Sertoli cells decrease microglial response and increase engraftment of human hNT neurons in the hemiparkinsonian rat striatum

Sertoli cells (SCs) provide immune protection and nutritive support to the developing germ cells in the testis. Sertoli cells have also been shown to provide immune protection to islets transplanted outside the testes. In thi s study, the ability of these cells to diminish the infiltration/activation of microglia into a neural graft implanted in the lesioned striatum of a h emiparkinsonian rat was investigated. Human neuron-like cells (hNT neurons) were implanted either atone or in combination with rat SCs. Three months l ater, the animals were sacrificed and immunohistochemistry was performed to determine the survival of the xenografted neurons as well as microglial in filtration/activation. Cotransplantation of the SCs with the hNT neurons in creased graft survival and was associated with an increase in graft size. F urthermore, there were fewer microglia present in the grafted tissue of the cotransplantation groups. These results show that SCs retain their immunos uppressive ability even within the brain. As immune responses to grafted ne ural tissue within the central nervous system become better understood, thi s ability of the SCs to provide localized immunosuppression to the transpla nted tissue may become more important. This is particularly true as the sea rch for alternative sources of neural tissue to treat neurodegenerative dis eases expands to encompass other species. (C) 1999 Elsevier Science Inc.