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Haeryfar SMM, Marshall JS, Patel KD, Marshall AJ. Celebrating a decade of Canadian immunology published in
Immunology & Cell Biology. Immunol Cell Biol 2022; 100:383-386. [DOI: 10.1111/imcb.12563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- SM Mansour Haeryfar
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry Western University London ON Canada
| | - Jean S Marshall
- Department of Microbiology and Immunology, Faculty of Medicine Dalhousie University Halifax NS Canada
| | - Kamala D Patel
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine University of Calgary Calgary AB Canada
| | - Aaron J Marshall
- Department of Immunology, Rady Faculty of Health Sciences University of Manitoba Winnipeg MB Canada
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Sadasivam M, Noel S, Lee SA, Gong J, Allaf ME, Pierorazio P, Rabb H, Hamad ARA. Activation and Proliferation of PD-1 + Kidney Double-Negative T Cells Is Dependent on Nonclassical MHC Proteins and IL-2. J Am Soc Nephrol 2019; 30:277-292. [PMID: 30622155 DOI: 10.1681/asn.2018080815] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 11/29/2018] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND CD4- CD8- double-negative (DN) αβ T cells with innate-like properties represent a significant component of T cells in human and mouse kidneys. They spontaneously proliferate in the steady state and protect against ischemic AKI. However, the mechanisms regulating DN T cell homeostasis and responses to external danger signals from "sterile" inflammation remain poorly understood. METHODS We used knockout mice, functional assays, and an established ischemic AKI model to investigate the role of various MHC class I and II molecules in regulating kidney DN T cells. We also studied human nephrectomy samples. RESULTS Deficiency of β2m-dependent MHC class I (but not MHC class II) molecules led to significant reduction in frequency or absolute numbers of kidney DN T cells due to impaired activation, proliferation, increased apoptosis, and loss of an NK1.1+ subset of DN T cells. The remaining DN T cells in β2m knockout mice mainly comprised a programmed cell death protein-1 receptor (PD-1+) subset that depends on IL-2 provided by conventional T cells for optimal homeostasis. However, this PD-1+ subset remained highly responsive to changes in milieu, demonstrated by responses to infused lymphocytes. It was also the major responder to ischemic AKI; the NK1.1+ subset and CD8+ T cells had minimal responses. We found both DN T cell subsets in normal and cancerous human kidneys, indicating possible clinical relevance. CONCLUSIONS DN T cells, a unique population of kidney T cells, depend on nonclassical β2m molecules for homeostasis and use MHC-independent mechanisms to respond to external stimuli. These results have important implications for understanding the role these cells play during AKI and other immune cell-mediated kidney diseases.
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Affiliation(s)
| | | | | | | | - Mohamad E Allaf
- Department of Urology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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Suryadevara CM, Desai R, Farber SH, Choi BD, Swartz AM, Shen SH, Gedeon PC, Snyder DJ, Herndon JE, Healy P, Reap EA, Archer GE, Fecci PE, Sampson JH, Sanchez-Perez L. Preventing Lck Activation in CAR T Cells Confers Treg Resistance but Requires 4-1BB Signaling for Them to Persist and Treat Solid Tumors in Nonlymphodepleted Hosts. Clin Cancer Res 2019; 25:358-368. [PMID: 30425092 PMCID: PMC6390292 DOI: 10.1158/1078-0432.ccr-18-1211] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 07/31/2018] [Accepted: 11/08/2018] [Indexed: 11/16/2022]
Abstract
PURPOSE Chimeric antigen receptor (CAR) T cells have shown promise against solid tumors, but their efficacy has been limited, due in part, to immunosuppression by CD4+FoxP3+ regulatory T cells (Tregs). Although lymphodepletion is commonly used to deplete Tregs, these regimens are nonspecific, toxic, and provide only a narrow window before Tregs repopulate hosts. Importantly, CARs have also been shown to inadvertently potentiate Tregs by providing a source of IL2 for Treg consumption. We explored whether disruption of the IL2 axis would confer efficacy against solid tumors without the need for lymphodepletion. EXPERIMENTAL DESIGN We developed second- (CD28z) and third- (CD28-4-1BBz) generation CARs targeting EGFRvIII. To eliminate secretion of IL2, 2 amino acid substitutions were introduced in the PYAP Lck-binding motif of the CD28 domain (ΔCD28). We evaluated CARs against B16 melanomas expressing EGFRvIII. RESULTS CD28z CARs failed to engraft in vivo. Although 4-1BB addition improved expansion, CD28-4-1BBz CARs required lymphodepletion to treat solid tumors. CARs deficient in Lck signaling, however, significantly retarded tumor growth without a need for lymphodepletion and this was dependent on inclusion of 4-1BB. To evaluate CAR vulnerability to Tregs, we lymphodepleted mice and transferred CARs alone or with purified Tregs. Cotransfer with Tregs abrogated the efficacy of CD28-4-1BBz CARs, whereas the efficacy of ΔCD28-4-1BBz CARs remained unperturbed. CONCLUSIONS In the absence of lymphodepletion, CARs targeting solid tumors are hindered by Treg immunosuppression and poor persistence. Here, CARs were modified to circumvent Treg suppression and to simultaneously improve in vivo engraftment. Modified CARs treated solid tumors without a need for lymphodepletion.
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Affiliation(s)
- Carter M Suryadevara
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina
- Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - Rupen Desai
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina
| | - S Harrison Farber
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina
| | - Bryan D Choi
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina
- Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - Adam M Swartz
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina
- Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - Steven H Shen
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina
- Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - Patrick C Gedeon
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina
| | - David J Snyder
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina
| | - James E Herndon
- Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina
| | - Patrick Healy
- Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina
| | - Elizabeth A Reap
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina
| | - Gary E Archer
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina
- Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - Peter E Fecci
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina
- Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - John H Sampson
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina.
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina
- Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - Luis Sanchez-Perez
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina.
- The Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina
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Eggermont LJ, Hammink R, Blank KG, Rowan AE, Tel J, Figdor CG. Cytokine-Functionalized Synthetic Dendritic Cells for T Cell Targeted Immunotherapies. ADVANCED THERAPEUTICS 2018. [DOI: 10.1002/adtp.201800021] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Loek J. Eggermont
- Department of Tumor Immunology; Radboud Institute for Molecular Life Sciences; Radboud University Medical Center; Geert Grooteplein 26 6525 GA Nijmegen The Netherlands
| | - Roel Hammink
- Department of Tumor Immunology; Radboud Institute for Molecular Life Sciences; Radboud University Medical Center; Geert Grooteplein 26 6525 GA Nijmegen The Netherlands
| | - Kerstin G. Blank
- Department of Molecular Materials; Institute for Molecules and Materials; Radboud University; Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
- Mechano(bio)chemistry; Max Planck Institute of Colloids and Interfaces; Potsdam-Golm Science Park 14424 Potsdam Germany
| | - Alan E. Rowan
- Department of Molecular Materials; Institute for Molecules and Materials; Radboud University; Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Jurjen Tel
- Department of Tumor Immunology; Radboud Institute for Molecular Life Sciences; Radboud University Medical Center; Geert Grooteplein 26 6525 GA Nijmegen The Netherlands
- Department of Biomedical Engineering and Institute for Complex Molecular Systems; Laboratory of Immunoengineering; Eindhoven University of Technology; De Zaale 15 5612 AP Eindhoven The Netherlands
| | - Carl G. Figdor
- Department of Tumor Immunology; Radboud Institute for Molecular Life Sciences; Radboud University Medical Center; Geert Grooteplein 26 6525 GA Nijmegen The Netherlands
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Mittal P, Abblett R, Ryan JM, Hagymasi AT, Agyekum-Yamoah A, Svedova J, Reiner SL, St Rose MC, Hanley MP, Vella AT, Adler AJ. An Immunotherapeutic CD137 Agonist Releases Eomesodermin from ThPOK Repression in CD4 T Cells. THE JOURNAL OF IMMUNOLOGY 2018; 200:1513-1526. [PMID: 29305435 DOI: 10.4049/jimmunol.1701039] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 12/06/2017] [Indexed: 12/24/2022]
Abstract
Agonists to the TNF/TNFR costimulatory receptors CD134 (OX40) and CD137 (4-1BB) elicit antitumor immunity. Dual costimulation with anti-CD134 plus anti-CD137 is particularly potent because it programs cytotoxic potential in CD8+ and CD4+ T cells. Cytotoxicity in dual-costimulated CD4 T cells depends on the T-box transcription factor eomesodermin (Eomes), which we report is induced via a mechanism that does not rely on IL-2, in contrast to CD8+ CTL, but rather depends on the CD8 T cell lineage commitment transcription factor Runx3, which supports Eomes expression in mature CD8+ CTLs. Further, Eomes and Runx3 were indispensable for dual-costimulated CD4 T cells to mediate antitumor activity in an aggressive melanoma model. Runx3 is also known to be expressed in standard CD4 Th1 cells where it fosters IFN-γ expression; however, the CD4 T cell lineage commitment factor ThPOK represses transcription of Eomes and other CD8 lineage genes, such as Cd8a Hence, CD4 T cells can differentiate into Eomes+ cytotoxic CD4+CD8+ double-positive T cells by terminating ThPOK expression. In contrast, dual-costimulated CD4 T cells express Eomes, despite the continued expression of ThPOK and the absence of CD8α, indicating that Eomes is selectively released from ThPOK repression. Finally, although Eomes was induced by CD137 agonist, but not CD134 agonist, administered individually, CD137 agonist failed to induce CD134-/- CD4 T cells to express Eomes or Runx3, indicating that both costimulatory pathways are required for cytotoxic Th1 programming, even when only CD137 is intentionally engaged with a therapeutic agonist.
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Affiliation(s)
- Payal Mittal
- Department of Immunology, University of Connecticut School of Medicine, Farmington, CT 06030
| | - Rebecca Abblett
- Department of Immunology, University of Connecticut School of Medicine, Farmington, CT 06030
| | - Joseph M Ryan
- Department of Immunology, University of Connecticut School of Medicine, Farmington, CT 06030
| | - Adam T Hagymasi
- Department of Immunology, University of Connecticut School of Medicine, Farmington, CT 06030
| | | | - Julia Svedova
- Department of Immunology, University of Connecticut School of Medicine, Farmington, CT 06030
| | - Steven L Reiner
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032; and.,Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Marie-Clare St Rose
- Department of Immunology, University of Connecticut School of Medicine, Farmington, CT 06030
| | - Matthew P Hanley
- Department of Immunology, University of Connecticut School of Medicine, Farmington, CT 06030
| | - Anthony T Vella
- Department of Immunology, University of Connecticut School of Medicine, Farmington, CT 06030
| | - Adam J Adler
- Department of Immunology, University of Connecticut School of Medicine, Farmington, CT 06030;
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Murakami T, Hatano S, Yamada H, Iwakura Y, Yoshikai Y. Two Types of Interleukin 17A-Producing γδ T Cells in Protection Against Pulmonary Infection With Klebsiella pneumoniae. J Infect Dis 2016; 214:1752-1761. [PMID: 27651419 DOI: 10.1093/infdis/jiw443] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 09/11/2016] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Klebsiella pneumoniae frequently causes life-threatening infection in children. Interleukin 17A (IL-17A) is known to be involved in protection against K. pneumoniae infection through activation of neutrophils. METHODS AND RESULTS We found that IL-17A-producing γδ T cells existed more frequently in younger mice on examination of IL-17A-producing lymphocytes in the lung of naive mice at various ages. We hence compared the protective role of IL-17A-producing γδ T cells against pulmonary K. pneumoniae infection in young (3 weeks old) and adult (8-12 weeks old) mice. IL-17A-deficient mice were susceptible to K. pneumonia regardless of age. Cγ-, Vγ4/6-, or Vδ1-deficient mice were susceptible to K. pneumonia at young age, while interleukin 23p19 (IL-23p19)-deficient mice were susceptible at adult age. IL-17A-producing Vγ1-Vγ4- γδ T cells expressing canonical Vγ6/Vδ1 genes were dominant over IL-17A-producing Vγ4+ γδ T cells in the lungs of young mice after infection. The IL-17A-producing Vγ1-Vγ4- γδ T cells expressed an activation marker, CD69, and proliferated in an IL-23-independent manner, while the IL-17A-producing Vγ4+ γδ T cells expressing IL-23 receptor but no CD69 proliferated in IL-23-dependent manner. CONCLUSIONS These results suggest that 2 types of IL-17A-producing γδ T cells are activated for host defense against K. pneumoniae infection by IL-23-dependent or independent mechanism.
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Affiliation(s)
- Tesshin Murakami
- Division of Host Defense, Medical Institute of Bioregulation, Kyushu University, Fukuoka
| | - Shinya Hatano
- Division of Host Defense, Medical Institute of Bioregulation, Kyushu University, Fukuoka
| | - Hisakata Yamada
- Division of Host Defense, Medical Institute of Bioregulation, Kyushu University, Fukuoka
| | - Yoichiro Iwakura
- Center for Animal Disease Models, Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Japan
| | - Yasunobu Yoshikai
- Division of Host Defense, Medical Institute of Bioregulation, Kyushu University, Fukuoka
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Han KH, Kim KW, Yan JJ, Lee JG, Lee EM, Han M, Cho EJ, Kang SS, Lim HJ, Koo TY, Ahn C, Yang J. Effects of stimulating interleukin -2/anti- interleukin -2 antibody complexes on renal cell carcinoma. BMC Urol 2016; 16:2. [PMID: 26772545 PMCID: PMC4715282 DOI: 10.1186/s12894-016-0121-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 01/13/2016] [Indexed: 11/17/2022] Open
Abstract
Background Current therapies for advanced renal cell carcinoma (RCC) have low cure rates or significant side effects. It has been reported that complexes composed of interleukin (IL)-2 and stimulating anti-IL-2 antibody (IL-2C) suppress malignant melanoma growth. We investigated whether it could have similar effects on RCC. Methods A syngeneic RCC model was established by subcutaneously injecting RENCA cells into BALB/c mice, which were administered IL-2C or phosphate-buffered saline every other day for 4 weeks. RCC size was measured serially, and its weight was assessed 4 weeks after RENCA injection. Immune cell infiltration into RCC lesions and spleen was assessed by flow cytometry and immunohistochemistry. Results IL-2C treatment increased the numbers of CD8+ memory T and natural killer (NK) cells in healthy BALB/c mice (P < 0.01). In the spleen of RCC mice, IL-2C treatment also increased the number of CD8+ memory T, NK cells, and macrophages as compared to PBS-treated controls (P < 0.01). The number of interferon-γ- and IL-10-producing splenocytes increased and decreased, respectively after 4 weeks in the IL-2C-treated mice (P < 0.01). Tumor-infiltrating immune cells including CD4+ T, CD8+ T, NK cells as well as macrophages were increased in IL-2C-treated mice than controls (P < 0.05). Pulmonary edema, the most serious side effect of IL-2 therapy, was not exacerbated by IL-2C treatment. However, IL-2C had insignificant inhibitory effect on RCC growth (P = 0.1756). Conclusions IL-2C enhanced immune response without significant side effects; however, this activity was not sufficient to inhibit RCC growth in a syngeneic, murine model.
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Affiliation(s)
- Kyu-Hyun Han
- Transplantation Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
| | - Ki Won Kim
- Nephrology clinic, Center for Clinical Specialty, National Cancer Center, Seoul, Republic of Korea.
| | - Ji-Jing Yan
- Transplantation Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
| | - Jae-Ghi Lee
- Transplantation Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
| | - Eun Mi Lee
- Transplantation Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
| | - Miyeon Han
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
| | - Eun Jin Cho
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
| | - Seong Sik Kang
- Transplantation Center, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 110-744, Republic of Korea.
| | - Hye Jin Lim
- Transplantation Center, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 110-744, Republic of Korea.
| | - Tai Yeon Koo
- Transplantation Center, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 110-744, Republic of Korea.
| | - Curie Ahn
- Transplantation Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea. .,Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea. .,Transplantation Center, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 110-744, Republic of Korea.
| | - Jaeseok Yang
- Transplantation Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea. .,Transplantation Center, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 110-744, Republic of Korea.
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Lin GHY, Snell LM, Wortzman ME, Clouthier DL, Watts TH. GITR-Dependent Regulation of 4-1BB Expression: Implications for T Cell Memory and Anti–4-1BB–Induced Pathology. THE JOURNAL OF IMMUNOLOGY 2013; 190:4627-39. [DOI: 10.4049/jimmunol.1201854] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Sabbagh L, Andreeva D, Laramée GD, Oussa NAE, Lew D, Bisson N, Soumounou Y, Pawson T, Watts TH. Leukocyte-specific protein 1 links TNF receptor-associated factor 1 to survival signaling downstream of 4-1BB in T cells. J Leukoc Biol 2013; 93:713-21. [PMID: 23446150 DOI: 10.1189/jlb.1112579] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
4-1BB is a member of the TNFR superfamily, which contributes to the activation of signaling pathways required for the survival of activated and memory T cells. We have shown previously that TRAF1, an adaptor protein recruited to 4-1BB, is required for 4-1BB-mediated CD8 T cell survival in vivo. With the use of a proteomics approach in primary T cells, we have identified LSP1 as a novel protein recruited to the 4-1BB signaling complex in a TRAF1-dependent manner. Further characterization of the interaction between TRAF1 and LSP1 revealed that LSP1 requires the TRAF-N domain of TRAF1 for direct association. Similarly to TRAF1(-/-) T cells, LSP1(-/-) T cells exhibit impaired ERK activation following stimulation through 4-1BB and consequently, are unable to down-modulate expression of the proapoptotic Bcl-2 family member Bim. Moreover, we demonstrate that the absence of LSP1 expression leads to defective expansion and survival of T cells in response to 4-1BB stimulation. Thus, we have identified LSP1 as a new mediator involved in 4-1BB signaling and T cell survival. Collectively, our work shows that TRAF1 and LSP1 cooperate downstream of 4-1BB to activate ERK signaling and down-modulate the levels of Bim leading to enhanced T cell survival.
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Affiliation(s)
- Laurent Sabbagh
- Maisonneuve-Rosemont Hospital Research Centre, Montreal, Quebec, Canada.
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