Following immune attack, solid tumors upregulate coinhibitory ligands that bind to inhibitory receptors on T cells. This adaptive resistance compromises the efficacy of chimeric antigen receptor (CAR) T cell therapies, which redirect T cells to solid tumors. Here, we investigated whether programmed death-1–mediated (PD-1–mediated) T cell exhaustion affects mesothelin-targeted CAR T cells and explored cell-intrinsic strategies to overcome inhibition of CAR T cells. Using an orthotopic mouse model of pleural mesothelioma, we determined that relatively high doses of both CD28- and 4-1BB–based second-generation CAR T cells achieved tumor eradication. CAR-mediated CD28 and 4-1BB costimulation resulted in similar levels of T cell persistence in animals treated with low T cell doses; however, PD-1 upregulation within the tumor microenvironment inhibited T cell function. At lower doses, 4-1BB CAR T cells retained their cytotoxic and cytokine secretion functions longer than CD28 CAR T cells. The prolonged function of 4-1BB CAR T cells correlated with improved survival. PD-1/PD-1 ligand [PD-L1] pathway interference, through PD-1 antibody checkpoint blockade, cell-intrinsic PD-1 shRNA blockade, or a PD-1 dominant negative receptor, restored the effector function of CD28 CAR T cells. These findings provide mechanistic insights into human CAR T cell exhaustion in solid tumors and suggest that PD-1/PD-L1 blockade may be an effective strategy for improving the potency of CAR T cell therapies.
Leonid Cherkassky, Aurore Morello, Jonathan Villena-Vargas, Yang Feng, Dimiter S. Dimitrov, David R. Jones, Michel Sadelain, Prasad S. Adusumilli
The alternatively spliced products of
John M. Lee, Chika Nobumori, Yiping Tu, Catherine Choi, Shao H. Yang, Hea-Jin Jung, Timothy A. Vickers, Frank Rigo, C. Frank Bennett, Stephen G. Young, Loren G. Fong
Adoptive cell transfer (ACT) of purified naive, stem cell memory, and central memory T cell subsets results in superior persistence and antitumor immunity compared with ACT of populations containing more-differentiated effector memory and effector T cells. Despite a clear advantage of the less-differentiated populations, the majority of ACT trials utilize unfractionated T cell subsets. Here, we have challenged the notion that the mere presence of less-differentiated T cells in starting populations used to generate therapeutic T cells is sufficient to convey their desirable attributes. Using both mouse and human cells, we identified a T cell–T cell interaction whereby antigen-experienced subsets directly promote the phenotypic, functional, and metabolic differentiation of naive T cells. This process led to the loss of less-differentiated T cell subsets and resulted in impaired cellular persistence and tumor regression in mouse models following ACT. The T memory–induced conversion of naive T cells was mediated by a nonapoptotic Fas signal, resulting in Akt-driven cellular differentiation. Thus, induction of Fas signaling enhanced T cell differentiation and impaired antitumor immunity, while Fas signaling blockade preserved the antitumor efficacy of naive cells within mixed populations. These findings reveal that T cell subsets can synchronize their differentiation state in a process similar to quorum sensing in unicellular organisms and suggest that disruption of this quorum-like behavior among T cells has potential to enhance T cell–based immunotherapies.
Christopher A. Klebanoff, Christopher D. Scott, Anthony J. Leonardi, Tori N. Yamamoto, Anthony C. Cruz, Claudia Ouyang, Madhu Ramaswamy, Rahul Roychoudhuri, Yun Ji, Robert L. Eil, Madhusudhanan Sukumar, Joseph G. Crompton, Douglas C. Palmer, Zachary A. Borman, David Clever, Stacy K. Thomas, Shashankkumar Patel, Zhiya Yu, Pawel Muranski, Hui Liu, Ena Wang, Francesco M. Marincola, Alena Gros, Luca Gattinoni, Steven A. Rosenberg, Richard M. Siegel, Nicholas P. Restifo
Tumor angiogenesis is critical for cancer progression. In multiple murine models, endothelium-specific epsin deficiency abrogates tumor progression by shifting the balance of VEGFR2 signaling toward uncontrolled tumor angiogenesis, resulting in dysfunctional tumor vasculature. Here, we designed a tumor endothelium–targeting chimeric peptide (UPI) for the purpose of inhibiting endogenous tumor endothelial epsins by competitively binding activated VEGFR2. We determined that the UPI peptide specifically targets tumor endothelial VEGFR2 through an unconventional binding mechanism that is driven by unique residues present only in the epsin ubiquitin–interacting motif (UIM) and the VEGFR2 kinase domain. In murine models of neoangiogenesis, UPI peptide increased VEGF-driven angiogenesis and neovascularization but spared quiescent vascular beds. Further, in tumor-bearing mice, UPI peptide markedly impaired functional tumor angiogenesis, tumor growth, and metastasis, resulting in a notable increase in survival. Coadministration of UPI peptide with cytotoxic chemotherapeutics further sustained tumor inhibition. Equipped with localized tumor endothelium–specific targeting, our UPI peptide provides potential for an effective and alternative cancer therapy.
Yunzhou Dong, Hao Wu, H.N. Ashiqur Rahman, Yanjun Liu, Satish Pasula, Kandice L. Tessneer, Xiaofeng Cai, Xiaolei Liu, Baojun Chang, John McManus, Scott Hahn, Jiali Dong, Megan L. Brophy, Lili Yu, Kai Song, Robert Silasi-Mansat, Debra Saunders, Charity Njoku, Hoogeun Song, Padmaja Mehta-D’Souza, Rheal Towner, Florea Lupu, Rodger P. McEver, Lijun Xia, Derek Boerboom, R. Sathish Srinivasan, Hong Chen
The generation of potent opioid analgesics that lack the side effects of traditional opioids may be possible by targeting truncated splice variants of the μ-opioid receptor. μ-Opioids act through GPCRs that are generated from the
Zhigang Lu, Jin Xu, Grace C. Rossi, Susruta Majumdar, Gavril W. Pasternak, Ying-Xian Pan
BACKGROUND. Individuals treated with the cholesteryl ester transfer protein (CETP) inhibitor anacetrapib exhibit a reduction in both LDL cholesterol and apolipoprotein B (ApoB) in response to monotherapy or combination therapy with a statin. It is not clear how anacetrapib exerts these effects; therefore, the goal of this study was to determine the kinetic mechanism responsible for the reduction in LDL and ApoB in response to anacetrapib.
METHODS. We performed a trial of the effects of anacetrapib on ApoB kinetics. Mildly hypercholesterolemic subjects were randomized to background treatment of either placebo (
RESULTS. Anacetrapib markedly reduced the LDL-ApoB-100 pool size (PS) in both the placebo and ATV groups. These changes in PS resulted from substantial increases in LDL-ApoB-100 FCRs in both groups. Anacetrapib had no effect on LDL-ApoB-100 PRs in either treatment group. Moreover, there were no changes in the PCSK9 PS, FCR, or PR in either group. Anacetrapib treatment was associated with considerable increases in the LDL triglyceride/cholesterol ratio and LDL size by NMR.
CONCLUSION. These data indicate that anacetrapib, given alone or in combination with a statin, reduces LDL-ApoB-100 levels by increasing the rate of ApoB-100 fractional clearance.
TRIAL REGISTRATION. ClinicalTrials.gov NCT00990808.
FUNDING. Merck & Co. Inc., Kenilworth, New Jersey, USA. Additional support for instrumentation was obtained from the National Center for Advancing Translational Sciences (UL1TR000003 and UL1TR000040).
John S. Millar, Gissette Reyes-Soffer, Patricia Jumes, Richard L. Dunbar, Emil M. deGoma, Amanda L. Baer, Wahida Karmally, Daniel S. Donovan, Hashmi Rafeek, Laura Pollan, Junichiro Tohyama, Amy O. Johnson-Levonas, John A. Wagner, Stephen Holleran, Joseph Obunike, Yang Liu, Rajasekhar Ramakrishnan, Michael E. Lassman, David E. Gutstein, Henry N. Ginsberg, Daniel J. Rader
Multiple myeloma (MM) is an age-dependent hematological malignancy. Evaluation of immune interactions that drive MM relies on in vitro experiments that do not reflect the complex cellular stroma involved in MM pathogenesis. Here we used Vk*MYC transgenic mice, which spontaneously develop MM, and demonstrated that the immune system plays a critical role in the control of MM progression and the response to treatment. We monitored Vk*MYC mice that had been crossed with
Camille Guillerey, Lucas Ferrari de Andrade, Slavica Vuckovic, Kim Miles, Shin Foong Ngiow, Michelle C.R. Yong, Michele W.L. Teng, Marco Colonna, David S. Ritchie, Martha Chesi, P. Leif Bergsagel, Geoffrey R. Hill, Mark J. Smyth, Ludovic Martinet
Oxidative stress contributes to the loss of neurons in many disease conditions as well as during normal aging; however, small-molecule agents that reduce oxidation have not been successful in preventing neurodegeneration. Moreover, even if an efficacious systemic reduction of reactive oxygen and/or nitrogen species (ROS/NOS) could be achieved, detrimental side effects are likely, as these molecules regulate normal physiological processes. A more effective and targeted approach might be to augment the endogenous antioxidant defense mechanism only in the cells that suffer from oxidation. Here, we created several adeno-associated virus (AAV) vectors to deliver genes that combat oxidation. These vectors encode the transcription factors NRF2 and/or PGC1a, which regulate hundreds of genes that combat oxidation and other forms of stress, or enzymes such as superoxide dismutase 2 (SOD2) and catalase, which directly detoxify ROS. We tested the effectiveness of this approach in 3 models of photoreceptor degeneration and in a nerve crush model. AAV-mediated delivery of NRF2 was more effective than SOD2 and catalase, while expression of PGC1a accelerated photoreceptor death. Since the NRF2-mediated neuroprotective effects extended to photoreceptors and retinal ganglion cells, which are 2 very different types of neurons, these results suggest that this targeted approach may be broadly applicable to many diseases in which cells suffer from oxidative damage.
Wenjun Xiong, Alexandra E. MacColl Garfinkel, Yiqing Li, Larry I. Benowitz, Constance L. Cepko
The use of adeno-associated virus (AAV) as a gene therapy vector has been approved recently for clinical use and has demonstrated efficacy in a growing number of clinical trials. However, the safety of AAV as a vector has been challenged by a single study that documented hepatocellular carcinoma (HCC) after AAV gene delivery in mice. Most studies have not noted genotoxicity following AAV-mediated gene delivery; therefore, the possibility that there is an association between AAV and HCC is controversial. Here, we performed a comprehensive study of HCC in a large number of mice following therapeutic AAV gene delivery. Using a sensitive high-throughput integration site-capture technique and global expressional analysis, we found that AAV integration into the RNA imprinted and accumulated in nucleus (
Randy J. Chandler, Matthew C. LaFave, Gaurav K. Varshney, Niraj S. Trivedi, Nuria Carrillo-Carrasco, Julien S. Senac, Weiwei Wu, Victoria Hoffmann, Abdel G. Elkahloun, Shawn M. Burgess, Charles P. Venditti
Alpha-1 antitrypsin deficiency (AATD) is a rare genetic disease that results from mutations in the alpha-1 antitrypsin (
Shuling Guo, Sheri L. Booten, Mariam Aghajan, Gene Hung, Chenguang Zhao, Keith Blomenkamp, Danielle Gattis, Andrew Watt, Susan M. Freier, Jeffery H. Teckman, Michael L. McCaleb, Brett P. Monia
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