Between hospital and research

Christina Zielinski always wanted to become a doctor, but then research got hold of her, or, more precisely, human T cells did. Christina Zielinski has been focusing on these major players in the immune system since her PhD thesis—while she was undergoing specialist dermatology and allergy training and when she became a certified medical specialist. For about a year, the physician and scientist has been a DZIF professor at the TU Munich. Her specialty: immunodiagnostics of infectious diseases.

“My research is about understanding how the human body’s immune system employs efficient defence mechanisms against infectious pathogens and simultaneously tolerates its own cells,” she explains at the beginning of the talk. “When these mechanisms malfunction, chronic infectious disease and autoaggressive inflammations result.” Christina Zielinski speaks quietly and is rather reserved, waiting for questions from her counterpart. However, as soon as she has warmed up and started speaking about her work, we get a sense of the tremendous energy behind this delicate person. “For me, doing research is a luxury. I can completely dedicate myself to my interests from morning to evening, and then even call it my job,” she says, and, with a grin adds, “of course you have to be a little crazy and interest-driven, otherwise it sometimes does gets difficult.”

Christina Zielinski started her medical studies at the University of Heidelberg. She was interested in science from the start, and was captivated by cancer research in particular. The partner site Heidelberg certainly contributed to this interest with its strong scientific environment and the range of seminars it provided. After six semesters, she decided to go abroad for a year in order to concentrate fully on her research. Supported by a grant from the German Academic Scholarship Foundation, she went to the University of Yale to do her doctoral dissertation. “I was really very courageous here,” she remembers, “because I applied to the author of my immunology textbook, who was preeminent in the field of immunology at the time.” Her courage was rewarded, Zielinski went to Yale. She had followed her interests and set foot in immunology.

International travel

After Yale, further spectacular stays abroad at top-class research institutions followed: as an international visiting scholar, Christina Zielinski visited Stanford University in Palo Alto, Duke Medical School in Durham and, last but not least, Harvard Medical School in Boston. “I did enjoy travelling,” the scientist admits, “but it was actually primarily more about getting top-class education at the best research establishments.” She only briefly mentions that she needed scholarships to go to these selected places, and does not mention at all that she was actually granted them on the basis of her excellent performance. It almost seems as if the young scientist has been planning her career strategically. When asked about this, she ponders for a longer while. “I’m not sure, I actually always decided very spontaneously,” and then goes on to explain, “I simply keep my eyes open and try to do my work as well as possible. And this is how interesting opportunities keep arising.”

When, after her studies, Christina Zielinski started her specialist medical training, it was clear that she wanted to continue with immunology. She started her training in Tübingen—in dermatology, a field which permits her to experience immunology live through many different diseases. She worked as a physician at the University Hospital for almost two years. Then, one morning, she had to present a paper in a journal club meeting, describing the discovery of TH17 cells, and this reignited her researcher spirit. She spontaneously decided to go to Bellinzona in Switzerland as a postdoc, where first-class immunology research with a special focus on human immunology was being conducted. “I could sense that this discovery was a really big thing and wanted to ride the wave of developments immunology was experiencing through this.”

When research calls

T cells, or more precisely T lymphocytes, are white blood cells that especially constitute a part of the so-called acquired human immune system. They are produced in the thymus and specifically react to foreign substances, so-called antigens. What was so interesting about these immune system helpers that made Christina Zielinski change course from one day to the next? “T cells are an incredibly interesting community,” Christina Zielinski tries to explain. “An imbalance often manifests painfully in the affected person.”

However, what especially interests Zielinski about research on these cells is investigating their major potential to fight diseases. For example, TH17 cells produce interleukin-17, a substance which causes tissue damage in many auto-immune diseases, as is seen in the known and dreaded disorder psoriasis. After this link had been identified, an interleukin blocking molecule that almost completely suppresses psoriasis could be produced relatively quickly. Unfortunately, the drug is still very expensive but, nonetheless, it exemplifies the kind of incentives that drive T cell researchers. Translation, meaning rapidly transferring results from research to treatment, has long been a reality in this field.

Clinical scientist

After her postdoc in Switzerland, Christina Zielinski decided to complete her specialist training. She acquired her medical specialty certification in dermatology at the Charité in Berlin, an “immunology hotspot” as she puts it, and went on to do additional further specialist allergy training. In 2015, the DZIF posted a professorship in the field of immunology for which she applied. “I was actually not exactly looking for a job,” she admits, “but I always kept my eyes open and suddenly several professorships were on offer.” The strong scientific environment and outstanding facilities in Munich were the deciding factors for her to move there. “I now feel very much at home here and have already been integrated into several research associations.”

Now, the focus of her work at the DZIF is investigating the interactions between immune cells and infections. How is it possible that T cells, which are responsible for detecting and combating intruders, are able to simply tolerate so many other microorganisms in the body? And what happens when the immune system suddenly reacts to everything and starts fighting itself, as is the case in autoimmune disorders. Evidently, T cells learn from microorganisms and vice-versa. For example, the researchers now know that T cells can have both anti-inflammatory and inflammatory effects. Molecular switches, which bacteria and fungi are also able to “flip”, determine their equilibrium. Recently, scientists have again discovered a new type of T cell. Things will therefore remain interesting in this field, Zielinski is sure.

Almost a year after moving from Berlin to Munich, Christina Zielinski feels at home in this very different city. “Berlin was chaotic in every respect, but very charming,” she remembers. “I enjoyed living there, in Prenzlauer Berg. In contrast, Munich is very well organised and a little conservative, which suits my current phase in life.” With a two year old son and a husband at her side, who is also engaged in research, good organisation is the most important thing. And, without regret, she admits that her interest in culture is more in the background. Her tenure-track professorship, which will be evaluated after six years, is however taking its toll. A permanent professorship will only be guaranteed through achievements, so this is not an easy path for a young mother. However, with everything Christina Zielinski has already achieved, this should certainly also be possible.