Age-related attenuation in the expression of the major heat shock proteins in human peripheral lymphocytes

A defining characteristic of human ageing is the reduced ability to maintain homeostasis in the face of adverse environmental stresses. This progressive impairment may be a major cause for the increased incidence of infections, and general morbidity and mortality in the elderly. Heat shock proteins (hsps) or stress proteins, induced in response to hyperthermia and to various other physical, chemical and biological stressors, are often also expressed constitutively at a lower level and perform many essential functions in the cell. Here we investigate age-related changes in the heat induced expression of a comprehensive range of hsps at the translational level using primary human peripheral lymphocytes in short term culture. Our study reveals age-related attenuation in the response of the well characterised up-regulated molecular chaperone system hsp 70, the steroid-receptor binding hsp 90 and the chaperonin hsp 60. A diminution with age is also demonstrated in the heat induced response of hsps 105, 56, 47, 40, 27, and 16. Differentially down-regulated proteins at 100, 38, and 18 kDa were also noted.