Thymocyte subpopulations in youn and adult mice 1. separtion by density tradient and steroid treatment

Publisher Website
Google Scholar
Abstract
Thymocyte subpopulations obtained after centrifugation on Ficoll density gradients have been studied in youn and 6-week-old mice. Whereas the totality of the thymocytes appeared Θpositive, gradient fractionaton showed the existence of a subpopulation of immunoglobulin and Θnegative lymphocytes among the lightest cells. Similar separation was obtained in both age groups in terms of the distribution of such Θnegative cells as well as of phytomitogen responses. However, cell pools with characteristics of cortical cells were less well represented in 2 to 10-day-old mice than in adult mice, indicating that post- natal thymic development is essentially associated with the appearance of cortical cell. The gradient did not however, provide a clear separation assessed on other parameterws such as Θantigen, concanavalin A and phytohemagglutinin responses and steroid sensitivity. Cellular heterogeneity for a given cell density is discussed in relation to the hypothesis of two separate maturation pathways of thyocytes.