Potential Use of Extracellular Vesicles Generated by Microbubble-Assisted Ultrasound as Drug Nanocarriers for Cancer Treatment

Extracellular vesicles (EVs)-carrying biomolecules derived from parental cells have achieved substantial scientific interest for their potential use as drug nanocarriers. Ultrasound (US) in combination with microbubbles (MB) have been shown to trigger the release of EVs from cancer cells. In the current study, the use of microbubbles-assisted ultrasound (USMB) to generate EVs containing drug cargo was investigated. The model drug, CellTracker™ green fluorescent dye (CTG) or bovine serum albumin conjugated with fluorescein isothiocyanate (BSA FITC) was loaded into primary human endothelial cells in vitro using USMB. We found that USMB loaded CTG and BSA FITC into human endothelial cells (HUVECs) and triggered the release of EVs containing these compounds in the cell supernatant within 2 h after treatment. The amount of EV released seemed to be correlated with the increase of US acoustic pressure. Co-culturing these EVs resulted in uptake by the recipient tumour cells within 4 h. In conclusion, USMB was able to load the model drugs into endothelial cells and simultaneously trigger the release of EVs-carrying model drugs, highlighting the potential of EVs as drug nanocarriers for future drug delivery in cancer

Interleukin-7 and Toll-like receptor 7 induce synergistic B cell and T cell activation.

OBJECTIVES: To investigate the potential synergy of IL-7-driven T cell-dependent and TLR7-mediated B cell activation and to assess the additive effects of monocyte/macrophages in this respect. METHODS: Isolated CD19 B cells and CD4 T cells from healthy donors were co-cultured with TLR7 agonist (TLR7A, Gardiquimod), IL-7, or their combination with or without CD14 monocytes/macrophages (T/B/mono; 1 : 1 : 0,1). Proliferation was measured using 3H-thymidine incorporation and Ki67 expression. Activation marker (CD19, HLA-DR, CD25) expression was measured by FACS analysis. Immunoglobulins were measured by ELISA and release of cytokines was measured by Luminex assay. RESULTS: TLR7-induced B cell activation was not associated with T cell activation. IL-7-induced T cell activation alone and together with TLR7A synergistically increased numbers of both proliferating (Ki67+) B cells and T cells, which was further increased in the presence of monocytes/macrophages. This was associated by up regulation of activation markers on B cells and T cells. Additive or synergistic induction of production of immunoglobulins by TLR7 and IL-7 was associated by synergistic induction of T cell cytokines (IFNγ, IL-17A, IL-22), which was only evident in the presence of monocytes/macrophages. CONCLUSIONS: IL-7-induced CD4 T cell activation and TLR7-induced B cell activation synergistically induce T helper cell cytokine and B cell immunoglobulin production, which is critically dependent on monocytes/macrophages. Our results indicate that previously described increased expression of IL-7 and TLR7 together with increased numbers of macrophages at sites of inflammation in autoimmune diseases like RA and pSS significantly contributes to enhanced lymphocyte activation

MicroRNA-130a Contributes to Type-2 Classical DC-activation in Sj\uf6gren's Syndrome by Targeting Mitogen- and Stress-Activated Protein Kinase-1

Objectives: Considering the critical role of microRNAs (miRNAs) in regulation of cell activation, we investigated their role in circulating type-2 conventional dendritic cells (cDC2s) of patients with primary Sjogren's syndrome (pSS) compared to healthy controls (HC).Methods: CD1c-expressing cDC2s were isolated from peripheral blood. A discovery cohort (15 pSS, 6 HC) was used to screen the expression of 758 miRNAs and a replication cohort (15 pSS, 11 HC) was used to confirm differential expression of 18 identified targets. Novel targets for two replicated miRNAs were identified by SILAC in HEK-293T cells and validated in primary cDC2s. Differences in cytokine production between pSS and HC cDC2s were evaluated by intracellular flow-cytometry. cDC2s were cultured in the presence of MSK1-inhibitors to investigate their effect on cytokine production.Results: Expression of miR-130a and miR-708 was significantly decreased in cDC2s from pSS patients compared to HC in both cohorts, and both miRNAs were downregulated upon stimulation via endosomal TLRs. Upstream mediator of cytokine production MSK1 was identified as a novel target of miR-130a and overexpression of miR-130a reduced MSK1 expression in cDC2s. pSS cDC2s showed higher MSK1 expression and an increased fraction of IL-12 and TNF-alpha-producing cells. MSK1-inhibition reduced cDC2 activation and production of IL-12, TNF-alpha, and IL-6.Conclusions: The decreased expression of miR-130a and miR-708 in pSS cDC2s seems to reflect cell activation. miR-130a targets MSK1, which regulates pro-inflammatory cytokine production, and we provide proof-of-concept for MSK1-inhibition as a therapeutic avenue to impede cDC2 activity in pSS

IL-7 and TLR7 synergistically increases CD4 T cell proliferation in T and B co-cultures.

<p>Representative FACS stainings for KI67⁺ CD4 T cells from unstimulated, IL-7, and TLR7/IL-7 stimulated T/B cell co-cultures in the absence or presence of monocytes/macrophages are shown (n = 5). IL-7 significantly stimulates proliferation of CD4 T cells, which is synergistically increased when combined with TLR7 stimulation (<b>A, B</b>). IL-7-induced CD4 T cell proliferation is enhanced in the presence of monocytes/macrophages, but no additive effect is observed with a combination of IL-7 and TLR7 stimulation (<b>C, D</b>).*p<0.05 and **p<0.001 indicate statistical significance compared to medium values.</p

IL-7 synergistically increases proliferation of TLR7-stimulated B cells in co-culture with CD4 T cells, which is enhanced by monocytes/macrophages.

<p>Isolated B cells co-cultured 1∶1 (5.10⁵ each) together with CD4 T cells for 6 days show an increased lymphocytic proliferation upon TLR7 or IL-7 stimulation, which is additively increased upon combined stimulation with IL-7/TLR7 (n = 8) (A). A similar, but overall enhanced effect for the total proliferation is seen when monocytes/macrophages are added to the culture (5.10⁴ B). Representative FACS stainings for KI67⁺ B cells from an unstimulated, TLR7, IL-7, and TLR7/IL-7 stimulated CD4 T/B cell co-culture -/+ monocytes/macrophages are shown as well as the average data (n = 5) (C, D). TLR7 induces a significant increase in the percentage of KI67⁺ B cells. IL-7 stimulation induces a small, but statistically significant increase in Ki67⁺ B cells. When TLR7 and IL-7 are added together a synergistic increase in proliferation is observed (C). Overall the effects are enhanced by addition of monocytes/macrophages to the T/B cell co-cultures (D). * and ** indicate a statistical significant differences of p<0.05 and p<0.01, respectively, as compared to medium values or between treatments.</p