Immunotherapy Bridge 2019
SITC session—mechanisms of success and failure in immunotherapy
Oral communications
1 Gal9/Tim-3 expression level is higher in patient with failed chemotherapy in AML
Paola Dama, Marshall Tang, Noreen Fulton, Justin Kline, Hongtao Liu
University of Chicago Medicine Hematology/Oncology Section, 5841 S Maryland Ave, Chicago, IL, 60637, USA
Correspondence: Paola Dama - dmapla@gmail.com, p.dama@sussex.ac.uk; Hongtao Liu - hliu2@medicine.bsd.uchicago.edu
Journal of Translational Medicine 2020, 18(Supp 1):1
Background: Activation of immune checkpoint pathways in Acute Myeloid Leukemia (AML) may interfere with effective T-cell anti-tumor immunity, and is associated with immune evasion in pre-clinical leukemia models as it has been demonstrated [1, 2]. It was previously reported that overexpression of CTLA4 and PD-1 is associated with more aggressive leukemia and progression from MDS to AML or AML relapse. While PD-1/PD-L1 blockade therapy can be effective as cancer immunotherapy, interruption of PD-1/PD-L1 interactions alone does not completely restore T cell function in some patients indicating the involvement of additional negative regulatory pathways, such as Tim-3/Gal-9, in T cell exhaustion. Immune checkpoint pathways active in Acute Myeloid Leukemia (AML) patients, especially during the course of remission induction chemotherapy, have not been well-studied. We characterized these pathways in newly diagnosed AML patients enrolled in a phase I dose escalation trial that combined Selinexor a Selective Inhibitor of Nuclear Export (SINE) with high-dose cytarabine (HiDAC) and mitoxantrone (Mito) (NCT02573363) as induction therapy.
Methods and study design: Multi-parameter flow-cytometry was performed on bone marrow specimens at diagnosis and following remission induction therapy in 26 patients with AML enrolled to the study to monitor the changes in expression of immune checkpoint receptors. Expression of CD47, PD-L1, PD-L2 and Gal-9 was assessed on CD34+ AML blasts and CD34- cell populations. In parallel, expression of inhibitory (PD1, CTLA4, LAG3, TIM3) and stimulatory co-receptors (CD28, ICOS, CD137, OX40, CD40L, HLA-DR) on CD4+ and CD8+ T cell subsets were evaluated. The positivity and frequency of parent in percentage of each markers was gauged by comparing with their FMO controls. Samples were analyzed using LSR Fortessa or LSRII Cytometers. The Mann–Whitney Test, Spearman’s rank correlation and Runs Test analysis were applied. For all analyses, P-values < 0.05 were considered statistically significant.
Results: The percentage of CD34− Gal9+ cells was significantly higher and was positively correlated with higher numbers of TIM-3-expressing T cells at the time of diagnosis in patients who experienced treatment failure (TF) after chemotherapy, compared to those in complete remission (CR). When comparing TIM-3 expression on CD4+ and CD8+ T cells in pre-treatment (diagnosis) to post induction therapy samples, the magnitude of increase measured by median fluorescence intensity (MFI) inversely correlated to response to therapy with increase TIM-3 MFI of > 50% in patients with TF.
Conclusions: This study provides preliminary evidence to support a rationale for incorporating antibodies against the Gal9/TIM3 pathway during and/or following remission induction therapy for AML.
References
-
1.
Zhang L, Gajewski TF, Kline J, PD-1/PD-L1 interactions inhibit antitumor immune responses in a murine acute myeloid leukemia model. Blood. 2009; 114(8):1545–52.
-
2.
Zhou Q, Munger ME, Blazar BR, Coexpression of Tim-3 and PD-1 identifies a CD8+ T-cell exhaustion phenotype in mice with disseminated acute myelogenous leukemia. Blood. 2011;117(17):4501–10.
The study was approved by the Institutional Review Board at The University of Chicago (IRB15-0412) (Fig. 1).
2 Gender differences in prognostic value of immune-related biomarkers in colon cancer patients randomized to surgery or surgery and adjuvant chemotherapy treatment
Lisa Villabona, Jacob Karlsson, Giuseppe Masucci, Peter Ragnhammar
Dept of oncology/pathology, Karolinska Institutet, Stockholm, Sweden
Correspondence: Lisa Villabona - Lisa.villabona@ki.se
Journal of Translational Medicine 2020, 18(Supp 1):2
Background: HLA-A*02, a common allele in the Scandinavian population, is a negative prognostic factor in epithelial ovarian cancer. It is a strong predictor of patient outcome, only inferior to clinical staging. This prognostic trait in epithelial ovarian cancer is stronger by the presence of the gene compared with the expression of its protein, MHC class I. Microsatellite instability (MSI) is used as a biomarker for prognosis and is suggested an increased tumor mutational burden which can make the tumor more susceptible for T cell mediated immunotherapy. Our aim was to analyze the prognostic markers HLA-A*02 genotype, MHC class I on tumor cells, the CD8+ lymphocyte infiltration and MSI status in colon cancer patients with randomized treatment.
Methods: Clinical information and primary tumors were collected from 520 colon cancer patients and followed for overall survival for 120 months. Patients hade stage II and III colon cancer and were randomized to surgery alone or surgery and adjuvant chemotherapy. HLA-A*02 genotype was determined by conventional PCR. MHC class I, MSI status and CD8+ lymphocyte infiltration were determined by immunohistochemistry.
Results: Female patients with a stage III tumor and HLA-A*02 genotype had a better outcome if they had received adjuvant chemotherapy instead of just surgery (p = 0.03), whereas this was not the case for patients with other HLA-A genotypes or in the male patients where HLA-type did not correlate to outcome. MHC class I expression did not act as a prognostic factor, however the presence of CD8+ lymphocytes in the invasive margin and inside the tumor was a positive prognostic factor for overall survival (p = 0.01), although only statistically significant in the male patients (p = 0.03). 21% patients had a tumor with MSI (23% of the female and 19% of the male patients respectively). MSI tumors had a slightly better outcome and this was irrespective of gender and HLA-type.
Conclusions: The prognostic traits of HLA-A*02 appear in this colon cancer cohort to act differently in male and female patients. Also CD8+ infiltration is different between genders. These findings suggest that men and women may have two different immune responses to malignancy (Table 1).
3 Role of Microvesicles in the transfer and in the transformation of melanoma cell lines
Giusy Gentilcore1, Selma Maacha1, Abbirami Shatappan1, Giuseppe Palmieri2, Paolo A. Ascierto3 and Jean-Charles Grivel1
1Deep Phenotyping Core, Sidra Medicine, Doha, Qatar; 2Istituto Nazionale Tumori Fondazione G. Pascale, I-80131, Naples, Italy; 3Unit of Cancer Genetics, Institute of Biomolecular Chemistry, CNR, I-07100, Sassari, Italy
Correspondence: Giusy Gentilcore - ggentilcore@sidra.org
Journal of Translational Medicine 2020, 18(Supp 1):3
Background: Melanoma remains one of the most aggressive and heterogeneous skin cancer, which is often refractory to conventional chemotherapy. Nevertheless, it responds well to both immuno-and targeted therapy, which is focused on inhibiting the most common signaling pathway involved in melanoma transformation including the mitogen-activated protein kinase (MAPK) pathway. However, mechanisms of drug resistance have been described, some involving the release of extracellular vesicles (EVs). EVs are play an important role as intercellular communication mediators that can influence the phenotype and function of receiving cells. The aim of our study is to investigate the role of EVs in the mechanisms of drug resistance and phenotypic alteration in primary melanoma cell lines MEL50 BRAF-V600mut and M257 BRAF-Wild Type.
Materials and methods: In order to define phenotypic and functional differences between the two cell types, we characterized their surfaceome with a panel of 361-PE-conjugated antibodies specific for cell surface proteins. We compared the extracellular vesicles produced by both cell line, quantitatively and qualitatively by NTA and flow cytometry.
Results: We identified 49 markers expressed by more than 30% of MEL50 cells and 69 markers expressed by more than 30% of M257 cells. Among these markers, 10 are exclusively expressed by MEL50 and 36 are exclusively expressed by M257. Defining a distinctive surfaceome for both cell lines. We have also characterized the EVs produced by these cell lines and showed that MEL50 produces 3 times as much EVs than M257. These EVs are indistinguishable by Nanoparticle tracking analysis. Preliminary flow cytometric characterization of individual EVs did not show a significant difference in the expression of the classic EVs markers CD81, CD82, CD63 and CD9.
Conclusions: The characterization of the cancer cell surfaceome of two primary melanoma cell lines, one BRAF-V600mut and one BRAF-Wild Type, uncovered very distinctive phenotypes. While the expression of classic EVs markers was similar for EVs produced by either cell line, the extension of EVs marker characterization to the whole surfaceome of the parental cell line, may reveal the same heterogeneity, which could be used as biomarkers to identify BRAF mutated or wild type melanomas in liquid biopsies, and opens the door to investigating the role of specific EVs in drug resistance and phenotypic transformation.