Nanoparticle size influences the magnitude and quality of mucosal immune responses after intranasal immunization

Background: The development of nanoparticulate antigen-delivery systems is an important emerging area of vaccinology, being sought to amplify immune responses to recombinant antigens that are poorly immunogenic. Nanoparticle size may play an important role in influencing the activity of such particulate-based adjuvants. Methods: To explore how the size of nanoparticles that are in the range of many common viruses can modulate the magnitude and quality of mucosal immune responses, the model antigen ovalbumin (OVA) was conjugated to 30 nm or 200 nm polypropylene sulfide nanoparticles (NPs) and administered intranasally to C57BL/6 mice. Results: We show that by increasing the size of the NPs from 30 to 200 nm, OVA was more effectively delivered into both MHC class I and MHC class II-presentation pathways. Intranasal immunization with the 200 nm NPs increased the magnitude of CD4(+) T cell responses in the lungs, as well as systemic and mucosal humoral responses. Most importantly, 200 nm NPs increased the proportion of antigen-specific polyfunctional CD4(+) T cells as compared to 30 nm NPs. Conclusions: The 200 nm NPs are a very interesting antigen nanocarrier for prophylactic vaccines against mucosal pathogens that require multifunctional CD4(+) T cells for protection. These results contribute to our understanding of how the size of an antigen-conjugated nanoparticle modulates mucosal immune responses to a protein antigen and may be useful to engineer subunit vaccines able to elicit appropriate mucosal immune responses that correlate with protection. (C) 2012 Elsevier Ltd. All rights reserved

A high-throughput nanoimmunoassay chip applied to large-scale vaccine adjuvant screening

Large-scale experimentation is becoming instrumental in enabling new discoveries in systems biology and personalized medicine. We developed a multiplexed high-throughput nanoimmunoassay chip capable of quantifying four biomarkers in 384 5 nL samples, for a total of 1536 assays. Our platform, compared to conventional methods, reduces volume and reagent cost by similar to 1000-fold. We applied our platform in the context of systems vaccinology, to assess the synergistic production of inflammatory cytokines from dendritic cells (DCs) stimulated with 10 different adjuvants that target members of the Toll-like receptor (TLR) family. We quantified these adjuvants both alone and in all pairwise combinations, for a total of 435 conditions, revealing numerous synergistic pairs. We evaluated two synergistic interactions, MPLA + Gardiquimod and MPLA + CpG-B, in a mouse model, where we measured the same inflammatory cytokines in bronchoalveolar lavage and in blood serum at 4 different time points using our chip, and observed similar synergistic effects in vivo, demonstrating the potential of our microfluidic platform to predict agonistic immunogenicity. More generally, a high-throughput, matrix-insensitive, low sample volume technology can play an important role in the discovery of novel therapeutics and research areas requiring large-scale biomarker quantitation

MOESM1 of Oral administration of Lactobacillus paracasei NCC 2461 for the modulation of grass pollen allergic rhinitis: a randomized, placebo-controlled study during the pollen season

Additional file 1. Population, protocols and supplementary figures

Nanoparticle conjugation of CpG enhances adjuvancy for cellular immunity and memory recall at low dose

In subunit vaccines, strong CD8(+) T-cell responses are desired, yet they are elusive at reasonable adjuvant doses. We show that targeting adjuvant to the lymph node (LN) via ultrasmall polymeric nanoparticles (NPs), which rapidly drain to the LN after intradermal injection, greatly enhances adjuvant efficacy at low doses. Coupling CpG-B or CpG-C oligonucleotides to NPs led to better dual-targeting of adjuvant and antigen (codelivered on separate NPs) in cross-presenting dendritic cells compared with free adjuvant. This led to enhanced dendritic cell maturation and T helper 1 (Th1)-cytokine secretion, in turn driving stronger effector C8(+) T-cell activation with enhanced cytolytic profiles and, importantly, more powerful memory recall. With only 4 mu g CpG, NP-CpG-B could substantially protect mice from syngeneic tumor challenge, even after 4 mo of vaccination, compared with free CpG-B. Together, these results show that nanocarriers can enhance vaccine efficacy at a low adjuvant dose for inducing potent and long-lived cellular immunity

VEGF-C promotes immune tolerance in B16 melanomas and cross-presentation of tumor antigen by lymph node lymphatics

Tumor expression of the lymphangiogenic factor VEGF-C is correlated with metastasis and poor prognosis, and although VEGF-C enhances transport to the draining lymph node (dLN) and antigen exposure to the adaptive immune system, its role in tumor immunity remains unexplored. Here, we demonstrate that VEGF-C promotes immune tolerance in murine melanoma. In B16 F10 melanomas expressing a foreign antigen (OVA), VEGF-C protected tumors against preexisting antitumor immunity and promoted local deletion of OVA-specific CD8(+) T cells. Naive OVA-specific CD8(+) T cells, transferred into tumor-bearing mice, were dysfunctionally activated and apoptotic. Lymphatic endothelial cells (LECs) in dLNs cross-presented OVA, and naive LECs scavenge and cross-present OVA in vitro. Cross-presenting LECs drove the proliferation and apoptosis of OVA-specific CD8(+) T cells ex vivo. Our findings introduce a tumor-promoting role for lymphatics in the tumor and dLN and suggest that lymphatic endothelium in the local microenvironment may be a target for immunomodulation

Novel approach to visualize the inter-dependencies between maternal sensitization, breast milk immune components and human milk oligosaccharides in the LIFE Child cohort.

BackgroundNumerous studies have shown that specific components of breast milk, considered separately, are associated with disease status in the mother or the child using univariate analyses. However, very few studies have considered multivariate analysis approaches to evaluate the relationship between multiple breast milk components simultaneously.AimHere we aimed at visualizing breast milk component complex interactions in the context of the allergy status of the mother or the child.MethodsMilk samples were collected from lactating mothers participating in the Leipziger Forschungszentrum für Zivilisationskrankheiten (LIFE) Child cohort in Leipzig, Germany. A total of 156 breast milk samples, collected at 3 months after birth from mother/infant pairs, were analyzed for 51 breast milk components. Correlation, principal component analysis (PCA) and graphical discovery analysis were used.ResultCorrelations ranging from 0.40 to 0.96 were observed between breast milk fatty acid and breast milk phospholipids levels and correlations ranging from 0 to 0.76 between specific human milk oligosaccharides (HMO) were observed. No separation of the data based on the risk of allergy in the infants was identified using PCA. When graphical discovery analysis was used, dependencies between maternal plasma immunoglobulin E (IgE) level and the breast milk immune marker transforming growth factor-beta 2 (TGF-ß2), between TGF-ß2, breast milk immunoglobulin A (IgA) and TGF-ß1 as well as between breast milk total protein and birth weight were observed. Graphical discovery analysis also exemplifies a possible competition for the fucosyl group between 2'FL, LNFP-I and 3'FL in the HMO group. Additionally, dependencies between immune component IgA and specific HMO (6'SL and blood group A antigen tetraose type 5 or PI-HMO) were identified.ConclusionGraphical discovery analysis applied to complex matrices such as breast milk composition can aid in understanding the complexity of interactions between breast milk components and possible relations to health parameters in the mother or the infant. This approach can lead to novel discoveries in the context of health and diseases such as allergy. Our study thus represents the first attempt to visualize the complexity and the inter-dependency of breast milk components