What we do

In the Wallet Lab, we are focused on pathogenesis of inflammation. This field of immunology spans infectious diseases, autoimmunity, cancer and other conditions where the immune system is a key part of pathology. Our lab studies human immunology and the experiments that we perform rely on access to human leukocytes. We obtain these cells from healthy blood donors or from individuals who agree to participate in biomedical research at the University of Florida Diabetes Institute. Sometimes though, donated cells are not enough to answer complex questions about how genes regulate the many functions of immune cells. To get around this hurdle, we have been working with induced pluripotent stem cells (iPSCs).

 

iPSCs

In 2006, a major discovery was made by Kazutoshi Takahashi and his mentor Shinya Yamanaka at Kyoto University in Japan. Their team was the first to identify a strategy to create stem cells from more differentiated lineages. Pluripotent stem cells are unique in their ability to become any type of cell in the body. By harnessing the power of stem cells, it is possible to create new cells of virtually any type (neurons [brain cells], cardiomyocytes [heart muscle], leukocytes [white blood cells], etc.). This is incredibly useful for so many reasons. Obviously, stem cells could be a source of new cells to replace those that are damaged or missing due to disease or injury. But there is another benefit of stem cells that we wanted to utilize in the Wallet lab. By growing stem cells in a dish and then converting those cells into various different types of immune cells, we could essentially grow a human immune system in a dish. Then, by using new gene editing techniques such as CRISPR/Cas9, we can manipulate the cells to understand how individual genetic variations lead to diseases such as type 1 diabetes, a major focus of the lab. Dr. Yamanaka was a recipient of the Nobel Prize in 2012 for his contribution to stem cell research.

CRIPSR/Cas9

About the time that Dr. Yamanaka was receiving his Nobel Prize, another field of research was erupting onto the scene. Based on earlier work by Yoshizumi Ishino at Osaka University in Japan, the laboratories of Emmanuelle Charpentier (Umea University, Sweden) and Jennifer Doudna (UC Berkely) found described a method to use part of an ancient bacterial defense strategy to develop an revolutionary new tool for scientists. CRISPR/Cas9 allows scientists to quickly and precisely change the DNA sequence of a living cell without harming the cell itself. This tool can be used to delete individual genes as a strategy to understand their function. It can also be used to repair broken genes in hereditary diseases. We have adopted this strategy to study how individual genes or combinations of genes affect the function of human immune cells. When paired with iPSC, we can modify a single gene in the stem cell and the differentiate the iPSCs into several different immune lineages (monocytes, macrophages, dendritic cells, T cells, etc.) then determine how the genetic changes affect each cell type. This approach has the potential to accelerate discovery research because we now have an unlimited number of cells on which to perform experiments.

 

Type 1 Diabetes Research: