Imaging and targeted delivery to macrophages are promising new approaches to study and treat a variety of inflammatory diseases such as atherosclerosis. In this manuscript, we have designed and synthesized iron oxide based magnetic nanoparticles bearing hyaluronic acid (HA) on the surface to target activated macrophages. The HA-coated nanoparticles were prepared through a co-precipitation procedure followed by postsynthetic functionalization with HA and fluorescein. The nanoparticles were characterized by transmission electron microscopy, thermogravimetric analysis, elemental analysis, dynamic light scattering, and high-resolution magic angle spinning NMR and were biocompatible with cells and colloidally stable in the presence of serum. The HA immobilized on the nanoparticles retained their specific biological recognition with the HA receptor CD44, which is present on activated macrophages in high-affinity forms. Cell uptake studies demonstrated significant uptake of HA nanoparticles by activated macrophage cell line THP-1, which enabled magnetic resonance imaging of THP-1 cells. The uptake of nanoparticles was found to be both HA and CD44 dependent. Interestingly, Prussian blue staining showed that the magnetite cores of the HA-coated nanoparticles were only transiently present inside the cells, thus reducing the potential concerns of nanotoxicity. Furthermore, fluorescein on the nanoparticle was found to be delivered to the cell nucleus. Therefore, with further development, these HA functionalized magnetic nanoparticles can potentially become a useful carrier system for molecular imaging and targeted drug delivery to activated macrophages.

A Co atom enhances the HER activity of monolayer MoS2 whereas a Ni atom exhibits the opposite effect on the same basal site.

Plants and herbivorous insects can each be dramatically affected by temperature. Climate warming may impact plant invasion success directly but also indirectly through changes in their natural enemies. To date, however, there are no tests of how climate warming shifts the interactions among invasive plants and their natural enemies to affect invasion success. Field surveys covering the full latitudinal range of invasive Alternanthera philoxeroides in China showed that a beetle introduced for biocontrol was rare or absent at higher latitudes. In contrast, plant cover and mass increased with latitude. In a 2-year field experiment near the northern limit of beetle distribution, we found the beetle sustained populations across years under elevated temperature, dramatically decreasing A. philoxeroides growth, but it failed to overwinter in ambient temperature. Together, these results suggest that warming will allow the natural enemy to expand its range, potentially benefiting biocontrol in regions that are currently too cold for the natural enemy. However, the invader may also expand its range further north in response to warming. In such cases where plants tolerate cold better than their natural enemies, the geographical gap between plant and herbivorous insect ranges may not disappear but will shift to higher latitudes, leading to a new zone of enemy release. Therefore, warming will not only affect plant invasions directly but also drive either enemy release or increase that will result in contrasting effects on invasive plants. The findings are also critical for future management of invasive species under climate change.

Immunotherapy targeting tumor cell surface carbohydrates is a promising approach for cancer treatment. However, the low immunogenecity of carbohydrates presents a formidable challenge. We describe here the enhancement of carbohydrate immunogenicity by an ordered display on the surface of the cowpea mosaic virus (CPMV) capsid. The Tn glycan, which is overexpressed on numerous cancer cell surfaces, was selected as the model antigen for our study. Previously it has been shown that it is difficult to induce a strong T cell-dependent immune response against the monomeric form of Tn presented in several ways on different carriers. In this study, we first synthesized Tn antigens derivatized with either a maleimide or a bromoacetamide moiety that was conjugated selectively to a cysteine mutant of CPMV. The glycoconjugate was then injected into mice and pre- and post-immune antibody levels in the mice sera were measured by enzyme-linked immunosorbant assays. High total antibody titers and, more importantly, high IgG titers specific for Tn were obtained in the post-immune day 35 serum, suggesting the induction of T cell-dependent antibody isotype switching by the glycoconjugate. The antibodies generated were able to recognize Tn antigens presented in their native conformations on the surfaces of both MCF-7 breast cancer cells and the multidrug resistant breast cancer cell line NCI-ADR RES. These results suggest that the CPMV capsid can greatly enhance the immunogenicity of weak antigens such as Tn and this can provide a promising tool for the development of carbohydrate based anti-cancer vaccines.

IntroductionPBMCs in healthy individuals consist of roughly 70% T cells, 10% B cells, 10% monocytes, and 1% each of natural killer (NK) cells and dendritic cells (DCs). Three distinct blood monocyte subsets can be identified on the basis of CD14 and CD16 expression: ϳ 90% CD14 ϩϩ CD16 Ϫ , 10% CD14 ϩ CD16 ϩϩ , and a minor population of CD14 ϩϩ CD16 ϩ . 1 DCs are potent APCs with a nearly unique capacity to prime naive T lymphocytes. 1 Because of their paucity in blood, DCs are typically generated by culturing monocytes ex vivo with cytokines. 2,3 Little is known about the interaction of PBMCs with viruses that principally replicate in nonimmune cells. Here, we investigate the effect of infecting PBMCs with 3 representative nonhemotropic viruses that are highly lytic to their normal host cells. Methods PBMC infectionFresh buffy coat preparations were obtained from healthy anoymous donors at the National Institutes of Health (NIH) blood bank who provided informed consent. We also obtained whole blood from healthy donors with informed consent in accordance with the Declaration of Helsinki approved by University of California at Los Angeles Institutional Review Board. PBMCs or purified monocytes were incubated with virus for 1 hour at room temperature in balanced salt solution with 0.1% BSA and then resuspended at 1 ϫ 10 6 cells per well in complete RPMI 1640. Six or 18 hours after infection, cells were stained with mAbs including PerCP-eFluor 710-conjugated anti-CD3, -CD14, -CD19, and -CD56 or a combination of these "lineage marker" mAbs (all eBioscience); eFluor 450-conjugated anti-HLA-DR, AlexaFluor700 anti-CD11c, and PE-Cy7-conjugated anti-CD123 (all eBioscience); AlexaFluor488 anti-hemagglutinin (Bennink-Yewdell Lab, National Institute of Allergy and Infectious Diseases); PE-Cy7-conjugated anti-TNF, eFluor605NC anti-CD16, and PE anti-CD83 (all eBioscience); PE anti-CD1c (Miltenyi Biotec); PE anti-CD141 (BD Biosciences); FITC anti-CLEC4C (Miltenyi Biotec); and APC anti-CLEC9A (R&D Systems). Real-time PCRAfter 6 hours' infection, total RNA purified from influenza A virus (IAV)-infected monocytes primed with random hexamers was PCR analyzed with Profiler PCR arrays for DC APC and IFN/IFN receptor gene expression (SABiosciences PAHS-406 and PAHS-064), with expression normalized to 5 internal housekeeping genes. A custom array was obtained from SABiosciences for the detection of the human genes CCR7, CD1C,, and LAMP3 (DC-LAMP). Results and discussionWe chose 3 representative viruses: IAV, vesicular stomatitis (VSV), and vaccinia virus (VV). For VV and VSV, we measured infection by expression of enhanced green fluorescent protein inserted into the viral genome. For IAV, infection was monitored by cell surface expression of hemagglutinin. After infecting PBMCs for 6 or 18 hours, cells were characterized by standard flow cytometry phenotypic markers ( Figure 1A).For each of the 3 viruses tested, T cells (CD3 ϩ ), B cells (CD19 ϩ ), and NK cells (CD56 ϩ ) expressed negligible or undetectable levels of viral proteins over...

Sensitivity is essential in CD8+ T-cell killing of virus-infected cells and tumor cells. Although the affinity of the T-cell receptor (TCR) for antigen is relatively low, the avidity of T cell-antigen-presenting cell interactions is greatly enhanced by increasing the valence of the interaction. It is known that TCRs cluster into protein islands after engaging their cognate antigen (peptides bound to MHC molecules). Here, we show that mouse K b class I molecules segregate into preformed, long-lasting (hours) clusters on the antigen-presenting cell surface based on their bound viral peptide. Peptide-specific K b clustering occurs when source antigens are expressed by vaccinia or vesicular stomatitis virus, either as proteasome-liberated precursors or free intracellular peptides. By contrast, K b -peptide complexes generated by incubating cells with synthetic peptides are extensively intermingled on the cell surface. Peptide-specific complex sorting is first detected in the Golgi complex, and compromised by removing the K b cytoplasmic tail. Peptide-specific clustering is associated with increased T-cell sensitivity: on a per-complex basis, endogenous SIINFEKL activates T cells more efficiently than synthetic SIINFEKL, and wild-type K b presents endogenous SIINFEKL more efficiently than tailless K b . We propose that endogenous processing generates peptide-specific clusters of class I molecules to maximize the sensitivity and speed of T-cell immunosurveillance.MHC class I clustering | CD8 T cell recognition | dual-color TIRF imaging | antigen processing/presentation | intracellular trafficking

Soil biota community structure can change with latitude, but the effects of changes on native plants, invasive plants, and their herbivores remain unclear. Here, we examined latitudinal variation in the soil biota community associated with the invasive plant Alternanthera philoxeroides and its native congener A. sessilis, and the effects of soil biota community variation on these plants and the beetle Agasicles hygrophila. We characterized the soil bacterial and fungal communities and root-knot nematodes of plant rhizospheres collected from 22 °N to 36.6 °N in China. Soil biota community structure changed with latitude as a function of climate and soil properties. Root-knot nematode abundance and potential soil fungal pathogen diversity (classified with FUNGuild) decreased with latitude, apparently due to higher soil pH and lower temperatures. A greenhouse experiment and lab bioassay showed native plant mass, seed production, and mass of beetles fed native foliage increased with soil collection latitude. However, there were no latitudinal patterns for the invasive plant. These results suggest that invasive and native plants and, consequently, their herbivores have different responses to latitudinal changes in soil-borne enemies, potentially creating spatial variation in enemy release or biotic resistance. This highlights the importance of linking above- and below-ground multitrophic interactions to explore the role of soil biota in non-native plant invasions with a biogeographic approach.

Climate change may shift interactions of invasive plants, herbivorous insects and native plants, potentially affecting biological control efficacy and non-target effects on native species. Here, we show how climate warming affects impacts of a multivoltine introduced biocontrol beetle on the non-target native plant Alternanthera sessilis in China. In field surveys across a latitudinal gradient covering their full distributions, we found beetle damage on A. sessilis increased with rising temperature and plant life history changed from perennial to annual. Experiments showed that elevated temperature changed plant life history and increased insect overwintering, damage and impacts on seedling recruitment. These results suggest that warming can shift phenologies, increase non-target effect magnitude and increase non-target effect occurrence by beetle range expansion to additional areas where A. sessilis occurs. This study highlights the importance of understanding how climate change affects species interactions for future biological control of invasive species and conservation of native species.