Principal Investigator
Kari obtained his Ph.D. at the University of Helsinki in 2011. In his doctoral research, in the lab of Dr. Tomi Mäkelä, Kari investigated mesenchymal and epithelial cell interactions in the context of gastrointestinal tumorigenesis. During his postdoctoral training in the lab of Prof. Michael Sixt (2012-2015; IST Austria), Kari investigated lymphatic endothelial chemokine CCL21 presentation during antigen-presenting dendritic cell transmigration. To deepen his knowledge on lymphatic system, Kari moved back to Finland for a second postdoctoral period in the lab of Prof. Kari Alitalo (2015-2018). In September 2018, Kari established his independent Cell Communication Laboratory at the Faculty of Medicine, University of Helsinki. Current research interests are focused on, how dynamic cell-cell interactions i) shape complex multicellular structures, such as lymphatic system, and ii) cell migration/interaction guidance cues.
Postdoctoral Researcher
Amanda earned her Ph.D. in Biochemistry and Molecular Biology from the University of Nebraska Medical Center in 2025. In her dissertation research, Amanda investigated the central role of the Golgi apparatus in pathogenesis and progression of prostate cancer and alcohol-associated liver disease. She focused on the mechanisms that maintain the Golgi’s structural integrity and the impact of Golgi disorganization on protein processing, secretion, and function. In the Vaahtomeri lab, Amanda has shifted down the secretory pathway to focus on regulation of exocytosis. She is now studying the spatiotemporal regulation of dendritic cell migration through the lymphatic endothelium. Her research focuses on: 1) the conditional secretion of cytokines and chemokines and 2) the consequences of dendritic cell transmigration on the lymphatic endothelium.
Doctoral Student
Maria compeleted her B.Sc. in Molecular Biosciences in 2022, and M.Sc. in Translational Medicine in 2024, at the University of Helsinki. With major interest in immune-interactions, Maria did her master’s thesis under the supervision of Kari Vaahtomeri, on the topic of lymphatic endothelial cell antigen trafficking, while simultaneously contributing to studies in lymphatic endothelial cell chemokine secretion. Currently Maria is working on her Ph.D. as part of the national doctoral education pilot, under IMMUDOCs consortium. Her project focuses on unveiling the mechanisms of lymphatic endothelial cell immunomodulation and antigen trafficking.
Doctoral Student
Jeremia joined Vaahtomeri group while studying for a master’s degree in cell and developmental biology, in the University of Helsinki. Working in the lab he compiled a thesis characterising induced growth in lymphatic capillaries and graduated in 2024. Afterwards, he continued onto a Ph.D. as part of the national doctoral education pilot, under IMMUDOCs consortium. As for motivation he states: “It is at least slightly interesting that we pretty reliably end up with complex anatomy, like eyes, ears and dermal capillary lymphatic vessels, instead of as amorphous masses of cells, and to think that its cells communicating and co-operating with each other, which makes our bodies possible”. Jeremia’s PhD project expands on the topic of his master’s thesis, further exploring the details of sprouting lymphangiogenesis, a process where existing lymphatic vessel grows a new side-branch to increase vascular network density and functional output. Such sprouting occurs during development, but also in adulthood under inflammation. Hence, a central question is how the cells of the lymphatic vessels orchestrate their behaviour to grow new branches without damaging existing vessel integrity.
Doctoral Student
Mario completed his M.Sc. in Stem cells, organogenesis and regenerative medicine at the Lebanese University, Beirut. His previous research mainly focused on the inter-communication between stem cell populations in the bone marrow, as well as studying the organotropism exhibited by some metastatic cancer cells towards specific organs. Mario joined the Vaahtomeri lab in June 2024 to pursue his doctoral studies. He recently received the UH-funded doctoral position as part of the Integrative Life Sciences (ILS) doctoral program.
His Ph.D. studies explore the molecular mechanisms controlling lymphatic endothelial guidance cue presentation and their direct effect on dendritic cell transmigration through lymphatic endothelial junctions. His work presents a blend of advanced biological imaging, state-of-the-art mouse model experimentation, and in vitro cell interaction setups, all aiming to elucidate potential cues for fine-tuning dendritic cell migration in the lymphatics.
Master's Degree Student
Ellen earned her BCs in Biochemistry at the University of Oulu in 2024. Her Bachelor’s thesis concerned the use of chimeric antigen receptor T cells (CAR-T cells) in cancer therapy. She continued her studies in the master’s program of molecular medicine and, due to her great interest in immunology, proceeded to work on her master’s thesis in the Vaahtomeri lab. Her current research deals with the mechanims regulating CCL21 delivery to multicellular junctions in the context of dendritic cell guidance to the lymphatic system.
Master's Degree Student
Anne received her Bachelor's degree in Biology at the University of Helsinki in 2025. She is currently pursuing a Master's degree in Genetics and Molecular Biosciences, specializing in cell and developmental biology. With a strong interest in developmental processes and cell signaling, she works as a research assistant in the Vaahtomeri lab, contributing to a project focused on sprouting lymphangiogenesis.
Inam Liaqat, Ph.D.
Ida Hilda, M.Sc.
Otto Litkey
Jasmin Haltilahti
Emma Jakobsson, M.Sc.
Sonja Granroth, M.Sc.
Emmi Tiilikainen M.Sc.