Disease relevance of IL15RA

• A single nucleotide polymorphism in exon 7 of IL15RA was strongly associated with muscle hypertrophy and accounted for 7.1% of the variation in regression modeling [1].
• By using fluorescence resonance energy transfer and confocal microscopy, we have shown that IL-2R alpha, IL-15R alpha, IL-2/15R beta and gamma(c)-subunits, as well as MHC class I and II glycoproteins formed supramolecular receptor clusters in lipid rafts of the T lymphoma line Kit 225 FT7.10 [2].

High impact information on IL15RA

• Despite secretion of IL-15, LCs lack IL-15R-alpha for surface presentation of IL-15 [3].
• Reverse transcription-coupled polymerase chain reaction (RT-PCR) showed that the cell lines had the mRNA of IL-15R alpha [4].
• The size of sIL-15R alpha (42 kDa), together with the analysis of deletion mutants in the ectodomain of IL-15R alpha, indicates the existence of cleavage sites that are proximal to the plasma membrane [5].
• Cutting edge: murine dendritic cells require IL-15R alpha to prime NK cells [6] .

Biological context of IL15RA

• Furthermore, the IL15RA and IL2RA genes have a similar intron-exon organization and are closely linked in both human and murine genomes [7].
• These results suggest that IL-15 is an important mediator of muscle mass response to resistance exercise training in humans and that genetic variation in IL15RA accounts for a significant proportion of the variability in this response [1].
• Although the molecular biology of the brain IL-2/IL-2R system (including its relation to IL-15/IL-15R alpha) is not yet fully established by cloning and complete sequencing of all respective components, similarities (and to some extent differences) to peripheral counterparts are now apparent [8].
• Human T cell lymphotropic virus type I Tax activates IL-15R alpha gene expression through an NF-kappa B site [9].
• IL-15/IL-15R alpha intracellular trafficking in human cells and protection from apoptosis [10].

Anatomical context of IL15RA

• We conclude that normal and T84 colonic epithelial cells express IL-15R alpha and are able to bind IL-15 [11].
• IL-2 and IL-15 receptor alpha-subunits are coexpressed in a supramolecular receptor cluster in lipid rafts of T cells [2].
• In contrast to resting cells, mitogen-activated macrophages, NK cells, and CD4+ and CD8+ T cells express IL-15R alpha chains [12] .
• However, the levels of IL-15 and IL-15Ralpha mRNA were higher in the hippocampus and cerebellum in comparison with cortex and thalamus [13].

Associations of IL15RA with chemical compounds

• Dexamethasone, but not cyclosporine or rapamycin, blocks mitogen-induced IL-15R alpha expression [12].
• On the other hand, enhanced basal expression of IL-15Ralpha was detected in leucocytes from SLE patients, with defective induction upon stimulation with phytohaemagglutinin or phorbol myristate acetate/ionomycin [14].

Other interactions of IL15RA

• CONCLUSIONS: We demonstrate the upregulation of immune-related genes IL-15Ralpha, Lpn and NKG5 in secretory versus proliferative human endometrium [15].
• OBJECTIVE: To assess the functional status of the IL-15/IL-15Ralpha cytokine system in different leucocyte subsets from patients with systemic lupus erythematosus (SLE) [14].

Analytical, diagnostic and therapeutic context of IL15RA

• By RT-PCR analysis, purified GL from these patients were found to express the message for IL-15 receptor alpha chain [16].
• In this report, using a highly sensitive radioimmunoassay, we show the existence of a soluble form of human IL-15R alpha (sIL-15R alpha) that arises from proteolytic shedding of the membrane-anchored receptor [5].
• Accordingly, surface IL-2R beta protein was identified only in M-07e and M-07SB cells, by indirect immunofluorescence, while no expression of IL-2R alpha and IL-15R alpha was detected [17].
• Cross-linking and immunoprecipitation experiments have shown that the high affinity IL-15 receptors comprises IL-2R beta/gamma, in association with IL-15R alpha and that the three chains can be efficiently cross-linked to IL-15 and co-immunoprecipitated [18].
• We report here the characterization and molecular cloning of a distinct murine IL-15R alpha chain [19].

References