Trafficking Patterns Research Articles

Different Trafficking Phenotypes of Niemann-Pick C1 Gene Mutations Correlate with Various Alterations in Lipid Storage, Membrane Composition and Miglustat Amenability.

Niemann-Pick Type C (NPC) is an autosomal recessive lysosomal storage disease leading to progressive neurodegeneration. Mutations in the NPC1 gene, which accounts for 95% of the cases, lead to a defect in intra-lysosomal trafficking of cholesterol and an accumulation of storage material including cholesterol and sphingolipids in the endo-lysosomal system. Symptoms are progressive neurological and visceral deterioration, with variable onset and severity of the disease. This study investigates the influence of two different NPC1 mutations on the biochemical phenotype in fibroblasts isolated from NPC patients in comparison to healthy, wild type (WT) cells. Skin derived fibroblasts were cultured from one patient compound-heterozygous for D874V/D948Y mutations, which presented wild-type like intracellular trafficking of NPC1, and a second patient compound- heterozygous for I1061T/P887L mutations, which exhibited a more severe biochemical phenotype as revealed in the delayed trafficking of NPC1. Biochemical analysis using HPLC and TLC indicated that lipid accumulations were mutation-dependent and correlated with the trafficking pattern of NPC1: higher levels of cholesterol and glycolipids were associated with the mutations that exhibited delayed intracellular trafficking, as compared to their WT-like trafficked or wild type (WT) counterparts. Furthermore, variations in membrane structure was confirmed in these cell lines based on alteration in lipid rafts composition as revealed by the shift in flotillin-2 (FLOT2) distribution, a typical lipid rafts marker, which again showed marked alterations only in the NPC1 mutant showing major trafficking delay. Finally, treatment with N-butyldeoxynojirimycin (NB-DNJ, Miglustat) led to a reduction of stored lipids in cells from both patients to various extents, however, no normalisation in lipid raft structure was achieved. The data presented in this study help in understanding the varying biochemical phenotypes observed in patients harbouring different mutations, which explain why the effectiveness of NB-DNJ treatment is patient specific.

Donor Leukocyte Trafficking and Damage-associated Molecular Pattern Expression During Ex Vivo Lung Perfusion.

Background.While ex vivo lung perfusion (EVLP) has become established in lung transplantation, the cellular processes occurring during this period are not yet fully understood. Prior studies demonstrated that donor leukocytes (DLs) migrate from the graft into the perfusate during EVLP, but the distribution of DLs in graft and perfusate compartments has not been characterized. Moreover, cell death of DLs has been implicated in mediating graft injury during EVLP, but the underlying mechanisms have not been elucidated. We hypothesized the following: (1) there is a nonspecific migration of DLs from the graft into perfusate and (2) cell death of DLs releases damage-associated molecular patterns (DAMPs) that contribute to the inflammatory milieu during EVLP.Methods.EVLP was performed on rat lungs for 3 hours (N = 6). At the end of EVLP, flow cytometry was used to quantify the distribution of different DL cell types in both the graft and perfusate compartments. During EVLP, the perfusate was also sampled hourly to measure levels of DAMPs and downstream inflammatory cytokines generated during EVLP.Results.At the conclusion of EVLP, there was a significantly higher proportion of T and B cells present in the perfusate compartment compared with the graft compartment. There was a time-dependent increase in extracellular DNA and tumor necrosis factor α in the perfusate during EVLP.Conclusions.T cells and B cells are enriched in the perfusate compartment during EVLP. Cell death of DLs contributes to an accumulation of DAMPs during EVLP.

International Cooperation in Prevention and Combating Human Trafficking in Southeast Asian Region: A Case Study of Vietnam

In recent years, Vietnam has recorded as transnational hubs among of complicate region relating human trafficking. The distinguish features of geography shared borderland with three countries, namely Cambodia, China and Laos, making cross-border trafficking in persons more dynamic and even more challenged for law enforcement agencies to prevent and combat this crime. Alongside with internal efforts to anticipate human trafficking, from 2010 to 2020, Vietnam’s government implemented officially two national programs on prevention and combating human trafficking with a number of specific projects and its related goals. Amongst, to enhance international cooperation between neighbored countries and regional and international partnerships that is considered as one of the most prioritized strategies of Vietnam. This paper focuses on analysis policies and implications of Vietnam through providing details of the current viewpoints in international cooperation to fight trafficking in human beings. Some main trends and patterns of human trafficking in Vietnam in the past years will illustrate the nature of complex situation. Then, some recommendations call for further research to ensure the effectiveness of international cooperation. Keywords: Human trafficking; crime prevention; international cooperation; Vietnam DOI: 10.7176/JLPG/94-04 Publication date: February 29 th 2020

Drug-trafficking as a Non-traditional Security Threat: Emerging Trends and Responses

India‟s proximity to two of the world‟s largest producers of opium and synthetic drugs and its large pharmaceutical base has made the country not only a conduit but also a source for drug trafficking. This illegal movement of narcotics and drugs pose significant threats to national security: breach of security of the international borders and the country, money generated by the sale of drugs and narcotics are used for terror funding and criminal groups engaged in drug trafficking develop nexus with terror networks. The trends and patterns of drug trafficking in the country demonstrate that there has been a gradual shift from traditional/natural drugs towards synthetic drugs that are being trafficked and consumed in the country. The paper analyses the steps taken by the State to curb the process and its effectiveness so far.

APOL1 Kidney Risk Variants Induce Cell Death via Mitochondrial Translocation and Opening of the Mitochondrial Permeability Transition Pore

Genetic Variants in Apolipoprotein L1 (APOL1) are associated with large increases in CKD rates among African Americans. Experiments in cell and mouse models suggest that these risk-related polymorphisms are toxic gain-of-function variants that cause kidney dysfunction, following a recessive mode of inheritance. Recent data in trypanosomes and in human cells indicate that such variants may cause toxicity through their effects on mitochondria. To examine the molecular mechanisms underlying APOL1 risk variant-induced mitochondrial dysfunction, we generated tetracycline-inducible HEK293 T-REx cells stably expressing the APOL1 nonrisk G0 variant or APOL1 risk variants. Using these cells, we mapped the molecular pathway from mitochondrial import of APOL1 protein to APOL1-induced cell death with small interfering RNA knockdowns, pharmacologic inhibitors, blue native PAGE, mass spectrometry, and assessment of mitochondrial permeability transition pore function. We found that the APOL1 G0 and risk variant proteins shared the same import pathway into the mitochondrial matrix. Once inside, G0 remained monomeric, whereas risk variant proteins were prone to forming higher-order oligomers. Both nonrisk G0 and risk variant proteins bound components of the mitochondrial permeability transition pore, but only risk variant proteins activated pore opening. Blocking mitochondrial import of APOL1 risk variants largely eliminated oligomer formation and also rescued toxicity. Our study illuminates important differences in the molecular behavior of APOL1 nonrisk and risk variants, and our observations suggest a mechanism that may explain the very different functional effects of these variants, despite the lack of consistently observed differences in trafficking patterns, intracellular localization, or binding partners. Variant-dependent differences in oligomerization pattern may underlie APOL1's recessive, gain-of-function biology.

Impact of ANXA7 I1 Expression on PDGFRA and MET Endosomal Trafficking in Glioblastoma

Glioblastomas (GBM) are highly malignant tumors that arise from astrocytes. GBMs rely on signaling through receptor tyrosine kinases (RTK) to ensure tumorigenicity. EGFR, PDGFRA and MET are distinct RTKs; each is capable of binding a ligand, which promotes receptor dimerization and kinase activation. Annexin A7 (ANXA7), a protein involved in membrane binding and vesicle trafficking, is spliced into 2 isoforms - isoforms 1 (I1) and isoform 2 (I2). A normal adult brain will express both isoforms, however, in GBM, I1 expression is prevented. We determined that I1, but not I2, is tumor suppressive, in part, because it promotes the endocytic degradation of EGFR. Because I1 is typically not expressed in GBM, EGFR signaling persists unabated and tumors thrive. Recently, we extended these observations and determined that I1 also impacts additional RTKs, including PDGFRA and MET. By understanding how ANXA7 I1 impacts PDGFRA and MET signaling, we hope to target multiple tumorigenic RTKs and improve therapy for patients with GBM. To understand how and when I1 downregulates PDGFRα and MET, U251-malignant glioma (MG) cells, which only express I2 (P), were modified to express I1. Cells were serum starved overnight, and then stimulated with PDGFAA and HGF(20 ng/ml), which activate the aforementioned receptors respectively. As a positive control, cells were stimulated with EGF to activate EGFR. Total protein was then collected and analyzed by western blot analyses. Next, we sought to determine whether I1 was competent to down-regulate several RTKs coincidentally. To do this, P and I1 cells were serum starved, stimulated with EGF, PDGFAA or both, and total protein levels were evaluated. The levels of activated EGFR, PDGFRα and MET are dramatically reduced in those cells that express I1 as compared to cells expressing I2 (P). Upon activation with both PDGFAA and EGF, in cells expressing I1 (I1), levels of PDGFRα and EGFR were markedly reduced 30 minutes post-stimulation as compared to cells expressing I2. Our results suggest I1 may be a master regulator of RTK endocytosis and degradation. Further investigations of the impact of I1 on endocytic trafficking patterns using immunofluorescence and confocal microscopy are underway. Collectively, understanding how I1 functions and targets multiple tumorigenic RTKs will provide the foundation for future selective therapies that restore I1 expression in GBM and reduce tumorigenicity.

Omega-3 polyunsaturated fatty acids impinge on CD4+ T cell motility and adipose tissue distribution via direct and lipid mediator-dependent effects.

Adaptive immunity contributes to the pathogenesis of cardiovascular metabolic disorders (CVMD). The omega-3 polyunsaturated fatty acids (n-3PUFA) are beneficial for cardiovascular health, with potential to improve the dysregulated adaptive immune responses associated with metabolic imbalance. We aimed to explore the mechanisms through which n-3PUFA may alter T cell motility and tissue distribution to promote a less inflammatory environment and improve lymphocyte function in CVMD. Using mass spectrometry lipidomics, cellular, biochemical, and in vivo and ex vivo analyses, we investigated how eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the main n-3PUFA, modify the trafficking patterns of activated CD4+ T cells. In mice subjected to allogeneic immunization, a 3-week n-3PUFA-enriched diet reduced the number of effector memory CD4+ T cells found in adipose tissue, and changed the profiles of eicosanoids, octadecanoids, docosanoids, endocannabinoids, 2-monoacylglycerols, N-acyl ethanolamines, and ceramides, in plasma, lymphoid organs, and fat tissues. These bioactive lipids exhibited differing chemotactic properties when tested in chemotaxis assays with activated CD4+ T cells in vitro. Furthermore, CD4+ T cells treated with EPA and DHA showed a significant reduction in chemokinesis, as assessed by trans-endothelial migration assays, and, when implanted in recipient mice, demonstrated less efficient migration to the inflamed peritoneum. Finally, EPA and DHA treatments reduced the number of polarized CD4+ T cells in vitro, altered the phospholipid composition of membrane microdomains and decreased the activity of small Rho GTPases, Rhoα, and Rac1 instrumental in cytoskeletal dynamics. Our findings suggest that EPA and DHA affect the motility of CD4+ T cells and modify their ability to reach target tissues by interfering with the cytoskeletal rearrangements required for cell migration. This can explain, at least in part, the anti-inflammatory effects of n-3PUFA supporting their potential use in interventions aiming to address adipocyte low-grade inflammation associated with cardiovascular metabolic disease.

A Four-year Analysis of Labor Trafficking Cases in the United States: Exploring Characteristics and Labor Trafficking Patterns

ABSTRACT The scope of labor trafficking in the United States has been difficult to estimate due to a number of factors including the hidden nature of the crimes of labor trafficking. This study explores a cross-section of arrests of labor traffickers from 2013 to 2016. Arrests if 125 labor traffickers from 47 cases were analyzed. Labor trafficking arrests were found in 20 states over the four years with Texas (34.4%) having the highest percentage of arrests. Victims of labor trafficking were from 16 countries, with Mexico being the country where most victims originated. Victims experienced labor trafficking in homes (35.2%), restaurants (34.4%), hotels (8%), apartments (6.4%), agriculture fields (4.8%), and group homes (4.8%). Staffing agencies were used prominently as recruiting tools by labor traffickers and violence was often used to retain the victim in the trafficking situation. Gender differences and differences between independent labor traffickers and criminal organizations were explored. Recommendations include the need for increased trainings for law enforcement and community members to improve detection as well as the need to enhance the current level of services available to labor trafficking victims.

Abstract 362: Live Tracking Mouse Model for Endogenous Exosomes from Heart

Exosomes are emerging new category of messengers communicating among cells, tissues and organs. Understanding the kinetics of exosome communication in vivo are a critical foundation for studying exosome functions and developing exosome based drug-delivery models. Current studies of exosome in vivo trafficking largely rely on the administration of labeled exogenous exosomes. These methods may not fully represent endogenous exosome kinetics due to ex vivo exosome manipulations. Here, we established the first inducible endogenous exosome tracking mouse model that tracks endogenous exosome released from cardiomyocytes in vivo . The ultrasensitive and stable Nano-luciferase (NanoLuc) was selected as a reporter due to its 150-fold stronger signal intensity compared to traditional Firefly and Renilla luciferases, and the longest luminescent half-life amongst all known luciferases. We fused NanoLuc reporter with exosome surface marker CD63 for specific labeling of exosomes. The cardiomyocyte-specific αMHC promoter followed by a loxP-STOP-loxP cassette was engineered for a temporal control of labeled exosomes originating from cardiomyocytes. We crossed this cardiomyocyte-specific transgenic mouse with a tamoxifen-inducible Cre mouse (R26CreERT2) to achieve an inducible expression of the reporter. The exosome labeling and distribution were assessed by a luciferase assay and non-invasive bioluminescent live imaging. As expected, CD63NanoLuc expression was tightly controlled and only detected in cardiomyocytes upon induction. The endogenous exosomes released from cardiomyocytes were labeled and detected in vitro in a cell culture supernatant, and in vivo in the animal plasma. A paracrine uptaken of the Nanoluc-labeled exosomes by cardiac fibroblasts in vivo was demonstrated and quantified. A signature distribution profile of the endogenous exosomes released from cardiomyocytes was exhibited. For the first time, this exosome tracking model enables elucidating the endogenous exosome trafficking pattern, and allows future studies of exosome behavior under different conditions. It provides a useful tool for the exploration of biological functions, mechanisms and clinical applications of exosomes in a broad spectrum of researches.

14-3-3 signal adaptor and scaffold proteins mediate GPCR trafficking

Receptor trafficking is pivotal for the temporal and spatial control of GPCR signaling and is regulated by multiple cellular proteins. We provide evidence that GPCRs interact with 14-3-3 signal adaptor/scaffold proteins and that this interaction regulates receptor trafficking in two ways. We found GPCR/14-3-3 interaction signals can be agonist-induced or agonist-inhibited. Some GPCRs associate with 14-3-3 proteins at the cell membrane and agonist treatments result in disrupted GPCR/14-3-3 interaction signals. The diminished GPCR/14-3-3 interaction signals are temporally correlated with increased GPCR/β-arrestin interaction signals in response to agonist treatment. Other GPCRs showed agonist-induced GPCR/14-3-3 interaction signal increases that occur later than agonist-induced GPCR/β-arrestin interaction signals, indicating that GPCR/14-3-3 interaction occurred after receptor endocytosis. These two types of GPCR/14-3-3 interaction patterns correlate with different receptor trafficking patterns. In addition, the bioinformatic analysis predicts that approximately 90% of GPCRs contain at least one putative 14-3-3 binding motif, suggesting GPCR/14-3-3 association could be a general phenomenon. Based on these results and collective evidence, we propose a working model whereby 14-3-3 serves as a sorting factor to regulate receptor trafficking.

Mapping Trafficking of Women in China: Evidence from Court Sentences

ABSTRACT In recent years, exposés on the trafficking of women have caught the public’s attention in China. However, due to data scarcity, the scope and nature of such criminal activity are not well understood. The authors of this study provide a new angle in the analysis of human trafficking by digitizing and analyzing court sentencing documents on trafficking in China during 2014–2015. Through mapping court data to geographic information and performing network analysis, the study presented a comprehensive picture of intra-provincial, inter-provincial, and international trafficking patterns. The data showed that international trafficking has become the largest category in the trafficking of women, and victims were typically young women in their 20s originating from Vietnam, Myanmar, and North Korea who were sold into central provinces. Domestically, inter-provincial trafficking outnumbers intra-provincial cases. Across provincial borders, women were trafficked from southwest to central provinces. Intra-provincial trafficking was concentrated in four provinces: Henan, Anhui, Shandong, and Hebei.

Abstract 173: Upregulated EPHB2 and SRC pathways modulate spatial EGFR dynamics and malignant phenotypes and predict poor prognosis in prostate cancer

Abstract Dysregulated dynamics and trafficking of receptor tyrosine kinases (RTK) have been linked to oncogenesis and metastasis. The mechanisms for disfunction of RTK dynamics are emerging and still not clear. Using single-particle tracking (SPT) techniques, we studied the dynamics and trafficking patterns of epidermal growth factor receptor (EGFR) and underlying mechanisms using prostate cancer cells (PCa) (LNCaP, DU145 and PC3) exhibiting variant metastatic capability. Through SPT and super-resolution imaging, it was revealed that cortical actin disorganization modulates increased dynamics of EGFRs, including high EGFR diffusivity, enlarged EGFR confinement size on the plasma membrane and faster EGFR internalization in advanced invasive cells. The elevated EGFR dynamics were associated with advanced aggressive behaviors, and highly upregulated EGFR, EPHB and SRC signaling as identified using single cell RNA-seq. Strong EGFR activation with relatively low EGFR expression in PC3 implicated some other mechanisms, likely biophysical, beyond EGFR quantity. Moreover, the upregulated EPHB and SRC pathways have been shown to regulate actin organization and metastasis and our in silico analysis indicated that genes in the two pathways predict poor prognosis for disease free and survival statuses in The Cancer Genome Atlas prostate cancer patient cohort. To interrogate the roles of EPHB and SRC pathways in actin organization and EGFR dynamics, a series of drug inhibitions and siRNA knockdown were applied to PCa cells followed by mRNA profiling, evaluations of EGFR dynamics, and cell behaviors. Functional knockdown of EPHB2 and SRC led to decreased EGFR dynamics, cell proliferation, migration and invasion. The loss-of-function effects were more profound in advanced invasive PCa. In this study, we discovered the roles of EPHB and SRC pathways in modulating actin organization and EGFR dynamics and leading to aggressive metastatic phenotypes. Additionally, EGFR dynamics were potential biophysical parameters to differentiate the highly-invasive from the non- and less-invasive PCa. Thus, we believe that the SPT-based EGFR dynamics can serve as a new biophysical assay to probe the metastatic malignancy of cancer cells and to monitor their response to anti-cancer drug treatment. Citation Format: Yen-Liang Liu, Aaron M. Horning, Che-Kuang Lin, Brandon Lieberman, Chia-Nung Hung, Chih-Wei Chou, Chiou-Miin Wang, Michael A. Liss, Mirae Kim, Rohan Vasisht, Evan P. Perillo, Katherine Blocher, Hannah Horng, Xi Tian, Chun-Lin Lin, Andrew K. Dunn, Tim H.-M. Huang, Hsin-Chih Yeh, Chun-Liang Chen. Upregulated EPHB2 and SRC pathways modulate spatial EGFR dynamics and malignant phenotypes and predict poor prognosis in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 173.

The Emergent Situation of Human Trafficking in Southeast Asia: A Case Study of Vietnam

Vietnam is recorded as one of the transnational hubs of the Southeast Asian region in terms of human trafficking, particularly with women and children. In recent years, several cases are trafficking in persons in and through Vietnam towards their shared neighbours' countries, including Cambodia, China, and Laos, and beyond at third countries in the world. Although the Government of Vietnam recognized this new situation of human trafficking in domestic and regional scale and also deployed many programs to control, the effectiveness of these activities has been still limited. Within the scope of the paper, this study provides the general context of trafficking in persons in Vietnam with its specific characteristics in terms of both offenders and their related victims. Also, the current trends and patterns of human trafficking in Vietnam in comparison to the regional situation are also assessed and analyzed. There are main reasons to explain why these trends occur and exist in Vietnam as well as make clear some fundamental barriers to prevent and combat human trafficking at the current time. The paper also calls for practical recommendations to improve the effectiveness of preventing and fighting to traffic in persons in Vietnam in the future.

Policies and Implementations to Prevent and Combat Trafficking in Persons in Vietnam

As similar as different countries in the Southeast Asian region, Vietnam has considered as both destination and transition hub in human trafficking in recent years. To deal with this modern slavery disaster, the Government of Vietnam had established and applied many strategies and policies from 2000 until the present. Apart from the positive contributions to prevent and combat human trafficking, Vietnam is still facing potential risks and possible threats of human trafficking, particularly with transnational trafficking in person. The paper provides the overall context of current trends and patterns of human trafficking in Vietnam with some specific characteristics of traffickers and its related victims as well as analyses primary modus operandi of this crime in domestic and international markets. The next section reviews two new national action plans, 2011-2015 and 2016-2020, with its specific objectives, targets, and activities. The paper concretizes two main projects in the national strategies, including improving prevention and combat human trafficking and enhance international cooperation to fight this battle between Vietnam and partners. Finally, some recommendation to solve trafficking in persons in Vietnam's context that also call for further discussion and exchange between scholars and policy-makers.

Aquaporin 4 inhibition alters chemokine receptor expression and T cell trafficking

Aquaporins (AQPs) are water channels that mediate a variety of biological processes. However, their role in the immune system is poorly understood. We recently reported that AQP4 is expressed by naïve and memory T cells and that AQP4 blockade with a small molecule inhibitor prolongs murine heart allograft survival at least partially through diminishing T cell activation, proliferation and trafficking. The goal of this study was to determine how AQP4 function impacts T cells in the absence of antigen stimulation. AQP4 inhibition transiently reduced the number of circulating CD4+ and CD8+ T cells in naïve non-transplanted mice in the absence of systemic T cell depletion. Adoptive transfer studies demonstrated T cell intrinsic effect of AQP4 inhibition. AQP4 blockade altered T cell gene and protein expression of chemokine receptors S1PR1 and CCR7, and their master regulator KLF-2, and reduced chemotaxis toward S1P and CCL21. Consistent with the in vitro data, in vivo AQP4 inhibition reduced T lymphocyte numbers in the lymph nodes with simultaneous accumulation in the liver. Our findings indicate that blocking AQP4 reversibly alters T lymphocyte trafficking pattern. This information can be explored for the treatment of undesirable immune responses in transplant recipients or in patients with autoimmune diseases.

Disulfide bond of Mycoplasma pneumoniae community-acquired respiratory distress syndrome toxin is essential to maintain the ADP-ribosylating and vacuolating activities.

Mycoplasma pneumoniae is the leading cause of bacterial community-acquired pneumonia among hospitalised children in United States and worldwide. Community-acquired respiratory distress syndrome (CARDS) toxin is a key virulence determinant of M. pneumoniae. The N-terminus of CARDS toxin exhibits ADP-ribosyltransferase (ADPRT) activity, and the C-terminus possesses binding and vacuolating activities. Thiol-trapping experiments of wild-type (WT) and cysteine-to-serine-mutated CARDS toxins with alkylating agents identified disulfide bond formation at the amino terminal cysteine residues C230 and C247. Compared with WT and other mutant toxins, C247S was unstable and unusable for comparative studies. Although there were no significant variations in binding, entry, and retrograde trafficking patterns of WT and mutated toxins, C230S did not elicit vacuole formation in intoxicated cells. In addition, the ADPRT domain of C230S was more sensitive to all tested proteases when compared with WT toxin. Despite its in vitro ADPRT activity, the reduction of C230S CARDS toxin-mediated ADPRT activity-associated IL-1β production in U937 cells and the recovery of vacuolating activity in the protease-released carboxy region of C230S indicated that the disulfide bond was essential not only to maintain the conformational stability of CARDS toxin but also to properly execute its cytopathic effects.

Capturing the Fantastic Voyage of Monocytes Through Time and Space.

Monocytes are a subset of cells that are categorized together with dendritic cells (DCs) and macrophages in the mononuclear phagocyte system (MPS). Despite sharing several phenotypic and functional characteristics with MPS cells, monocytes are unique cells with the ability to function as both precursor and effector cells in their own right. Before the development of hematopoietic stem cells (HSCs) in utero, monocytes are derived from erythro-myeloid precursors (EMPs) in the fetal liver that are important for populating the majority of tissue resident macrophages. After birth, monocytes arise from bone marrow (BM)-derived HSCs and are released into the circulation upon their maturation, where they survey peripheral tissues and maintain endothelial integrity. Upon sensing of microbial breaches or inflammatory stimuli, monocytes migrate into tissues where their plasticity allows them to differentiate into cells that resemble macrophages or DCs according to the environmental niche. Alternatively, they may also migrate into tissues in the absence of inflammation and remain in an undifferentiated state where they perform homeostatic roles. As monocytes are typically on the move, the availability of intravital imaging approaches has provided further insights into their trafficking patterns in distinct tissue compartments. In this review, we outline the importance of understanding their functional behavior in the context of tissue compartments, and how these studies may contribute towards improved vaccine and future therapeutic strategies.

Regulation of global CD8+ T-cell positioning by the actomyosin cytoskeleton.

CD8+ T cells have evolved as one of the most motile mammalian cell types, designed to continuously scan peptide-major histocompatibility complexes class I on the surfaces of other cells. Chemoattractants and adhesion molecules direct CD8+ T-cell homing to and migration within secondary lymphoid organs, where these cells colocalize with antigen-presenting dendritic cells in confined tissue volumes. CD8+ T-cell activation induces a switch to infiltration of non-lymphoid tissue (NLT), which differ in their topology and biophysical properties from lymphoid tissue. Here, we provide a short overview on regulation of organism-wide trafficking patterns during naive T-cell recirculation and their switch to non-lymphoid tissue homing during activation. The migratory lifestyle of CD8+ T cells is regulated by their actomyosin cytoskeleton, which translates chemical signals from surface receptors into mechanical work. We explore how properties of the actomyosin cytoskeleton and its regulators affect CD8+ T cell function in lymphoid and non-lymphoid tissue, combining recent findings in the field of cell migration and actin network regulation with tissue anatomy. Finally, we hypothesize that under certain conditions, intrinsic regulation of actomyosin dynamics may render NLT CD8+ T-cell populations less dependent on input from extrinsic signals during tissue scanning.

A six-year analysis of sex traffickers of minors: exploring characteristics and sex trafficking patterns

ABSTRACTFew studies have explored the characteristics and arrest patterns of sex traffickers, particularly sex traffickers of persons under the age of 18 (minors) in the U.S. The purpose of this study is to understand the behavior and characteristics of a national cross sectional sample of sex traffickers of minors during a six-year period. This study explored cases involving the arrest of sex traffickers of minors or persons under the age of 18 in the United States from 2010 to 2015. Sex traffickers of minors was defined as a person who facilitates and/or benefits by receiving something of value for the commercial sexual exploitation of a minor (person under the age of 18) or attempts to do so. During a systematic online search, 1,416 sex traffickers of minors were identified. The arrests were found in 46 states in the United States, two U.S. territories, and Washington D.C. The sex traffickers of minors were mostly males (n = 1067, 75.4%), and of those with race identified (only 51.6%), 71.7% were African American. Their ages ranged from 15 to 70 years old (M = 28.5, SD = 8.54). Characteristics of the sex trafficker and the sex trafficking situation are analyzed and implications discussed.

Niemann‐Pick C1 Pathophysiology Associates with Different Classes of Protein Trafficking Phenotypes Elicited by NPC‐1 Mutations

Niemann‐Pick Type C disease (NP‐C) is caused by a defect in the trafficking of endocytosed cholesterol with sequestration of cholesterol in lysosomes and late endosomes. Over 400 mutations have been identified in the NPC1 gene that account for almost 95 % of the NP‐C disease. It is still unclear how a mutation does affect the biosynthetic presentation and the intracellular localization of NPC1. We therefore asked whether mutations in the NPC1 gene generate different protein phenotypes that vary in their trafficking, intracellular localization and function, hence ultimately correlating with the pattern and severity of clinical symptoms in NP‐C patients. Three major classes of mutations could be identified based on the transport of NPC1 mutants along the secretory pathway, their association with lipid rafts and cellular localization. Many of the mutants analyzed were blocked in the ER as immature mannose‐rich proteins, while others were either partially trafficked through the Golgi to the lysosomes or trafficked in a comparable fashion to wild type NPC1. Interestingly, a particular trafficking phenotype is not elicited by mutations confined to a particular domain in NPC1, since these protein trafficking phenotypes arise from mutations that are distributed over different regions of NPC1. Furthermore, the interaction of the NPC1 mutants with lipid rafts varies among the different mutants analyzed in this study, indicating that their trafficking pattern could be associated with the reduced or abolished trafficking of cholesterol out of the lysosomes. Altogether, our study discloses a novel concept in the pathogenesis of NP‐C that relies on the diversity of the trafficking phenotypes of the NPC1 mutants. Expectedly, the ER‐located NPC1 mutants do not associate with lipid rafts since cholesterol or sphingolipids are not abundant in this organelle. On the other hand, the level of association of the partially‐trafficked mutants with lipid rafts is low and correlates with the level of maturation of these mutants. Remarkably, the correctly trafficked wild‐type‐like mutant NPC1‐L1213F as well as the wild type NPC1 varied substantially in their association levels with lipid rafts as compared to the other two classes. Nevertheless, the mature forms of the wild type‐like mutants revealed a higher solubility than their wild type counterpart, compatible with reduced levels of lipid rafts components in the cells overexpressing the mutant. Undoubtedly, membrane lipid analysis of cells overexpressing these mutants is required to support the hierarchical concept of trafficking. In conclusion, the current study proposes a direct link between the three classes of the NPC1 trafficking phenotype mutants, with the heterogeneous disease pattern including neurological, visceral, or psychiatric manifestations, hence the severity of NP‐C disease.Support or Funding InformationActelion, Switzerland to HYN; CNRS grant (CNRS‐01‐14‐12), Lebanon to SR; DAAD, Germany to HS.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.