Heat-shock protein synthesis by human peripheral mononuclear cells from SLE patients

Peripheral blood mononuclear cells (PBMC) from systemic lupus erythematosus (SLE) patients have heat shock protein (hsp) 70 and hsp 85 as well as the response to various temperatures of normal PBMC and are inducible for these proteins over about 5-8 levels with heat exposure in short-term culture. Synthesis of hsp 70 and hsp 85 as well as the response to various temperatures and the time course of induction were typical for mammalian cell systems. This enhancement with heat-shock treatment was blocked by actinomycin D added before heat exposure. This demonstration that hsp genes are activated in PBMC from active SLE patients without heat exposure supports the hypothesis that gene activation can serve some roles in these cells and be related to the PBMC function in SLE patients. These observations are at least correlative and consistent with a possible homeostatic function for hsps in this system.