How firefly research helped gene therapy

Sometimes on a calm summer or fall night, one is able to observe the beautiful dance of blinking fireflies. Scientists began to explore mechanisms to describe this unique natural phenomenon as early as the late 1800’s. After a series of experiments with solutions at different temperature with ground up abdomens of fireflies, Raphael Dubois named the enzyme luciferase and the substrate luciferin that were the cause of the light-producing reaction (1).  But it wasn’t until recently in 1985 that scientists were able to clone the gene for luciferase and express it in bacteria to produce the luciferase.

firefly

Figure 1: Picture of firefly. Source: http://www.fireflyexperience.org/photos/

Once the gene was cloned, genetic researchers realized the importance of the findings and started to use it as a reporter gene for experimental gene therapy. Gene therapies involve transfection of new genetic material into the host’s DNA and can be applied not only for therapies for diseases of genetic origin, but can be used for cancer therapy and diagnostic purposes.

By incorporating the gene for luciferase along with the gene of interest, the Hai-Quan Mao lab in the Department of Materials Science and Engineering at Johns Hopkins University can detect whether or not their nanoparticles used for gene delivery have been successful simply by adding luciferin to the cells. If the gene transfer was successful, then the luciferase will act on the substrate luciferin to emit light.

Sources

1)     Fraga, Hugo. “Firefly luminescence: A historical perspective and recent developments.” Photochemical & Photobiological Sciences 7.2 (2008): 146-158.

About the author: John Hickey is a second year Biomedical Engineering PhD candidate in the Jon Schneck lab researching the use of different biomaterials for immunotherapies and microfluidics in identifying rare immune cells.

For all press inquiries regarding INBT, its faculty and programs, contact Mary Spiro, mspiro@jhu.edu or 410-516-4802.

 

Nanotechnology for gene therapy

Editor’s Note: The following is a summary of one of the talks from the 2013 Nano-bio Symposium hosted by Johns Hopkins Institute for NanoBioTechnology held May 17. This summary was written by Randall Meyer, a doctoral candidate in the biomedical engineering and a member of the Cancer Nanotechnology Training Center. Look for other symposium summaries on the INBT blog.

One of the key features of nanotechnology is its wide range of applicability across multiple biological scenarios ranging from gene therapy to immune system modulation. Jordan Green, an assistant professor of Biomedical Engineering at Johns Hopkins University, summarized some of the fascinating applications of nanotechnology on which his laboratory has been working. Green is an INBT affiliated faculty member.

One of the Green lab projects involves the design and implementation of nanoparticle based vectors for delivery of genetic material to the cell. Green demonstrated how these particles could be used to deliver DNA and induce expression of a desired gene, or small interfering RNA (siRNA) to silence the expression of a target gene. These genetic therapeutics are being developed to target a wide variety of retinal diseases and cancers.

Jordan Green (Photo by Marty Katz)

Jordan Green (Photo by Marty Katz)

 

As opposed to viral based vectors for gene therapy, nonviral vectors such as nanoparticles are safer, more flexible in their range of cellular targets, and can carry larger cargoes than viruses, Green explained.

 

Another project in the Green lab involves the development of micro and nano dimensional artificial antigen presenting cells (aAPCs) for cancer immunotherapy. These aAPCs mimic the natural signals that killer T-cells receive when there is an invader (bacteria, virus, cancer cell, etc.) in the body. The Green lab is currently working with these particles to stimulate the immune system to fight melanoma.

 

Green Group