Disruption of placental ACKR3 impairs growth and hematopoietic development of offspring.

ACKR3 scavenges and degrades the stem cell recruiting chemokine CXCL12, which is essential for proper embryonic and, in particular, haematopoietic development. Here, we demonstrate strong expression of ACKR3 on trophoblasts. Using a maternally administered pharmacological blocker and Cre-mediated genetic approaches, we demonstrate that trophoblast ACKR3 is essential for preventing movement of CXCL12 from the mother to the embryo, with elevated plasma CXCL12 levels being detected in embryos from ACKR3-blocker-treated mothers. Mice born to mothers treated with the blocker are lighter and shorter than those born to vehicle-treated mothers and, in addition, display profound anaemia associated with a markedly reduced bone marrow haematopoietic stem cell population. Importantly, although the haematopoietic abnormalities are corrected as mice age, our studies reveal a postnatal window during which offspring of ACKR3-blocker-treated mice are unable to mount effective inflammatory responses to inflammatory/infectious stimuli. Overall, these data demonstrate that ACKR3 is essential for preventing CXCL12 transfer from mother to embryo and for ensuring properly regulated CXCL12 control over the development of the haematopoietic system.

A mixed methods investigation of reasons underlying fear of positive evaluation.

Fear of negative evaluation (FNE) is a hallmark feature of social anxiety disorder (SAD). There is also evidence that people with SAD fear receiving positive evaluation and that fear of positive evaluation (FPE) is distinct from FNE. However, researchers have speculated that concerns related to negative evaluation may actually underlie FPE. This study sought to advance our understanding of FPE by employing both quantitative and qualitative methods to assess the reasons underlying participants' endorsement of FPE on the Fear of Positive Evaluation Scale and the extent to which these reasons reflect FNE versus FPE in a sample of individuals with SAD (n = 47) and a nonclinical comparison group (n = 49). Results indicated that responses to the FPES items primarily reflected an underlying FNE. Consistent with contemporary cognitive-behavioural theories of SAD, fear of proximal or eventual negative judgement emerged as the most common reason for participants' responses on the FPES. However, participants reported other reasons that did not reflect FNE, such as fear of hurting people's feelings and uncertainty associated with positive evaluation. All of the reasons underlying participants' ratings on the FPES were reported by both the SAD group and the nonclinical comparison group; however, individuals with SAD endorsed each of the reasons to a greater extent. These findings suggest that the FPES does not exclusively assess FPE as intended; however, the emergence and endorsement of reasons other than FNE suggest that FPE exists as a distinct construct.

Analysis of combinatorial chemokine receptor expression dynamics using multi-receptor reporter mice.

Inflammatory chemokines and their receptors are central to the development of inflammatory/immune pathologies. The apparent complexity of this system, coupled with lack of appropriate in vivo models, has limited our understanding of how chemokines orchestrate inflammatory responses and has hampered attempts at targeting this system in inflammatory disease. Novel approaches are therefore needed to provide crucial biological, and therapeutic, insights into the chemokine-chemokine receptor family. Here, we report the generation of transgenic multi-chemokine receptor reporter mice in which spectrally distinct fluorescent reporters mark expression of CCRs 1, 2, 3, and 5, key receptors for myeloid cell recruitment in inflammation. Analysis of these animals has allowed us to define, for the first time, individual and combinatorial receptor expression patterns on myeloid cells in resting and inflamed conditions. Our results demonstrate that chemokine receptor expression is highly specific, and more selective than previously anticipated.

Diverse myeloid cells are recruited to the developing and inflamed mammary gland.

The immune system plays fundamental roles in the mammary gland, shaping developmental processes and controlling inflammation during infection and cancer.Here, we reveal unanticipated heterogeneity in the myeloid cell compartment duringdevelopment of virgin, pregnant, lactating and involuting mouse mammary glands,and in milk. We investigate the functional consequences of individual and compoundchemokine receptor deficiency on cell recruitment. Diverse myeloid cell recruitmentwas also shown in models of sterile inflammation and bacterial infection.Strikingly, we have shown that inflammation and infection can alter the abundanceof terminal end buds, a key developmental structure, within the pubertal mammarygland. This previously unknown effect of inflammatory burden during puberty couldhave important implications for understanding pubertal development.

Examination of emotional contagion and social anxiety using novel video stimuli.

BACKGROUND AND OBJECTIVES: Socially anxious individuals often exhibit signs of anxiety that might elicit discomfort in others and negatively influence their interactions, due in part to emotional contagion. However, there is limited research examining the phenomenon of emotional contagion in social anxiety, which is the topic of the current study. DESIGN AND METHODS: An experimental design was used in which undergraduate psychology students (N = 128) were assigned to either an experimental condition (watching a video of a socially anxious presenter) or a control condition (watching a video of a nonanxious presenter). Various measures were administered to assess social anxiety, emotional contagion, state anxiety, and related constructs. RESULTS: After controlling for baseline anxiety levels, participants in the experimental condition reported significantly higher levels of anxiety during and immediately after watching the video compared to individuals in the control condition (multivariate analysis of covariance, analysis of variance). Similar results were found across both conditions in participants with higher levels of trait social anxiety and higher public speaking anxiety (moderated regression analyses). CONCLUSIONS: The findings suggest that social anxiety may be emotionally contagious, and provides insight into the role that emotional contagion may play in the association between social anxiety and interpersonal functioning.

Chemokine receptors coordinately regulate macrophage dynamics and mammary gland development.

Macrophages are key regulators of developmental processes, including those involved in mammary gland development. We have previously demonstrated that the atypical chemokine receptor ACKR2 contributes to the control of ductal epithelial branching in the developing mammary gland by regulating macrophage dynamics. ACKR2 is a chemokine-scavenging receptor that mediates its effects through collaboration with inflammatory chemokine receptors (iCCRs). Here, we reveal reciprocal regulation of branching morphogenesis in the mammary gland, whereby stromal ACKR2 modulates levels of the shared ligand CCL7 to control the movement of a key population of CCR1-expressing macrophages to the ductal epithelium. In addition, oestrogen, which is essential for ductal elongation during puberty, upregulates CCR1 expression on macrophages. The age at which girls develop breasts is decreasing, which raises the risk of diseases including breast cancer. This study presents a previously unknown mechanism controlling the rate of mammary gland development during puberty and highlights potential therapeutic targets.

Analysis of lung stromal expression of the atypical chemokine receptor ACKR2 reveals unanticipated expression in murine blood endothelial cells.

Analysis of chemokine receptor, and atypical chemokine receptor, expression is frequently hampered by the lack of availability of high-quality antibodies and the species specificity of those that are available. We have previously described methodology utilizing Alexa-Fluor-labeled chemokine ligands as versatile reagents to detect receptor expression. Previously this has been limited to hematopoietic cells and methodology for assessing expression of receptors on stromal cells has been lacking. Among chemokine receptors, the ones most frequently expressed on stromal cells belong to the atypical chemokine receptor subfamily. These receptors do not signal in the classic sense in response to ligand but scavenge their ligands and degrade them and thus sculpt in vivo chemokine gradients. Here, we demonstrate the ability to use either intratracheal or intravenous, Alexa-Fluor-labeled chemokine administration to detect stromal cell populations expressing the atypical chemokine receptor ACKR2. Using this methodology, we demonstrate, for the first time, expression of ACKR2 on blood endothelial cells. This observation sets the lung aside from other tissues in which ACKR2 is exclusively expressed on lymphatic endothelial cells and suggest unique roles for ACKR2 in the pulmonary environment.

Placental chemokine compartmentalisation: A novel mammalian molecular control mechanism.

Atypical chemokine receptor 2 (ACKR2) is a chemokine-scavenging receptor. ACKR2-/-embryos display a reduction in size of a novel, to our knowledge, embryonic skin macrophage population referred to as 'intermediate' cells. CC chemokine receptor 2 (CCR2)-/-embryos display an identical phenotype, indicating that these cells require CCR2 to enable them to populate embryonic skin. Further analysis revealed that ACKR2-/-embryos have higher circulating concentrations of the CCR2 ligand, CC ligand 2 (CCL2); thus, ACKR2 regulates intraembryonic CCL2 levels. We show that ACKR2 is strongly expressed by trophoblasts and that it blocks movement of inflammatory chemokines, such as CCL2, from the maternal decidua into the embryonic circulation. We propose that trophoblastic ACKR2 is responsible for ensuring chemokine compartmentalisation on the maternal decidua, without which chemokines enter the embryonic circulation, disrupting gradients essential for directed intraembryonic cell migration. Overall, therefore, we describe a novel, to our knowledge, molecular mechanism whereby maternal decidual chemokines can function in a compartmentalised fashion without interfering with intraembryonic leukocyte migration. These data suggest similar functions for other atypical chemokine receptors in the placenta and indicate that defects in such receptors may have unanticipated developmental consequences.

Bovine Staphylococcus aureus Superantigens Stimulate the Entire T Cell Repertoire of Cattle.

Superantigens (SAgs) represent a diverse family of bacterial toxins that induce Vß-specific T cell proliferation associated with an array of important diseases in humans and animals, including mastitis of dairy cows. However, an understanding of the diversity and distribution of SAg genes among bovine Staphylococcus aureus strains and their role in the pathogenesis of mastitis is lacking. Population genomic analysis of 195 bovine S. aureus isolates representing 57 unique sequence types revealed that strains encode 2 to 13 distinct SAgs and that the majority of isolates contain 5 or more SAg genes. A genome-scale analysis of bovine reference strain RF122 revealed a complement of 11 predicted SAg genes, which were all expressed in vitro Detection of specific antibodies in convalescent cows suggests expression of 7 of 11 SAgs during natural S. aureus infection. We determined the Vß T cell activation profile for all functional SAgs encoded by RF122, revealing evidence for bovine host-specific activity among the recently identified RF122-encoded SAgs SElY and SElZ. Remarkably, we discovered that some strains have evolved the capacity to stimulate the entire T cell repertoire of cattle through an array of diverse SAgs, suggesting a key role in bovine immune evasion.

The Atypical Chemokine Receptor Ackr2 Constrains NK Cell Migratory Activity and Promotes Metastasis.

Chemokines have been shown to be essential players in a range of cancer contexts. In this study, we demonstrate that mice deficient in the atypical chemokine receptor Ackr2 display impaired development of metastasis in vivo in both cell line and spontaneous models. Further analysis reveals that this relates to increased expression of the chemokine receptor CCR2, specifically by KLRG1+ NK cells from the Ackr2-/- mice. This leads to increased recruitment of KLRG1+ NK cells to CCL2-expressing tumors and enhanced tumor killing. Together, these data indicate that Ackr2 limits the expression of CCR2 on NK cells and restricts their tumoricidal activity. Our data have important implications for our understanding of the roles for chemokines in the metastatic process and highlight Ackr2 and CCR2 as potentially manipulable therapeutic targets in metastasis.

HOspitals and patients WoRking in Unity (HOW R U?): telephone peer support to improve older patients' quality of life after emergency department discharge in Melbourne, Australia-a multicentre prospective feasibility study.

OBJECTIVES: To ascertain the feasibility and acceptability of the HOW R U? programme, a novel volunteer-peer postdischarge support programme for older patients after discharge from the emergency department (ED). DESIGN: A multicentre prospective mixed-methods feasibility study. SETTING: Two tertiary hospital EDs in metropolitan Melbourne, Australia. PARTICIPANTS: A convenience sample of 39 discharged ED patients aged 70 years or over, with symptoms of social isolation, loneliness and/or depression. INTERVENTION: The HOW R U? intervention comprised weekly social support telephone calls delivered by volunteer peers for 3 months following ED discharge. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcomes were feasibility of study processes, intervention acceptability to participants and retention in the programme. Secondary outcomes were changes in loneliness level (UCLA-3-3-item Loneliness Scale), mood (5-item Geriatric Depression Scale) and health-related quality of life (EQ-5D-5L and EQ-VAS) postintervention. RESULTS: Recruitment was feasible, with 30% of eligible patients successfully recruited. Seventeen volunteer peers provided telephone support to patient participants, in addition to their usual hospital volunteer role. HOW R U? was well received, with 87% retention in the patient group, and no attrition in the volunteer group.The median age of patients was 84 years, 64% were female, and 82% lived alone. Sixty-eight per cent of patients experienced reductions in depressive symptoms, and 53% experiencing reduced feelings of loneliness, and these differences were statistically significant Patient feedback was positive and volunteers reported great satisfaction with their new role. CONCLUSION: HOW R U? was feasible in terms of recruitment and retention and was acceptable to both patients and volunteers. The overall results support the potential for further research in this area and provide data to support the design of a definitive trial to confirm the observed effects. TRIAL REGISTRATION NUMBER: ANZCTRN12615000715572; Results.

An Examination of Feedback Seeking in Individuals With Social Anxiety Disorder, Generalized Anxiety Disorder, or No History of Mental Disorder Using a Daily Diary Method.

This study examined excessive reassurance seeking (or positive feedback seeking; PFS) and negative feedback seeking (NFS) in individuals with social anxiety disorder (SAD), generalized anxiety disorder (GAD), or no history of mental health difficulties. A 2-week daily diary method was used to examine potential group differences in the frequency, topics, and targets of PFS and NFS. The SAD and GAD groups reported significantly higher feedback seeking (FS) than the healthy group on self-report questionnaires. The most common targets of FS in each group were other people (e.g., romantic partner, family members). According to diary data, there were no significant group differences in the frequency of PFS, NFS, overall FS, or overall FS adjusted for self-reported compliance with diary completion (after applying Bonferroni correction). There were also no significant group differences in FS topics according to diary data. Future research directions and potential implications of these findings are discussed.

Hoarding in the elderly: a critical review of the recent literature.

BACKGROUND: Hoarding is now a stand-alone diagnosis in DSM-5. The objective of this review is to critically evaluate the most recent literature on hoarding disorder (HD) in ageing patients. METHODS: A literature search was conducted using PubMed and PsychINFO to identify papers from 2000 to 2015 that examined HD and hoarding symptoms in late-life participants. RESULTS: Thirteen studies met inclusion criteria. Selected studies had significant methodological limitations with regard to participant sampling, diagnostic criteria, and methods for identifying co-morbid conditions. Hoarding in the elderly generally had onset before age 40 years, increased in severity after middle age, and was linked with social isolation. Depression was associated with hoarding in 14-54% of geriatric cases. Co-morbid anxiety and PTSD were also found. A variety of medical conditions were more common in seniors with hoarding including arthritis and sleep apnea. Late-life hoarding was associated with deficits in memory, attention, and executive function. CONCLUSIONS: HD in the elderly has distinct features. A combination of self-neglect, psychiatric and medical co-morbidities, and executive dysfunction may contribute to the progression of hoarding symptoms in the elderly.

CXCR2 deficient mice display macrophage-dependent exaggerated acute inflammatory responses.

CXCR2 is an essential regulator of neutrophil recruitment to inflamed and damaged sites and plays prominent roles in inflammatory pathologies and cancer. It has therefore been highlighted as an important therapeutic target. However the success of the therapeutic targeting of CXCR2 is threatened by our relative lack of knowledge of its precise in vivo mode of action. Here we demonstrate that CXCR2-deficient mice display a counterintuitive transient exaggerated inflammatory response to cutaneous and peritoneal inflammatory stimuli. In both situations, this is associated with reduced expression of cytokines associated with the resolution of the inflammatory response and an increase in macrophage accumulation at inflamed sites. Analysis using neutrophil depletion strategies indicates that this is a consequence of impaired recruitment of a non-neutrophilic CXCR2 positive leukocyte population. We suggest that these cells may be myeloid derived suppressor cells. Our data therefore reveal novel and previously unanticipated roles for CXCR2 in the orchestration of the inflammatory response.

Spread of Psoriasiform Inflammation to Remote Tissues Is Restricted by the Atypical Chemokine Receptor ACKR2.

Elucidating the poorly defined mechanisms by which inflammatory lesions are spatially restricted in vivo is of critical importance in understanding skin disease. Chemokines are the principal regulators of leukocyte migration and are essential in the initiation and maintenance of inflammation. The membrane-bound psoriasis-associated atypical chemokine receptor 2 (ACKR2) binds, internalizes and degrades most proinflammatory CC-chemokines. Here we investigate the role of ACKR2 in limiting the spread of cutaneous psoriasiform inflammation to sites that are remote from the primary lesion. Circulating factors capable of regulating ACKR2 function at remote sites were identified and examined using a combination of clinical samples, relevant primary human cell cultures, in vitro migration assays, and the imiquimod-induced model of psoriasiform skin inflammation. Localized inflammation and IFN-γ together up-regulate ACKR2 in remote tissues, protecting them from the spread of inflammation. ACKR2 controls inflammatory T-cell chemotaxis and positioning within the skin, preventing an epidermal influx that is associated with lesion development. Our results have important implications for our understanding of how spatial restriction is imposed on the spread of inflammatory lesions and highlight systemic ACKR2 induction as a therapeutic strategy in the treatment and prevention of psoriasis and potentially a broad range of other immune-mediated diseases.

Atypical chemokine receptor ACKR2 controls branching morphogenesis in the developing mammary gland.

Macrophages are important regulators of branching morphogenesis during development and postnatally in the mammary gland. Regulation of macrophage dynamics during these processes can therefore have a profound impact on development. We demonstrate here that the developing mammary gland expresses high levels of inflammatory CC-chemokines, which are essential in vivo regulators of macrophage migration. We further demonstrate that the atypical chemokine receptor ACKR2, which scavenges inflammatory CC-chemokines, is differentially expressed during mammary gland development. We have previously shown that ACKR2 regulates macrophage dynamics during lymphatic vessel development. Here, we extend these observations to reveal a novel role for ACKR2 in regulating the postnatal development of the mammary gland. Specifically, we show that Ackr2-/- mice display precocious mammary gland development. This is associated with increased macrophage recruitment to the developing gland and increased density of the ductal epithelial network. These data demonstrate that ACKR2 is an important regulator of branching morphogenesis in diverse biological contexts and provide the first evidence of a role for chemokines and their receptors in postnatal development processes.

HOspitals and patients WoRking in Unity (HOW R U?): protocol for a prospective feasibility study of telephone peer support to improve older patients' quality of life after emergency department discharge.

INTRODUCTION: Older people presenting to an emergency department (ED) have a higher likelihood of social isolation, loneliness and depression; which are all associated with negative health outcomes and increased health service use, including higher rates of ED attendance. The HOW R U? study aims to ascertain the feasibility and acceptability of a postdischarge telephone support programme for older ED patients following discharge. The intervention, which aims to improve quality of life, will be delivered by hospital-based volunteers. METHODS AND ANALYSIS: A multicentre prospective uncontrolled feasibility study will enrol 50 community-dwelling patients aged ≥70 years with symptoms of loneliness or depression who are discharged home within 72 hours from the ED or acute medical ward. Participants will receive weekly supportive telephone calls over a 3-month period from a volunteer-peer. Feasibility will be assessed in terms of recruitment, acceptability of the intervention to participants and level of retention in the programme. Changes in level of loneliness (UCLA-3 item Loneliness Scale), mood (Geriatric Depression Scale-5 item) and health-related quality of life (EQ-5D-5L and EQ-VAS) will also be measured postintervention (3 months). ETHICS AND DISSEMINATION: Research ethics and governance committee approval has been granted for this study by each participating centre (reference: 432/15 and 12-09-11-15). Study findings will inform the design and conduct of a future multicentre randomised controlled trial of a postdischarge volunteer-peer telephone support programme to improve social isolation, loneliness or depressive symptoms in older patients. Results will be disseminated through peer-reviewed journal publication, and conference and seminar presentation. TRIAL REGISTRATION NUMBER: ACTRN12615000715572, Pre-results.

Mycobacterial receptor, Clec4d (CLECSF8, MCL), is coregulated with Mincle and upregulated on mouse myeloid cells following microbial challenge.

The C-type lectin receptor (CTLR), Clec4d (MCL, CLECSF8), is a member of the Dectin-2 cluster of CTLRs, which also includes the related receptors Mincle and Dectin-2. Like Mincle, Clec4d recognizes mycobacterial cord factor, trehalose dimycolate, and we recently demonstrated its key role in anti-mycobacterial immunity in mouse and man. Here, we characterized receptor expression in naïve mice, under inflammatory conditions, and during Mycobacterium bovis BCG infection using newly generated monoclonal antibodies. In naïve mice, Clec4d was predominantly expressed on myeloid cells within the peritoneal cavity, blood, and bone marrow. Unexpectedly, basal expression of Clec4d was very low on leukocytes in the lung. However, receptor expression was significantly upregulated on pulmonary myeloid cells during M. bovis BCG infection. Moreover, Clec4d expression could be strongly induced in vitro and in vivo by various microbial stimuli, including TLR agonists, but not exogenous cytokines. Notably, we show that Clec4d requires association with the signaling adaptor FcRγ and Mincle, but not Dectin-2, for surface expression. In addition, we provide evidence that Clec4d and Mincle, but not Dectin-2, are interdependently coregulated during inflammation and infection. These data show that Clec4d is an inducible myeloid-expressed CTLR in mice, whose expression is tightly linked to that of Mincle.