of Pennsylvania, Philadelphia 19104.
Auerbach
R
R
D000818:Animals; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D017252:CD3 Complex; D015704:CD4 Antigens; D018956:CD5 Antigens; D016827:CD8 Antigens; D002454:Cell Differentiation; D002885:Chromosomes, Human, Pair 16; D003238:Connective Tissue / Q000196:embryology; D004195:Disease Models, Animal; D004314:Down Syndrome / Q000276:immunology; D006801:Humans; D066298:In Vitro Techniques; D008562:Membrane Glycoproteins; D051379:Mice; D008817:Mice, Mutant Strains; D011948:Receptors, Antigen, T-Cell; D018800:Thy-1 Antigens; D013950:Thymus Gland / Q000196:embryology / Q000276:immunology*; D014314:Trisomy
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D017252:CD3 Complex; D015704:CD4 Antigens; D018956:CD5 Antigens; D016827:CD8 Antigens; D008562:Membrane Glycoproteins; D011948:Receptors, Antigen, T-Cell; D018800:Thy-1 Antigens