A model for antimicrobial gene therapy: demonstration of human beta-defensin 2 antimicrobial activities in vivo.
We transfected host cells with an antimicrobial peptide/protein-encoding gene as a way to enhance host defense mechanisms against infection. The human beta-defensin 2 (HBD-2) gene was chosen as a model because its protein does not require cell type-specific processing. Using a retroviral vector carrying HBD-2 cDNA, we treated several mouse or human cell lines and primary cell cultures including fibroblasts, salivary gland cells, endothelial cells, and T cells. All transduced cells produced detectable HBD-2. In Escherichia coli gel overlay experiments, secreted HBD-2 from selected cell lines showed potent antimicrobial activity electrophoretically identical to that of purified HBD-2. We then used a mouse model (nonobese diabetic/severely compromised immunodeficient [NOD/SCID]) to test HBD-2 antimicrobial activities in vivo. HT-1080 cells carrying HBD-2 or control vector were implanted subcutaneously into NOD/SCID mice to allow tumor formation. Escherichia coli was then injected into each tumor mass. Tumors were resected after 16 hr and homogenized for bacterial colony-forming unit analysis. Compared with control tumors, HBD-2-bearing tumors contained only 7.8 +/- 3.3% viable bacteria. On the basis of this demonstration of HBD-2 in vivo antimicrobial activity, enhancement of antibacterial host defense by HBD-2 gene therapy may be feasible.
Huang
George T-J
GT
Division of Associated Clinical Specialties, Section of Endodontics, 23-087 CHS, UCLA School of Dentistry, 10833 Le Conte Avenue, Los Angeles, CA 90095, USA. gtjhuang@ucla.edu
Zhang
Hai-Bo
HB
Kim
Daniel
D
Liu
Lide
L
Ganz
Tomas
T
D000818:Animals; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D002460:Cell Line; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000235:genetics; D015316:Genetic Therapy; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D012190:Retroviridae / Q000235:genetics; D014161:Transduction, Genetic; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured; D023083:beta-Defensins / Q000235:genetics*
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; C106641:DEFB4A protein, human; D023083:beta-Defensins