HETEROTOPIC TRANSPLANTS OF BONE MARROW

TLDR

The study discusses how preosteoblasts and hematopoietic stem cells interact to induce osteogenesis. The authors used chromosome markers and reverse transplantation to trace donor versus recipient origins of osteogenic and hematopoietic cells in semisyngeneic heterotopic bone marrow transplants. Syngeneic and semisyngeneic grafts generate bone and marrow, whereas allogeneic grafts produce only bone that is resorbed; in long‑term semisyngeneic transplants, marrow cells are recipient derived while bone and osteogenic precursors remain donor derived.

Abstract

In semisyngeneic heterotopic bone marrow transplants the donor or recipient origin of cells of osteogenic and hematopoietic tissues was identified by chromosome markers (T6) and by reverse transplantation into the initial donor line. In syngeneic and semisyngeneic grafts of bone marrow under the renal capsule bone and bone marrow are formed. In allogeneic grafts only bone is formed; this bone is subsequently resorbed. In 14-month semisyngeneic transplants the bone marrow consists of recipient cells. This is true for both the proliferating pool and the stem cells of hematopoietic tissue. At the same time, osteogenic precursor cells and bone tissue in these transplants are of donor origin. A discussion is presented of the interrelationship between determinated osteogenic precursor cells (preosteoblasts) and hematopoietic stem cells (or their descendants) in which osteogenesis is inducible.