GH3 pituitary adenoma cells can reverse thymic aging in rats
Keith W. Kelley,Susan Brief,Hollie J. Westly,Jan E Novakofski,Peter J. Bechtel,Joseph Simon,Edwin B. Walker +6 more
Reads0
Chats0
TLDR
The data show that it is possible to regenerate normal thymic tissue in situ and reverse the natural loss in cell-mediated immunity that occurs with aging.Abstract:
Thymic size and T-cell function decrease with age, and it has not yet been possible to totally reverse this thymic atrophy and completely restore T-cell-dependent immune functions. In this study, GH3 pituitary adenoma cells, which secrete growth hormone and prolactin, were implanted subcutaneously into 16- and 22-month-old female Wistar-Furth rats and the rats were sacrificed approximately 2 months later. Only thymic remnants were detected in aged, non-implanted rats, but thymus glands were found in both the 18- and the 24-month-old rats that had been implanted with GH3 cells. Thymus glands from the GH3-implanted 18-month-old rats contained distinct cortical thymocytes and medullary epithelial cells. Depending on the concentration of phytohemagglutinin or concanavalin A, T-cell proliferative responses of splenocytes from these implanted rats were 2- to 5-fold greater than those of 18-month-old controls. At the optimal concentration of mitogen, proliferative responses to either lectin could be restored to those levels observed in splenocytes from 3-month-old Wistar-Furth females. Thymus glands from 24-month-old GH3-implanted rats contained more cortical thymocytes and fewer fat vacuoles than controls, but they were not totally reconstituted. No significant lectin-induced T-cell proliferative responses or IL-2 secretion were detected in 24-month-old control rats, but splenocytes from GH3-implanted rats showed augmented T-cell proliferative responses and increased synthesis of IL-2. Fluorescence-activated cell-sorter analysis of thymocytes revealed that 24-month-old rats implanted with GH3 cells had a higher proportion of lymphocytes with the Thy-1.1 and helper-T-cell phenotypes. These data show that it is possible to regenerate normal thymic tissue in situ and reverse the natural loss in cell-mediated immunity that occurs with aging.read more
Citations
More filters
Journal ArticleDOI
Age-related changes in lymphocyte development and function
TL;DR: This review aims to provide an overview of age-related changes in lymphocyte development and function and discusses current controversies in the field of aging research.
Journal ArticleDOI
Immunosenescence: emerging challenges for an ageing population
TL;DR: This review attempts to highlight the age‐dependent defects in the innate and adaptive immune systems, with emphasis on the extrinsic factors, and particular attention will be focused on thymic involution.
Journal ArticleDOI
Increased production of IL-7 accompanies HIV-1–mediated T-cell depletion: implications for T-cell homeostasis
Laura A. Napolitano,Robert M. Grant,Steven G. Deeks,D K Schmidt,Stephen C. De Rosa,Leonore A. Herzenberg,Brian G. Herndier,Jan Andersson,Joseph M. McCune +8 more
TL;DR: It is proposed that IL-7 production increases as part of a homeostatic response to T-cell depletion, and is produced by dendritic-like cells within peripheral lymphoid tissues and is greatly increased in lymphocyte-depleted tissues.
Journal ArticleDOI
T cells and aging.
TL;DR: In this paper, a review aims to consider the current state of knowledge on the scientific basis for and potential clinical relevance of those factors in immunosenescence, including stem cell defects, thymus involution, defects in antigen presenting cells (APC), aging of resting immune cells, disrupted activation pathways in immune cells and replicative senescence of clonally expanding cells.
Journal ArticleDOI
Suppression of macrophage activation and T-lymphocyte function in hypoprolactinemic mice
TL;DR: The critical influence of pituitary prolactin release on maintenance of lymphocyte function and on lymphokine-dependent macrophage activation suggests that, in mice, lymphocytes are an important target tissue for circulating prolactIn, bromocryptine treatment reduced the number of deaths resulting from inoculation of mice with Listeria; exogenous prolact in significantly reversed this effect.
References
More filters
Journal ArticleDOI
The limited in vitro lifetime of human diploid cell strains
TL;DR: The survival curves obtained with human diploid cell strains are comparable to “multiple-hit” or “ multiple-target” curves obtain with other biological systems where an initial threshold dose is required before an exponential form of the curve is established.
Journal ArticleDOI
Establishment of clonal strains of rat pituitary tumor cells that secrete growth hormone.
TL;DR: Three clonal strains of epithelial cells established from a transplantable rat pituitary tumor have been serially propagated for 14–25 months and there has been no decrease in the rate of cell division nor decline in growth hormone secretion since the cells were established in culture.
Book ChapterDOI
Age influence on the immune system.
TL;DR: It is evident that a decline in T cell function gradually occurs and this affects the entire immune system, and Antibody formation and B cell function appear to be secondarily altered.
Journal ArticleDOI
Age-related change in the twenty-four-hour spontaneous secretion of growth hormone.
TL;DR: Growth hormone was secreted during both awake and asleep periods but the number of secretory episodes was less than in adole...
Journal ArticleDOI
Immunological studies of aging. Decreased production of and response to T cell growth factor by lymphocytes from aged humans.
TL;DR: Data lend support to the hypothesis that defects in the capacity to either produce or respond to TCGF may be a fundamental cause of immune deficiency and suggest a possible molecular mechanism for the impaired proliferative response of elderly human T cells.