Nonclassical Monocytes in Health and Disease Narasimhan, Prakash Babu; Marcovecchio, Paola; Hamers, Anouk A.J ...
Annual review of immunology,
04/2019, Letnik:
37, Številka:
1
Journal Article
Recenzirano
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 (CD14
...+
CD16
−
in humans and Ly6C
hi
in mice), intermediate (CD14
+
CD16
+
in humans and Ly6C
+
Treml4
+
in mice), and nonclassical (CD14
−
CD16
+
in humans and Ly6C
lo
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.
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 only poorly understood.
OBJECTIVE:We characterized leukocytes from healthy and atherosclerotic mouse aortas in-depth by single cell RNA-sequencing (scRNAseq) and mass cytometry (CyTOF) to define an atlas of the immune cell landscape in atherosclerosis.
METHODS AND RESULTS:Employing scRNAseq of aortic leukocytes from chow (CD) and western diet (WD) fed Apoe and Ldlr mice, we detected 11 principal leukocyte clusters with distinct phenotypical and spatial characteristics, while the cellular repertoire in healthy aortas was less diverse. Gene set enrichment analysis on a 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 Apoe and Ldlr mice. We confirmed the phenotypic diversity of these clusters with a novel CyTOF 35-marker panel with metal-labelled 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 scRNAseq, CyTOF, and FACS, we detected three principal B-cell subsets with alterations in surface markers, functional pathways, and in vitro cytokine secretion. Finally, we used leukocyte cluster gene signatures to enumerate 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 immunological mechanisms and cell-type specific pathways, and establishes a functional relevance for lesional leukocytes in human atherosclerosis.
BACKGROUND AND PURPOSE The G protein‐coupled receptor 119 (GPR119) mediates insulin secretion from pancreatic β cells and glucagon‐like peptide 1 (GLP‐1) release from intestinal L cells. While ...GPR119‐mediated insulin secretion is glucose dependent, it is not clear whether or not GPR119‐mediated GLP‐1 secretion similarly requires glucose. This study was designed to address the glucose‐dependence of GPR119‐mediated GLP‐1 secretion, and to explore the cellular mechanisms of hormone secretion in L cells versus those in β cells.
EXPERIMENTAL APPROACH GLP‐1 secretion in response to GPR119 agonists and ion channel modulators, with and without glucose, was analysed in the intestinal L cell line GLUTag, in primary intestinal cell cultures and in vivo. Insulin secretion from Min6 cells, a pancreatic β cell line, was analysed for comparison.
KEY RESULTS In GLUTag cells, GPR119 agonists stimulated GLP‐1 secretion both in the presence and in the absence of glucose. In primary mouse colon cultures, GPR119 agonists stimulated GLP‐1 secretion under glucose‐free conditions. Moreover, a GPR119 agonist increased plasma GLP‐1 in mice without a glucose load. However, in Min6 cells, GPR119‐mediated insulin secretion was glucose‐dependent. Among the pharmacological agents tested in this study, nitrendipine, an L‐type voltage‐dependent calcium channel blocker, dose‐dependently reduced GLP‐1 secretion from GLUTag cells, but had no effect in Min6 cells in the absence of glucose.
CONCLUSIONS AND IMPLICATIONS Unlike that in pancreatic β cells, GPR119‐mediated GLP‐1 secretion from intestinal L cells was glucose‐independent in vitro and in vivo, probably because of a higher basal calcium tone in the L cells.
Summary Background The human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine was immunogenic, generally well tolerated, and effective against HPV-16 or HPV-18 infections, and associated ...precancerous lesions in an event-triggered interim analysis of the phase III randomised, double-blind, controlled PApilloma TRIal against Cancer In young Adults (PATRICIA). We now assess the vaccine efficacy in the final event-driven analysis. Methods Women (15–25 years) were vaccinated at months 0, 1, and 6. Analyses were done in the according-to-protocol cohort for efficacy (ATP-E; vaccine, n=8093; control, n=8069), total vaccinated cohort (TVC, included all women receiving at least one vaccine dose, regardless of their baseline HPV status; represents the general population, including those who are sexually active; vaccine, n=9319; control, n=9325), and TVC-naive (no evidence of oncogenic HPV infection at baseline; represents women before sexual debut; vaccine, n=5822; control, n=5819). The primary endpoint was to assess vaccine efficacy against cervical intraepithelial neoplasia 2+ (CIN2+) that was associated with HPV-16 or HPV-18 in women who were seronegative at baseline, and DNA negative at baseline and month 6 for the corresponding type (ATP-E). This trial is registered with ClinicalTrials.gov , number NCT00122681. Findings Mean follow-up was 34·9 months (SD 6·4) after the third dose. Vaccine efficacy against CIN2+ associated with HPV-16/18 was 92·9% (96·1% CI 79·9–98·3) in the primary analysis and 98·1% (88·4–100) in an analysis in which probable causality to HPV type was assigned in lesions infected with multiple oncogenic types (ATP-E cohort). Vaccine efficacy against CIN2+ irrespective of HPV DNA in lesions was 30·4% (16·4–42·1) in the TVC and 70·2% (54·7–80·9) in the TVC-naive. Corresponding values against CIN3+ were 33·4% (9·1–51·5) in the TVC and 87·0% (54·9–97·7) in the TVC-naive. Vaccine efficacy against CIN2+ associated with 12 non-vaccine oncogenic types was 54·0% (34·0–68·4; ATP-E). Individual cross-protection against CIN2+ associated with HPV-31, HPV-33, and HPV-45 was seen in the TVC. Interpretation The HPV-16/18 AS04-adjuvanted vaccine showed high efficacy against CIN2+ associated with HPV-16/18 and non-vaccine oncogenic HPV types and substantial overall effect in cohorts that are relevant to universal mass vaccination and catch-up programmes. Funding GlaxoSmithKline Biologicals.
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.
Genetic factors have long been a concern in the extinction and viability of species with the short‐term effects focusing on inbreeding depression. Genetic rescue has been suggested as a means to ...overcome the detrimental effects of inbreeding depression. However, it has been difficult to document the genetic dynamics over time of genetic rescue, inbreeding depression and other genetic relationships in endangered species. We show here using a detailed pedigree and genomic data that genetic rescue in the gray wolf Canis lupus population on Isle Royale had only a temporary positive effect reducing inbreeding depression and then the genetic changes from the immigration event resulted in a population decline and now imminent extinction of the population. Examining the genetic details of this situation shows how genetic dynamics after the initial positive effects of genetic rescue have passed can return a small population to a path toward extinction. Thus, the successful conservation of critically small populations would likely depend on alleviating the cause of having become critically small, such as habitat restoration, or periodic re‐application of genetic rescue in a manner that does not result in negative genetic dynamics.
Genetic factors have long been a concern in the extinction and viability of species with the short‐term effects focusing on inbreeding depression. Genetic rescue has been suggested as a means to overcome the detrimental effects of inbreeding depression. We show in our manuscript that genetic rescue in the wolf Canis lupus population on Isle Royale had only a temporary positive effect and then resulted in a population decline and now imminent extinction of the population. Examining the details of this situation shows how genetic dynamics after the positive effects of genetic rescue have passed can return a small population to a path toward extinction.
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, we define monocytes by incorporating all cell surface markers simultaneously. Using visual interactive stochastic neighbor embedding, 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.
In the developed world, extreme prematurity is the leading cause of neonatal mortality and morbidity due to a combination of organ immaturity and iatrogenic injury. Until now, efforts to extend ...gestation using extracorporeal systems have achieved limited success. Here we report the development of a system that incorporates a pumpless oxygenator circuit connected to the fetus of a lamb via an umbilical cord interface that is maintained within a closed 'amniotic fluid' circuit that closely reproduces the environment of the womb. We show that fetal lambs that are developmentally equivalent to the extreme premature human infant can be physiologically supported in this extra-uterine device for up to 4 weeks. Lambs on support maintain stable haemodynamics, have normal blood gas and oxygenation parameters and maintain patency of the fetal circulation. With appropriate nutritional support, lambs on the system demonstrate normal somatic growth, lung maturation and brain growth and myelination.
In this phase 2 trial, children and young adults with newly diagnosed overt type 1 diabetes were randomly assigned to receive golimumab, a human monoclonal antibody to tumor necrosis factor
α
, or ...placebo. Golimumab resulted in better endogenous insulin production and less exogenous insulin use than placebo.
•Cesarean delivery is historically at the discretion of individual providers.•Individualized care is highly variable and lacks consistency.•Enhanced recovery after surgery (ERAS) programs provide ...standardization of care.•ERAS protocols reduce opioid use and length of stay.•ERAS protocols after cesarean delivery improve outcomes.
Despite significant improvements in outcomes following non-obstetric surgery with implementation of enhanced recovery after surgery (ERAS) protocols, development of these protocols for cesarean delivery is lacking. We evaluated implementation of an ERAS protocol for patients undergoing elective cesarean delivery, specifically the effect on opioid consumption, pain scores and length of stay as well as complications and re-admissions.
An ERAS protocol was developed and implemented for women undergoing elective cesarean delivery. The protocol construction included specific evidence-based items applicable to peripartum management and these were grouped into the three major phases of patient care: antepartum, intrapartum and postpartum. A before-and-after study design was used to compare maternal outcomes. To account for confounders between groups, a propensity matched scoring analysis was used. The primary outcome was postpartum opioid use in mg-morphine equivalents (MMEQ).
We included 357 (n=196 before; n=161 after) women who underwent elective cesarean delivery. A significant difference in opioid consumption (28.4 ± 24.1 vs 46.1 ± 37.0 MMEQ, P <0.001) and in per-day postoperative opioid consumption (10.9 ± 8.7 vs 15.1 ± 10.3 MMEQ, P <0.001), lower peak pain scores (7 5–9 vs 8 7–9, P=0.007) and a shorter hospital length of stay (2.5 ± 0.5 vs 2.9 ± 1.2 days, P <0.001) were found after the introduction of the ERAS protocol.
Implementation of ERAS protocols for elective cesarean delivery is associated with significant improvements in analgesic and recovery outcomes. These improvements in quality of care suggest ERAS protocols should be considered for elective cesarean delivery.
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