JITC Digest June 2021


Inside this Issue:

Letter from the Editor

Hello JITC Readers,pedro-romero_1__1_.jpg

This edition of the JITC Digest is extra special because June is Cancer Immunotherapy Month™. As JITC readers, you are already aware of the transformational impact of immunotherapy and we welcome you to take advantage of the myriad educational growth and professional development opportunities for clinicians, researchers, and patients offered by SITC during June.
June has already been a banner month for immunotherapy, especially for our clinical colleagues. Those of you who attended the American Society for Clinical Oncology Annual Meeting just a few weeks ago—or who followed JITC’s Twitter commentary—likely saw the panoply of oral abstracts, posters, plenary addresses, and education sessions all featuring impressive data showing benefit for a variety of immunotherapy approaches across numerous disease settings. If the results of RELATIVITY have you seeking more information on LAG3 or other targets, be sure to revisit JITC’s Immune Checkpoints Beyond PD-1 Series.
Of course, the clinical successes of immunotherapy stemmed from years of basic and translational research, more of which is needed to bring about the next generation of therapeutic agents to overcome resistance and expand the population of patients that may benefit. This month’s original research offers insight into mechanisms of resistance to a variety of immunotherapeutic modalities, with intriguing implications for future development.
Francisco J Cueto et al uncover paradoxical inhibition of Flt3L-mediated tumor clearance mediated by a surface receptor involved in cross-priming. Improved tumor control in mice with a novel, extended half-life recombinant IL-15 is demonstrated by Takahiro Miyazaki and colleagues. For the first time, hypoxia is shown to mediate anti-PD-1 resistance in head and neck cancer by Dan P Zandberg et al. Finally, Zhiliang Bai and colleagues identify functional differences in CAR T cells generated from healthy donors and patients.
After reading this month’s JITC, continue to celebrate Cancer Immunotherapy Month™ by supporting our sister journals in the immunotherapy space. You can find links to other specialized publications aiming to advance the field forward in this month’s special highlights section.
Best regards,

Pedro J. Romero, MD
Editor-in-Chief, Journal for ImmunoTherapy of Cancer

JITC Editor Picks

DNGR-1 limits Flt3L-mediated antitumor immunity by restraining tumor-infiltrating type I conventional dendritic cells

Francisco J Cueto, Carlos del Fresno, Paola Brandi, Alexis J. Combes, Elena Hernández-García, Alfonso R Sánchez-Paulete, Michel Enamorado, Christian P Bromley, Manuel J Gomez, Ruth Conde-Garrosa, Santos Mañes, Santiago Zelenay, Ignacio Melero, Salvador Iborra, Matthew F. Krummel, David Sancho

Journal for ImmunoTherapy of Cancer 2021;9:e002054 (12 May 2021)


DNGR-1 is a surface receptor on conventional type 1 dendritic cells (cDC1s) that recognizes F-actin exposed on necrotic cells leading to cross-presentation of dead cell-associated antigens and generation of tissue-resident CD8+ memory T cells after viral infection. Francisco J Cueto and colleagues demonstrate an unexpected inhibitory role for DNGR-1 in Flt3L-mediated anti-tumor immunity in the context of murine B16 melanoma and MC38 colorectal cancer models. Tumor growth kinetics at steady state were not altered by the loss of DNGR-1, nor was the loading of tumor antigens onto migratory or resident dendritic cells. Upon systemic Flt3L overexpression, however, tumors grew more slowly in DNGR-1-deficient mice. DNGR-1 deficiency led to increased numbers of intratumoral CD8+ T cells, but not CD4+ T cells. Flt3L overexpression in a DNGR-1-deficient background led to more pronounced intratumoral accumulation of CD103+ cDC1s without affecting infiltration by cDC2s and similar results were seen with exogenous DNGR-1 blockade via monoclonal antibodies. Expression of several gene sets related to cDC1 activation was enriched after Flt3L overexpression in DNGR-1-deficient mice, including tumor necrosis factor alpha signaling and inflammatory response markers, notably the chemomkines CCL5 and CCL3. Administration of the CCR5 signaling and migration response inhibitor maraviroc (originally developed to block HIV entry) along with Flt3L overexpression led to lower accumulation of cDC1s after DNGR-1 blockade. Cyclophosphamide, which increases serum Flt3L levels, also synergized with DNGR-1 deficiency, leading to delayed tumor growth. Analysis of The Cancer Genome Atlas (TCGA) datasets showed that patients with high coexpression of FLT3LG and CCL5 had longer overall survival compared with those intermediate and low expression levels. The findings identify DNGR-1 as a potential target to enhance intratumoral cDC1 infiltration and improve anti-tumor immunity in disease settings with high Flt3L expression.

NKTR-255, a novel polymer-conjugated rhIL-15 with potent antitumor efficacy

Takahiro Miyazaki, Mekhala Maiti, Marlene Hennessy, Thomas Chang, Peiwen Kuo, Murali Addepalli, Palakshi Obalapur, Sara Sheibani, Joanna Wilczek, Rhoneil Pena, Phi Quach, Janet Cetz, Andrew Moffett, Yinyan Tang, Peter Kirk, Jicai Huang, Dawei Sheng, Ping Zhang, Werner Rubas, Loui Madakamutil, Saul Kivimäe, Jonathan Zalevsky

Journal for ImmunoTherapy of Cancer 2021;9:e002024  (17 May 2021)



Despite strong mechanistic rationale for interleukin (IL)-15 as an immunotherapy via potent effects on NK and CD8+ T cell development and effector functions, recombinant versions of the cytokine displayed a mean plasma half-life of merely 2.5 hours in human trials, limiting clinical development. Takahiro Miyazaki et al confirm that NKTR-225, a novel polyethylene glycol-conjugated recombinant human IL-15 (rhIL-15) currently being evaluated in a phase I first-in-human trial (NCT04136756), shows similar in vitro activities to the parent cytokine with improved pharmacokinetic properties and anti-lymphoma activities in mouse models. A single dose of 0.3 mg/kg IV NKTR-225 had reduced clearance and longer half-life compared to rhIL-15 (2.31 mL/hour/kg vs 507 mL/hour/kg and 15.2 hours vs 0.168 hours, respectively). NKTR-255 and rhIL-15 induced STAT signaling with similar potency in NK and T cells. Rapid and sustained induction of phosphorylated STAT5 in NK and CD8+ T cells was seen after NKTR-225 stimulation with levels returning to baseline after 120 hours post-treatment compared to 6 hours post-treatment for rhIL-15. Multiple doses of NKTR-225 in vivo did not cause signs of tachyphylaxis, and the Ki67+ proliferating populations of NK and CD8+ T cells were increased in number with similar kinetics across repeated doses as after a single dose. In two independent efficacy studies in SCID mice bearing Daudi lymphoma xenografts, NKTR-255 reproducibly increased survival compared to treatment with pre-bound rhIL-15/IL-15 receptor complexes and rhIL-15 alone. Both treatment conditions induced comparable increases in granzyme B-expressing NK cells, yet NKTR-255 treatment led to durable and sustained effector production 6 days after treatment compared to the precomplexed cytokine. The results provide a framework for further development of rhIL-15-based immunotherapies.

Tumor hypoxia is associated with resistance to PD-1 blockade in squamous cell carcinoma of the head and neck

Dan P Zandberg, Ashley V Menk, Maria Velez, Daniel Normolle, Kristin DePeaux, Angen Liu, Robert L Ferris, Greg M Delgoffe
Journal for ImmunoTherapy of Cancer
2021;9:e002088 (13 May 2021)


Altered metabolism is increasingly becoming recognized as a key determinant of anti-tumor immunity. In the first examination of the metabolic effects of PD-1 blockade in the context of squamous cell carcinoma of the head and neck (HNSCC), Dan P Zandberg et al show that the development of immunotherapy resistance is accompanied by an upregulation of oxidative phosphorylation along with a concomitant increase in intratumoral hypoxia. Anti-PD-1 resistant tumors were generated by serial passage of a murine tonsillar epithelial cell line stably expressing E6, E7 and H-Ras (MEER). Seahorse technology showed that anti-PD-1 resistant MEER had significantly higher oxidative metabolism than the parental cell lines, which coincided with significantly increased intratumoral hypoxia as assayed by in vivo pimonidazole tracing. In tissue samples biobanked from 36 human patients with relapsed/metastatic HNSCC treated with anti-PD-1, the ratio of percent area to mean intensity of carbonic anhydrase IX in tumor as a measure of hypoxia (CAIX/I) as well as the CD8+/Treg ratio were both significantly associated with disease control in multivariate analysis. Low CAIX/I was also significantly associated with improved PFS and OS in univariate analysis. The study not only identifies tumor hypoxia as a predictive biomarker, but also identifies potential targets to enhance responses to PD-1 blockade.

Single-cell multiomics dissection of basal and antigen-specific activation states of CD19-targeted CAR T cells

Zhiliang Bai, Stefan Lundh, Dongjoo Kim, Steven Woodhouse, David M Barrett, Regina M Myers, Stephan A Grupp, Marcela V Maus, Carl H June, Pablo G Camara, J Joseph Melenhorst, Rong Fan

Journal for ImmunoTherapy of Cancer 2021;9:e002328 (18 May 2021)



Autologous CD19-targeting chimeric antigen receptor (CAR) T cells have become integrated into standard care for relapsed or refractory hematologic malignancies, yet despite impressive initial response rates, recurrent disease remains common in a substantial fraction of patients. To characterize the molecular underpinnings associated with disparate clinical outcomes after CAR T cell therapy, Zhiliang Bai and colleagues performed single cell RNA sequencing in conjunction with the highly multiplexed protein marker detection and transcriptomics platform CITE-seq on 23,349 single 4-1BB costimulated second generation CAR T cells (ie, tisagenlecleucel) generated from one healthy donor (HD) as well as two patients with acute lymphoblastic leukemia, one of whom had minimal residual disease negative complete remission (CR) after treatment and one of whom who had non-responsive disease (NR). Unsupervised clustering analysis showed that a majority of HD- or CR-derived resting CAR T cells had predominantly stem cell-like memory or central memory differentiation status, whereas an effector memory phenotype was prevalent in NR-derived cells. Compared to the NR-derived CAR T cells, HD and CR cells had higher expression of oxidative phosphorylation-related genes and decreased glycolysis as well as fatty acid oxidation metabolism. Notable differences in major histocompatibility locus class II upregulation were observed between HD and CR cells. After co-culture with CD19-expressing cells, NR cells exhibited upregulation of exhaustion markers and glycolysis, whereas HD cells showed an even more pronounced activation signature compared with CR cells. Similar patterns were seen in published single cell RNA sequencing datasets from 4-1BB costimulated CD19 CAR T cells under similar experimental conditions. Cytokine production and effector function was independent of expression for the gene that encodes GM-CSF—a factor that has been implicated in cytokine release syndrome—across all samples. Furthermore, analysis of HD-derived CD28 costimulated CD19 CAR T cells (ie, axicabtagene ciloleucel) highlighted enhanced central memory and stem cell-like memory phenotypes in the 4-1BB costimulated products at baseline. The findings reveal functional, phenotypic, and metabolic differences in CAR T cells correlated with clinical outcomes and provide rationale for further development of “off the shelf” CAR T cell products.

Spotlight on Cancer Immunotherapy Journals

In honor of Cancer Immunotherapy Month™, JITC would like to recognize fellow cancer immunotherapy-specialized journals helping to advance the field forward. Together with JITC, the editors and organizations associated with these journals carry a message of determination to achieve a future that is immune to cancer.

Journal for ImmunoTherapy of Cancer

Associated with the Society for Immunotherapy of Cancer (SITC)
Launched in 2013 and currently under the leadership of Founding Editor Pedro J Romero

Cancer Immunology, Immunotherapy

Associated with the Association for Cancer Immunotherapy (CIMT), Canadian Cancer Immunotherapy Consortium (CCIC), The Japanese Association for Cancer Immunology (JACI), Network Italiano per la Bioterapia dei Tumori (NIBIT), and Sociedad Española de Inmunologia-Grupo Español de InmunoTerapia (SEI-GEIT)
Launched in 1976 under the leadership of Founding Editor Georges Mathé and currently edited by Haidong Dong

Cancer Immunology Research*

Associated with American Association for Cancer Research (AACR)
Launched in 2013 under the leadership of Founding Editor Glenn Dranoff and currently edited by Robert D Schreiber and Philip D Greenberg
*Includes the archives of Cancer Immunity, the journal of the Cancer Research Institute, published between 2001 and 2013 under the leadership of Lloyd J Old

Journal of Immunotherapy

Launched as the Journal of Biological Response Modifiers in 1982 and currently edited by Steven A Rosenberg

Immuno-Oncology and Technology (IOTECH)

Associated with the European Society for Medical Oncology (ESMO)
Launched in 2019 and currently under the leadership of Founding Editor John B Haanen


Launched in 2012 and currently under the leadership of Founding Editors Guido Kroemer, Laurence Zitvogel, and Lorenzo Galluzzi

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SITC Members Receive 50 Percent Submission Discount in 2021

*As a way to thank the SITC members who work tirelessly to advance the science and improve the lives of cancer patients, SITC will provide members with a 50 percent discount on processing fees for all JITC articles accepted in 2021.