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The effect of age on the cognate function of CD4 + T cells
Author(s) -
Haynes Laura,
Eaton Sheri M.
Publication year - 2005
Publication title -
immunological reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.839
H-Index - 223
eISSN - 1600-065X
pISSN - 0105-2896
DOI - 10.1111/j.0105-2896.2005.00255.x
Subject(s) - cd154 , biology , adoptive cell transfer , immunology , cd40 , antigen , interleukin 2 , effector , t cell , in vivo , in vitro , microbiology and biotechnology , antibody , immune system , cytotoxic t cell , genetics
Summary: With increasing age, the ability to produce protective antibodies in response to immunization declines, resulting in reduced efficacy of vaccination. We have examined how reductions in CD4 + T‐cell function contribute to reduced humoral responses, using a model that allows us to compare identical numbers of antigen‐specific naive T cells from young and aged T‐cell receptor transgenic mice. Naive cells from aged mice exhibit reduced responses, both in vitro and in vivo . In vitro , responses of aged T cells can be enhanced by addition of interleukin (IL)‐2. In vivo , using an adoptive transfer model with young hosts, naive cells from aged mice exhibit significant reductions in cognate helper function, leading to reduced B‐cell expansion and differentiation. These age‐related defects could be overcome by prior in vitro T helper 2 effector generation with aged T cells. This improvement in cognate function of the aged effectors may be related to the enhancement of CD154 expression, which occurs on aged T cells in the presence of exogenous IL‐2. We also found no difference in B‐cell expansion and differentiation when young cells were transferred to young or aged hosts. Our results indicate that age‐related reductions in humoral responses are mainly due to defects in the cognate helper function of naive CD4 + T cells from aged individuals.