Kinetics of thymus repopulation by intrathymic progenitors after intravenous injection: evidence for successive repopulation by an IL-2R+, Pgp-1- and by an IL-2R-, Pgp-1+ progenitor.
A kinetic study of thymus repopulation after intravenous injection of L3T4-, Lyt-2- thymocytes further depleted of IL-2R+ or Pgp-1+ cells indicates that donor cells within the thymus at Day 8 after injection descend primarily from an IL-2R+, Pgp-1- progenitor, while at Day 17 after injection most progeny of donor phenotype descend from an IL-2R-, Pgp-1+ progenitor. Repopulation studies in organ culture demonstrate that IL-2R+, Pgp-1+ cells also have progenitor activity. All three progenitors give rise to differentiated cell types normally present in the thymus. These results are consistent with the interpretation that the L3T4-, Lyt-2- population is composed of a heterogeneous collection of progenitors which repopulate the thymus with differing kinetics and imply that it will be difficult to establish lineage relationships within this population in the absence of a clonal assay for thymocyte progenitors.
Lesley
J
J
Department of Cancer Biology, Salk Institute, San Diego, CA 92138.
Schulte
R
R
Hyman
R
R
D000818:Animals; D000954:Antigens, Surface / Q000096:biosynthesis; D002455:Cell Division; D005434:Flow Cytometry; D007275:Injections, Intravenous; D007700:Kinetics; D051379:Mice; D008806:Mice, Inbred AKR; D009924:Organ Culture Techniques; D010641:Phenotype; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis; D016201:Receptors, Lymphocyte Homing; D013234:Stem Cells / Q000166:cytology* / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology / Q000637:transplantation; D013950:Thymus Gland / Q000166:cytology* / Q000276:immunology
D000954:Antigens, Surface; D015375:Receptors, Interleukin-2; D016201:Receptors, Lymphocyte Homing