Effect of cytokines on IL-15 receptor expression in human oral keratinocytes cell line

Interleukin-15 [IL-15] is a cytokine produced by mononuclear phagocytes and probably many other cell types in response to viral infections, lipopoly-saccharides [LPS], and other signals that trigger innate immunity. IL -15 mRNA is expressed in non-lymphoid tissues such as heart, lungs, liver, kidneys, placenta, skeletal muscle and also in keratinocytes and dendritic cells in skin. The actions of IL-15 are mediated via its receptor [IL-15R]. IL-15 is known to be expressed in a variety of tissues, including epithelial cells, beta-1 cells, and natural killer cells. It is not known whether these are present in the oral buccal mucosa. The present study was carried out at The department of Oral Pathology, Queen Mary College of Medicine and Dentistry, Barts and The London, UK, to determine whether a human oral buccal mucosal [keratino-cytes] cell line, TR 146, expressed IL-15 receptor and whether the expression of IL-15R is varied when TR146 cells were exposed to different cytokines such as IL-15, IL-8, IL-1beta, or TNF-alpha Immunocytochemistry analysis revealed that TR146 cells expressed IL-15R when incubated with IL-15 and IL-8 and a modest increase was seen with IL-1beta /TNF-alpha. RT-PCR indicated that the TR-146 cells constitutively expressed IL-15R which did not appear to be up-regulated upon exposure to the cytokines use

Development of a fusion toxin IL15M-PEdelta293 based on a receptor-specific IL-15 antagonist / 生物工程学报

IL-15 and IL-15 receptors (IL-15R) play a crucial role in the pathogenesis of adult T-cell leukemia (ATL), multiple myeloma and inflammatory autoimmune diseases. To develop a novel therapeutic agent capable of eliminating IL-15R-over-expressing abnormal cells, the gene coding for human IL-15 antagonist (IL-15M) was fused with a DNA fragment coding for the mutated form of Pseudomonas exotoxin, PEdelta293. The resulting gene fusion was cloned into pET16b under the control of T7 promoter, giving rise to the expression plasmid pET-IL15M-PEdelta293. Using Ni2+ -NTA affinity chromatography, IL15M-PEdelta293 was purified from E. coli BL21 (DE3) pLysS transformed with pET-IL15M-PEdelta293. The fusion toxin showed cytotoxicity to IL-15R-bearing myelogenous leukemia cell line K562 and K562-derived multidrug resistant cell line K562/AO2. However, IL-15R negative cell line Jurkat was insensitive to IL15M-PEdelta293. In addition, the toxic effect of IL15M-PEdelta293 on K562 was completely blocked by excessive amount of recombinant human IL-15. These results demonstrated that the selective cytotoxicity of IL15M-PEdelta293 correlated with the appropriate IL-15R expression on target cells. The present data suggest that the chimeric toxin constructed in this report may have therapeutic potential in the treatment of diseases associated with abnormal expression of IL-15/IL-15R, even in the treatment of chemotherapy refractory tumors.