Hematopoietic thymocyte precursors. I. Assay and kinetics of the appearance of progeny.

摘要: A quantitative assay for the hematopoietic precursor of thymocytes has been developed. Using this kinetics appearance progeny transfused bone marrow and spleen cells in thymus irradiated (760 R) mice studied. Precursor are seven to eightfold more common than absent from peripheral lymph nodes. They decline number as animals age. When injected immediately after lethal irradiation only a small actually enter gland. Their not detectable 8-12 days. The time their detection depends both upon size residual endogenous thymocyte population progenitor injected. Evidence presented that excludes thymic injury basis delay donor type indicates neither production "homing" signal animal nor development limiting factors rate repopulation. These studies indicate an exceedingly (less 100) prothymocytes required repopulate mouse. This restricted progenitors must produce entire repertory T-cell immunologic responsiveness seen first weeks