Michael Oellerich George-August-University Göttingen
>> Tuesday 13:30 in TBA
Jules Griffin Imperial College London
Imaging the unimaginable with imaging mass cytometry Fritz Koning LUMC
Prof. Frits Koning is a staff member in the department of Immunohematology and Blood Transfusion (150 fte) of the Leiden University Medical Centre since 1993. He is the chairman of the scientific advisory board of the LUMC. He is well recognized for his contributions to the field of immune mediated disorders, celiac disease in particular. Through his work it is now well established which gluten fragments are disease causative and how they are recognized by disease-related T cells, providing a molecular basis for the genetic association between HLA-DQ and celiac disease. In his most recent work he uses high dimensional (imaging) mass cytometry to unravel the involvement of the innate and adaptive immune system in the mucosal immune system in health and disease.
The fetus is thought to be protected from exposure to foreign antigens, yet CD45RO+ T cells reside in the fetal intestine. Here we combined functional assays with mass cytometry, single-cell RNA sequencing and high-throughput T cell antigen receptor (TCR) sequencing to characterize the CD4+ T cell compartment in the human fetal intestine. We identified 22 CD4+ T cell clusters, including naive-like, regulatory-like and memory-like subpopulations, which were confirmed and further characterized at the transcriptional level. Memory-like CD4+ T cells had high expression of Ki-67, indicative of cell division, and CD5, a surrogate marker of TCR avidity, and produced the cytokines IFN-? and IL-2. Pathway analysis revealed a differentiation trajectory associated with cellular activation and proinflammatory effector functions, and TCR repertoire analysis indicated clonal expansions, distinct repertoire characteristics and interconnections between subpopulations of memory-like CD4+ T cells. Imaging mass cytometry indicated that memory-like CD4+ T cells colocalized with antigen-presenting cells. Collectively, these results provide evidence for the generation of memory-like CD4+ T cells in the human fetal intestine that is consistent with exposure to foreign antigens.