Bovine Chromaffin Cells for CNS Transplantation do not Elicit Xenogeneic T Cell Proliferative Responses in Vitro

Abstract

Adrenal chromaffin cells have been utilized for several neural grafting applications, but limitations in allogeneic donor availability and dangers inherent in autografting limit the widespread use of this approach clinically. While xenogeneic donors offer promise as a source for cell transplantation in the central nervous system (CNS), immunologic responses to cellular components of the adrenal medulla have not been well characterized. To further study the host T cell xenogeneic response to chromaffin and passenger cells of the adrenal medulla, an in vitro lymphocyte proliferation assay was used. Lymphocyte proliferation was determined by mixing rat lymphocytes with potential stimulator cell subpopulations of the bovine adrenal medulla: isolated chromaffin cells, isolated endothelial cells, or passenger nonchromaffin cells, which include a mixture of fibroblasts, smooth muscle cells, and endothelial cells. As a positive control, bovine aortic endothelial cells were also used. 3[H]-thymidine incorporation, corresponding to lymphocyte proliferation, was measured. Results indicated that isolated bovine chromaffin cells produce only a mild, statistically insignificant stimulation of rat lymphocytes. In contrast, there was a significant response to passenger nonchromaffin cells of the adrenal medulla, especially endothelial cells. The inclusion of low levels of cyclosporin A in the cultures completely eliminated the mild proliferative response to isolated bovine chromaffin cells, while near toxic levels were necessary to abrogate the response to endothelial cells. Immunocytochemical analysis revealed that routine chromaffin cell isolation procedures result in the inclusion of a small percentage of endothelial cells, which may be responsible for the slight lymphocyte stimulation. The results of this study indicate that isolated chromaffin cells possess low immunogenicity, and suggest that passenger cells in the adrenal medulla, particularly endothelial cells, may be primarily responsible for progressive rejection in CNS grafts. Thus, removal of passenger nonchromaffin cells from xenogeneic donor tissues prior to transplantation may produce a more tolerated graft in rodent models of neural transplantation.

Generation and initial characterization of conditionally immortalized chromaffin cells

“…The cell biology and developmental responsiveness during differentiation of chromaffin cells [Unsicker, 1993] reveals clues to the differentiation program of conditionally immortalized chromaffin cell lines in vitro. The enzyme TH (EC1.14.3.x) catalyzes the ratelimiting step [Livett et al, 1965] in the biosynthesis of catecholamines in chromaffin cells in the adrenal medulla [Pickel et al, 1975;Totzauer et al, 1995] and has been used as one of the antigenic markers for the mature chromaffin phenotype of primary rat and bovine chromaffin cells in vitro [Czech et al, 1996], as well as D␤H and PNMT. Both the rat RAD5.2 and bovine BADA.20 chromaffin cell lines express these catecholamine enzyme immunoreactivities at both permissive (low levels) and nonpermissive temperatures, when the cells are proliferating or differentiating, respectively, although levels of the D␤H enzyme appear to change with differentiation at nonpermissive temperature (39°C).…”

In Vivo Biocompatibility of Alginate-PLL Microcapsules with Chromaffin Cells for the Alleviation of Chronic Pain

“…Cell isolation and encapsulation procedure. Chromaffin cells were isolated from bovine adrenal medullary tissue by conventional methods [11] and purified using the differential plating method [12]. The purified chromaffin cells, with 1.4% alginate (Sigma, USA), were dropped into a calcium chloride bath and coated with 0.05% poly-L-Lysine and 0.2% alginate in turn.…”