Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany
Paloma Martzloff
Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany
Christiane Harenberg
Department of Molecular Neurobiology, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
Keerthana Ravichandran
Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, Homburg, Germany
Midhat H Abdulreda
Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, Miami, United States; Department of Surgery, University of Miami Miller School of Medicine, Miami, United States; Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, United States; Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, United States
Per-Olof Berggren
Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, Miami, United States; Department of Surgery, University of Miami Miller School of Medicine, Miami, United States; Diabetes Research Institute Federation, Hollywood, United States; The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
Understanding T cell function in vivo is of key importance for basic and translational immunology alike. To study T cells in vivo, we developed a new knock-in mouse line, which expresses a fusion protein of granzyme B, a key component of cytotoxic granules involved in T cell-mediated target cell-killing, and monomeric teal fluorescent protein from the endogenous Gzmb locus. Homozygous knock-ins, which are viable and fertile, have cytotoxic T lymphocytes with endogeneously fluorescent cytotoxic granules but wild-type-like killing capacity. Expression of the fluorescent fusion protein allows quantitative analyses of cytotoxic granule maturation, transport and fusion in vitro with super-resolution imaging techniques, and two-photon microscopy in living knock-ins enables the visualization of tissue rejection through individual target cell-killing events in vivo. Thus, the new mouse line is an ideal tool to study cytotoxic T lymphocyte biology and to optimize personalized immunotherapy in cancer treatment.
