Interleukin-2 differentially regulates IL-2 receptors on murine cloned cytolytic and helper T cells

Use of recombinant interleukin-2 in traumatic disease in veterinary medicine

Тhe article presents analysis of current information on the possibility of using recombinant interleukin-2 in traumatic disease in veterinary medicine. The analysis included publications from the following databases - P ubMed, MedLine, BIOSIS, ToxiNet, CANCERLIT, CINAHL, CISCOM, EMBASE, International Pharmaceutical Abstracts, and NAPRALERT, using 10 keywords and their combinations. It was shown that in trauma of any genesis, an immunodeficiency state occurs associated with an imbalance of Th1/Th2 cytokines. The use of recombinant interleukin-2 restores synthesis of endogenous interleukin-2, provides adequate targeted drug correction of immune dysfunctions, increasing the clinical and immunological effectiveness of therapeutic measures.

Glucocorticoid, interleukin-2, and prostaglandin interactions in a clonal human leukemic T-cell line

We have studied the growth effects of conditioned media, interleukin-2 and PGE prostaglandin analogs on the glucocorticoid-sensitive human leukemic T-cell clone, CEM-C7. After 4 days, the glucocorticoid dexamethasone at approximately 10 nM kills 50% of CEM-C7 cells. To test the hypothesis that glucocorticoid-mediated lymphocytolysis was due to suppression of lymphokine expression only, we attempted to protect CEM-C7 cells from lysis by provision of lymphokine(s). Conditioned media from interleukin-2 secreting Jurkat T-cells as well as the glucocorticoid-insensitive, but receptor positive clone, CEM-C1, failed to prevent lymphocytolysis; exogenous interleukin-2 also did not provide protection. There were complex, biphasic interactions between dexamethasone and the synthetic PGEs, enisoprost and enisoprost free acid. Low doses of enisoprost alone (0.01 to 1 microgram/ml) stimulated growth, and in combinations completely reversed the growth inhibitory effects of 10 nM dexamethasone. Higher concentrations of enisoprost were inherently lethal and were additive to the steroid effect. Thus the glucocorticoid-induced lymphocytolysis in this human leukemic T-cell line may be modified biphasically by PGE prostaglandins, depending on their concentration. However, interleukin-2 or components in the conditioned media assayed had no effect in ameliorating the lethal response to glucocorticoid.

The interleukin-2 receptor on cord blood and nulliparous mononuclear cells is downregulated by maternal and cord blood serum

The concentration of interleukin-2 receptor (IL-2R) on maternal, cord blood and unrelated nulliparous mononuclear cells has been studied after a previous phytohaemagglutinin (PHA) stimulation. Furthermore, the inhibitive action of maternal and cord blood serum on the IL-2R expression of stimulated nulliparous and cord blood lymphocytes has been shown. A downregulation of the [3H]-thymidine uptake by these PHA treated cells previously incubated in maternal and cord blood serum has been observed. Retroplacental serum was the most inhibitive experimental medium. The IL-2R modulation property of maternal serum has been studied during the pregnancy. Appearing quite early (in the sixth week), the maternal serum dependent inhibitive factor vanished, 2 to 3 weeks after delivery. After a study of the different serum components, it is suggested that the IL-2R downregulating molecule is included in the maternal immunoglobulin (IgG) fraction. Further experiments suggest that the addition of recombinant IL-2 during the action of low doses of maternal IgG allows a partial re-expression of the IL-2R. However, at physiological concentrations of IgG, the IL-2R downregulation becomes irreversible.

Modulation of the interleukin 2 receptor by maternal and cord blood serum

In this report, the potential inhibitive action, of maternal serum (retroplacental and peripheral), and cord blood serum on the expression of the Il2r has been studied. Calf and male serum were used as a control. In order to have an optimal Il2r expression, a previous PHA cellular stimulation was performed. The maternal serum's Il2r inhibitive property was measured during and after the pregnant period. The presence of Il2r on maternal lymphocytes, cord blood cells, and unrelated donor mononuclear cells has been investigated (after a PHA stimulation assay). The downregulated Il2r expression of neoplastic cell line (Hut78 cell line) under the influence of maternal serum has been observed. The examination of the inhibitive action due to maternal serum has suggested that a factor included in the IgG fraction is mainly responsible for the downregulating property concerning the Il2r expression. A possible mechanism for the action of this factor has been studied. Further experiments suggest that the addition of recombinant Il2 during the action of low doses of maternal IgG allows a partial reexpression of the Il2 receptor. However, at physiological concentrations of IgG, the Interleukin 2 receptor downregulation becomes irreversible.