title: Thymic stromal cells produce soluble factors which increase polarization of chicken thymocytes.
abstract: The effects were examined of soluble factors present in culture supernatant (CS) of thymic stromal cells (TSC) on the differentiation and locomotor activity of chicken thymocytes. The locomotor activity of thymocytes was assessed by cell polarization assay. When thymocytes were incubated in the presence of TSC-CS, the proportion of polarized cells increased. This indicates that thymocytes acquired a potent locomotor activity. A high proportion of peanut agglutinin-positive (PNA + ) thymocytes, as well as CD4(-)CD8(-) and CD4(+)CD8(+) thymocytes showed polarization in TSC-CS. Bone marrow cells exhibited higher level of polarizing activity compared to CD4(+)CD8(-) and CD4(-)CD8(+) thymocytes and spleen T cells. These results suggest that thymic stromal cells secrete a soluble factor(s) which enhances mobilizing activity of immature T cells. The factor may take part in the intrathymic migration of progenitor T cells into the site of differentiation.
authors.affiliation: Laboratory of Veterinary Immunology, Department of Veterinary Science, College of Agriculture, Osaka Prefecture University, Sakai, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Mukamoto
authors.forename: H
authors.initials: H
authors.lastname: Kodama
authors.forename: T
authors.initials: T
authors.lastname: Baba