Prolongation of the Effective Duration of Cytomedical Therapy by Re-injecting SK2 Hybridoma Cells Microencapsulated within Alginate-Poly(L)lysine-Alginate Membranes into Human Interleukin-6 Transgenic Mice

Abstract

We previously reported that SK2 hybridoma cells that secreted anti-human interleukin-6 (hIL-6) monoclonal antibodies (SK2 mAb) were microencapsulated within alginate-poly(L)lysine-alginate (APA) membranes (APA-SK2 cells) for immunoisolation, and a single intraperioneal injection of these APA-SK2 cells remarkably improved IgG1 plasmacytosis in hIL-6 transgenic mice (hIL-6 Tgm). However, the duration of the effectiveness of APA-SK2 cells as a cytomedicine was unfortunately limited. In this study, we attempted to re-inject APA-SK2 cells into hIL-6 Tgm for the purpose of prolonging the cytomedical therapy. In hIL-6 Tgm re-injected with APA-SK2 cells, the plasma IgG1 level did not show any increase in 37 week old mice, and their survival time was at least three times longer than those of untreated hIL-6 Tgm These results suggest that re-injected APA-SK2 cells survived and secreted SK2 mAn in the allogeneic mice. Thus, the limited duration of the cytomedical effects of APA-SK2 cells was probably caused by the disappearance of the inner space of microcapsules for cell proliferation, not by the rejection of the host's immune system. Therefore, if we can regulate the proliferation of the cells microencapsulated within a semipermeable membrane, we may be able to develop a cytomedicine which will continue its function longer after a single injection.