Dominika Pohlmann & Julian Braun
Longitudinal characterization of cellular immune components in non-infectious chorioretinitis using mass cytometry (CyTOF)
Non-infectious Chorioretinitis comprises a group of eye diseases with intraocular inflammation of the retina, the retinal pigment epithelium and the choroidea. The diseases display a clinically progressive, remitting-relapsing disease course with the destruction of the retinal photoreceptors and have a mostly bad visual prognosis, even until blindness. The etiology, however, remains to be elucidated.
Therefore, in this project, we have analyzed immune statuses of the patients in a longitudinal manner to identify differences dependent on either diagnosis in general or disease activity.
To this end, peripheral lymphocytes of roughly 80 patients and 40 healthy subjects were taken at three different timepoints. By using a frozen antibody cocktail and cryopreserving the stained and fixed cells, it was possible to stain the samples freshly and measure at a later timepoint. In preparation for the measurement using mass cytometry (CyTOF), the samples were accordingly thawed, and the cells of the individual samples were barcoded so that pooled samples could be measured. In total, over 300 Mio. cells were immunophenotyped and bioinformatically analyzed using Astrolabe. Our first results already showed significant differences in the memory CD4+ T cells (TH17 and TH17.1) in the patients group compared to the healthy control group. In addition, the enrichment of TH2 and inflammatory monocytes indicates that the examined eye diseases have an autoimmune etiology. Through this project and this method, we have gained new insights into the pathophysiology of a group of eye diseases and hope to develop targeted treatment strategies for the patients to prevent blindness.
Dominika is a medical specialist in Ophthalmology at Charité-Universitätsmedizin Berlin and takes part in the Clinician Scientist Program at the Berlin Institut of Health (BIH). Her scientific focus is to combine clinical and experimental research. She is interested in non-infectious intraocular inflammations and its immunological aspects, which she chose to characterize by using mass cytometry (CyTOF).
Julian is Postdoc in the group of Andreas Thiel at the BIH Center for Regenerative Therapies. After he researched on mesenchymal stem cells, he switched to immunology with a focus on ageing and ophtalmologic research using conventional and mass cytometry. Since two years, his work focuses in understanding the impact of cross-reactivity on SARS-CoV-2 epidemiology and COVID-19 disease course.
Dr. med. Dominika Pohlmann, FEBO, Charité – Universitätsmedizin Berlin, Department of Ophthalmology, Berlin, Germany
Dr. rer. nat. Julian Braun, Regenerative Immunology and Aging, BIH Center for Regenerative Therapies at Charité – Universitätsmedizin Berlin, Germany