Draft:Katherine Ralston

Katherine Ralston

Katherine Ralston is an Associate Professor and researcher in microbiology and molecular genetics from the United States. Ralston began working at the University of California, Davis, in 2014 and primarily researches the microbial eukaryote Entamoeba histolytica. Ralston has won several awards and was named a 2016 Pew Scholar for her research on Entamoeba histolytica and the discovery of amoeba “cell nibbling.”

Education and Career

Ralston received a Bachelor of Science in Genetics from the University of California, Davis, in 2001. Ralston received a Ph.D in Microbiology from the University of California, Los Angeles, in 2009. After completing her Ph.D, Ralston performed postdoctoral research at the University of Virginia. At the University of Virginia, Ralston first discovered cell nibbling by Entomoeba histolytica. In 2014, Ralston joined the University of California, Davis’s College of Biological Sciences, under the title of Assistant Professor. In 2022, Ralston was promoted to Associate Professor and obtained tenure.

Research

Ralston is best known for her discoveries surrounding the parasitic amoebozoan, Entamoeba histolytica. This organism causes amoebiasis, or severe diarrhea and ulceration. In 2011, Ralston and a colleague published a paper characterizing previously unknown methods used by the amoebozoan to kill human cells and invade tissues. Ralston discovered that Entamoeba histolytica kills human cells by “nibbling” on them, or biting off and ingesting pieces of living cell tissue.

In 2019, Ralston tested another hypothesis, whether or not amoebic trogocytosis leads to Entamoeba histolytica displaying human cell membrane proteins. Ralston and colleagues determined that the amoebozoan does indeed display human cell membrane proteins on its surface and discovered that this strategy works as a protective mechanism against the human immune system.

Notable Publications

Miller, Hannah & Suleiman, Rene & Ralston, Katherine. (2019). Trogocytosis by Entamoeba histolytica Mediates Acquisition and Display of Human Cell Membrane Proteins and Evasion of Lysis by Human Serum. mBio. 10. 10.1128/mBio.00068-19.

Bettadapur, Akhila & Miller, Hannah & Ralston, Katherine. (2020). Biting Off What Can Be Chewed: Trogocytosis in Health, Infection, and Disease. Infection and Immunity. 88. 10.1128/IAI.00930-19.

Ralston, Katherine. (2015). Taking a bite: Amoebic trogocytosis in Entamoeba histolytica and beyond. Current opinion in microbiology. 28. 26-35. 10.1016/j.mib.2015.07.009.

Ralston, Katherine & Solga, Michael & Mackey-Lawrence, Nicole & , Somlata & Bhattacharya, Alok & Petri, William. (2014). Trogocytosis by Entamoeba histolytica contributes to cell killing and tissue invasio. Nature. 508. 10.1038/nature13242.

Awards

In 2016, The Pew Charitable Trusts named Ralston a Pew Scholar. The Pew Charitable Trusts identifies young researchers each year who are engaged in innovative research in areas advancing human health and the biomedical sciences. Among 22 total scholars, Ralston received a multi-year grant for parasitology. The grant funded Ralston’s continued study of Entamoeba histolytica and the mechanisms behind its invasion of human host tissues. Ralston’s research transformed modern research in parasitology. Using this grant, Ralston investigated how exactly Entamoeba histolytica nibbles on human cells and why this leads to cell death.

Also in 2016, Ralston was named a Hellman Fellow. Based in San Francisco, the Hellman Fellows Fund gives money each year to Univeristy of California, Davis, to fund early-career researchers. This fellowship aided Ralston in developing novel genetic tools to study trogocytosis in Entamoeba histolytica.

In 2019, Ralston received the UC Davis Early Career Faculty Award for Creativity and Innovation to aid in continuing research of trogocytosis.