Data show mean SEM from a representative experiment ( 0

Data show mean SEM from a representative experiment ( 0.0001 analyzed by one-way ANOVA (c) or two-way ANOVA (d) with Tukey’s multiple comparisons post-test, or (e) log-rank (Mantel-Cox) test. 4. TC-1 tumors in all treated animals. Taken together, our work highlights the simplicity, versatility, and potency of dual TLR agonist nanodiscs for applications in vaccines and cancer immunotherapy. values 0.05 were considered statistically significant. All values are reported as means SEM with the indicated sample size. No samples were excluded from analysis. 3. Results and discussion 3.1. Preparation and characterization of adjuvant-loaded nanodiscs Nanodiscs (ND) made up of MPLA and/or CpG were prepared by the lyophilization method (Fig. 1a) [29, 31,32]. Briefly, MPLA was added together with DMPC and 22A in acetic acid, followed by lyophilization and hydration in PBS to form ND made up of MPLA (ND-MPLA). As measured AG-014699 (Rucaparib) by HPLC equipped with ELSD, MPLA was efficiently loaded onto ND with over 80% incorporation efficiency, likely due to the lipid-like properties of MPLA [40]. As visualized by TEM, ND samples were homogeneous with the average diameter of 10 nm (Fig. 1b). To co-load MPLA and CpG into ND samples, pre-formed ND-MPLA was incubated with cholesterol altered CpG for 30 min at room heat (Fig. 1a). The incorporation efficiency of CpG as determined by GPC was over 95%, as long as the amount of CpG added was 200 g/mL per 2 mg/mL (lipid amount) of ND (Fig. 1c). When 400 g/mL of CpG was added, a significant amount of CpG remained unincorporated (Fig. 1c). Based on this, we chose to use no 200 g/mL of CpG to prepare CpG-loaded ND samples. We also examined the Mouse monoclonal to HK1 hydrodynamic size of ND-MPLA/CpG with DLS immediately after synthesis versus after an extended storage. ND-MPLA/CpG samples that were lyophilized, stored for 2 months at 20 C, and reconstituted in endotoxin-free water exhibited an essentially comparative hydrodynamic size of 10.1 0.8 nm as freshly prepared ND-MPLA/CpG samples (Fig. 1d), indicating their suitability for long-term storage. Overall, these results indicate that adjuvant-loaded nanodiscs are homogenous and ultra-small in size, which may contribute to efficient lymph node draining as we have shown previously [33]. In addition, these dual adjuvant nanodiscs can be readily stored in a lyophilized form for an extended AG-014699 (Rucaparib) period of time without affecting their size and homogeneity, which may facilitate the transport, storage, and clinical use of adjuvant-loaded nanodiscs. Open in a separate window Fig. 1 Preparation and characterization of AG-014699 (Rucaparib) dual adjuvant nanodiscs. (a) Schematic for preparation of dual adjuvant nanodiscs (ND-MPLA/CpG). (b) TEM of nanodiscs, scale bar=100 nm. (c) When ND-MPLA was incubated with different concentrations (0, 50, 100, 200, and 400 g/mL) of Cho-CpG for 30 min at room heat, Cho-CpG at concentrations lower than 200 g/mL were efficiently loaded onto ND with over 95% efficiency. (d) The sizes of freshly prepared ND-MPLA/ CpG versus freeze-dried ND-MPLA/CpG reconstituted with endotoxin-free water after 2 months of storage at 20 C. 3.2. Potent DC activation by adjuvant-loaded nanodiscs One of the major effects of adjuvants is usually to induce costimulatory signals on antigen-presenting cells and promote secretion of pro-inflammatory cytokines, which are required for potent elicitation of adaptive immune responses. Using HEK-TLR4 and HEK-TLR9 cell lines, AG-014699 (Rucaparib) we confirmed that this extent of TLR4 or TLR9 activation was comparable between ND-MPLA/CpG and respective treatment with either ND-MPLA or ND-CpG (Fig. 2a), whereas TLR2 activation was minimal. These results indicated that this dual ND-MPLA/CpG adjuvant system maintained the TLR4 and TLR9 activating-capacity of MPLA and CpG. To examine the impact of ND-mediated adjuvant delivery on APCs, we incubated BMDCs in vitro with various adjuvant formulations and evaluated costimulatory signals and cytokine release. The extent of BMDC uptake for blank ND, ND-MPLA, NP-CpG, and ND-MPLA/CpG AG-014699 (Rucaparib) was comparable (Fig. 2b). BMDCs incubated with blank ND without any adjuvants did not upregulate co-stimulatory markers, CD80 or CD86 (Fig. 2c,d). Compared with soluble MPLA, delivery of MPLA via ND (ND-MPLA) resulted in 2-fold and 3.7-fold increases in the expression levels of CD80 and CD86, respectively ( 0.0001, Fig. 2cCf). Compared with soluble CpG, delivery of CpG via ND (ND-CpG) resulted in 1.2-fold increase in the expression level of CD80 ( 0.05, Fig. 2c,d). Co-delivery of MPLA and CpG in ND (ND-MPLA/CpG) led to.