Interleukin 2 induces rapid phosphorylation of cellular proteins in murine T‐lymphocytes

Abstract

When quiescent murine T‐lymphocyte cells were stimulated by the addition of interleukin 2 (IL‐2), they reinitiated DNA synthesis after a lag period of 5 h. Under these conditions, rapid but transient phosphorylation of two cellular proteins with M r, values of 27000 and 26000 was detected; maximal phosphorylation occurred within 10–15 min after the addition of IL‐2. The protein of M r, 27 000 contained phosphoserine, while the protein of M r 26000 contained phosphothreonine.

2‐Mercaptoethanol Acts as a Potentiating Factor of Interleukin‐2‐Dependent Lymphocyte Proliferation

“…The TN-9 cells were fairly synchronized in G1 stage by IL-2-starvation for 12 hr. In this condition, the cells began to incorporate thymidine 6-8 hr after the simultaneous addition of IL-2 and 2-ME and the maximum incorporation was observed after 12-15 hr (9). As shown in Table 2, no significant thymidine incorporation was observed when the cells were stimulated by IL-2 alone after the IL-2-starvation in the presence or absence of 2-ME though the cells survived for over 48 hr.…”

Interleukin 2 and a lactogen regulate proliferation and protein phosphorylation in Nb2 cells

“…Contaminants, though perhaps a problem in the rat IL-2 preparation, cannot account for the activity of the highly purified mouse IL-2 produced by recombinant techniques. Thus IL-2 appears to regulate phosphorylation in Nb2 cells, as it does in other T-lymphocytes [21,22]. A preliminary report [31] has suggested that lactogens also regulate phosphorylation of a 33000-Da protein in Nb2 cells, and it is likely that future studies will show that phosphorylation of additional proteins also is regulated by hGH and IL-2.…”

“…Studies [14,15] have shown that IL-2 also increases c-myc mRNA in T cells; thus some actions of prolactin and IL-2 in T cells may share a common mechanism. One of the initial actions of IL-2 may be activation of protein kinase C, because IL-2 stimulates translocation of this enzyme in T cells [16], and phorbol esters, which are potent activators of kinase C [17], mimic the effects of IL-2 on inhibition of adenylate cyclase activity [18], production of interferon [19], stimulation of cell proliferation [20] and phosphorylation [21,22]. The mitogenic actions of prolactin in Nb2 cells also may involve kinase C, because an inhibitor of this enzyme decreases prolactin-induced thymidine uptake [23].…”

2‐Mercaptoethanol acts at the restricted stage of interleukin‐2 dependent lymphocyte proliferation

“…The activity of IL-2 preparation thus obtained was 1 x lo5 units/mg protein. After addition of 50 pg/ml bovine until TN-9' a NK-like line' was estab-Serum albumin for stabilization of IL-2, the preparation lished in this laboratory from Con A-stimulated splenic was sterilized by filtering and stored at lymphoctyes of C3H mice (Kohno et al, 1986). G-CTLL 1, a T cell line specifically cytotoxic to syngeneic glioma use.…”