AAV2-mediated interleukin-12 in the treatment of malignant brain tumors through activation of NK cells.
Interleukin-12 has been elucidated as a powerful anti-cancer factor in pre-clinical research. However, the obstacles of this modality that emerged from human clinical trails included the toxicity of repeated large dose administration and short effective duration. Therefore, a prolonged, constant therapeutic level of interleukin-12 is required to reduce the adverse effects and enhance the therapeutic efficacy. In this study, 54 nude mice were divided into three groups treated with rAAV2 encoding interleukin-12, rAAV2 vector, and PBS, respectively. All nude mice received human glioblastoma multiforme cell line DBTRG implantation. The biochemistry studies included serum levels of interleukin-12, isotypes of immunoglobulin, interferon-gamma, and TNF-alpha. The activated NK cells were sorted from the spleen by flow cytometry and the cytotoxicity of NK cells were evaluated by LDH assay. In the rAAV2 encoding interleukin-12 group, substantial expression of interleukin-12 was obtained with a serum level of 120-150 pg/ml through the experimental course and a significant increase of activated NK cells was achieved. The splenocytes extracted from the spleen in rAAV2 encoding IL-12 mice strongly exhibited cytotoxic activity compared to the control groups (p<0.001). The IgG1, IgG2a, and IgM also showed a significant increase in the rAAV2 encoding IL-12 group compared to the control groups (p<0.05). The tumor growth rate decreased obviously in the rAAV2 encoding IL-12 group with a significant difference from the control groups (p<0.001). This study demonstrated an encouraging result of immunomodulative therapy in malignant brain tumors by rAAV2 carrying IL-12 through activating NK cells.
Chiu
Tsung-Lang
TL
Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan, R.O.C. poluschiou@gmail.com
Lin
Shinn-Zong
SZ
Hsieh
Wan-Hua
WH
Peng
Chih-Wen
CW
D000818:Animals; D001932:Brain Neoplasms / Q000276:immunology / Q000628:therapy*; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic; D000229:Dependovirus; D005434:Flow Cytometry; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D005909:Glioblastoma / Q000276:immunology / Q000628:therapy*; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D007150:Immunohistochemistry; D018664:Interleukin-12 / Q000276:immunology / Q000378:metabolism / Q000627:therapeutic use*; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000276:immunology / Q000628:therapy; D023041:Xenograft Model Antitumor Assays
D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D018664:Interleukin-12