Senolytic CAR T cells reverse senescence-associated pathologies
Authors: Michel Sadelain
Josef Leibold
Shauna Houlihan
Jacob A Boyer
Alessandra Piersigilli
Theodoros Giavridis
Yu-Jui Ho
Direna Alonso-Curbelo
Ellinor Peerschke
Amanda Kulick
Scott L Friedman
Vladimir Ponomarev
Judith Feucht
Xiang Li
Scott W Lowe
Corina Amor
Jorge Mansilla-Soto
Changyu Zhu
Journal: Nature (2020)
Discipline: Multidisciplinary
Keywords: Cellular senescence; tumour-suppressive mechanism; senescent cells; inflammatory milieu; chronic tissue damage
Affiliations: Louis V. Gerstner Jr Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Department of Cancer Biology and Genetics, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Center for Cell Engineering, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Molecular Pharmacology and Chemistry Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Weill Cornell Graduate School of Medical Sciences, New York, NY, USA., Department of Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Division of Liver Diseases, Icahn School of Medicine at Mount Sinai, New York, NY, USA., Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA., Laboratory of Comparative Pathology, Rockefeller University, Weill Cornell Medicine and Memorial Sloan Kettering Cancer Center, New York, NY, USA., Center for Cell Engineering, Memorial Sloan Kettering Cancer Center, New York, NY, USA. ., Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA. ., Department of Cancer Biology and Genetics, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA. ., Howard Hughes Medical Institute, Chevy Chase, MD, USA. .

Abstract:  Cellular senescence is characterized by stable cell-cycle arrest and a secretory program that modulates the tissue microenvironment1,2. Physiologically, senescence serves as a tumour-suppressive mechanism that prevents the expansion of premalignant cells3,4 and has a beneficial role in wound-healing responses5,6. Pathologically, the aberrant accumulation of senescent cells generates an inflammatory milieu that leads to chronic tissue damage and contributes to diseases such as liver and lung fibrosis, atherosclerosis, diabetes and osteoarthritis1,7. Accordingly, eliminating senescent cells from damaged tissues in mice ameliorates the symptoms of these pathologies and even promotes longevity1,2,8-10. Here we test the therapeutic concept that chimeric antigen receptor (CAR) T cells that target senescent cells can be effective senolytic agents. We identify the urokinase-type plasminogen activator receptor (uPAR)11 as a cell-surface protein that is broadly induced during senescence and show that uPAR-specific CAR T cells efficiently ablate senescent cells in vitro and in vivo. CAR T cells that target uPAR extend the survival of mice with lung adenocarcinoma that are treated with a senescence-inducing combination of drugs, and restore tissue homeostasis in mice in which liver fibrosis is induced chemically or by diet. These results establish the therapeutic potential of senolytic CAR T cells for senescence-associated diseases. 

Retracted: No

PubPeer comments:
 Dear Authors, We have read your paper u201cSenolytic CAR T cells reverse senescence-associated pathologiesu201d with great interest during our weekly literature meeting. However, as we have spotted a few things that we would have liked to see explained (or corrected) in future publications, we permit ourselves to present some suggestions for improvements: General comments: 1. We feel that there is a slight exploitation of the concept of targeting senescence cells in the paper. The models used in the study are models of pathologies-associated with senescence (as stated in the title). However, in the text it is described as if the targeted cells were senescent. However, this is not true, as the models are not inducing cellular senescence as such, but only the associated-pathologies. 2. Although data presented in the paper convincingly show that uPAR could be used as a target for CAR T cells, there are a few things that suggest that future studies should proceed with caution: - As shown in Fig. 1a and b, uPAR can be secreted. Proteins which can be secreted are not good targets for CAR therapy, because they can block CAR or trigger it unspecifically. Even if the CAR will target only uncleaved version of uPAR, how will potential subsequent cleavage affect binding or the function of the CAR-T cell? - uPAR was selected based on the lack of expression in vital tissues, however limited knowledge about uPAR function in healthy tissues does not mean that it is redundant. Knowledge gaps give a risk of inadvertently targeting cells that could give serious side effects if anti-uPAR CAR T cells were to be tested on humans. - uPAR expression on immune cells suggest that they could be easily targeted by anti-uPAR CAR T cells in blood. Moreover, targeting immune cells can increase chances of developing serious side effects, like cytokine storm. 3. Showing data as mean with SEM is not wrong, but it is not a really honest way of data presentation either. It would be better for the reader to judge results by seeing all the data points. Presenting medians with range would have been better. 4. Extended data Fig.2 and 3 have very helpful titles naming the model and tissue placed between figure panels. It would help the reader if all the other figures have similar titles describing panels. 5. Showing one set of data out of 3 representative experiments is not an honest way of data presentation. Especially if the data was quantifiable and could have been easily presented on a single graph. Specific comments: 1. Extended data Fig. 1b, c u2013 CAR T cells can only target proteins, which are expressed on the cell surface. However, proteins defined by UniProtKB as located in the plasma membrane do not necessarily have to be present on the cell surface. A good example is ACTN1, which is a cytoskeletal protein, bound to the inner side of the plasma membrane. 2. Extended data Fig. 1e u2013 How relevant is the protein expression data from Human Protein Atlas and the Human Proteome Map for elderly people? As the paperu2019s goal is to find senescence-associated targets, it would be wise to compare the protein expression with the most relevant datasets. 3. Fig. 1d and e u2013 Did authors correlate uPAR expression with any other senescence markers in their models? 4. Extended data Fig. 3 - Correlating uPAR expression with senescence-associated pathologies does not necessarily mean that it is a marker of senescence. It only means that it is a marker for these specific pathologies. 5. Fig. 2a u2013 Data from m.uPAR-h.28z and h.19-h28z is surprisingly overlapping. Does the graph present data from 1 representative experiment or from 3 independent experiments? Is the E:T ratio the only difference between these graphs and graphs presented in extended data fig.4? 6. Fig. 2b u2013 Why is the E:T ratio so different from fig. 2a? Is it still a comparable scale of efficiency? 7. Fig. 2d u2013 It would be interesting to see data from a similar NRAS system with m.uPAR-h.28z cells, but using uPAR negative mice. 8. Fig. 2g u2013 The LNGFR abbreviation is not explained in the text. 9. Fig. 2h u2013 The X-axis should stop at 100% as it is not possible to get cell populations consisting of more than that. 10. Fig. 4b u2013 Picture in the second column and the second row should show desmin alone, without merging with uPAR signal. 11. Fig. 4? u2013 Graphs under panel b are orphaned. They should have been designated with a panel letter, as it is hard to define to which panel they belong to. ,