Transplantation of alginate microcapsules - Generation of antibodies against alginates and encapsulated porcine islet-like cell clusters

Citation
B. Kulseng et al., Transplantation of alginate microcapsules - Generation of antibodies against alginates and encapsulated porcine islet-like cell clusters, TRANSPLANT, 67(7), 1999, pp. 978-984
Citations number
26
Categorie Soggetti
Medical Research Diagnosis & Treatment
Journal title
TRANSPLANTATION
ISSN journal
00411337 → ACNP
Volume
67
Issue
7
Year of publication
1999
Pages
978 - 984
Database
ISI
SICI code
0041-1337(19990415)67:7<978:TOAM-G>2.0.ZU;2-K
Abstract
Background. Microencapsulation of islets of Langherhans in alginate poly-l- lysine capsules provides an effective protection against cell-mediated immu ne destruction, and ideally should allow the transplantation of islets in t he absence of immunosuppression. It has previously been suggested that algi nate rich in mannuronic acid (high M) is more immunogenic than alginate ric h in guluronic acid (high G). The ability of these alginates to induce an a ntibody response in the recipient or act as an adjuvant to antibody respons es against antigens leaked from the capsule was investigated in the present study. Methods. Empty capsules made from these different types of alginate were tr ansplanted intraperitoneally to Wister rats or Balb/c mice. In addition, so me animals were also injected with bovine serum albumin to assess the abili ty of the alginates to act as an adjuvant to this antigen, Antibody respons es to intraperitoneally transplanted free and microencapsulated fetal porci ne islet like cell clusters (ICC) were also evaluated, in animals treated w ith or without cyclosporine. Results. Antibodies against high M-alginate capsules were detected in the s era of mice transplanted with this capsule type. However, this response was not seen after the transplantation of high G capsules. When Wister rats we re used as recipients, no antibody responses were detected against any type of alginate capsules. Neither type of capsule acted as an adjuvant. Antibo dies against ICC were present, in rats transplanted with both nonencapsulat ed and encapsulated ICCs, Administration of cyclosporine could abolish this production of antibodies against ICC, Conclusions. High G-alginate capsules are less immunogenic than high M caps ules. Because encapsulation did not protect against the generation of antib odies against ICC, it can be assumed that antigen leakage from the capsules occurs, as no evidence was found for capsules breaking in vivo.