Human leptomeningeal-derived cells express GFAP and HLADR when grafted into rat spinal cord.

The following series of experiments explores the post-xenografting differentiation of a naturally occurring, non-neuronal cell cultured from the leptomeninges of an 84-year-old woman. In culture, flat process-bearing human cells from the leptomeninges were positive for GFAP and 200 kDa neurofilament protein (negative for 68, 160 kDa neurofilament protein). The C3 spinal cord was exposed in 30 adult athymic rats. The hindlimb dorsal columns were transected at C3 and the nerve fibers aspirated to form a pocket, into which 10(6) fast blue-labeled, human leptomeningeal-derived cells were placed. The C3 spinal cord was studied immunohistochemically over 60 days. Three days later the dorsal horn contained fast blue-GFAP-positive astrocyte-like cells that were negative for neurofilament protein. By 7 days, large, process-bearing, fast blue-GFAP-positive (neurofilament protein-negative), astrocyte-like cells joined the native astrocytes of the pia-glia membrane and were in the gray matter of the spinal cord. Some of these astrocyte-like cells were also positive for the human specific histocompatibility complex, HLADR. These data extend the age, species and tissue of origin for pluripotential cells for CNS transplantation.