Homing of a cloned multipotential stem cell line in spleen and intraperitoneal membrane.

B6SUT is a murine cell line cloned from nonadherent cells of viral-infected long-term marrow cultures. In soft agar it can form colonies of three different hemopoietic lineages and is considered to be a hemopoietic stem cell line. We studied its ability to "home" in the spleen of lethally irradiated mice. These cells formed large surface colonies on days 8 and 12, the colonies on day 12 being greater than 3 mm in diameter. Microscopically, these colonies consisted of undifferentiated cells, suggesting that B6SUT cells are capable of homing and proliferation in hemopoietic tissues, but not differentiation. To confirm this, cells were labeled with 51Cr and infused into the peritoneum of mice bearing cellulose ester membranes (CEM). We noted significant uptake of radioactivity that could be inhibited in the presence of excess unlabeled B6SUT cells. Electron-microscopic studies showed binding and migration of these cells into the CEM coat. The membrane of B6SUT cells was mapped for lectin and sugar-recognizing receptors and found to possess receptors for PHA, Con A, WGA, and RCA, but not UEA, fucosyl, galactosyl, or mannosyl residues. We conclude that cell line B6SUT is capable of homing into hemopoietic tissues, and that surface glycoproteins may be responsible for this phenomenon. This cell line permits the study of the "homing" phenomenon apart from proliferation and differentiation.