Single-cell protein analysis in support of biomarker evaluation for breast cancer immunotherapeutics.

2018 ◽  
Vol 36 (5_suppl) ◽  
pp. 10-10
Author(s):  
Vicki Plaks

10 Background: Triple-negative breast cancer (TNBC) is being tested for PD-1/PD-L1 checkpoint inhibitors combination therapy. The relationship between tumor expression of PD-L1 and patient outcomes has been established using immunohistochemistry (IHC) biomarker assays across various malignancies. PD-L1 is expressed in tumor and immune cells within the tumors in TNBC, but only immune-cell PD-L1 is associated with response to anti-PD-L1 (atezolizumab) so differentiating tumor vs. immune PD-L1 expression is essential. The currently available IHC biomarker assays that relay on tissue biopsies struggle to provide clinically meaningful identification of responders vs. non-responders. Poor sensitivity and specificity is partially attributed to tumor heterogeneity that is not well-represented in these biopsies. In addition, PD-L1 expression may vary over time due to disease progression or treatment. Since tissue biopsy collection is often an invasive procedure, it is restricted. Needle biopsies can mitigate some of these issues as a minimally invasive method to probe multiple regions within several cancer lesions across several time points. MILO, a new single cell Western Blot (WB) technology allows quantitative measurements of multiple protein biomarkers within one cell in small samples. Methods: To evaluate the capability of MILO to differentiate between PD-L1 in immune and tumor cell populations, we interrogated BC cell lines as well as peripheral blood mononuclear cells (PBMCs) mixed in known ratios. We used MDA-MB-231 that shows high PD-L1 and low HER2 expression and BT-474, which shows the inverse expression profile for these biomarkers along with PBMCs as PD-L1+ immune cells. Primary breast tumor tissues are currently interrogated to establish utility in needle biopsies. Results: MILO demonstrated heterogeneity at the single-cell level of HER2 and PD-L1 expression in BC tumor cells and enabled differentiation between PD-L1 expression in immune vs. tumor cells using cell-specific markers and low cell numbers. Conclusions: MILO can improve patient selection and prediction of response to immune checkpoint inhibition by promoting the utility of needle biopsies to complement IHC of core biopsies.

2021 ◽  
Author(s):  
Zhibin Li ◽  
chengcheng Sun ◽  
Fei Wang ◽  
Xiran Wang ◽  
Jiacheng Zhu ◽  
...  

Background: Immune cells play important roles in mediating immune response and host defense against invading pathogens. However, insights into the molecular mechanisms governing circulating immune cell diversity among multiple species are limited. Methods: In this study, we compared the single-cell transcriptomes of 77 957 immune cells from 12 species using single-cell RNA-sequencing (scRNA-seq). Distinct molecular profiles were characterized for different immune cell types, including T cells, B cells, natural killer cells, monocytes, and dendritic cells. Results: The results revealed the heterogeneity and compositions of circulating immune cells among 12 different species. Additionally, we explored the conserved and divergent cellular cross-talks and genetic regulatory networks among vertebrate immune cells. Notably, the ligand and receptor pair VIM-CD44 was highly conserved among the immune cells. Conclusions: This study is the first to provide a comprehensive analysis of the cross-species single-cell atlas for peripheral blood mononuclear cells (PBMCs). This research should advance our understanding of the cellular taxonomy and fundamental functions of PBMCs, with important implications in evolutionary biology, developmental biology, and immune system disorders


2021 ◽  
Vol 35 ◽  
pp. 205873842110565
Author(s):  
Shaoping Shen ◽  
Qiyan Wu ◽  
Jialin Liu ◽  
Liangliang Wu ◽  
Rong Zhang ◽  
...  

One biomarker for a better therapeutic effect of immune checkpoint inhibitors is high expression of checkpoint in tumor microenvironment The purpose of this study is to investigate the expression of immune checkpoints in human glioma microenvironment and peripheral blood mononuclear cells. First, single-cell suspension from 20 fresh high-grade glioma (HGG) specimens were obtained, and analyzed for lymphocyte composition, then six co-inhibitory immune checkpoints were analyzed at the same time. Second, 36 PBMC specimens isolated from HGG blood samples were analyzed for the same items. In GME, there were four distinct subtypes of cells, among them, immune cells accounted for an average of 51.3%. The myeloid cell population (CD11b+) was the most common immune cell identified, accounting for 36.14% on average; the remaining were most CD3+CD4+ and CD3+/CD8−/CD4− T lymphocytes. In these cells, we detected the expression of BTLA, LAG3, Tim-3, CTLA-4, and VISTA on varying degrees. While in PBMCs, the result showed that when compared with healthy volunteers, the proportion of NK cells decreased significantly in HGG samples ( p < 0.01). Moreover, the expression of BTLA, LAG3, and Tim-3 in CD45+ immune cells in PBMC was more remarkable in glioma samples. In conclusion, the CD11b+ myeloid cells were the predominant immune cells in GME. Moreover, some immune checkpoints displayed a more remarkable expression on the immune cells in GME. And the profile of checkpoint expression in PBMC was partially consistent with that in GME.


Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1863
Author(s):  
Nan Chen ◽  
Nicole Higashiyama ◽  
Valentina Hoyos

Immune checkpoint inhibitors utilize the immune system to kill cancer cells and are now widely applied across numerous malignancies. Pembrolizumab has two breast-specific indications in triple-negative disease. Currently, programmed death ligand-1 (PD-L1) expression on tumor and surrounding immune cells is the only validated predictive biomarker for immune checkpoint inhibitors (ICIs) in breast cancer; however, it can be imprecise. Additional biomarkers are needed to identify the patient population who will derive the most benefit from these therapies. The tumor immune microenvironment contains many biomarker candidates. In tumor cells, tumor mutational burden has emerged as a robust biomarker across malignancies in general, with higher burden cancers demonstrating improved response, but will need further refinement for less mutated cancers. Preliminary studies suggest that mutations in breast cancer gene 2 (BRCA-2) are associated with increased immune infiltration and response to ICI therapy. Other genomic alterations are also being investigated as potential predictive biomarkers. In immune cells, increased quantity of tumor-infiltrating lymphocytes and CD8+ cytotoxic T cells have correlated with response to immunotherapy treatment. The role of other immune cell phenotypes is being investigated. Peripherally, many liquid-based biomarker strategies such as PD-L1 expression on circulating tumor cells and peripheral immune cell quantification are being studied; however, these strategies require further standardization and refinement prior to large-scale testing. Ultimately, multiple biomarkers utilized together may be needed to best identify the appropriate patients for these treatments.


Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 514
Author(s):  
Denise Utami Putri ◽  
Cheng-Hui Wang ◽  
Po-Chun Tseng ◽  
Wen-Sen Lee ◽  
Fu-Lun Chen ◽  
...  

The heterogeneity of immune response to COVID-19 has been reported to correlate with disease severity and prognosis. While so, how the immune response progress along the period of viral RNA-shedding (VRS), which determines the infectiousness of disease, is yet to be elucidated. We aim to exhaustively evaluate the peripheral immune cells to expose the interplay of the immune system in uncomplicated COVID-19 cases with different VRS periods and dynamic changes of the immune cell profile in the prolonged cases. We prospectively recruited four uncomplicated COVID-19 patients and four healthy controls (HCs) and evaluated the immune cell profile throughout the disease course. Peripheral blood mononuclear cells (PBMCs) were collected and submitted to a multi-panel flowcytometric assay. CD19+-B cells were upregulated, while CD4, CD8, and NK cells were downregulated in prolonged VRS patients. Additionally, the pro-inflammatory-Th1 population showed downregulation, followed by improvement along the disease course, while the immunoregulatory cells showed upregulation with subsequent decline. COVID-19 patients with longer VRS expressed an immune profile comparable to those with severe disease, although they remained clinically stable. Further studies of immune signature in a larger cohort are warranted.


2021 ◽  
Vol 9 (1) ◽  
pp. e001762
Author(s):  
Punit Upadhyaya ◽  
Johanna Lahdenranta ◽  
Kristen Hurov ◽  
Sailaja Battula ◽  
Rachel Dods ◽  
...  

BackgroundIn contrast to immune checkpoint inhibitors, the use of antibodies as agonists of immune costimulatory receptors as cancer therapeutics has largely failed. We sought to address this problem using a new class of modular synthetic drugs, termed tumor-targeted immune cell agonists (TICAs), based on constrained bicyclic peptides (Bicycles).MethodsPhage libraries displaying Bicycles were panned for binders against tumor necrosis factor (TNF) superfamily receptors CD137 and OX40, and tumor antigens EphA2, Nectin-4 and programmed death ligand 1. The CD137 and OX40 Bicycles were chemically conjugated to tumor antigen Bicycles with different linkers and stoichiometric ratios of binders to obtain a library of low molecular weight TICAs (MW <8 kDa). The TICAs were evaluated in a suite of in vitro and in vivo assays to characterize their pharmacology and mechanism of action.ResultsLinking Bicycles against costimulatory receptors (e.g., CD137) to Bicycles against tumor antigens (e.g., EphA2) created potent agonists that activated the receptors selectively in the presence of tumor cells expressing these antigens. An EphA2/CD137 TICA (BCY12491) efficiently costimulated human peripheral blood mononuclear cells in vitro in the presence of EphA2 expressing tumor cell lines as measured by the increased secretion of interferon γ and interleukin-2. Treatment of C57/Bl6 mice transgenic for the human CD137 extracellular domain (huCD137) bearing EphA2-expressing MC38 tumors with BCY12491 resulted in the infiltration of CD8+ T cells, elimination of tumors and generation of immunological memory. BCY12491 was cleared quickly from the circulation (plasma t1/2 in mice of 1–2 hr), yet intermittent dosing proved effective.ConclusionTumor target-dependent CD137 agonism using a novel chemical approach (TICAs) afforded elimination of tumors with only intermittent dosing suggesting potential for a wide therapeutic index in humans. This work unlocks a new path to effective cancer immunotherapy via agonism of TNF superfamily receptors.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Marlies P Noz ◽  
Siroon Bekkering ◽  
Laszlo Groh ◽  
Tim MJ Nielen ◽  
Evert JP Lamfers ◽  
...  

Atherosclerosis is the major cause of cardiovascular disease (CVD). Monocyte-derived macrophages are the most abundant immune cells in atherosclerotic plaques. In patients with atherosclerotic CVD, leukocytes have a hyperinflammatory phenotype. We hypothesize that immune cell reprogramming in these patients occurs at the level of myeloid progenitors. We included 13 patients with coronary artery disease due to severe atherosclerosis and 13 subjects without atherosclerosis in an exploratory study. Cytokine production capacity after ex vivo stimulation of peripheral blood mononuclear cells (MNCs) and bone marrow MNCs was higher in patients with atherosclerosis. In BM-MNCs this was associated with increased glycolysis and oxidative phosphorylation. The BM composition was skewed towards myelopoiesis and transcriptome analysis of HSC/GMP cell populations revealed enrichment of neutrophil- and monocyte-related pathways. These results show that in patients with atherosclerosis, activation of innate immune cells occurs at the level of myeloid progenitors, which adds exciting opportunities for novel treatment strategies.


Author(s):  
Roosheel S. Patel ◽  
Joy E. Tomlinson ◽  
Thomas J. Divers ◽  
Gerlinde R. Van de Walle ◽  
Brad R. Rosenberg

ABSTRACTTraditional laboratory model organisms represent a small fraction of the diversity of multicellular life, and findings in any given experimental model often do not translate to other species. Immunology research in non-traditional model organisms can be advantageous or even necessary (e.g. for host-pathogen interaction studies), but presents multiple challenges, many stemming from an incomplete understanding of potentially species-specific immune cell types, frequencies and phenotypes. Identifying and characterizing immune cells in such organisms is frequently limited by the availability of species-reactive immunophenotyping reagents for flow cytometry, and insufficient prior knowledge of cell type-defining markers. Here, we demonstrate the utility of single cell RNA sequencing (scRNA-Seq) to characterize immune cells for which traditional experimental tools are limited. Specifically, we used scRNA-Seq to comprehensively define the cellular diversity of equine peripheral blood mononuclear cells (PBMCs) from healthy horses across different breeds, ages, and sexes. We identified 30 cell type clusters partitioned into five major populations: Monocytes/Dendritic Cells, B cells, CD3+PRF1+ lymphocytes, CD3+PRF1- lymphocytes, and Basophils. Comparative analyses revealed many cell populations analogous to human PBMC, including transcriptionally heterogeneous monocytes and distinct dendritic cell subsets (cDC1, cDC2, plasmacytoid DC). Unexpectedly, we found that a majority of the equine peripheral B cell compartment is comprised of T-bet+ B cells; an immune cell subpopulation typically associated with chronic infection and inflammation in human and mouse. Taken together, our results demonstrate the potential of scRNA-Seq for cellular analyses in non-traditional model organisms, and form the basis for an immune cell atlas of horse peripheral blood.


2021 ◽  
Author(s):  
Xinru Qiu ◽  
Jiang Li ◽  
Jeff Bonenfant ◽  
Lukasz Jaroszewski ◽  
Walter Klein ◽  
...  

AbstractSystemic infections, especially in patients with chronic diseases, result in sepsis: an explosive, uncoordinated immune response that can lead to multisystem organ failure with a high mortality rate. Sepsis survivors and non-survivors oftentimes have similar clinical phenotypes or sepsis biomarker expression upon diagnosis, suggesting that the dynamics of sepsis in the critical early stage may have an impact on these opposite outcomes. To investigate this, we designed a within-subject study of patients with systemic gram-negative bacterial sepsis with surviving and fatal outcomes and performed single-cell transcriptomic analyses of peripheral blood mononuclear cells (PBMC) collected during the critical period between sepsis recognition and 6 hours. We observed that the largest sepsis-induced expression changes over time in surviving versus fatal sepsis were in CD14+ monocytes, including gene signatures previously reported for sepsis outcomes. We further identify changes in the metabolic pathways of both monocytes and platelets, the emergence of erythroid precursors, and T cell exhaustion signatures, with the most extreme differences occurring between the non-sepsis control and the sepsis non-survivor. Our single-cell observations are consistent with trends from public datasets but also reveal specific effects in individual immune cell populations, which change within hours. In conclusion, this pilot study provides the first single-cell results with a repeated measures design in sepsis to analyze the temporal changes in the immune cell population behavior in surviving or fatal sepsis. These findings indicate that tracking temporal expression changes in specific cell-types could lead to more accurate predictions of sepsis outcomes. We also identify molecular pathways that could be therapeutically controlled to improve the sepsis trajectory toward better outcomes.Summary sentenceSingle cell transcriptomics of peripheral blood mononuclear cells in surviving and fatal sepsis reveal inflammatory and metabolic pathways that change within hours of sepsis recognition.


2021 ◽  
Vol 12 (11) ◽  
Author(s):  
Guojuan Jiang ◽  
Juchuanli Tu ◽  
Lei Zhou ◽  
Mengxue Dong ◽  
Jue Fan ◽  
...  

AbstractBreast cancer stem-like cells (BCSCs) play vital roles in tumorigenesis and progression. However, the origin and dynamic changes of BCSCs are still to be elucidated. Using the breast cancer mouse model MMTV-PyMT, we constructed a single-cell atlas of 31,778 cells from four distinct stages of tumor progression (hyperplasia, adenoma/MIN, early carcinoma and late carcinoma), during which malignant transition occurs. We identified that the precise cell type of ERlow epithelial cell lineage gave rise to the tumors, and the differentiation of ERhigh epithelial cell lineage was blocked. Furthermore, we discovered a specific signature with a continuum of gene expression profiles along the tumor progression and significantly correlated with clinical outcomes, and we also found a stem-like cell cluster existed among ERlow epithelial cells. Further clustering on this stem-like cluster showed several sub-clusters indicating heterogeneity of stem-like epithelial cells. Moreover, we distinguished normal and cancer stem-like cells in this stem-like epithelial cell cluster and profiled the molecular portraits from normal stem-like cell to cancer stem-like cells during the malignant transition. Finally, we found the diverse immune cell infiltration displayed immunosuppressive characteristics along tumor progression. We also found the specific expression pattern of cytokines and their corresponding cytokine receptors in BCSCs and immune cells, suggesting the possible cross-talk between BCSCs and the immune cells. These data provide a useful resource for illuminating BCSC heterogeneity and the immune cell remodeling during breast tumor progression, and shed new light on transcriptomic dynamics during the progression at the single-cell level.


2020 ◽  
Author(s):  
Gang Xu ◽  
Furong Qi ◽  
Hanjie Li ◽  
Qianting Yang ◽  
Haiyan Wang ◽  
...  

Understanding the mechanism that leads to immune dysfunction induced by SARS-CoV2 virus is crucial to develop treatment for severe COVID-19. Here, using single cell RNA-seq, we characterized the peripheral blood mononuclear cells (PBMC) from uninfected controls and COVID-19 patients, and cells in paired broncho-alveolar lavage fluid (BALF). We found a close association of decreased dendritic cells (DC) and increased monocytes resembling myeloid-derived suppressor cells (MDSC) which correlated with lymphopenia and inflammation in the blood of severe COVID-19 patients. Those MDSC-like monocytes were immune-paralyzed. In contrast, monocyte-macrophages in BALFs of COVID-19 patients produced massive amounts of cytokines and chemokines, but secreted little interferons. The frequencies of peripheral T cells and NK cells were significantly decreased in severe COVID-19 patients, especially for innate-like T and various CD8+ T cell subsets, compared to health controls. In contrast, the proportions of various activated CD4+ T cell subsets, including Th1, Th2 and Th17-like cells were increased and more clonally expanded in severe COVID-19 patients. Patients' peripheral T cells showed no sign of exhaustion or augmented cell death, whereas T cells in BALFs produced higher levels of IFNG, TNF, CCL4 and CCL5 etc. Paired TCR tracking indicated abundant recruitment of peripheral T cells to the patients' lung. Together, this study comprehensively depicts how the immune cell landscape is perturbed in severe COVID-19.


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