The role of the thymus in immune reconstitution in aging, bone marrow transplantation, and HIV-1 infection

Citation
Bf. Haynes et al., The role of the thymus in immune reconstitution in aging, bone marrow transplantation, and HIV-1 infection, ANN R IMMUN, 18, 2000, pp. 529-560
Citations number
121
Categorie Soggetti
Immunology
Journal title
ANNUAL REVIEW OF IMMUNOLOGY
ISSN journal
07320582 → ACNP
Volume
18
Year of publication
2000
Pages
529 - 560
Database
ISI
SICI code
0732-0582(2000)18:<529:TROTTI>2.0.ZU;2-X
Abstract
The human thymus is a complex chimeric organ comprised of central (thymic e pithelial space) and peripheral (perivascular space) components that functi ons well into adult life to produce naive T lymphocytes. Recent advances in identifying thymic emigrants and development of safe methods to study thym ic function in vivo in adults have provided new opportunities to understand the role that the human thymus plays in immune reconstitution in aging, in bone marrow transplantation, and in HIV-1 infection. The emerging concept is that there are age-dependent contributions of thymic emigrants and proli feration of postthymic T cells to maintain the peripheral T cell pool and t o contribute to T cell regeneration, with the thymus contributing more at y ounger ages and peripheral T cell expansion contributing more in older subj ects. New studies have revealed a dynamic interplay between postnatal thymu s output and peripheral T cell pool proliferation, which play important rol es in determining the nature of immune reconstitution in congenital immunod eficiency diseases, in bone marrow transplantation, and in HIV-1 infection. In this paper, we review recent data on human postnatal thymus function th at, taken together, support the notion that the human thymus is functional well into the sixth decade and plays a role throughout life to optimize hum an immune system function.