A portrait of veterinary pathologist Anja Kipar, Professor at the University of Zurich: her discoveries of the effect of SARS-CoV-2 on the brain, and how she is able – as a Swiss university researcher – to participate in a Horizon Europe project on Long COVID.

When Anja Kipar welcomes us to her office on the grounds of the University of Zurich’s Vetsuisse Faculty, she already has a busy morning behind her. First a two-hour lecture on the “pathology of the stomach”, then reviewing pathological findings of a kite found dead and a deceased bovine, followed by internal finance and personnel discussions, and ending with an online meeting with a research colleague in Australia on a joint COVID-19 project.

Being a professor of veterinary pathology means she wears several hats and has the responsibilities that come with them. As a full professor she is responsible for teaching and research: leading research teams, managing research projects, and maintaining an international research network. As Director of the Institute of Veterinary Pathology she leads a laboratory that provides diagnostic services for animal diseases and is also accredited for epizootic animal disease diagnostics, and hosts a national and international reference centre. Anja Kipar herself participates in diagnostics at the institute, stating that, “as head of the institute, I have to keep up to date diagnostically, so I am on duty as senior pathologist in the necropsy diagnostics for a few weeks every year.”

How does she meet all these demands? How does she manage her approximately 40 employees?

“As pathologists, we are all contributing to diagnostic work, teaching and undertaking research. We do so by having clearly defined tasks and flat hierarchies. For example, the laboratory team is led by an experienced laboratory technician, and the team in our diagnostic office by an established administrator. Experienced pathologists head the post mortem, biopsy and cytology diagnostic services as well as the electron microscopy unit. We ensure that all qualified pathologists have specific areas of expertise. With an eye on the future of veterinary pathology, our diagnostic material serves to train future pathologists, and at any time, several veterinarians are enrolled in the four-year postgraduate training at our institute. These veterinarians aim to become Diplomates of the European College of Veterinary Pathologists, a pathway that culminates in a very demanding Europe-wide examination.”

Anja Kipar is a pathologist by passion. The Institute of Veterinary Pathology, which finances itself to a large extent by service income, has excelled as a competitive interface between research and practice. To this end, she has systematically expanded the technical infrastructure since she was appointed director in Zurich in 2013, thus ensuring that the institute maintains state-of-the-art equipment and facilities for both diagnostics and research.

Of men and mice

“Please join me, I will show you our laboratories,” Anja Kipar says and leads us to the ground floor, where her laboratory manager is already waiting for us. Sabina Wunderlin and her seven-strong team are responsible for processing, among many other things, the specimens for further analysis by the pathologists: from the fixed organs of the dissected animals to a stained section.

To demonstrate the different work processes, Sabina Wunderlin uses the example of a research project on COVID-19 that Anja Kipar is currently conducting in collaboration with a molecular virologist at the University of Liverpool. As part of this pathogenicity study Anja Kipar is investigating how the Omicron BA.2 variant spreads in mice. For this purpose, she receives from her colleagues in Liverpool not only the lungs but also the skulls of experimentally infected laboratory mice fixed in formalin. Sabina Wunderlin carefully takes a mouse skull out of the container and cuts it longitudinally with a fine diamond saw so that the two halves of the brain become visible. In several steps, the skull parts are then decalcified, dehydrated and cast into small blocks with liquid paraffin. Sections of 2-3 µm thickness are then prepared from these with a microtome, drawn onto glass slides in a water bath, freed from paraffin in a special device and stained by machine. After final covering, the slides are ready for pathological analysis under the microscope or as a scan on the screen. The laboratory work requires a high level of expertise and a great deal of dexterity by Sabina Wunderlin and her team, aided by the most modern equipment that they have at their disposal.

In the beginning, there was the cat

Back in her office, Anja Kipar tells us why she is undertaking research into COVID-19. “I actually came to coronavirus research via the cat around 2000, when I worked on my Venia legendi in Leipzig and Giessen on the pathogenesis of feline infectious peritonitis (FIP), a fatal disease in cats that is caused by a coronavirus. FIP has been known since the 1950s, but its pathogenesis is still not fully understood.”

Over the years, Anja Kipar has continued to research the immunopathogenesis of FIP with collaboration partners in the UK and Zurich. Thus, when the novel coronavirus SARS-CoV-2 triggered a pandemic in early 2020, her expertise was twice in demand – as a researcher who has already worked on coronaviruses and as a renowned, well-connected, and well-equipped pathologist with specific experience in mouse models of virus-associated respiratory diseases.

Anja Kipar established excellent relationships with virologists during her career at the Universities of Liverpool and Helsinki, which became longstanding collaborations, researching relevant aspects of human viral diseases. These colleagues asked her to collaborate with them on planned infection trials in laboratory mice and hamsters to investigate the pathogenesis of COVID-19. At the time, the scientific community was under enormous public pressure to quickly deliver solutions on how to deal with the pandemic. Anja Kipar immediately established protocols to be able to carry out the pathological evaluation of these experiments. In April 2020, the first collaborative COVID-19 study began with the University of Liverpool. Further COVID-19 projects with the University of Helsinki followed in the summer of 2020. Since then, numerous additional studies have been undertaken, including several on the development of vaccines and the prevention and treatment of SARS-CoV-2 infection.

What are the most interesting findings of Anja Kipar’s research on COVID-19 over the last two years? “We have gained a wealth of interesting results. But what I find particularly exciting is the finding that in certain laboratory mice, infection with all the virus variants known so far except Omicron is not limited to the nose and lungs, but very often reaches the brain – probably via the olfactory bulb – and triggers a mild inflammatory reaction without obvious damage to nerve cells. We have recently published these results and now aim to find out whether the virus also remains in the brain for a longer period of time.”

Consortium “Long COVID”

By now, research is no longer only concerned with acute COVID-19. Many people develop Long COVID as a long-term consequence of the virus infection. Symptoms include fatigue, exhaustion, headaches, coughing, persistent loss of sense of smell and taste, and cognitive impairment. The diagnosis and treatment of Long COVID prove to be difficult, as the clinical picture is often non-specific and varies greatly between individual patients. Therefore, in September 2021, twelve universities, clinics and research laboratories from Finland, Germany, Estonia, Italy, the Netherlands and Switzerland joined forces to form a consortium and submitted a project to the EU as part of the Horizon Europe research programme to address the many open questions regarding Long COVID. With the project, the consortium aims to clarify the causes and manifestations of the disease and provide physicians with practical knowledge and tools for the diagnosis and treatment of Long COVID. Anja Kipar and her team are part of this consortium. Together with virologists at the University of Helsinki they are conducting studies to identify possible pathomechanisms underlying Long COVID.

“We hypothesise that inflammatory reactions in the brain are central to the pathogenesis of Long COVID. We do not yet know whether the virus directly induces these or whether it triggers systemic reactions in the body that then affect the brain. We are investigating this by taking a closer look at the direct effect of the virus on nerve cells and the effect of infection of other cell types on nerve cells. For this purpose, we use in vitro systems of human cells and established mouse infection models as well as different virus variants. We place particular emphasis on the analysis of the brains of infected mice.” For this demanding analytical work, Anja Kipar has brought two highly specialised colleagues on board, neuropathologist Frauke Seehusen and ultrastructural pathologist Udo Hetzel. The infection experiments are carried out at the University of Helsinki, the subsequent examinations in Zurich. In the meantime, the “Long COVID” project has started. In May 2022, the consortium signed the contract with the EU, and the kick-off meeting was held in Helsinki at the end of June.

Participating in Horizon Europe

Many researchers in Switzerland are disappointed and upset by being unable to submit their own projects to the EU’s Horizon Europe research programme, or to take on project coordination. As a result of the breakdown of negotiations on an institutional framework agreement, the EU denied Switzerland full association with Horizon Europe. How did Anja Kipar manage to be part of the ambitious “Long COVID” project? In fact, the exclusion of Switzerland from Horizon Europe is not as complete as it may be perceived. Swiss researchers can still participate in collaborative EU projects as partners. And, the work within large interdisciplinary consortia is appealing to Anja Kipar. “My strength has always been in interdisciplinary collaboration. This is indeed inherent in veterinary pathology. We often come from diagnostic work, develop an interest in specific diseases and gain our knowledge mainly at the interface and in collaboration with other experts, less frequently in large individual projects, such as those funded by the European Research Council ERC.”

Throughout her career, Anja Kipar has established an excellent international network of collaborators, through which she is constantly involved in new and interesting projects. “I enjoy working in these large international consortia where people complement, appreciate and trust each other. They are the optimal counterpart to my other research, in which I investigate the pathogenesis of individual relevant animal diseases.”

Before we go, we would like to know from Anja Kipar how her busy work day will end. “Actually, I wanted to attend a lecture of a researcher from the London School of Tropical Medicine who is in Zurich today. But it’s too late for that now. So, I will go home soon, take care of my family for a bit – let’s see what we’re having for dinner. And then I urgently need to review some applications and read a paper!”

Interview with Anja Kipar