Defective expression of p70/75 interleukin 2 receptor in T cells from patients with systemic lupus erythematosus: a possible defect in the process of increased intracellular calcium leading to p70/75 expression.
Phytohemagglutinin (PHA) stimulated T cells from patients with systemic lupus erythematosus (SLE) showed hyporesponsiveness to interleukin 2 (IL-2) and expressed less p70/75 IL-2R than healthy controls. Ionomycine (IM, calcium ionophore) which selectively upregulated p70/75 expression, induced less p70/75 in patients with SLE than in healthy controls. However, intracellular calcium levels of T cells from patients with SLE increased as much as those from healthy controls, when T cells were stimulated by IM or PHA. Our results suggest that an impaired expression of p70/75 IL-2R in T cells from patients with SLE is not due to a defective calcium influx but to the events after the rise of calcium levels.
Saiki
O
O
Third Department of Internal Medicine, Osaka University Medical School, Japan.
Tanaka
T
T
Kishimoto
S
S
D000328:Adult; D002118:Calcium / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D007425:Intracellular Membranes / Q000378:metabolism*; D015759:Ionomycin / Q000494:pharmacology; D008180:Lupus Erythematosus, Systemic / Q000378:metabolism* / Q000473:pathology; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D010835:Phytohemagglutinins / Q000494:pharmacology; D015375:Receptors, Interleukin-2 / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism* / Q000473:pathology
D007376:Interleukin-2; D010835:Phytohemagglutinins; D015375:Receptors, Interleukin-2; D015759:Ionomycin; D002118:Calcium