Dr Mariana Borsa joined Prof Katja Simon's lab at the Kennedy Institute of Rheumatology (KIR) in 2019. After securing a competitive Starting Grant from the Swiss National Science Foundation, Mariana has been appointed an Assistant Professor at the Department of Biomedicine at the University of Basel, Switzerland. In September 2025 she will launch the new Immune Cell Biology Laboratory to drive an exciting research question: to what extent does the ageing of cellular components influence ageing at the whole-body level? Being an immunologist at heart, her lab will focus on developing strategies to promote healthier immune ageing.
Kennedy legacy: cellular ageing versus body ageing
Over the last few years, Mariana has studied autophagy – a process of cellular recycling by which damaged cellular components are targeted and degraded, allowing the cell to stay 'rubbish free'. Mariana found that autophagy controls early T cell fate decisions by regulating the asymmetric inheritance of heterogenous pools of mitochondria in T cells. Following T cell division, two types of daughter cells emerge: short-lived cells retaining old mitochondria and long-lived cells devoid of old organelles and capable of doing autophagy – these are the cells that become memory T cells and are at the core of successful vaccination setups.
Reflecting on the decision to become a PI, she said: 'I wanted to start my own lab because I am truly fascinated by the antagonistic relationship between ageing and stem cells - there are so many unanswered questions, but I only have two hands! Now that I am starting a lab, I can't wait to hear what new ideas my future group members will come up with.'
Technologies, collaborations, and training at the Kennedy Institute
At the Kennedy Institute, the advanced microscopy facilities at the Oxford-ZEISS Centre of Excellence in Biomedical Imaging were critical to Mariana's success. 'I don't think I'll ever find such a good setup', she says. 'My work relied heavily on high-fidelity cellular imaging.'
Prof Katja Simon recently moved her laboratory to Berlin, while Mariana stayed at the Kennedy Institute. About Mariana, Katja said: 'Mariana is an extraordinary postdoc and scientist, who not only worked intelligently and hard on her own project but also helped many others in my labs in Oxford and Berlin. She obtained every grant she applied for, and raised therefore her salary over 6 years. Amazingly again she obtained starting grant funding that should set her up nicely for the junior group leader position in Basel. I wish her all the best and will truly miss her.'
'After Katja moved, I was adopted by Prof. Mike Dustin's lab,' says Mariana. 'Working with Mike, I learned a lot about the T cell synapse, which is highly relevant to my work on asymmetric T cell fates. I also had synergistic interactions with the labs of Prof Audrey Gérard, Prof Marco Fritzsche and Prof Alex Clarke.'
Mariana recently completed the EMBO Lab Leadership Course for Postdocs and found it extremely helpful for her transition from postdoc to PI. 'It helped me to become more assertive', she said. 'I just wish I had done it earlier!' While at the Kennedy Institute, Mariana was part of both the KIR Postdoc Committee and the NDORMS Equality, Diversity and Inclusion (EDI) Committee, and emphasised the value of learning how others communicate – especially as part of a diverse scientific community. 'It's so important to understand that people think in different ways.'
Mariana's advice to other Postdocs
When asked if she has advice for Postdocs who wish to start their own lab, Mariana suggested 'use your time wisely. We spend lots of time in the lab, of course, but make sure to build a network beyond your institute. You'll meet the people who you will collaborate with in the future, but also those that will review your papers and grants. I've also found some great mentors.'
Shortly after Mariana joined the institute in 2019, she applied for grants which sustained her research for six years. Mariana found that as she applied for grants, her network grew. Later on, applying for jobs had the same effect. 'It was beautiful to go for interviews and be met with such a friendly and cooperative environment, even among people competing for the same job,' she said. 'Put your face out there and let yourself be known, don't stay in your bubble!'
Mariana's research group in Basel will focus on the ageing of cellular components within T cells and study how this affects T cell function and fate. 'We know that T cells drive ageing - if your T cells are unhealthy, your body ages,' said Mariana. 'This is probably driven by the contribution of T cells to what we call inflamm-ageing (low-grade chronic inflammation), but it is not entirely clear what is happening at the cellular level or how we can modulate intracellular networks. We will investigate whether there is a reciprocal relationship between the maintenance of cellular damage and the ageing of the organism. To do this, we will focus on the age-dependent function of organelles that are important for cellular metabolism: mitochondria and peroxisomes. We aim to identify biomarkers of organelle ageing in T cells and potentially ways to modulate their inheritance to promote T cell rejuvenation.'
Dr Mariana Borsa is funded by the Wellcome Trust, the Swiss National Science Foundation, and the Horizon Europe framework. If you would be interested to join her lab, please drop her an email.