Evolving immunity

Dr. Tanita Wein, slated to join the Department of Systems Immunology as a principal investigator in March 2024, studies the mechanism by which bacteria defend themselves against viruses.

“What was super interesting to me is that some of the systems present in bacteria are still present in humans,” she says of systems retained from the tiny organisms from which humans evolved to the immune systems that exist today.

As a graduate student in Germany, Dr. Wein studied gasdermin―a specific protein that is involved in several biological processes. Five members of the gasdermin family serve as major factors in health and disease, including cancers, infections, and immune disorders.

Gasdermin, which Dr. Wein calls “very cool,” causes pores in the cell membrane. When the protein is activated, it creates pores all over the cell, leading to the release of inflammatory signaling molecules and cell death, she explains. The death of the infected cell prevents the virus from replicating and infecting other cells.

Cellular suicide

Dr. Wein has discovered that this same process exists in bacteria. “The bacteria sense the infection: ‘Oh my god, there’s a virus!’ and the cell then kills itself, so the virus cannot form new viruses. This is very well-known in higher organisms, but a relatively new concept in bacteria.”

Why would one bacterium, a single-cell organism, “kill itself”? In a multicellular organism, it makes sense as if an infected cell sacrifices itself, it benefits the whole body, she explains. But her findings shed new light on bacteria, which exist in colonies.

“They’re surrounded by their kin. If one ‘sacrifices’ itself, the rest of the bacterial colony will survive,” she says.

Dr. Wein is intrigued by the question of whether the bacteria “saved” by a single bacterium’s death can somehow sense that the process has occurred. While scientists do not currently know how such signaling works in bacteria, the subject is something she says she would “love” to study in the future.

Given that once a human cell dies various components, such as cytokines, are released into the body, Dr. Wein says she would like to take her work on bacterial immune defenses further: “Our whole system is turned on, and it would be amazing to find something comparable in bacteria”—if not precisely the same mechanism, then an apparatus that works the same way.

Evolutionary connections

Prior to focusing on microbiology and immunology, Dr. Wein delved into evolutionary biology—studying the development of specific biological components on an evolutionary timescale.

As a principal investigator at the Weizmann Institute, she plans to apply her background in comparative genomics and evolutionary principles to establish a new research direction in the field of evolutionary immunology. Dr. Wein will investigate the evolutionary connections between immunity in prokaryotes (unicellular organisms) and eukaryotes (multicellular organisms) by studying host-pathogen interactions across evolutionary timescales and lifestyles.

Her interest in nature―with a particular affinity for “the small stuff”―dates back to her early childhood in Germany, and she says she knew from an early age that she wanted to study insects or snails, which were the smallest things she knew about.

Dr. Wein says she always knew she would have a career in biology, and when she started her studies, she discovered what she describes as “a hidden world” of even smaller things—bacteria and viruses.

Entranced by the tiny organisms and the even smaller viruses, Dr. Wein’s PhD research at Kiel University in Germany involved working with mobile genetic elements called plasmids.

“I was very fascinated by the small stuff around us, I guess. That’s why I chose microbiology,” she shares.

Dr. Wein has published prolifically, writing or contributing to over 20 papers since 2017, serving as corresponding author on six of them. In 2020, she began a postdoctoral fellowship in the lab of Prof. Rotem Sorek in the Department of Molecular Genetics at the Weizmann Institute of Science, where her success prompted the Institute to offer her a position as a principal investigator.

Among the things Dr. Wein says she most appreciates about the Weizmann Institute are the widely available resources such as sequencing or proteomics services, which she explains are not as easily accessible at other universities or research institutions.

She is also impressed by the caliber of the people. “I think Weizmann has excellent students. I had a lot of rotation students [MSc candidates at the Weizmann Institute begin their studies by spending a few months in different labs, until they find a good fit for their degree research]. I’ve rarely met such bright students,” she says.

Dr. Wein, who completed her MSc and PhD under the supervision of Israeli-German Prof. Tal Dagan, describes her connection to Israel as “very strong.” She and her partner, a scientist at the Agriculture Research Organization-Volcani Institute, live in Tel Aviv.

Education and select awards

BSc, Kiel University, Germany (2013)

MSc, Helmholtz Centre of Ocean Research, Germany (2016)

PhD summa cum laude, Kiel University in association with the International Max Planck Research School for Evolutionary Biology (2019)

Postdoc, Weizmann Institute of Science (2020-2024)

Kiel University’s ZMB Young Scientist Grant (2017, 2018); Prize for Excellent PhD Research from Germany’s Association for General and Applied Microbiology (2020); Koshland Prize (2020); Dean’s Fellowship from the Weizmann Institute Faculty of Biology (2020); Minerva Foundation Postdoctoral Fellowship (2020-2021); Azrieli Systems Biology Innovative Award (2020); European Molecular Biology Organization Long-Term Postdoctoral Fellowship (2021); Feinberg Graduate School Prize for Outstanding Achievements in Postdoctoral Research (2022)