Furthermore, we are monitoring and optimizing strategies of adoptive T cell therapy in cancer mouse models.
Recently, we could identify the human bone marrow as a potential target of acute graft-versus-host disease (GvHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Acute leukemic patients and here in particular those displaying systemic acute GvHD and/or those receiving a full-intensity conditioning regimen, showed increased bone marrow T-cell infiltration associated with the loss of osteoblasts and delayed onset of B-cell neogenesis (Figure 1).
Currently, we are interested in 1) unravelling the potential mechanism of human bone marrow GvHD, 2) identifying mechanisms responsible for long-term memory B-cell deficiency post-transplant and 3) the possibility to use “long-living” memory B cells residing in the bone marrow for adoptive cell transfer in immunodeficient patients.
In the field of primary immunodeficiency, we are currently investigating potential pathogenic pathways in patients with primary selective IgM deficiency. We apply a combined approach of NGS whole exome sequencing (in collaboration with the Institute for Medical Genetics, Charité) and analysis of related immune cell function.
Using bioluminescence-reporter mice we are able to easily study the in vivo migration, tumor-infiltration and activation of adoptively transferred T cells. Our aim is to optimize the efficiency of tumor rejection by adoptive T cell therapy (ATT) and to minimize the off-target organ toxicity presenting as GvHD. We have generated a transgenic reporter mouse expressing an NFAT-inducible Click-beetle luciferase (CB/NFAT) in order to be able to visualize T-cell activation in vivo (Figure 2A/B).
As a test of our CB/NFAT reporter system in a mouse model of GvHD, we transplanted lethally irradiated male B6 mice with female B6 bone marrow and splenic CB/NFAT T cells and analyzed the transferred transgenic donor T cells via bioluminescence imaging (BLI). Two weeks after transplantation, NFAT activation could be seen predominantly in spleen and gut of male recipients most likely triggered by alloreactivity against the minor antigen HY. Thus, we are able to track adoptively transferred T cells and their spatio-temporal activation pattern mediating GvHD. Furthermore, Renilla luciferase (RLuc) transgenic mice were crossbred with H-Y specific TCR transgenic Marilyn and MataHari mice in order to obtain H-Y specific TCR, RLuc double transgenic CD4+ and CD8+ T cells respectively, used for adoptive transfer into female Rag recipients bearing H-Y antigen expressing tumors like 200.09 or MB49. Transferred RLuc+ MataHari T cells preferentially accumulated within HY antigen positive tumors (Figure 2C). Currently, we are generating a mouse triple transgenic for CB/NFAT, RLuc and the HY-TCR, in order to simultaneously visualize T cell migration and activation in an HY minor mismatched model.
Our clinically relevant transplantation model will enable us to evaluate and improve novel strategies to separate graft-versus-tumor from GvHD effects in the context of ATT.
Prof. Dr. Carmen Scheibenbogen, Institute of Immunology, Berlin, Germany
Prof. Dr. Thomas Blankenstein, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
Prof. Dr. Renate Arnold, Hematology and Oncology, Charite CVK, Berlin, Germany
Prof. Dr. Lutz Uharek, Hematology and Oncology, Charite CVK, Berlin, Germany
Dr. Simon Fillatreau, Deutsches Rheuma-Forschungszentrum, Berlin, Germany
Dr. Chiara Romagnani, Deutsches Rheuma-Forschungszentrum, Berlin, Germany
Prof. Dr. Marcel van den Brink, Memorial Sloan-Kettering Cancer Center, New York, USA
Prof. Dr. Michel Sadelain, Memorial Sloan-Kettering Cancer Center, New York, USA