Rhesus macaque Interleukin-15 (rMamu IL-15)
IL-15 shares many sctivities exerted by IL-2 including the stimulation and expansion of T cells thymocytes, B cells and natural killer cells owing to the fact that the receptors for IL-2 and IL-15 share the same and subunits. At least in murine models, IL-15 unlike IL-2 fails to significantly activate the apoptotic pathways when stimulating T cells as well as other responding lineages, suggesting that IL-15 promotes the establishment of long-term memory T cells, IL-15 is produced by a variety of tissues, including myeloid PBMCs, skeletal muscle, kidney, placenta, hematopoietic stromal cells etc.
rMamu IL-15 cDNA code for a 162 aa polypeptide (resulting in a 114 aa mature polypeptide) (Genbank accession number U19843) that is 97.5% homologous to human IL-15 (Villinger et al, J Immunol 1995 155:3946-3954). Anecdotal reports from the use of human IL-15 in rhesus macaques suggests rapid induction of neutralizing antibodies to the xenogeneic protein precluding repeated administration of human IL-15 to monkeys.
rMamu IL-15 is produced as a mature polypeptide in E coli using the pET32 expression vector with an enterokinase digestion site to ensure the absence of extraneous residues at the aminoterminus.
Purity is verified by PAGE electrophoresis and absence of endotoxin by LAL tests.
Bioactivity of each lot is tested based on induction of proliferation of the IL-2 dependent HT-2 cell line. Biological activity levels vary from batch to batch but is generally of the order of 1x107 U/mg.
Half-life of rMamu IL-15 in vivo following subcutaneous administration is 1.3 hours.