CYTOLOGICAL EVIDENCE FOR A RELATIONSHIP BETWEEN NORMAL HEMATOPOIETIC COLONY-FORMING CELLS AND CELLS OF THE LYMPHOID SYSTEM

TLDR

The study examines whether thymic and lymph node precursors are identical to or share a common precursor with hematopoietic colony‑forming cells. The authors used a chromosome‑marker technique to trace hematopoietic colony‑forming stem cells in the thymus and lymph nodes of unirradiated mice. A high proportion of thymic and lymph node cells share clones with hematopoietic colony‑forming cells, and these shared clones can mediate immune responses, supporting a common stem‑cell origin for hematopoietic and immune cells.

Abstract

The relationship between hematopoietic colony-forming stem cells and cells in the thymus and lymph nodes of unirradiated mice has been investigated using a chromosome-marker technique. It was found that a high proportion of cells in the thymus may belong to the same clone as normal hematopoietic colony-forming cells. It was also found that cells belonging to the same clone as colony-forming cells may reach the lymph nodes, and that nodes containing such cells can participate in an immunological response against sheep red cells. Either the precursors of cells in thymus and lymph node are identical with hematopoietic colony-forming cells, or they are both descendants of a common precursor which has not yet been identified. The results are compatible with the view that cells of the hematopoietic system and the immune system may be derived from the same stem cell.