Objective Serious non-AIDS disease events (SNAE) are experienced disproportionately by immunologic non-responders (INRs), HIV-infected individuals who do not restore CD4 T cells in blood despite ...effective viral suppression. We aimed to characterize the inflammatory biomarker profile of the INR phenotype. Methods Blinded cross-sectional cohort study comparing markers of immune activation and gut homing between INR and non-INR individuals. HIV-positive participants had HIV RNA suppression on antiretroviral therapy and were categorized as either INR (N = 36) or Clinical Responders ("CR"; CD4>350/mm.sup.3 ; N = 47). 18 HIV-negative comparator individuals were included. Cellular markers were assessed by flow cytometry, with soluble markers assessed by ELISA and LC/MS-MS. Multivariable linear regression models estimated the association between INR phenotype and markers, adjusting for age, sex, duration of ART, and recent infection/vaccination. Results INR participants demonstrated a reduced CD4/CD8 ratio (p<0.001), 35% more CD8 activation (p = 0.02), 36% greater alpha4beta7+ CD4 T cells (p<0.01), 54% more HLA-DR+ CD4 T cells (p<0.001), and 20% higher plasma VCAM (p<0.01) compared to CRs. The INR phenotype was not associated with levels of Kyn/Trp, CRP, TNF, IFNgamma, IL-8, IL-6, sCD14, D-Dimer, I-FABP, MCP-1, ICAM or CD8%HLA-DR+. Conclusions Peripheral CD4 non-recovery during long-term treated HIV infection is characterized by elevated CD8 activation and CD4 gut homing. Gut-focused interventions may be warranted in the INR context, and CD8 activation may serve as a surrogate endpoint for clinical interventions.
While gonadotropin‐releasing hormone (GnRH) is considered as the major hypothalamic factor controlling pituitary gonadotrophins in mammals and most other vertebrates, its stimulatory actions may be ...opposed by the potent inhibitory actions of dopamine (DA) in teleosts. This dual neuroendocrine control of reproduction by GnRH and DA has been demonstrated in various, but not all, adult teleosts, where DA participates in an inhibitory role in the neuroendocrine regulation of the last steps of gametogenesis (final oocyte maturation and ovulation in females and spermiation in males). This has major implications for inducing spawning in aquaculture. In addition, DA may also play an inhibitory role during the early steps of gametogenesis in some teleost species, and thus interact with GnRH in the control of puberty. Various neuroanatomical investigations have shown that DA neurones responsible for the inhibitory control of reproduction originate in a specific nucleus of the preoptic area (NPOav) and project directly to the region of the pituitary where gonadotrophic cells are located. Pharmacological studies showed that the inhibitory effects of DA on pituitary gonadotrophin production are mediated by DA‐D2 type receptors. DA‐D2 receptors have now been sequenced in several teleosts, and the coexistence of several DA‐D2 subtypes has been demonstrated in a few species. Hypophysiotropic DA activity varies with development and reproductive cycle and probably is controlled by environmental cues as well as endogenous signals. Sex steroids have been shown to regulate dopaminergic systems in several teleost species, affecting both DA synthesis and DA‐D2 receptor expression. This demonstrates that sex steroid feedbacks target DA hypophysiotropic system, as well as the other components of the brain‐pituitary gonadotrophic axis, GnRH and gonadotrophins. Recent studies have revealed that melatonin modulates the activity of DA systems in some teleosts, making the melatonin‐DA pathway a prominent relay between environmental cues and control of reproduction. The recruitment of DA neurons for the neuroendocrine control of reproduction provides an additional brain pathway for the integration of various internal and environmental cues. The plasticity of the DA neuroendocrine role observed in teleosts may have contributed to their large diversity of reproductive cycles.
Highlights ► Cloning of kisspeptin receptor in a basal teleost. ► Pituitary expression of kisspeptin receptor. ► Direct pituitary inhibition by kisspeptin of LHβ expression. ► Specific effect of ...kisspeptin on LH with no effect on other pituitary hormones.
•A single gnih paralog has been conserved after the teleost 3R.•The gnih gene encodes three GnIH peptides in a basal teleost, the European eel.•Gnih mRNA is mostly expressed in the diencephalon in ...the eel.•Eel GnIH peptides inhibit the expression of lhβ, fshβ, gpα and gnrh-r2 in vitro.
Since its discovery in birds, gonadotropin-inhibitory hormone (GnIH) has triggered investigation in the other groups of vertebrates. In the present study, we have identified a single gnih gene in the European eel (Anguilla anguilla), a representative species of a basal group of teleosts (Elopomorphs). We have also retrieved a single gnih gene in Osteoglossomorphs, as well as in more recently emerged teleosts, Clupeocephala. Phylogeny and synteny analyses allowed us to infer that one of the two gnih paralogs emerged from the teleost-specific whole genome duplication (TWGD or 3R), would have been lost shortly after the 3R, before the emergence of the basal groups of teleosts. This led to the presence of a single gnih in extant teleosts as in other vertebrates. Two gnih paralogs were still found in some teleost species, such as in salmonids, but resulting from the additional whole genome duplication that specifically occurred in this lineage (4R). Eel gnih was mostly expressed in the diencephalon part of the brain, as analyzed by quantitative real-time PCR. Cloning of eel gnih cDNA confirmed that the sequence of the GnIH precursor encoded three putative mature GnIH peptides (aaGnIH-1, aaGnIH-2 and aaGnIH-3), which were synthesized and tested for their direct effects on eel pituitary cells in vitro. Eel GnIH peptides inhibited the expression of gonadotropin subunits (lhβ, fshβ, and common a-subunit) as well as of GnRH receptor (gnrh-r2), with no effect on tshβ and gh expression. The inhibitory effect of GnIH peptides on gonadotropic function in a basal teleost is in agreement with an ancestral inhibitory role of GnIH in the neuroendocrine control of reproduction in vertebrates.
In various vertebrate species, dopamine (DA) exerts an inhibitory action on reproduction. In the European eel, DA plays a pivotal role in the inhibitory control of gonadotroph function and the ...blockade of puberty. In vivo studies have suggested that this effect is mediated by receptors pharmacologically related to the D2 family. In the European eel, two distinct D2 receptor (D2‐R) paralogous genes have been identified (D2A‐R and D2B‐R) and both were shown to be expressed in the pituitary. We investigated the potential role of each paralogue in the control of gonadotroph function in this species. Eel recombinant D2A‐R or D2B‐R were expressed in HEK 293 cells, with a universal Gα subunit, and receptor activation was followed by inositol phosphate production. Recombinant D2‐Rs exhibited a comparable affinity for DA, although they had differential affinities for mammalian D2‐R agonists and antagonists, supporting subtle structure/activity differences. Furthermore, using eel pituitary cell primary cultures, the expression by gonadotroph cells of both native eel D2‐R paralogues was examined by in situ hybridisation of D2A‐R or D2B‐R transcripts, coupled with immunofluorescence of luteinising hormone (LH)β or follicle‐stimulating (FSH)β. LH and to a lesser extent, FSH cells expressed both D2‐R transcripts but with a clear predominance of D2B‐R. Notably, D2B‐R transcripts were detected for the majority of LH cells. Accordingly, using these cultures, we showed that DA potently inhibited basal and testosterone‐stimulated LHβ expression and less potently basal and activin‐stimulated FSHβ expression. We also tested some D2‐R antagonists, aiming to select the most adequate one to be used in innovative protocols for induction of eel sexual maturation. We identified eticlopride as the most potent inhibitor of DA action on basal and stimulated LH expression in vitro. Our data suggest a differential functionalisation of the duplicated receptor genes and demonstrate that mainly D2B‐R is involved in the dopaminergic inhibitory control of eel gonadotroph function.
We developed an integrative perspective on the empirical evidence supporting the influence of particular variables on the warning process based on a broad review of the warning literature. The ...warning process is described in terms of the following four components: notice, encode, comprehend, and comply. Relevant variables are classified as person variables (characteristics of the individual interacting with the warning) and warning variables (characteristics of the warning itself or the context in which the warning appears). This integrative perspective yields general principles about the variables that influence the warning process and serves as a resource for warning developers and as a guide to facilitate effective analysis of warnings. We also identify aspects of the warning process that are not well understood, directions for effective methods of intervention, and a research agenda for future efforts. Actual or potential applications of this research include improving the design of warnings.
Immunologic non-responders (INRs) are a subset of individuals living with HIV who have suboptimal blood CD4+ T cell recovery despite effective antiretroviral therapy (ART). They are at an increased ...risk of serious non-AIDS co-morbidities and death, and demonstrate enhanced systemic immune activation. In other populations diet has been correlated with markers of systemic inflammation through the Diet Inflammatory Index (DII), but this association has not been studied in persons living with HIV (PLWH). Blood was collected from 28 INR PLWH with a blood CD4+ T cell count <350/μL despite ≥2 years of effective ART. Participants completed a Canadian Diet History Questionnaire, and their responses were used to calculate the DII. Plasma inflammatory markers (IFNγ, TNF, IL-6, sVCAM, D-dimer, sCD14 and CRP) were assayed by ELISA, cellular immune activation (HLA-DR and CD38 on CD4+ and CD8+ T cells) was quantified using flow cytometry, and small bowel permeability assessed by calculation of the urine LacMan ratio after drinking a mix of lactulose and mannitol. Participants were a median age of 57 years, had been on effective ART for 15 years, and the median DII was −1.91 (range of −3.78 to +2.23). No correlation was observed between DII and plasma markers of inflammation, levels of T cell activation, gut permeability, or the biomarker of bacterial translocation sCD14. Self-reported alcohol intake, a potential confounder of the relationship between diet and inflammatory biomarkers, was also not associated with systemic inflammation or gut permeability. Our findings suggest that other mechanisms, rather than diet, are likely to be the major driver of systemic inflammation in INR individuals.
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