The role of high-dimensional profiling of the systemic immune response on optimal sequencing of radiotherapy (RT) and immune checkpoint blockade (ICB).

2019 ◽  
Vol 37 (8_suppl) ◽  
pp. 13-13
Author(s):  
Kevin Lee Min Chua ◽  
Michael Fehlings ◽  
Pek Lim Chu ◽  
Xiao-Tian Lin ◽  
Eugenia Yeo ◽  
...  

13 Background: Combinatorial RT-ICB potentiates anti-tumour reactivity by modulating the immune response. We therefore performed in-depth phenotypic profiling of the systemic T cell compartment following treatment with RT-ICB. Methods: We recruited 20 patients with biopsy-proven metastatic renal cell and non-small cell lung carcinoma, who were treated with a sandwich regime of ICB-RT-ICB under a prospective observational study protocol, and compared against a RT alone-treated cohort (N = 10). All patients received ablative RT (8-50 Gy/1-5 fr) for oligoprogression and/or local palliation. Blood samples were longitudinally collected at pre-RT, 14 d post-RT and cycle 2 ICB post-RT. Deep T cell profiling was performed by mass cytometry using a customised 41 parameter panel, together with high dimensional analysis tools. Results: Median follow-up of the overall cohort was 18 mo; median duration of ICB received in the ICB-RT-ICB arm was 15 mo. We observed significant diversity of the systemic T cell repertoire between patients at baseline, and this corresponded to significant interpatient heterogeneity in T cell responses specific to the central/effector memory, EMRA and Treg subsets post-RT. Dramatic local response (complete response at 1 mo post-RT) was significantly higher in the ICB-RT-ICB cohort compared to the RT alone cohort (12/20 vs 1/10, P <0.01). This clinical phenomenon corresponded to an increased % Ki67highCD8 and CD4 T cells post-RT exclusively in the combinatorial treated cohort, which was further enhanced upon resumption of ICB (mean = 10% vs 3% [CD8]; 13% vs 2% [CD4]; P <0.01). Deeper immunophenotyping of the Ki67high subsets revealed associated high expression of GranzymeB and Eomes. Conclusions: Here, we observed changes in the T cell phenotypes that varied remarkably across all patients following RT. We further highlight a RT-dependent T cell proliferation amongst all RT-ICB-treated patients that was further enhanced by ICB in prior responders. This immune phenomenon may account for the dramatic responses to combinatorial treatment, and informs on optimal sequencing strategies for combining RT and ICB.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rohan Sivapalan ◽  
Jinyan Liu ◽  
Krishnendu Chakraborty ◽  
Elisa Arthofer ◽  
Modassir Choudhry ◽  
...  

AbstractThe a priori T cell repertoire and immune response against SARS-CoV-2 viral antigens may explain the varying clinical course and prognosis of patients having a mild COVID-19 infection as opposed to those developing more fulminant multisystem organ failure and associated mortality. Using a novel SARS-Cov-2-specific artificial antigen presenting cell (aAPC), coupled with a rapid expansion protocol (REP) as practiced in tumor infiltrating lymphocytes (TIL) therapy, we generate an immune catalytic quantity of Virus Induced Lymphocytes (VIL). Using T cell receptor (TCR)-specific aAPCs carrying co-stimulatory molecules and major histocompatibility complex (MHC) class-I immunodominant SARS-CoV-2 peptide-pentamer complexes, we expand virus-specific VIL derived from peripheral blood mononuclear cells (PBMC) of convalescent COVID-19 patients up to 1000-fold. This is achieved in a clinically relevant 7-day vein-to-vein time-course as a potential adoptive cell therapy (ACT) for COVID-19. We also evaluate this approach for other viral pathogens using Cytomegalovirus (CMV)-specific VIL from donors as a control. Rapidly expanded VIL are enriched in virus antigen-specificity and show an activated, polyfunctional cytokine profile and T effector memory phenotype which may contribute to a robust immune response. Virus-specific T cells can also be delivered allogeneically via MHC-typing and patient human leukocyte antigen (HLA)-matching to provide pragmatic treatment in a large-scale therapeutic setting. These data suggest that VIL may represent a novel therapeutic option that warrants further clinical investigation in the armamentarium against COVID-19 and other possible future pandemics.


Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3276
Author(s):  
Alexandra Giatromanolaki ◽  
Avgi Tsolou ◽  
Eleftheria Daridou ◽  
Maria Kouroupi ◽  
Katerina Chlichlia ◽  
...  

Background: Inducible Nitric Oxygen Synthase (iNOS) promotes the generation of NO in tissues. Its role in tumor progression and immune response is unclear. Methods: The immunohistochemical expression patterns of iNOS were studied in a series of 98 tissue samples of non-small-cell lung carcinoma (NSCLC), in parallel with the expression of hypoxia and anaerobic metabolism markers, PD-L1 and tumor-infiltrating lymphocytes (TILs). Results: iNOS is expressed by cancer cells in 19/98 (19.4%), while extensive expression by cancer-associated fibroblasts occurs in 8/98 (8.2%) cases. None of these patterns relate to stage or prognosis. Extensive infiltration of the tumor stroma by iNOS-expressing TILs (iNOS+TILs) occurs in 47/98 (48%) cases. This is related to low Hypoxia-Inducible Factor 1α (HIF1α), high PD-L1 expression and a better overall survival (p = 0.002). Expression of PD-L1, however, mitigates the beneficial effect of the presence of iNOS+TIL. Conclusions: Extensive expression of iNOS by TILs occurs in approximately 50% of NSCLCs, and this is significantly related to an improved overall survival. This brings forward the role of iNOS in anti-neoplastic lymphocyte biology, supporting iNOS+TILs as a putative marker of immune response. The value of this biomarker as a predictive and treatment-guiding tool for tumor immunotherapy demands further investigation.


2020 ◽  
Author(s):  
Kyle T. Mincham ◽  
Jacob D. Young ◽  
Deborah H. Strickland

Purpose and appropriate sample typesThis 19-parameter, 18-colour flow cytometry panel was designed and optimised to enable the comprehensive and simultaneous immunophenotyping of distinct T-cell and B-cell subsets within murine lymphoid tissues (Table 1). Cellular populations identified by employing this OMIP include 4 major subsets of B-cells (memory, activated, plasma cells and plasmablasts) and 7 major subsets of CD4+ T-cells (naïve, central memory, effector memory, helper, regulatory, follicular helper and follicular regulatory). Staining was performed on freshly isolated splenocytes from 21-day-old neonatal BALB/c mice, however due to the omission of mouse strain-specific markers, this OMIP can be implemented across a range of murine models where in-depth immunophenotyping of the diverse repertoire of T-cell and B-cell populations localised within lymphoid tissues is required.


2020 ◽  
Author(s):  
Anno Saris ◽  
Tom D.Y. Reijnders ◽  
Esther J. Nossent ◽  
Alex R. Schuurman ◽  
Jan Verhoeff ◽  
...  

AbstractOur understanding of the coronavirus disease-19 (COVID-19) immune response is almost exclusively derived from studies that examined blood. To gain insight in the pulmonary immune response we analysed BALF samples and paired blood samples from 17 severe COVID-19 patients. Macrophages and T cells were the most abundant cells in BALF. In the lungs, both CD4 and CD8 T cells were predominantly effector memory cells and expressed higher levels of the exhaustion marker PD-1 than in peripheral blood. Prolonged ICU stay associated with a reduced proportion of activated T cells in peripheral blood and even more so in BALF. T cell activation in blood, but not in BALF, was higher in fatal COVID-19 cases. Increased levels of inflammatory mediators were more pronounced in BALF than in plasma. In conclusion, the bronchoalveolar immune response in COVID-19 has a unique local profile that strongly differs from the immune profile in peripheral blood.SummaryThe bronchoalveolar immune response in severe COVID-19 strongly differs from the peripheral blood immune profile. Fatal COVID-19 associated with T cell activation blood, but not in BALF.


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