A cytokine, lymphocyte blastogenesis inhibitory factor (LBIF), arrests mitogen-stimulated T lymphocytes at early G1 phase with no influence on interleukin 2 production and interleukin 2 receptor light chain expression

We have investigated the expression of the three components of the interleukin-2 receptor (IL-2Rα, IL-2Rβ, and IL-2Rγ) on the surface of the various peripheral blood mononuclear cell (PBMC) subsets by flow cytometry analysis. The PBMC were immediately isolated (ficoll) from blood collected on heparin as anticoagulant. The three IL-2R components are absent or only marginally detectable on CD4 T lymphocytes. No expression of the IL-2R chains is found for the B lymphocytes. In most donors, the three chains are not detectable on CD8 T lymphocytes, but for a few of them, IL-2Rβ or IL-2Rγ are clearly expressed. CD56 high (IL-2Rα+) and CD56 low (IL-2Rα−) natural killer (NK) cells express IL-2Rβ, but not IL-2Rγ. IL-2Rγ is expressed by monocytes of all donors although with variable intensity. When blood is collected on other anticoagulants or when cells are isolated 1 day after collection, IL-2Rα, IL-2Rβ, and IL-2Rγ are largely expressed on the surface of most PBMC. This observation provides a possible explanation for divergent data previously reported on IL-2R expression. Finally, we show that IL-2Rγ, which is not detectable on the cell surface of lymphocytes, is nevertheless expressed and stored as an intracellular component. This result is in agreement with the constitutive expression of the IL-2Rγ gene and suggests a specific regulatory mechanism for IL-2Rγ membrane translocation.

Download Full-text

Modulation of Soluble Interleukin -2-Receptor (sIL2R) in Human Immunodeficiency Virus Myeloma (HIV-M) Patients Treated with Biaxin Pentoxifylline Dexamethasone (BPD).

Blood ◽

10.1182/blood.v114.22.4965.4965 ◽

2009 ◽

Vol 114 (22) ◽

pp. 4965-4965

Author(s):

Eugene McPherson ◽

Sanjay Patel ◽

P. Tassy

Keyword(s):

Bone Marrow ◽

Proinflammatory Cytokines ◽

Light Chain ◽

Interleukin 2 ◽

Free Light Chain ◽

Serum Free ◽

Interleukin 2 Receptor ◽

Serum Free Light Chain ◽

Immune System Activation ◽

Soluble Interleukin 2 Receptor

Abstract Abstract 4965 Soluble interleukin-2-receptor (sIL2R) is a T-cell derived cytokine that induce proliferation of activated T-cells, modulates macrophage function and phenotype and participates in differentiation of B cells. sIL2R levels reflect immune-system activation. and is elevated in HIV-M and may be used to predict esponse to therapy with immunomodulation therapy with BPD.sIL2R has been reported in several malignant diseases with correlation to disease activity. Proinflammatory cytokines IL-6, TNF-alpha, and IL-1b are positively correlated to sIL2R.Plasma cells may produce IL-6 by autocrine mechanism but a paracrine mechanism is involved in IL-6 production in bone marrow stromal cells. Growth of myeloma cells can be induced IL-6. We present a 43 YOF with HIV-M with elevated levels of sIL2R, C-reactive protein (CRP), IgG-kappa,lambda,IgM kappa level with serum free light chain kappa/lambda ratio. Treatment with biaxin,pentoxifylline, and low dose dexamethasone for 12-24 weeks resulted in normal levels of sIL2R, CRP, IgG,IgM and serum free light chain ratios. Conclusion Modulation of sIL2R with BPD in HIV-M patients with elevated proinflammatory cytokines may arrest the disease proliferation by controlling the growth potential IL-6 in both bone marrow plasm cells and peripheral blood mononuclear cells and correlates with the duration of survival. Disclosures No relevant conflicts of interest to declare.

Download Full-text