Efficient systemic expression of bioactive IL-15 in mice upon delivery of optimized DNA expression plasmids.
Efficient expression vectors for interleukin 15 (IL-15) were developed combining RNA/codon optimization and modification of the IL-15 native long signal peptide. These changes resulted in elevated cytoplasmic levels of the optimized mRNA and more than 100-fold improved production of secreted human IL-15 protein. Similar modifications have also led to greatly increased rhesus macaque and murine IL-15 production. Comparison of different heterologous secretory signals showed that the tissue plasminogen activator signal is most efficient for the production of extracellular IL-15. Upon intramuscular injection of the fully optimized expression vectors in mice, IL-15 was readily detected in the serum. Serum levels represented <1% of intramuscular IL-15 and were sufficient in causing some systemic effects, such as increasing the frequency of natural killer (NK) cells in the liver. Upon hydrodynamic DNA delivery in mice, very high levels of IL-15 were produced, which increased the frequency of NK cells in liver as well as in spleen and lung. These optimized expression vectors have potential applications in vaccine and immunotherapy approaches against AIDS and cancer.
Jalah
Rashmi
R
Human Retrovirus Pathogenesis Section, Vaccine Branch, National Cancer Institute-Frederick, Frederick, Maryland 21702-1201, USA. felber@ncifcrf.gov
Rosati
Margherita
M
Kulkarni
Viraj
V
Patel
Vainav
V
Bergamaschi
Cristina
C
Valentin
Antonio
A
Zhang
Gen-Mu
GM
Sidhu
Maninder K
MK
Eldridge
John H
JH
Weiner
David B
DB
Pavlakis
George N
GN
Felber
Barbara K
BK
D000595:Amino Acid Sequence; D000818:Animals; D005260:Female; D015870:Gene Expression; D005822:Genetic Vectors; D006801:Humans; D019409:Interleukin-15 / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics*; D008253:Macaca mulatta; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009132:Muscles / Q000378:metabolism; D010957:Plasmids / Q000008:administration & dosage / Q000235:genetics; D021382:Protein Sorting Signals / Q000235:genetics; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000097:blood / Q000235:genetics; D017386:Sequence Homology, Amino Acid
D019409:Interleukin-15; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D011994:Recombinant Proteins