title: Age-associated increase in expression of the T cell surface markers Thy-1, Lyt-1, and Lyt-2 in congenitally athymic (nu/nu) mice: analysis by flow microfluorometry.
abstract: The expression of T cell-associated surface markers by lymphoid cells from congenitally athymic (nude) mice has been quantitatively investigated using flow microfluorometry. Spleen and lymph nodes from old (greater than 6 mo) nude mice on either a C57BL/6 or BALB/c genetic background were found to contain significant numbers (5 to 13% in spleen and 15 to 24% in lymph nodes) of cells expressing Thy-1 antigen. The proportion of Thy-1 positive cells in nude spleen was dramatically increased (to 22 to 67%) after passage of the cells over nylon wool columns. In contrast to older animals, young (1- to 2-mo-old) nude mice had undetectable levels (less than 1%) of Thy-1 bearing cells in spleen and reduced levels (6%) in lymph nodes. After passage of their spleen cells over nylon wool, some Thy-1 positive cells (10%) were detectable in 2-mo-old nude mice but none were detectable at 1 mo. In addition to Thy-1, we were able to detect the T cell alloantigens Lyt-1 and Lyt-2 on nylon wool-passed spleen cells from older C57BL/6 or BALB/c nu/nu mice. In general, the proportion of Lyt-1 bearing cells in nude lymphoid populations was similar to the proportion of Thy-1 positive cells. A smaller fraction of nude cells (corresponding to 35 to 59% of the total Thy-1 positive cells) were found to express Lyt-2. Analysis of the forward light scatter distributions of nude lymphoid cells bearing either Thy-1, Lyt-1, or Lyt-2 antigens further demonstrated that an overlapping population of relatively large-size cells expressed these surface markers. These data strongly imply that at least 2 subsets of T cells (i.e., Lyt-1+2- and Lyt-1+2+) develop in older nude mice in the apparent absence of thymic influence.
mesh_terms: D000375:Aging; D000818:Animals; D005470:Fluorometry; D007519:Isoantigens; D008027:Light; D008198:Lymph Nodes / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008819:Mice, Nude / Q000276:immunology*; D011817:Rabbits; D012542:Scattering, Radiation; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*
chemical_list: D007519:Isoantigens