Natural anti-CCR5 antibodies in HIV-infection and -exposure

Natural antibodies constitute a first-line of defence against pathogens; they may also play other roles in immune regulation and homeostasis, through their ability to bind host antigens, surface molecules and receptors. Natural anti-CCR5 antibodies can be decisive in preventing HIV infection in mucosal tissues and offer prompt and effective protection just at major sites of virus entry. Among natural anti-CCR5 antibodies, IgG and IgA to the ECL1 domain have been shown to block HIV effectively and durably without causing harm to the host. Their biological properties and their uncommon generation in subsets of HIV-infected and HIV-exposed individuals (so called ESN) will be introduced and discussed, with the aim at exploiting their potential in therapy and prevention

In Situ Distribution of HIV-Binding CCR5 and C-Type Lectin Receptors in the Human Endocervical Mucosa

The endocervical mucosa is believed to be a primary site of HIV transmission. However, to date there is little known about the distribution of the HIV co-receptor CCR5 and the HIV-binding C-type lectin receptors, including Langerin, dendritic cell (DC)-specific intercellular adhesion molecule-grabbing non-integrin (DC-SIGN) and mannose receptor (MR) at this site. We therefore characterized the expression of these molecules in the endocervix of HIV seronegative women by computerized image analysis. Endocervical tissue biopsies were collected from women (n = 6) undergoing hysterectomy. All study individuals were diagnosed with benign and non-inflammatory diseases. CCR5+ CD4+ CD3+ T cells were found within or adjacent to the endocervical epithelium. The C-type lectin Langerin was expressed by intraepithelial CD1a+ CD4+ and CD11c+ CD4+ Langerhans cells, whereas DC-SIGN+ MR+ CD11c myeloid dendritic cells and MR+ CD68+ macrophages were localized in the submucosa of the endocervix. The previously defined immune effector cells including CD8+, CD56+, CD19+ and IgD+ cells were also found in the submucosa as well as occasional CD123+ BDCA-2+ plasmacytoid dendritic cells. Understanding the spatial distribution of potential HIV target cells and immune effector cells in relation to the endocervical canal forms a basis for deciphering the routes of HIV transmission events in humans as well as designing HIV-inhibiting compounds

The Phospholipid Scramblases 1 and 4 Are Cellular Receptors for the Secretory Leukocyte Protease Inhibitor and Interact with CD4 at the Plasma Membrane

Secretory leukocyte protease inhibitor (SLPI) is secreted by epithelial cells in all the mucosal fluids such as saliva, cervical mucus, as well in the seminal liquid. At the physiological concentrations found in saliva, SLPI has a specific antiviral activity against HIV-1 that is related to the perturbation of the virus entry process at a stage posterior to the interaction of the viral surface glycoprotein with the CD4 receptor. Here, we confirm that recombinant SLPI is able to inhibit HIV-1 infection of primary T lymphocytes, and show that SLPI can also inhibit the transfer of HIV-1 virions from primary monocyte-derived dendritic cells to autologous T lymphocytes. At the molecular level, we show that SLPI is a ligand for the phospholipid scramblase 1 (PLSCR1) and PLSCR4, membrane proteins that are involved in the regulation of the movements of phospholipids between the inner and outer leaflets of the plasma membrane. Interestingly, we reveal that PLSCR1 and PLSCR4 also interact directly with the CD4 receptor at the cell surface of T lymphocytes. We find that the same region of the cytoplasmic domain of PLSCR1 is involved in the binding to CD4 and SLPI. Since SLPI was able to disrupt the association between PLSCR1 and CD4, our data suggest that SLPI inhibits HIV-1 infection by modulating the interaction of the CD4 receptor with PLSCRs. These interactions may constitute new targets for antiviral intervention

A systematic review of methods for increasing vegetable consumption in early childhood

PURPOSE OF REVIEW: This study aims to synthesise the body of research investigating methods for increasing vegetable consumption in 2- to 5-year-old children, while offering advice for practitioners. RECENT FINDINGS: Repeated exposure is a well-supported method for increasing vegetable consumption in early childhood and may be enhanced with the inclusion of non-food rewards to incentivise tasting. Peer models appear particularly effective for increasing 2-5-year-olds' vegetable consumption. There is little evidence for the effectiveness of food adaptations (e.g. flavour-nutrient learning) for increasing general vegetable intake among this age group, although they show some promise with bitter vegetables. SUMMARY: This review suggests that practitioners may want to focus their advice to parents around strategies such as repeated exposure, as well as the potential benefits of modelling and incentivising tasting with non-food rewards. Intervention duration varies greatly, and considerations need to be made for how this impacts on success

Increasing vegetable intakes: rationale and systematic review of published interventions

Purpose While the health benefits of a high fruit and vegetable consumption are well known and considerable work has attempted to improve intakes, increasing evidence also recognises a distinction between fruit and vegetables, both in their impacts on health and in consumption patterns. Increasing work suggests health benefits from a high consumption specifically of vegetables, yet intakes remain low, and barriers to increasing intakes are prevalent making intervention difficult. A systematic review was undertaken to identify from the published literature all studies reporting an intervention to increase intakes of vegetables as a distinct food group. Methods Databases—PubMed, PsychInfo and Medline—were searched over all years of records until April 2015 using pre-specified terms. Results Our searches identified 77 studies, detailing 140 interventions, of which 133 (81 %) interventions were conducted in children. Interventions aimed to use or change hedonic factors, such as taste, liking and familiarity (n = 72), use or change environmental factors (n = 39), use or change cognitive factors (n = 19), or a combination of strategies (n = 10). Increased vegetable acceptance, selection and/or consumption were reported to some degree in 116 (83 %) interventions, but the majority of effects seem small and inconsistent. Conclusions Greater percent success is currently found from environmental, educational and multi-component interventions, but publication bias is likely, and long-term effects and cost-effectiveness are rarely considered. A focus on long-term benefits and sustained behaviour change is required. Certain population groups are also noticeably absent from the current list of tried interventions

Functional Comparison of Innate Immune Signaling Pathways in Primates

Humans respond differently than other primates to a large number of infections. Differences in susceptibility to infectious agents between humans and other primates are probably due to inter-species differences in immune response to infection. Consistent with that notion, genes involved in immunity-related processes are strongly enriched among recent targets of positive selection in primates, suggesting that immune responses evolve rapidly, yet providing only indirect evidence for possible inter-species functional differences. To directly compare immune responses among primates, we stimulated primary monocytes from humans, chimpanzees, and rhesus macaques with lipopolysaccharide (LPS) and studied the ensuing time-course regulatory responses. We find that, while the universal Toll-like receptor response is mostly conserved across primates, the regulatory response associated with viral infections is often lineage-specific, probably reflecting rapid host–virus mutual adaptation cycles. Additionally, human-specific immune responses are enriched for genes involved in apoptosis, as well as for genes associated with cancer and with susceptibility to infectious diseases or immune-related disorders. Finally, we find that chimpanzee-specific immune signaling pathways are enriched for HIV–interacting genes. Put together, our observations lend strong support to the notion that lineage-specific immune responses may help explain known inter-species differences in susceptibility to infectious diseases

Developing healthy food preferences in preschool children through taste exposure, sensory learning and nutrition education

Purpose of Review: The present review was undertaken in order to summarize and evaluate recent research investigating taste exposure, sensory learning, and nutrition education interventions for promoting vegetable intake in preschool children. Recent Findings: Overall, taste exposure interventions yielded the best outcomes for increasing vegetable intake in early childhood. Evidence from sensory learning strategies such as visual exposure and experiential learning also show some success. While nutrition education remains the most common approach used in preschool settings, additional elements are needed to strengthen the educational program for increasing vegetable intake. There is a substantial gap in the evidence base to promote vegetable intake in food fussy children. Summary: The present review reveals the relative importance of different intervention strategies for promoting vegetable intake. To strengthen intervention effects for improving vegetable intake in preschool children, future research could consider integrating taste exposure and sensory learning strategies with nutrition education within the preschool curriculum

Neutralizing monoclonal antibodies to human immunodeficiency virus type 1 do not inhibit viral transcytosis through mucosal epithelial cells

HIV-1 transcytosis has been proposed as a potential mechanism allowing the virus to cross the epithelium during mucosal transmission. Epitopes of the HIV-1 envelope involved in this process have not been identified yet. Here, we assessed a large panel of HIV neutralizing antibodies recognizing well-characterized epitopes of the HIV-1 envelope for their ability to block HIV-1 transcytosis across a confluent epithelial monolayer. We found that all of the 13 HIV-1-specific monoclonal antibodies tested in the present study, including the three broadly neutralizing antibodies 2F5. 2G12 and lgG1bI2, lacked the ability to inhibit transcytosis of cell-free and cell-associated R5- as X4-tropic HIV-1 across a tight and polarized monolayer of HEC-1 epithelial cells. In contrast, anti-gp 160 polyclonal antibodies purified from serum or breast milk of HIV-1-infected individuals potently inhibited HIV-1 transcytosis. Furthermore, polymeric S-IgA exhibited similar ability to inhibit transcytosis compared to IgG despite their lower anti-gp 160 specific activity. Together, these results demonstrate that the major neutralizing envelope epitopes of HIV-1 are not involved in HIV-1 transcytosis, and suggest that surface agglutination of virus particles may participate to the blocking effect observed with both polyclonal and polymeric anti-gp 160 immunoglobulins