T cell development in normal and thymopentin-treated nude mice.
The extent and diversity of T cell differentiation in nude athymic mice are matters of dispute. In this study, we examined the splenic T cell population of pathogen-free and germ-free nu/nu mice, treated or not treated with the pentapeptide analogue of thymopoietin (TP-5), in terms of TL, Qa-1, and Lyt phenotypes. At all ages, 50-60% of nu/nu splenocytes, enriched for T lymphocytes by removal of sIg+ cells, expressed T markers, as compared with greater than 85% in normal mice. At 2 mo of age, all nu/nu splenic T cells expressed the surface phenotype TL+:Thy-1+:Ly-123. This is abnormal in two respects: first, because expression of TL is normally confined to thymocytes; and second, because there was no evidence of the usual diversification into the subsets Ly-1 and Ly-23. From 10 wk of age onwards, diversification into Ly subsets was evident in nu/nu spleen, although the usual predominance of Ly-1 over Ly-123 cells was not attained, and some TL+ cells persisted. Also, the ratio of Qa-1+ to Qa-1- cells rose progressively to as high as 4:1 at 4-6 mo, in contrast to the usual ratio of approximately 1:1, regardless of age. In the spleens of nu/nu mice treated with TP-5 from 5-8 weeks of age and tested 1 wk later, the proportion of T cells was raised, though not to normal levels, the number of TL+ cells was reduced, and there was diversification into Ly sets.
D000367:Age Factors; D000818:Animals; D000950:Antigens, Ly / Q000032:analysis; D000954:Antigens, Surface / Q000032:analysis; D005856:Germ-Free Life; D006728:Hormones / Q000494:pharmacology; D051379:Mice; D008819:Mice, Nude; D010446:Peptide Fragments / Q000494:pharmacology*; D010641:Phenotype; D013601:T-Lymphocytes / Q000276:immunology / Q000502:physiology*; D016305:Thymopentin; D013946:Thymopoietins / Q000494:pharmacology*; D013951:Thymus Hormones / Q000494:pharmacology*
D000950:Antigens, Ly; D000954:Antigens, Surface; D006728:Hormones; D010446:Peptide Fragments; D013946:Thymopoietins; D013951:Thymus Hormones; D016305:Thymopentin