The rejuvenating effects of leuprolide acetate on the aged baboon's thymus.

Journal Article (Journal Article)

Background

We have previously demonstrated that the juvenile thymus plays an essential role in tolerance induced by both renal transplantation and a short course of calcineurin inhibitors. Aged thymi have a decreased ability to induce tolerance. Luteinizing hormone-releasing hormone (LHRH) is known to pharmacologically rejuvenate the thymus in rodents. In order to develop a clinically applicable regimen of transplantation tolerance in adults, we sought to determine if thymic rejuvenation would occur with LHRH agonism in non-human primates.

Methods and results

Thymic rejuvenation was evaluated by magnetic resonance imaging (MRI), histology, as well as in-vitro cellular and molecular tests. Four aged male hamadryas baboons underwent subcutaneous injection of a 3-month depot of Lupron (11.25mg; LI) and were followed for 3 months. Thymi increased volumetrically by MRI. After LI, thymic cellularity markedly increased within the cortical and medullary thymus. Additionally, a significant increase in the CD4(+)/CD45RA(hi+) population in the peripheral blood occurred for 50 days after LI, and flow cytometry of thymic tissue revealed a large increase in the percentage of CD4(+)/CD8(+) cells. TREC assay corroborated enhancement in thymic function.

Conclusion

These data indicate that LI is associated with thymic rejuvenation in baboons, and further confirm that extrinsic factors play an important role in thymic rejuvenation in a non-human primate model.

Full Text

Duke Authors

Cited Authors

  • Scalea, JR; Torabi, R; Tena, A; Tasaki, M; Gillon, BC; Moran, S; Cormack, T; Villani, V; Shimizu, A; Sachs, DH; Yamada, K

Published Date

  • September 18, 2014

Published In

Volume / Issue

  • 31 / 3

Start / End Page

  • 134 - 139

PubMed ID

  • 25240733

Pubmed Central ID

  • PMC4188753

Electronic International Standard Serial Number (EISSN)

  • 1878-5492

International Standard Serial Number (ISSN)

  • 0966-3274

Digital Object Identifier (DOI)

  • 10.1016/j.trim.2014.09.001

Language

  • eng