Survival of astroglial cell lineage from adult brain transplant.

We previously described a transplantation model which enables the selective identification of rabbit astroglial cells in sections of mouse brain tissue. In the present paper, we report that cells of the astroglial lineage from an adult transplant are able to survive after implantation into the brain of an immature host. Surviving xenogenic cells are found outside the graft, forming colonies in the host brain parenchyma. However, after 3 months, transplant-derived astrocytes are no longer detected.

Implantation of rabbit embryo brain fragments into newborn mice: integration and survival of xenogeneic astrocytes.

Brain fragments containing embryonic rabbit glia were implanted into the brains of newborn mice. The hosts developed an astroglial reaction around the transplants and along the needle tracks. Transplant-derived astrocytes were identified in the operated brain by their expression of rabbit GFAP. During the first few days post-implantation (PI) glial cells were exchanged between the transplant and the host. Less than 3 to 5 days PI, the transplant was extensively invaded by host astrocytes. Xenogeneic astroglial cells were first detected 10 days PI in the immediate proximity of the transplant. At 2 to 11 weeks, they could be detected either close to or at distance from the point of implantation. Most often, transplant-derived astrocytes presented a morphology similar to that of neighboring host astrocytes. Xenogeneic glial cells were found to participate in various types of astroglial features: sub-pial, pericapillary, fibrous, and protoplasmic. This morphological integration suggests that they are physiologically integrated, at least to a certain degree, in the host tissue. In spite of their integration into the host, xenogeneic astrocytes disappear after 3 months without signs of an inflammatory reaction.

Interspecies identification of astrocytes after intracerebral transplantation.

Species-specificity of the Tp-GFAP 1 (glial fibrillary acidic protein) monoclonal antibodies raised against calf GFAP was established by means of immunochemical techniques. Since it was shown to combine with rabbit GFAP but not with mouse GFAP it allows the characterization of a new experimental model potentially useful in the study of the fate of implanted astrocytes after intracerebral graft of CNS fragments. Preliminary observations indicate that embryonic and newborn rabbit astrocytes are able to survive, express GFAP and migrate when implanted into newborn mouse brain.