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Age-related impairment of T cell proliferative responses related to the decline of CD28+ T cell subsets
- Source :
- Archives of Gerontology and Geriatrics. 26:55-70
- Publication Year :
- 1997
- Publisher :
- Elsevier BV, 1997.
-
Abstract
- The impairment of phytohaemagglutinin-triggered lymphocyte proliferation represents a prominent immunologic abnormality in elderly individuals. To assess whether the reduced function is related to a CD28/B7 signalling deficiency, purified T lymphocytes and antigen presenting cells (APCs) were analyzed for their phenotypic profile and/or functional capacities. T cell responses to immobilized OKT3 monoclonal antibodies (mAb) or a combination of anti-CD2 mAb and phorbol esters were unaffected in old subjects when compared to the younger counterpart. In contrast, CD28 costimulation in the presence of OKT3 or anti-CD2 mAb, gave rise to significantly diminished T cell proliferative responses. These findings correlated with a marked decline of CD28 + T cell frequency, which mainly involved the CD4 − CD45RO − cell subset. The defect in CD28 expression could not be reversed by T cell stimulation, as a comparable increase in CD28 levels occurred in both `aged' and `young' T cells after in vitro activation. Moreover, the elderly group did not exhibit a reduction of interleukin (IL)-2 synthesis, as assessed at 24 h of culture, regardless of the stimulant used. Finally, B7.2 (CD86) expression by `aged' CD14 + APCs was unaffected in both resting and interferon- γ activated cells. These results suggest that an intrinsic defect in CD28 expression might in part account for the age-related decline of T cell proliferative responses.
- Subjects :
- CD86
Aging
medicine.medical_specialty
Health (social science)
Chemistry
T cell
CD28
hemic and immune systems
chemical and pharmacologic phenomena
Lymphocyte proliferation
Interleukin 21
Endocrinology
medicine.anatomical_structure
Interferon
Internal medicine
Immunology
medicine
Cytotoxic T cell
Geriatrics and Gerontology
Antigen-presenting cell
Gerontology
medicine.drug
Subjects
Details
- ISSN :
- 01674943
- Volume :
- 26
- Database :
- OpenAIRE
- Journal :
- Archives of Gerontology and Geriatrics
- Accession number :
- edsair.doi.dedup.....e203a0b9d6b1e006694ab2738e8e7c97