Early Calcium Signaling and Calcium Requirements for the IL-2 Receptor Expression and IL-2 Production in Stimulated Lymphocytes

• Published in: Cellular immunology Vol. 173; no. 2; pp. 215 - 220
• Main Authors: Komada, Hiroshi, Nakabayashi, Hiroshi, Hara, Mari, Izutsu, Kosaku
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.11.1996
• Subjects: Calcium - metabolism; Child; Child, Preschool; Concanavalin A - pharmacology; DNA - biosynthesis; Humans; In Vitro Techniques; Interleukin-2 - biosynthesis; Lymphocyte Activation; Lymphocytes - drug effects; Lymphocytes - immunology; Lymphocytes - metabolism; Palatine Tonsil - cytology; Receptors, Interleukin-2 - biosynthesis; Signal Transduction; Wheat Germ Agglutinins - pharmacology
• ISSN: 0008-8749; 1090-2163
• DOI: 10.1006/cimm.1996.0270

Two kinds of lymphocyte populations were prepared from human resected tonsils: one was a mixed population consisting of T cells, B cells, other lymphocytes, and a few macrophages, and the other was a T-enriched population obtained by removing adherent cells from the mixed population with a nylon wool column. A transient rise in cytosolic free calcium ion concentration ([Ca2+]i) was observed in both the populations within a few minutes of stimulation with concanavalin A (Con A). However, emergence of cells which had high [Ca2+]iafter 4 min of Con A stimulation was observed practically only in the mixed population. The [Ca2+]ielevation occurring within a few minutes of stimulation in both populations was interpreted as being due to a release from the intracellular Ca-storing organelles, whereas the high [Ca2+]iin a group of cells after 4 min of Con A stimulation in the mixed population was caused by an influx of extracellular calcium that probably corresponds to a transient enhancement of Ca2+uptake observed only in the mixed population during early stimulation. Con A induced both interleukin 2 receptor (IL-2R) expression and interleukin 2 (IL-2) production. A nonmitogenic lectin, wheat germ agglutinin (WGA), also induced a rise in the [Ca2+]iwithin a few minutes. WGA induced IL-2 production, but did not induce IL-2R expression. Chelation of extracellular calcium with EGTA at the time of Con A addition resulted in a decrease in IL-2R expression, IL-2 production, and DNA synthesis, but not when CaCl2equimolar to EGTA was present in the culture medium. Chelation of calcium 12 hr after Con A stimulation decreased IL-2R expression, but had no effect on IL-2 production. These results indicate that IL-2 production required Ca2+only in the early (G0) stage and that IL-2R expression was dependent on Ca2+in both the G0and the G1stages.