Biodegradable polymer-based interleukin-12 gene delivery: role of induced cytokines, tumor infiltrating cells and nitric oxide in anti-tumor activity.
The objective of this study was to investigate the role of induced cytokines, tumor infiltrating cells and nitric oxide (NO) in anti-tumor activity upon intratumoral injection of free and condensed plasmid DNA encoding murine interleukin-12 (pmIL-12) into BALB/c mice bearing subcutaneous tumors. Poly[alpha-(4-aminobutyl)-L-glycolic acid] (PAGA) was used for complex formation with pmIL-12 in presence of 5% (w/v) glucose. Upon characterization, PAGA/pmIL-12 (3/1, +/-) complexes were found to be most effective in gene transfer and were used consistently throughout this study. The levels of mIL-12 p70 and induced cytokines were determined by ELISA in the supernatant of the cultured tumors of the CT-26 subcutaneous tumor bearing BALB/c female mice 48 h after intratumoral injection of PAGA/pmIL-12 complexes and naked pmIL-12. The levels of IL-12, IFN-gamma, TNF-alpha and NO were higher for the PAGA/pmIL-12 complexes than those for the naked pmIL-12, PAGA alone and 5% glucose injected groups. The relative presence of natural killer (NK) cells, CD4(+) T cells, and antigen presenting cells, such as macrophages and dendritic cells determined using immunohistochemistry was higher for PAGA/pmIL-12 complexes compared with naked pmIL-12. The presence of CMV promoter in plasmid encoding IL-12 cDNAs did not induce any type I interferon response. There was a significant improvement in the survival rate and the inhibition of tumor growth after repeated injections of PAGA/pmIL-12 complexes.
Center for Controlled Chemical Delivery, University of Utah, Salt Lake City 84112-5820, USA.
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Maheshwari
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Han
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RI
Mahato
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SW
Kim
D000230:Adenocarcinoma / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D000818:Animals; D001673:Biodegradation, Environmental; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000276:immunology; D005260:Female; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D018664:Interleukin-12 / Q000235:genetics* / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology; D008264:Macrophages; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D009569:Nitric Oxide / Q000378:metabolism; D010957:Plasmids; D011100:Polyglycolic Acid / Q000031:analogs & derivatives*; D015996:Survival Rate; D014407:Tumor Cells, Cultured
D016207:Cytokines; C414262:poly((4-aminobutyl)glycolic acid); D018664:Interleukin-12; D011100:Polyglycolic Acid; D009569:Nitric Oxide