Publications by authors named "Catherine C Hedrick"

92 Publications

Naive CD8 T Cells Expressing CD95 Increase Human Cardiovascular Disease Severity.

Arterioscler Thromb Vasc Biol 2020 12 15;40(12):2845-2859. Epub 2020 Oct 15.

Division of Inflammation Biology, La Jolla Institute for Immunology, CA (L.E.P., H.Q.D., R.W., D.E.G., D.J.A., H.W., C.C.H.).

Objective: Cardiovascular disease (CVD) remains a significant global health concern with a high degree of mortality. While CD4 T cells have been extensively studied in CVD, the importance of CD8 T cells in this disease, despite their abundance and increased activation in human atherosclerotic plaques, remains largely unknown. Thus, the objective of this study was to compare peripheral T-cell signatures between humans with a high (severe) risk of CVD (including myocardial infarction or stroke) and those with a low risk of CVD. Approach and Results: Using mass cytometry, we uncovered a naive CD8 T (T) cell population expressing CD95 (termed CD95CD8 stem cell memory T [CD8 T] cells) that was enriched in patients with high compared with low CVD. This T-cell subset enrichment within individuals with high CVD was a relative increase and resulted from the loss of CD95 cells within the T compartment. We found that CD8 T cells positively correlated with CVD risk in humans, while CD8 T cells were inversely correlated. Atherosclerotic apolipoprotein E-deficient (ApoE) mice also displayed respective 7- and 2-fold increases in CD8 T frequencies within the peripheral blood and aorta-draining paraaortic lymph nodes compared with C57BL/6J mice. CD8 T cells were 1.7-fold increased in aortas from western diet fed ApoE mice compared with normal laboratory diet-fed ApoE mice. Importantly, transfer of T cells into immune-deficient recipient mice that lacked T cells increased atherosclerosis, illustrating the importance of these cells in atherogenesis.

Conclusions: CD8 T cells are increased in humans with high CVD. As these T cells promote atherosclerosis, targeting them may attenuate atherosclerotic plaque progression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/ATVBAHA.120.315106DOI Listing
December 2020

CyTOF mass cytometry reveals phenotypically distinct human blood neutrophil populations differentially correlated with melanoma stage.

J Immunother Cancer 2020 09;8(2)

Inflammation Biology, La Jolla Institute for Immunology, La Jolla, California, USA

Background: Understanding neutrophil heterogeneity and its relationship to disease progression has become a recent focus of cancer research. Indeed, several studies have identified neutrophil subpopulations associated with protumoral or antitumoral functions. However, this work has been hindered by a lack of widely accepted markers with which to define neutrophil subpopulations.

Methods: To identify markers of neutrophil heterogeneity in cancer, we used single-cell cytometry by time-of-flight (CyTOF) coupled with high-dimensional analysis on blood samples from treatment-naïve patients with melanoma.

Results: Our efforts allowed us to identify seven blood neutrophil clusters, including two previously identified individual populations. Interrogation of these neutrophil subpopulations revealed a positive trend between specific clusters and disease stage. Finally, we recapitulated these seven blood neutrophil populations via flow cytometry and found that they exhibited diverse capacities for phagocytosis and reactive oxygen species production in vitro.

Conclusions: Our data provide a refined consensus on neutrophil heterogeneity markers, enabling a prospective functional evaluation in patients with solid tumors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/jitc-2019-000473DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7482580PMC
September 2020

Coexpression of CD71 and CD117 Identifies an Early Unipotent Neutrophil Progenitor Population in Human Bone Marrow.

Immunity 2020 08;53(2):319-334.e6

Center for Cancer Immunotherapy & Center for Autoimmunity and Inflammation, La Jolla Institute for Immunology, La Jolla, CA 92037, USA. Electronic address:

Neutrophils are the most abundant peripheral immune cells and thus, are continually replenished by bone marrow-derived progenitors. Still, how newly identified neutrophil subsets fit into the bone marrow neutrophil lineage remains unclear. Here, we use mass cytometry to show that two recently defined human neutrophil progenitor populations contain a homogeneous progenitor subset we term "early neutrophil progenitors" (eNePs) (LinCD66bCD117CD71). Surface marker- and RNA-expression analyses, together with in vitro colony formation and in vivo adoptive humanized mouse transfers, indicate that eNePs are the earliest human neutrophil progenitors. Furthermore, we identified CD71 as a marker associated with the earliest neutrophil developmental stages. Expression of CD71 marks proliferating neutrophils, which were expanded in the blood of melanoma patients and detectable in blood and tumors from lung cancer patients. In summary, we establish CD117CD71 eNeP as the inceptive human neutrophil progenitor and propose a refined model of the neutrophil developmental lineage in bone marrow.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.immuni.2020.07.017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7942809PMC
August 2020

Cellular sensing of extracellular purine nucleosides triggers an innate IFN-β response.

Sci Adv 2020 Jul 22;6(30):eaba3688. Epub 2020 Jul 22.

La Jolla Institute for Immunology, La Jolla, CA 92037, USA.

Mechanisms linking immune sensing of DNA danger signals in the extracellular environment to innate pathways in the cytosol are poorly understood. Here, we identify a previously unidentified immune-metabolic axis by which cells respond to purine nucleosides and trigger a type I interferon-β (IFN-β) response. We find that depletion of ADA2, an ectoenzyme that catabolizes extracellular dAdo to dIno, or supplementation of dAdo or dIno stimulates IFN-β. Under conditions of reduced ADA2 enzyme activity, dAdo is transported into cells and undergoes catabolysis by the cytosolic isoenzyme ADA1, driving intracellular accumulation of dIno. dIno is a functional immunometabolite that interferes with the cellular methionine cycle by inhibiting SAM synthetase activity. Inhibition of SAM-dependent transmethylation drives epigenomic hypomethylation and overexpression of immune-stimulatory endogenous retroviral elements that engage cytosolic dsRNA sensors and induce IFN-β. We uncovered a previously unknown cellular signaling pathway that responds to extracellular DNA-derived metabolites, coupling nucleoside catabolism by adenosine deaminases to cellular IFN-β production.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/sciadv.aba3688DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7375821PMC
July 2020

M1 tumor-associated macrophages boost tissue-resident memory T cells infiltration and survival in human lung cancer.

J Immunother Cancer 2020 07;8(2)

Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton, UK

Background: The role of tumor-associated macrophages (TAMs) in determining the outcome between the antitumor effects of the adaptive immune system and the tumor's anti-immunity stratagems, is controversial. Macrophages modulate their activities and phenotypes by integration of signals in the tumor microenvironment. Depending on how macrophages are activated, they may adopt so-called M1-like, antitumor or M2-like, protumor profiles. In many solid tumors, a dominance of M2-like macrophages is associated with poor outcomes but in some tumor types, strong M1-like profiles are linked to better outcomes. We aimed to investigate the interrelationship of these TAM populations to establish how they modulate the efficacy of the adaptive immune system in early lung cancer.

Methods: Macrophages from matched lung (non-tumor-associated macrophages (NTAMs)) and tumor samples (TAMs) from resected lung cancers were assessed by bulk and single-cell transcriptomic analysis. Protein expression of genes characteristic of M1-like (chemokine (C-X-C motif) ligand 9) or M2-like (matrix metallopeptidase 12) functions was confirmed by confocal microscopy. Immunohistochemistry related the distribution of TAM transcriptomic signatures to density of CD8 tissue-resident memory T cells (T) in tumors and survival data from an independent cohort of 393 patients with lung cancer.

Results: TAMs have significantly different transcriptomic profiles from NTAMs with >1000 differentially expressed genes. TAMs displayed a strong M2-like signature with no significant variation between patients. However, single-cell RNA-sequencing supported by immuno-stained cells revealed that additionally, in 25% of patients the M2-like TAMs also co-expressed a strong/hot M1-like signature (M1). Importantly, there was a strong association between the density of M1 TAMs and T cells in tumors that was in turn linked to better survival. Our data suggest a mechanism by which M1 TAMs may recruit T cells via CXCL9 expression and sustain them by making available more of the essential fatty acids on which T depend.

Conclusions: We showed that in early lung cancer, expression of M1-like and M2-like gene signatures are not mutually exclusive since the same TAMs can simultaneously display both gene-expression profiles. The presence of M1 TAMs was associated with a strong T tumor-infiltrate and better outcomes. Thus, therapeutic approaches to re-program TAMs to an M1 phenotype are likely to augment the adaptive antitumor responses.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/jitc-2020-000778DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7375465PMC
July 2020

Meta-Analysis of Leukocyte Diversity in Atherosclerotic Mouse Aortas.

Circ Res 2020 07 16;127(3):402-426. Epub 2020 Jul 16.

La Jolla Institute for Immunology, CA (C.C.H., Y.G., H.Q.D., K.L.).

The diverse leukocyte infiltrate in atherosclerotic mouse aortas was recently analyzed in 9 single-cell RNA sequencing and 2 mass cytometry studies. In a comprehensive meta-analysis, we confirm 4 known macrophage subsets-resident, inflammatory, interferon-inducible cell, and Trem2 (triggering receptor expressed on myeloid cells-2) foamy macrophages-and identify a new macrophage subset resembling cavity macrophages. We also find that monocytes, neutrophils, dendritic cells, natural killer cells, innate lymphoid cells-2, and CD (cluster of differentiation)-8 T cells form prominent and separate immune cell populations in atherosclerotic aortas. Many CD4 T cells express IL (interleukin)-17 and the chemokine receptor CXCR (C-X-C chemokine receptor)-6. A small number of regulatory T cells and T helper 1 cells is also identified. Immature and naive T cells are present in both healthy and atherosclerotic aortas. Our meta-analysis overcomes limitations of individual studies that, because of their experimental approach, over- or underrepresent certain cell populations. Mass cytometry studies demonstrate that cell surface phenotype provides valuable information beyond the cell transcriptomes. The present analysis helps resolve some long-standing controversies in the field. First, Trem2 foamy macrophages are not proinflammatory but interferon-inducible cell and inflammatory macrophages are. Second, about half of all foam cells are smooth muscle cell-derived, retaining smooth muscle cell transcripts rather than transdifferentiating to macrophages. Third, , which had been considered specific for platelets and megakaryocytes, is also prominently expressed in the main population of resident vascular macrophages. Fourth, a new type of resident macrophage shares transcripts with cavity macrophages. Finally, the discovery of a prominent innate lymphoid cell-2 cluster links the single-cell RNA sequencing work to recent flow cytometry data suggesting a strong atheroprotective role of innate lymphoid cells-2. This resolves apparent discrepancies regarding the role of T helper 2 cells in atherosclerosis based on studies that predated the discovery of innate lymphoid cells-2 cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/CIRCRESAHA.120.316903DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7371244PMC
July 2020

Functional crosstalk between T cells and monocytes in cancer and atherosclerosis.

J Leukoc Biol 2020 07 12;108(1):297-308. Epub 2020 Jun 12.

Division of Inflammation Biology, La Jolla Institute for Immunology, La Jolla, California, USA.

Monocytes and monocyte-derived cells, including Mϕs and dendritic cells, exhibit a diverse array of phenotypic states that are dictated by their surrounding microenvironment. These cells direct T cell activation and function via cues that range from being immunosuppressive to immunostimulatory. Solid tumors and atherosclerotic plaques represent two pathological niches with distinct immune microenvironments. While monocytes and their progeny possess a phenotypic spectrum found within both disease contexts, most within tumors are pro-tumoral and support evasion of host immune responses by tumor cells. In contrast, monocyte-derived cells within atherosclerotic plaques are usually pro-atherogenic, pro-inflammatory, and predominantly directed against self-antigens. Consequently, cancer immunotherapies strive to enhance the immune response against tumor antigens, whereas atherosclerosis treatments seek to dampen the immune response against lipid antigens. Insights into monocyte-T cell interactions within these niches could thus inform therapeutic strategies for two immunologically distinct diseases. Here, we review monocyte diversity, interactions between monocytes and T cells within tumor and plaque microenvironments, how certain therapies have leveraged these interactions, and novel strategies to assay such associations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/JLB.1MIR0420-076RDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8006924PMC
July 2020

Frontline Science: Kindlin-3 is essential for patrolling and phagocytosis functions of nonclassical monocytes during metastatic cancer surveillance.

J Leukoc Biol 2020 06 9;107(6):883-892. Epub 2020 May 9.

Center for Cancer Immunotherapy, La Jolla Institute for Immunology, La Jolla, California, USA.

Nonclassical monocytes maintain vascular homeostasis by patrolling the vascular endothelium, responding to inflammatory signals, and scavenging cellular debris. Nonclassical monocytes also prevent metastatic tumor cells from seeding new tissues, but whether the patrolling function of nonclassical monocytes is required for this process is unknown. To answer this question, we utilized an inducible-knockout mouse that exhibits loss of the integrin-adaptor protein Kindlin-3 specifically in nonclassical monocytes. We show that Kindlin-3-deficient nonclassical monocytes are unable to patrol the vascular endothelium in either the lungs or periphery. We also find that Kindlin-3-deficient nonclassical monocytes cannot firmly adhere to, and instead "slip" along, the vascular endothelium. Loss of patrolling activity by nonclassical monocytes was phenocopied by ablation of LFA-1, an integrin-binding partner of Kindlin-3. When B16F10 murine melanoma tumor cells were introduced into Kindlin-3-deficient mice, nonclassical monocytes showed defective patrolling towards tumor cells and failure to ingest tumor particles in vivo. Consequently, we observed a significant, 4-fold increase in lung tumor metastases in mice possessing Kindlin-3-deficient nonclassical monocytes. Thus, we conclude that the patrolling function of nonclassical monocytes is mediated by Kindlin-3 and essential for these cells to maintain vascular endothelial homeostasis and prevent tumor metastasis to the lung.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/JLB.4HI0420-098RDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7986576PMC
June 2020

Perivascular localization of macrophages in the intestinal mucosa is regulated by Nr4a1 and the microbiome.

Nat Commun 2020 03 12;11(1):1329. Epub 2020 Mar 12.

Department of Physiology and Pharmacology, Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4N1, Canada.

While the ontogeny and recruitment of the intestinal monocyte/macrophage lineage has been studied extensively, their precise localization and function has been overlooked. Here we show by imaging the murine small and large intestines in steady-state that intestinal CX3CR1 macrophages form an interdigitated network intimately adherent to the entire mucosal lamina propria vasculature. The macrophages form contacts with each other, which are disrupted in the absence of microbiome, monocyte recruitment (Ccr2), or monocyte conversion (Nr4a1). In dysbiosis, gaps exist between the perivascular macrophages correlating with increased bacterial translocation from the lamina propria into the bloodstream. The recruitment of monocytes and conversion to macrophages during intestinal injury is also dependent upon CCR2, Nr4a1 and the microbiome. These findings demonstrate a relationship between microbiome and the maturation of lamina propria perivascular macrophages into a tight anatomical barrier that might function to prevent bacterial translocation. These cells are also critical for emergency vascular repair.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-020-15068-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7067862PMC
March 2020

Macrophage Syk-PI3Kγ Inhibits Antitumor Immunity: SRX3207, a Novel Dual Syk-PI3K Inhibitory Chemotype Relieves Tumor Immunosuppression.

Mol Cancer Ther 2020 03 23;19(3):755-764. Epub 2020 Jan 23.

UCSD Department of Pediatrics, University of California, San Diego, San Diego, California.

Macrophages (MΦ) play a critical role in tumor growth, immunosuppression, and inhibition of adaptive immune responses in cancer. Hence, targeting signaling pathways in MΦs that promote tumor immunosuppression will provide therapeutic benefit. PI3Kγ has been recently established by our group and others as a novel immuno-oncology target. Herein, we report that an MΦ Syk-PI3K axis drives polarization of immunosuppressive MΦs that establish an immunosuppressive tumor microenvironment in syngeneic tumor models. Genetic or pharmacologic inhibition of Syk and/or PI3Kγ in MΦs promotes a proinflammatory MΦ phenotype, restores CD8 T-cell activity, destabilizes HIF under hypoxia, and stimulates an antitumor immune response. Assay for transposase-accessible Chromatin using Sequencing (ATAC-seq) analyses on the bone marrow-derived macrophages (BMDM) show that inhibition of Syk kinase promotes activation and binding of NF-κB motif in Syk BMDMs, thus stimulating immunostimulatory transcriptional programming in MΦs to suppress tumor growth. Finally, we have developed the "first-in-class" dual Syk/PI3K inhibitor, SRX3207, for the combinatorial inhibition of Syk and PI3K in one small molecule. This chemotype demonstrates efficacy in multiple tumor models and represents a novel combinatorial approach to activate antitumor immunity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1535-7163.MCT-19-0947DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7450492PMC
March 2020

Patrolling Monocytes Control NK Cell Expression of Activating and Stimulatory Receptors to Curtail Lung Metastases.

J Immunol 2020 01 25;204(1):192-198. Epub 2019 Nov 25.

Division of Inflammation Biology, La Jolla Institute for Immunology, La Jolla, CA 92037

The role of nonclassical, patrolling monocytes in lung tumor metastasis and their functional relationships with other immune cells remain poorly defined. Contributing to these gaps in knowledge is a lack of cellular specificity in commonly used approaches for depleting nonclassical monocytes. To circumvent these limitations and study the role of patrolling monocytes in melanoma metastasis to lungs, we generated C57BL/6J mice in which the Nr4a1 superenhancer E2 subdomain is ablated ( mice). mice lack nonclassical patrolling monocytes but preserve classical monocyte and macrophage numbers and functions. Interestingly, NK cell recruitment and activation were impaired, and metastatic burden was increased in mice. mice displayed unchanged "educated" (CD11bCD27) and "terminally differentiated" (CD11bCD27) NK cell frequencies. These perturbations were accompanied by reduced expression of stimulatory receptor Ly49D on educated NK cells and increased expression of inhibitory receptor NKG2A/CD94 on terminally differentiated NK cells. Thus, our work demonstrates that patrolling monocytes play a critical role in preventing lung tumor metastasis via NK cell recruitment and activation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4049/jimmunol.1900998DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7890694PMC
January 2020

Neuropilin-1 Expression on CD4 T Cells Is Atherogenic and Facilitates T Cell Migration to the Aorta in Atherosclerosis.

J Immunol 2019 12 18;203(12):3237-3246. Epub 2019 Nov 18.

Division of Inflammation Biology, La Jolla Institute for Immunology, La Jolla, CA 92037

Neuropilin 1 (Nrp1) is a type I transmembrane protein that plays important roles in axonal guidance, neuronal development, and angiogenesis. Nrp1 also helps migrate thymus-derived regulatory T cells to vascular endothelial growth factor (VEGF)-producing tumors. However, little is known about the role of Nrp1 on CD4 T cells in atherosclerosis. In ApoE mice fed a Western diet for 15 wk, we found a 2-fold increase in Nrp1Foxp3 CD4 T cells in their spleens, periaortic lymph nodes, and aortas, compared with chow-fed mice. Nrp1Foxp3 CD4 T cells had higher proliferation potential, expressed higher levels of the memory marker CD44, and produced more IFN-γ when compared with Nrp1 CD4 T cells. Treatment of CD4 T cells with oxLDL increased Nrp1 expression. Furthermore, atherosclerosis-susceptible mice selectively deficient for Nrp1 expression on T cells developed less atherosclerosis than their Nrp1-sufficient counterparts. Mechanistically, we found that CD4 T cells that express Nrp1 have an increased capacity to migrate to the aorta and periaortic lymph nodes compared to Nrp1 T cells, suggesting that the expression of Nrp1 facilitates the recruitment of CD4 T cells into the aorta where they can be pathogenic. Thus, we have identified a novel role of Nrp1 on CD4 T cells in atherosclerosis. These results suggest that manipulation of Nrp1 expression on T cells can affect the outcome of atherosclerosis and lower disease incidence.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4049/jimmunol.1900245DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8041247PMC
December 2019

Preparation of Whole Bone Marrow for Mass Cytometry Analysis of Neutrophil-lineage Cells.

J Vis Exp 2019 06 19(148). Epub 2019 Jun 19.

Division of Inflammation Biology, La Jolla Institute for Immunology;

In this article, we present a protocol that is optimized to preserve neutrophil-lineage cells in fresh BM for whole BM CyTOF analysis. We utilized a myeloid-biased 39-antibody CyTOF panel to evaluate the hematopoietic system with a focus on the neutrophil-lineage cells by using this protocol. The CyTOF result was analyzed with an open-resource dimensional reduction algorithm, viSNE, and the data was presented to demonstrate the outcome of this protocol. We have discovered new neutrophil-lineage cell populations based on this protocol. This protocol of fresh whole BM preparation may be used for 1), CyTOF analysis to discover unidentified cell populations from whole BM, 2), investigating whole BM defects for patients with blood disorders such as leukemia, 3), assisting optimization of fluorescence-activated flow cytometry protocols that utilize fresh whole BM.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3791/59617DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6726111PMC
June 2019

Nonclassical Monocytes in Health and Disease.

Annu Rev Immunol 2019 04;37:439-456

Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, USA; email: , , ,

Monocytes are innate blood cells that maintain vascular homeostasis and are early responders to pathogens in acute infections. There are three well-characterized classes of monocytes: classical (CD14CD16 in humans and Ly6C in mice), intermediate (CD14CD16 in humans and Ly6CTreml4 in mice), and nonclassical (CD14CD16 in humans and Ly6C in mice). Classical monocytes are critical for the initial inflammatory response. Classical monocytes can differentiate into macrophages in tissue and can contribute to chronic disease. Nonclassical monocytes have been widely viewed as anti-inflammatory, as they maintain vascular homeostasis. They are a first line of defense in recognition and clearance of pathogens. However, their roles in chronic disease are less clear. They have been shown to be protective as well as positively associated with disease burden. This review focuses on the state of the monocyte biology field and the functions of monocytes, particularly nonclassical monocytes, in health and disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1146/annurev-immunol-042617-053119DOI Listing
April 2019

Monocyte heterogeneity and functions in cancer.

J Leukoc Biol 2019 08 18;106(2):309-322. Epub 2019 Feb 18.

La Jolla Institute for Allergy and Immunology, La Jolla, California, USA.

Monocytes are innate immune cells of the mononuclear phagocyte system that have emerged as important regulators of cancer development and progression. Our understanding of monocytes has advanced from viewing these cells as a homogenous population to a heterogeneous system of cells that display diverse responses to different stimuli. During cancer, different monocyte subsets perform functions that contribute to both pro- and antitumoral immunity, including phagocytosis, secretion of tumoricidal mediators, promotion of angiogenesis, remodeling of the extracellular matrix, recruitment of lymphocytes, and differentiation into tumor-associated macrophages and dendritic cells. The ability of cancer to evade immune recognition and clearance requires protumoral signals to outweigh ongoing attempts by the host immune system to prevent tumor growth. This review discusses current understanding of monocyte heterogeneity during homeostasis, highlights monocyte functions in cancer progression, and describes monocyte-targeted therapeutic strategies for cancer treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/JLB.4RI0818-311RDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6658332PMC
August 2019

Human Monocyte Heterogeneity as Revealed by High-Dimensional Mass Cytometry.

Arterioscler Thromb Vasc Biol 2019 01;39(1):25-36

From the Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA (A.A.J.H., H.Q.D., G.D.T., P.M., A.B., C.S.N., C.C.H.).

Objective- Three distinct human monocyte subsets have been identified based on the surface marker expression of CD14 and CD16. We hypothesized that monocytes were likely more heterogeneous in composition. Approach and Results- We used the high dimensionality of mass cytometry together with the FlowSOM clustering algorithm to accurately identify and define monocyte subsets in blood of healthy human subjects and those with coronary artery disease (CAD). To study the behavior and functionality of the newly defined monocyte subsets, we performed RNA sequencing, transwell migration, and efferocytosis assays. Here, we identify 8 human monocyte subsets based on their surface marker phenotype. We found that 3 of these subsets fall within the CD16 nonclassical monocyte population and 4 subsets belong to the CD14 classical monocytes, illustrating significant monocyte heterogeneity in humans. As nonclassical monocytes are important in modulating atherosclerosis in mice, we studied the functions of our 3 newly identified nonclassical monocytes in subjects with CAD. We found a marked expansion of a SlanCXCR6 nonclassical monocyte subset in CAD subjects, which was positively correlated with CAD severity. This nonclassical subset can migrate towards CXCL16 and shows an increased efferocytosis capacity, indicating it may play an atheroprotective role. Conclusions- Our data demonstrate that human nonclassical monocytes are a heterogeneous population, existing of several subsets with functional differences. These subsets have changed frequencies in the setting of severe CAD. Understanding how these newly identified subsets modulate CAD will be important for CAD-based therapies that target myeloid cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/ATVBAHA.118.311022DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6697379PMC
January 2019

Neutrophils: New insights and open questions.

Sci Immunol 2018 12 7;3(30). Epub 2018 Dec 7.

Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA.

Neutrophils are the first line of defense against bacteria and fungi and help combat parasites and viruses. They are necessary for mammalian life, and their failure to recover after myeloablation is fatal. Neutrophils are short-lived, effective killing machines. Their life span is significantly extended under infectious and inflammatory conditions. Neutrophils take their cues directly from the infectious organism, from tissue macrophages and other elements of the immune system. Here, we review how neutrophils traffic to sites of infection or tissue injury, how they trap and kill bacteria, how they shape innate and adaptive immune responses, and the pathophysiology of monogenic neutrophil disorders.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/sciimmunol.aat4579DOI Listing
December 2018

Identification of an Early Unipotent Neutrophil Progenitor with Pro-tumoral Activity in Mouse and Human Bone Marrow.

Cell Rep 2018 08;24(9):2329-2341.e8

Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA. Electronic address:

Neutrophils are short-lived cells that play important roles in both health and disease. Neutrophils and monocytes originate from the granulocyte monocyte progenitor (GMP) in bone marrow; however, unipotent neutrophil progenitors are not well defined. Here, we use cytometry by time of flight (CyTOF) and single-cell RNA sequencing (scRNA-seq) methodologies to identify a committed unipotent early-stage neutrophil progenitor (NeP) in adult mouse bone marrow. Importantly, we found a similar unipotent NeP (hNeP) in human bone marrow. Both NeP and hNeP generate only neutrophils. NeP and hNeP both significantly increase tumor growth when transferred into murine cancer models, including a humanized mouse model. hNeP are present in the blood of treatment-naive melanoma patients but not of healthy subjects. hNeP can be readily identified by flow cytometry and could be used as a biomarker for early cancer discovery. Understanding the biology of hNeP should allow the development of new therapeutic targets for neutrophil-related diseases, including cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.celrep.2018.07.097DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6542273PMC
August 2018

Publisher Correction: Oxidized phospholipids are proinflammatory and proatherogenic in hypercholesterolaemic mice.

Nature 2018 09;561(7724):E43

Department of Medicine, University of California, San Diego, La Jolla, CA, USA.

In this Letter, affiliation number 1 was originally missing from the HTML; the affiliations were missing for author Ming-Yow Hung in the HTML; and the Fig. 4 legend erroneously referred to panels a-h, instead of a-g. These errors have been corrected online.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41586-018-0313-xDOI Listing
September 2018

Oxidized phospholipids are proinflammatory and proatherogenic in hypercholesterolaemic mice.

Nature 2018 06 6;558(7709):301-306. Epub 2018 Jun 6.

Department of Medicine, University of California, San Diego, La Jolla, CA, USA.

Oxidized phospholipids (OxPL) are ubiquitous, are formed in many inflammatory tissues, including atherosclerotic lesions, and frequently mediate proinflammatory changes . Because OxPL are mostly the products of non-enzymatic lipid peroxidation, mechanisms to specifically neutralize them are unavailable and their roles in vivo are largely unknown. We previously cloned the IgM natural antibody E06, which binds to the phosphocholine headgroup of OxPL, and blocks the uptake of oxidized low-density lipoprotein (OxLDL) by macrophages and inhibits the proinflammatory properties of OxPL. Here, to determine the role of OxPL in vivo in the context of atherogenesis, we generated transgenic mice in the Ldlr background that expressed a single-chain variable fragment of E06 (E06-scFv) using the Apoe promoter. E06-scFv was secreted into the plasma from the liver and macrophages, and achieved sufficient plasma levels to inhibit in vivo macrophage uptake of OxLDL and to prevent OxPL-induced inflammatory signalling. Compared to Ldlr mice, Ldlr E06-scFv mice had 57-28% less atherosclerosis after 4, 7 and even 12 months of 1% high-cholesterol diet. Echocardiographic and histologic evaluation of the aortic valves demonstrated that E06-scFv ameliorated the development of aortic valve gradients and decreased aortic valve calcification. Both cholesterol accumulation and in vivo uptake of OxLDL were decreased in peritoneal macrophages, and both peritoneal and aortic macrophages had a decreased inflammatory phenotype. Serum amyloid A was decreased by 32%, indicating decreased systemic inflammation, and hepatic steatosis and inflammation were also decreased. Finally, the E06-scFv prolonged life as measured over 15 months. Because the E06-scFv lacks the functional effects of an intact antibody other than the ability to bind OxPL and inhibit OxLDL uptake in macrophages, these data support a major proatherogenic role of OxLDL and demonstrate that OxPL are proinflammatory and proatherogenic, which E06 counteracts in vivo. These studies suggest that therapies inactivating OxPL may be beneficial for reducing generalized inflammation, including the progression of atherosclerosis, aortic stenosis and hepatic steatosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41586-018-0198-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6033669PMC
June 2018

Understanding the tumor immune microenvironment (TIME) for effective therapy.

Nat Med 2018 05 23;24(5):541-550. Epub 2018 Apr 23.

Department of Pathology, University of California, San Francisco, San Francisco, CA, USA.

The clinical successes in immunotherapy have been both astounding and at the same time unsatisfactory. Countless patients with varied tumor types have seen pronounced clinical response with immunotherapeutic intervention; however, many more patients have experienced minimal or no clinical benefit when provided the same treatment. As technology has advanced, so has the understanding of the complexity and diversity of the immune context of the tumor microenvironment and its influence on response to therapy. It has been possible to identify different subclasses of immune environment that have an influence on tumor initiation and response and therapy; by parsing the unique classes and subclasses of tumor immune microenvironment (TIME) that exist within a patient's tumor, the ability to predict and guide immunotherapeutic responsiveness will improve, and new therapeutic targets will be revealed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41591-018-0014-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5998822PMC
May 2018

Apolipoprotein AI prevents regulatory to follicular helper T cell switching during atherosclerosis.

Nat Commun 2018 03 15;9(1):1095. Epub 2018 Mar 15.

Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA, 92037, USA.

Regulatory T (Treg) cells contribute to the anti-inflammatory response during atherogenesis. Here we show that during atherogenesis Treg cells lose Foxp3 expression and their immunosuppressive function, leading to the conversion of a fraction of these cells into T follicular helper (Tfh) cells. We show that Tfh cells are pro-atherogenic and that their depletion reduces atherosclerosis. Mechanistically, the conversion of Treg cells to Tfh cells correlates with reduced expression of IL-2Rα and pSTAT5 levels and increased expression of IL-6Rα. In vitro, incubation of naive T cells with oxLDL prevents their differentiation into Treg cells. Furthermore, injection of lipid-free Apolipoprotein AI (ApoAI) into ApoE mice reduces intracellular cholesterol levels in Treg cells and prevents their conversion into Tfh cells. Together our results suggest that ApoAI, the main protein in high-density lipoprotein particles, modulates the cellular fate of Treg cells and thus influences the immune response during atherosclerosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-018-03493-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5854619PMC
March 2018

Atlas of the Immune Cell Repertoire in Mouse Atherosclerosis Defined by Single-Cell RNA-Sequencing and Mass Cytometry.

Circ Res 2018 06 15;122(12):1675-1688. Epub 2018 Mar 15.

Institute of Experimental Biomedicine, University Hospital Würzburg, Germany (C.C., A.Z.)

Rationale: Atherosclerosis is a chronic inflammatory disease that is driven by the interplay of pro- and anti-inflammatory leukocytes in the aorta. Yet, the phenotypic and transcriptional diversity of aortic leukocytes is poorly understood.

Objective: We characterized leukocytes from healthy and atherosclerotic mouse aortas in-depth by single-cell RNA-sequencing and mass cytometry (cytometry by time of flight) to define an atlas of the immune cell landscape in atherosclerosis.

Methods And Results: Using single-cell RNA-sequencing of aortic leukocytes from chow diet- and Western diet-fed and mice, we detected 11 principal leukocyte clusters with distinct phenotypic and spatial characteristics while the cellular repertoire in healthy aortas was less diverse. Gene set enrichment analysis on the single-cell level established that multiple pathways, such as for lipid metabolism, proliferation, and cytokine secretion, were confined to particular leukocyte clusters. Leukocyte populations were differentially regulated in atherosclerotic and mice. We confirmed the phenotypic diversity of these clusters with a novel mass cytometry 35-marker panel with metal-labeled antibodies and conventional flow cytometry. Cell populations retrieved by these protein-based approaches were highly correlated to transcriptionally defined clusters. In an integrated screening strategy of single-cell RNA-sequencing, mass cytometry, and fluorescence-activated cell sorting, we detected 3 principal B-cell subsets with alterations in surface markers, functional pathways, and in vitro cytokine secretion. Leukocyte cluster gene signatures revealed leukocyte frequencies in 126 human plaques by a genetic deconvolution strategy. This approach revealed that human carotid plaques and microdissected mouse plaques were mostly populated by macrophages, T-cells, and monocytes. In addition, the frequency of genetically defined leukocyte populations in carotid plaques predicted cardiovascular events in patients.

Conclusions: The definition of leukocyte diversity by high-dimensional analyses enables a fine-grained analysis of aortic leukocyte subsets, reveals new immunologic mechanisms and cell-type-specific pathways, and establishes a functional relevance for lesional leukocytes in human atherosclerosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/CIRCRESAHA.117.312513DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5993603PMC
June 2018

Patrolling Mechanics of Non-Classical Monocytes in Vascular Inflammation.

Front Cardiovasc Med 2017 19;4:80. Epub 2017 Dec 19.

Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, United States.

Non-classical monocytes have emerged as the preeminent vascular housekeepers. Continuous intravascular screening is enabled by slow patrolling on the endothelium and allows a rapid response to local perturbations. Intravital imaging has been crucial to elucidate the molecular mechanisms and migratory phenotype of patrolling. In this review, we discuss technical requirements of intravital microscopy such as imaging modalities, labeling strategies, and data analysis. We further focus on patrolling kinetics and adhesion receptors in different organs and vascular beds including arteries during homeostasis and vascular inflammation and define pertinent questions in the field.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fcvm.2017.00080DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5742122PMC
December 2017

Scavenger Receptor CD36 Directs Nonclassical Monocyte Patrolling Along the Endothelium During Early Atherogenesis.

Arterioscler Thromb Vasc Biol 2017 11 21;37(11):2043-2052. Epub 2017 Sep 21.

From the Department of Medicine, University of California San Diego School of Medicine, La Jolla (P.M.M., Y.I.M.); Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, CA (P.M.M., G.D.T., Z.M., E.E., K.A.L.M., A.B., R.W., K.L., C.C.H.); Department of Cardiology and Circulatory Diseases, Internal Medicine Clinic III, Eberhard Karls University Tübingen, Germany (K.A.L.M.); and Robert M. Berne Cardiovascular Research Center, Division of Cardiology, University of Virginia, Charlottesville (A.T.N., A.M.T., C.A.M.).

Objective: Nonclassical monocytes (NCM) function to maintain vascular homeostasis by crawling or patrolling along the vessel wall. This subset of monocytes responds to viruses, tumor cells, and other pathogens to aid in protection of the host. In this study, we wished to determine how early atherogenesis impacts NCM patrolling in the vasculature.

Approach And Results: To study the role of NCM in early atherogenesis, we quantified the patrolling behaviors of NCM in ApoE (apolipoprotein E) and C57BL/6J mice fed a Western diet. Using intravital imaging, we found that NCM from Western diet-fed mice display a 4-fold increase in patrolling activity within large peripheral blood vessels. Both human and mouse NCM preferentially engulfed OxLDL (oxidized low-density lipoprotein) in the vasculature, and we observed that OxLDL selectively induced NCM patrolling in vivo. Induction of patrolling during early atherogenesis required scavenger receptor CD36, as CD36 mice revealed a significant reduction in patrolling activity along the femoral vasculature. Mechanistically, we found that CD36-regulated patrolling was mediated by a SFK (src family kinase) through DAP12 (DNAX activating protein of 12KDa) adaptor protein.

Conclusions: Our studies show a novel pathway for induction of NCM patrolling along the vascular wall during early atherogenesis. Mice fed a Western diet showed increased NCM patrolling activity with a concurrent increase in SFK phosphorylation. This patrolling activity was lost in the absence of either CD36 or DAP12. These data suggest that NCM function in an atheroprotective manner through sensing and responding to oxidized lipoprotein moieties via scavenger receptor engagement during early atherogenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/ATVBAHA.117.309123DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5930003PMC
November 2017

Human Blood Monocyte Subsets: A New Gating Strategy Defined Using Cell Surface Markers Identified by Mass Cytometry.

Arterioscler Thromb Vasc Biol 2017 08 8;37(8):1548-1558. Epub 2017 Jun 8.

From the Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, CA (G.D.T., A.A.J.H., C.N., P.M., C.C.H.); and Division of Cardiology and Robert M. Berne Cardiovascular Center, University of Virginia, Charlottesville (A.M.T., C.M., A.T.N., C.A.M.).

Objective: Human monocyte subsets are defined as classical (CD14CD16), intermediate (CD14CD16), and nonclassical (CD14CD16). Alterations in monocyte subset frequencies are associated with clinical outcomes, including cardiovascular disease, in which circulating intermediate monocytes independently predict cardiovascular events. However, delineating mechanisms of monocyte function is hampered by inconsistent results among studies.

Approach And Results: We use cytometry by time-of-flight mass cytometry to profile human monocytes using a panel of 36 cell surface markers. Using the dimensionality reduction approach visual interactive stochastic neighbor embedding (viSNE), we define monocytes by incorporating all cell surface markers simultaneously. Using viSNE, we find that although classical monocytes are defined with high purity using CD14 and CD16, intermediate and nonclassical monocytes defined using CD14 and CD16 alone are frequently contaminated, with average intermediate and nonclassical monocyte purity of ≈86.0% and 87.2%, respectively. To improve the monocyte purity, we devised a new gating scheme that takes advantage of the shared coexpression of cell surface markers on each subset. In addition to CD14 and CD16, CCR2, CD36, HLA-DR, and CD11c are the most informative markers that discriminate among the 3 monocyte populations. Using these additional markers as filters, our revised gating scheme increases the purity of both intermediate and nonclassical monocyte subsets to 98.8% and 99.1%, respectively. We demonstrate the use of this new gating scheme using conventional flow cytometry of peripheral blood mononuclear cells from subjects with cardiovascular disease.

Conclusions: Using cytometry by time-of-flight mass cytometry, we have identified a small panel of surface markers that can significantly improve monocyte subset identification and purity in flow cytometry. Such a revised gating scheme will be useful for clinical studies of monocyte function in human cardiovascular disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/ATVBAHA.117.309145DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5828170PMC
August 2017

Hematopoietic stem cells gone rogue.

Science 2017 02;355(6327):798-799

La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA 92037, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/science.aam7939DOI Listing
February 2017

ATP Binding Cassette Transporter ABCA7 Regulates NKT Cell Development and Function by Controlling CD1d Expression and Lipid Raft Content.

Sci Rep 2017 01 16;7:40273. Epub 2017 Jan 16.

La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA.

ABCA7 is an ABC transporter expressed on the plasma membrane, and actively exports phospholipid complexes from the cytoplasmic to the exocytoplasmic leaflet of membranes. Invariant NKT (iNKT) cells are a subpopulation of T lymphocytes that recognize glycolipid antigens in the context of CD1d-mediated antigen presentation. In this study, we demonstrate that ABCA7 regulates the development of NKT cells in a cell-extrinsic manner. We found that in Abca7 mice there is reduced expression of CD1d accompanied by an alteration in lipid raft content on the plasma membrane of thymocytes and antigen presenting cells. Together, these alterations caused by absence of ABCA7 negatively affect NKT cell development and function.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep40273DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5238393PMC
January 2017

The transcription factor NR4A3 controls CD103+ dendritic cell migration.

J Clin Invest 2016 12 7;126(12):4603-4615. Epub 2016 Nov 7.

The transcription factor NR4A3 (also known as NOR-1) is a member of the Nr4a family of nuclear receptors and is expressed in myeloid and lymphoid cells. Here, we have shown that Nr4a3 is essential for the migration of CD103+ dendritic cells (DCs) to lymph nodes (LNs). Nr4a3-deficient mice had very few CD103+ migratory DCs (mDCs) present in LNs, and mixed-chimera studies revealed that this migratory defect was cell intrinsic. We further found that CD103+ DCs from Nr4a3-deficient mice displayed a marked loss of surface expression of the chemokine CCR7. This defect in CCR7 expression was confined to CD103+ DCs, as CCR7 expression on T lymphocytes was unaffected. Moreover, CCR7 was not induced on CD103+ DCs from Nr4a3-deficient mice in response to either administration of the TLR7 agonist R848 or infection with Citrobacter rodentium in vivo. The transcription factor FOXO1 has been shown to regulate CCR7 expression. We found that FOXO1 protein was reduced in Nr4a3-deficient DCs through an AKT-dependent mechanism. Further, we found a requirement for NR4A3 in the maintenance of homeostatic mitochondrial function in CD103+ DCs, although this is likely independent of the NR4A3/FOXO1/CCR7 axis in the regulation of DC migration. Thus, NR4A3 plays an important role in the regulation of CD103+ mDCs by regulating CCR7-dependent cell migration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/JCI87081DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5127666PMC
December 2016

Deleting an Nr4a1 Super-Enhancer Subdomain Ablates Ly6C Monocytes while Preserving Macrophage Gene Function.

Immunity 2016 11 1;45(5):975-987. Epub 2016 Nov 1.

Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA. Electronic address:

Mononuclear phagocytes are a heterogeneous family that occupy all tissues and assume numerous roles to support tissue function and systemic homeostasis. Our ability to dissect the roles of individual subsets is limited by a lack of technologies that ablate gene function within specific mononuclear phagocyte sub-populations. Using Nr4a1-dependent Ly6C monocytes, we present a proof-of-principle approach that addresses these limitations. Combining ChIP-seq and molecular approaches we identified a single, conserved, sub-domain within the Nr4a1 enhancer that was essential for Ly6C monocyte development. Mice lacking this enhancer lacked Ly6C monocytes but retained Nr4a1 gene expression in macrophages during steady state and in response to LPS. Because Nr4a1 regulates inflammatory gene expression and differentiation of Ly6C monocytes, decoupling these processes allows Ly6C monocytes to be studied independently.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.immuni.2016.10.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5694686PMC
November 2016