JITC Digest April 2021


Inside this Issue:

Letter from the Editor

Dear JITC Readers,pedro-romero_1__1_.jpg

It is a pleasure to welcome you to this month’s JITC digest. The original research articles highlighted in this edition are fantastic examples of mechanistic insight interwoven with new strategies for intervention and vice versa—the seamless reverse translational cycle that is central to the immunotherapy field.
Novel targets for immunotherapy are characterized by Aiqin Gao and colleagues, who show that blocking ILT4 relieves T cell immunosenescence via ERK-dependent metabolic perturbations, as well as François Anna et al, who take aim at HLA-G with the first chimeric antigen receptor (CAR) T cells against the dual function tumor-specific antigen and immune checkpoint.
Esther Redin and colleagues demonstrate that inhibition of the SRC-family kinase YES1 with the approved leukemia drug dasatinib decreases CD4+ Treg conversion and enhances the efficacy of PD-1 blockade in non-small cell lung cancer.
Another strategy to augment the anti-tumor effects of PD-1 inhibition is identified by Yoke Seng Lee et al, who establish a link between conventional type 1 dendritic cell counts and responses to immunotherapy in patients with melanoma as well as in a novel humanized mouse model.

Finally, Gino M Dettorre and colleagues validate a readily available index of hyperinflammation incorporating lymphopenia and hypoalbuminemia that predicts outcomes of SARS-CoV-2 infection in patients with cancer—research that hints at interventions to prevent severe disease and nicely complements recently published articles in JITC’s ongoing COVID-19 and Cancer Immunotherapy Review Series.

Best regards,

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

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JITC Editor Picks

Tumor-derived ILT4 induces T cell senescence and suppresses tumor immunity

Aiqin Gao, Xia Liu, Wenli Lin, Jingnan Wang, Shuyun Wang, Fusheng Si, Lan Huang, Yangjing Zhao, Yuping Sun, Guangyong Peng

Journal for ImmunoTherapy of Cancer 2021;9:e001536 (2 March 2021)


Both myeloid innate cells and tumor cells are known to express immunoglobulin-like transcript 4 (ILT4), yet the protein’s role in regulating tumor immunobiology has not been characterized. Aiqin Gao and colleagues reveal mechanistic underpinnings for tumor ILT4 expression-induced T cell immunosenescence based on ERK1/2-dependent fatty acid synthesis and lipid accumulation. Human tumor cell lines, including lung cancer (A549, H1299, and H1650), breast cancer (MCF7 and ZR751), melanoma (M628), and prostate cancer (PC-3) cells, expressed high levels of ILT4 protein and mRNA—similar patterns were seen in tissue samples. High ILT4 expression was associated with shortened progression-free survival and overall survival in patients with breast cancer and non-small cell lung cancer. In co-culture, pretreatment of tumor cells, but not T cells, with an anti-ILT4 neutralizing antibody prevented induced immunosenescence. Neutralization of ILT4 significantly decreased both senescent CD4+ and CD8+ T cell populations in co-culture while significantly increasing markers of DNA damage response including phosphorylation/activation of ATM, H2AX, 53BP1, and CHK2. Knockdown of ILT4 in lung (A549 and H1299) and breast cancer (ZR751) cell lines with high ILT4 expression significantly decreased surface expression, but not intracellular expression, of HLA-G, in addition to decreasing phosphorylation of ERK1/2, but not P38 and JNK. ILT4 neutralization led to significantly lower tumor cell expression of the limiting enzymes in fatty acid synthesis, ACC1 and FASN, as well as markedly reduced lipid droplet accumulation by oil red O staining. In E0771 tumor-bearing mice, knockdown of the ILT4 homologue PIR-B slowed tumor growth and augmented effector functions, while overexpression had the opposite effect. In the well-established B16 melanoma and Pmel (gp100-specific) TCR transgenic mouse model, knockdown of PIR-B in tumor cells prevented induced senescence in adoptively transferred cells and markedly increased IFN-gamma production in blood and tumor tissues.

First immunotherapeutic CAR-T cells against the immune checkpoint protein HLA-G

François Anna, Elodie Bole-Richard, Joel LeMaoult, Marie Escande, Martin Lecomte, Jean-Marie Certoux, Philippe Souque, Francine Garnache, Olivier Adotevi, Pierre Langlade-Demoyen, Maria Loustau, Julien Caumartin

Journal for ImmunoTherapy of Cancer 2021;9:e001998  (18 March 2021)



HLA-G is both a tumor-specific antigen and an immune checkpoint; however, the protein has defied development as immunotherapeutic target, in part due to its structural complexity and lack of a murine homolog. François Anna et al developed two HLA-G-directed third-generation chimeric antigen receptor (CAR) T cell sets that demonstrated anti-tumor efficacy in vitro and in vivo along with differentiation into long-term memory effector cells that did not lose function even after repeated stimulation. The new CARs were based on novel antibodies against specific isoforms of HLA-G, a human-derived CD28 transmembrane domain, CD28 and 4-1BB costimulation domains to improve CAR T cell cytotoxic function and persistence, and a human CD3-zeta chain. Each set included constructs with three different hinge domains to circumvent poor epitope accessibility. Both sets of anti-HLA-G CAR T cells upregulated CD25, CD69, and PD-1 at their surface after stimulation with HLA-G expressing target cells. Cytotoxicity was similar for CAR T cells with classical hinge and CH2-CH3 hinge domains, while the CH3 hinge had lower target cell killing in six independent experiments. After three stimulations, similar differentiation profiles comprised of majority T effector memory cells were seen for all CARs tested. No upregulation of the HLA-G ligand ILT2 was seen on T cells harboring the CARs, though PD-1 expression was significantly upregulated. Transduction efficiency was equivalent for ILT2+ and ILT2- cells, and no significant differences in cytotoxicity nor T helper 1 cytokine secretion profiles were observed. In mouse models, one of the CAR constructs efficiently eradicated HLA-G expressing tumors, whereas the other delayed tumor growth by roughly two weeks.

SRC family kinase (SFK) inhibitor dasatinib improves the antitumor activity of anti-PD-1 in NSCLC models by inhibiting Treg cell conversion and proliferation

Esther Redin, Irati Garmendia, Teresa Lozano, Diego Serrano, Yaiza Senent, Miriam Redrado, Maria Villalba, Carlos E De Andrea, Francisco Exposito, Daniel Ajona, Sergio Ortiz-Espinosa, Ana Remirez, Cristina Bertolo, Cristina Sainz, Juana Garcia-Pedrero, Ruben Pio, Juan Lasarte, Jackeline Agorreta, Luis M Montuenga, Alfonso Calvo
Journal for ImmunoTherapy of Cancer
2020;9:e001496 (3 March 2021)


The multikinase inhibitor dasatinib has been shown to cause clonal expansion of CD8+ T cells and natural killer (NK) cells in the tumor microenvironment in addition to direct tumor cell cytotoxicity and apoptosis through its action on various SRC-family kinase members. Using patient samples, The Cancer Genome Atlas (TCGA) datasets, and syngeneic mouse models, Esther Redin and colleagues demonstrate a link between the SRC-family kinase YES1 and Treg conversion, which could be exploited to enhance the efficacy of PD-1 blockade. In a single-center cohort of patients with non-small cell lung cancer (NSCLC) as well as TCGA datasets, high YES1 levels were significantly associated with shorter overall survival as well as elevated numbers of tumor-infiltrating CD4+ Tregs. The murine NSCLC cell lines 393P and UNSCC680AJ (both of which express YES1), showed dose-dependent inhibition of proliferation by dasatinib in vitro. In vivo, the combination of dasatinib with anti-PD-1 showed strong synergy, with 87% of treated mice displaying tumor regressions as well as immunological memory leading to impaired tumor growth upon rechallenge. Depletion experiments demonstrated that CD4+ and CD8+ T cell populations were necessary for prolonged anti-tumor efficacy of the anti-PD-1/dasatinib combination. Notably, dasatinib treatment led to significant decreases in intratumoral numbers of Tregs. In vitro, CD4+CD25- cell conversion was dramatically decreased by dasatinib in a dose-dependent manner. The study sets the stage for the investigation of dasatinib plus PD-1 blockade for NSCLC.

Human CD141+ dendritic cells (cDC1) are impaired in patients with advanced melanoma but can be targeted to enhance anti-PD-1 in a humanized mouse model

Yoke Seng Lee, Liam J O'Brien, Carina M Walpole, Frances E Pearson, Ingrid M Leal-Rojas, Kelly-Anne Masterman, Victoria Atkinson, Andrew Barbour, Kristen J Radford

Journal for ImmunoTherapy of Cancer 2021;9:e001963 (18 March 2021)



Quantitative and functional defects in the conventional type 1 dendritic cell (cDC1) compartment in patients with advanced melanoma are identified by Yoke Seng Lee et al, and experiments in a novel humanized mouse model indicate that interventions to enhance the numbers of CD141+ dendritic cells could augment the efficacy of checkpoint blockade. In fresh whole blood samples stimulated with the TLR3 agonist poly(I:C) combined with the TLR7/8 agonist R848 from healthy donors and patients with melanoma, CD83 upregulation was similar across CD1c+ and plasmacytoid dendritic cells. However, CD83 expression was significantly impaired in CD141+ DCs from patients with melanoma after activation. In plasma, while no differences were seen in the levels of the inflammatory cytokines IL-6, IL-10, TNF-alpha, IFN-beta, IFN-gamma, and CXCL10, significantly higher levels of IL-1-beta and IL-8 were found in melanoma patient samples compared with healthy donor samples after activation. In patients treated with anti-PD-1 and/or anti-CTLA-4 immunotherapy, significant declines in CD141+ DC counts after 24 weeks of treatment were seen in patients with non-responsive disease. Defects in CD83 and CD40 upregulation after stimulation were also associated with a lack of response to checkpoint blockade. In a humanized mouse model where human melanoma develops in the presence of a human immune system (NSG-SGM3 mice engrafted with human CD34+ hematopoietic stem cells from umbilical cord blood followed by transplantation of a human melanoma cell line), treatment with pembrolizumab had negligible effects on tumor growth. The addition of poly(I:C) and Flt3L to pembrolizumab, led to significantly reduced tumor growth as did intratumoral injections of CD141+ DCs. The findings provide rationale for future studies of CD141+ DC-targeting interventions to enhance the efficacy of checkpoint blockade.

Systemic pro-inflammatory response identifies patients with cancer with adverse outcomes from SARS-CoV-2 infection: the OnCovid Inflammatory Score

Gino M Dettorre, Saoirse Dolly, Angela Loizidou, John Chester, Amanda Jackson, Uma Mukherjee, Alberto Zambelli, Juan Aguilar-Company, Mark Bower, Christopher C T Sng, Ramon Salazar, Alexia Bertuzzi, Joan Brunet, Ricard Mesia, Ailsa Sita-Lumsden, Elia Seguí, Federica Biello, Daniele Generali, Salvatore Grisanti, Pavetha Seeva, Gianpiero Rizzo, Michela Libertini, Antonio Maconi, Charlotte Moss, Beth Russell, Nadia Harbeck, Bruno Vincenzi, Rossella Bertulli, Diego Ottaviani, Raquel Liñan, Andrea Marrari, M Carmen Carmona-García, Neha Chopra, Carlo Alberto Tondini, Oriol Mirallas, Valeria Tovazzi, Vittoria Fotia, Claudia Andrea Cruz, Nadia Saoudi-Gonzalez, Eudald Felip, Ariadna Roqué, Alvin J X Lee, Tom Newsom-Davis, David García-Illescas, Roxana Reyes, Yien Ning Sophia Wong, Daniela Ferrante, Lorenza Scotti, Javier Marco-Hernández, Isabel Ruiz-Camps, Andrea Patriarca, Lorenza Rimassa, Lorenzo Chiudinelli, Michela Franchi, Armando Santoro, Aleix Prat, Alessandra Gennari, Mieke Van Hemelrijck, Josep Tabernero, Nikolaos Diamantis, David J Pinato

Journal for ImmunoTherapy of Cancer 2021;9:e002277 (22 March 2021)



Patients with cancer are more likely to develop severe COVID-19, although the relative contribution of baseline cosegregating comorbidities and malignancy-specific factors to excess mortality with SARS-CoV-2 infection remain poorly understood. Both COVID-19 and cancer are associated with systemic inflammation, motivating Gino M Detorre and colleagues to evaluate the prognostic utility of commonly used inflammatory indices in SARS-CoV-2-infected patients with cancer in Europe. Dynamic changes in neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), modified Glasgow Prognostic Score (mGPS), Prognostic Index (PI), and Prognostic Nutritional Index (PNI), which was renamed the OnCovid Inflammatory Score (OIS), were seen in a multicenter cohort that included 1071 patients with COVID-19 and cancer. NLR, OIS, and mGPS all worsened at COVID-19 diagnosis compared with pre- and post-COVID-19 measurements. Multivariable analyses revealed that the OIS, which takes into account hypoalbuminemia and lymphopenia, was the factor that was most independently predictive of survival in independent training (n=529) and validation (n=542) sets. Intriguingly, inflammatory responses appeared to be unevenly distributed across tumor sites, with patients with breast cancer having lower mortality overall; however, the OIS retained prognostic value regardless of the underlying malignancy. The results identify OIS in SARS-CoV-2-infected patients with cancer as a readily available, inexpensive, and validated predictor of outcome and suggested that interventions aimed at modulating the hyperinflammatory acute phase response may reduce COVID-19-related mortality in patients with cancer.


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.