Immune Profiling of Polysaccharide Submicron Vesicles

Alginate (ALG) and chitosan (CS) have been extensively used for biomedical applications; however, data relative to immune responses exerted by them are scarce. We synthesized a submicron vesicle system (SV) displaying a CS shell over an ALG core. Intravenous injection of these promising carriers could be a possible route of delivery; therefore, we evaluated their impact on human peripheral blood mononuclear cells (PBMCs). By this ex vivo approach, we established how SV chemical–physical characteristics affected the immune cells in terms of cellular uptake, viability, and state of activation. By flow cytometry, we demonstrated that SVs were internalized by PBMCs with differential trends. No substantial necrotic and apoptotic signals were recorded, and SVs weakly affected activation status of PBMCs (concerning the markers CD69, CD25, CD80, and the cytokines TNF-α and IL-6), showing high immune biocompatibility and low immunomodulating properties. Our findings gain particular value toward the biomedical applications of SVs and make these polymer-based structures more attractive for translation into clinical uses

MSRV-type mRNA expression by PBMC from IM patients and healthy donors (HD).

<p>The amounts of MSRV-type HERV-Wenv transcripts were evaluated by discriminatory real time RT-PCR, and normalized by the 2^−ΔCt method (see Methods for details). Data are expressed as medians (line), with maximum and minimum values (whiskers); boxes represent interquartile range of the samples. Statistical significance was evaluated by the Mann-Whitney U-test for comparison of two groups, and by the Kruskal-Wallis test for three or four groups. (<b>A</b>) Comparison of IM patients (N = 17) and all healthy donors (HD, N = 24). (<b>B</b>) Comparison of IM patients (N = 17) and HD donors stratified according to plasmatic anti-EBNA-1 IgG titers, as EBV-negative (EBV−, N = 9), <600 IU/ml (N = 7), and >600 IU/ml (N = 8). Kruskall-Wallis test gave p = 0.0005 for all four groups, and p = 0.014 for the three HD groups.</p

Demographic and clinical characteristics of patients hospitalized with infectious mononucleosis and of healthy controls.

a<p>data are expressed as EBNA-1 DNA copies/ml of plasma. Detection limits: 100 copies/ml of plasma;</p>b<p>bl, borderline;</p>c<p>not done.</p