Human Immunodeficiency Virus (HIV) Virus-Like Particles (VLPs) composed of HIV Gag and HIV gp120/gp41 envelope are a pseudovirion vaccine capable of presenting antigens in their native conformations. To enhance the immunogenicity of the HIV Env antigen, VLPs were coupled to VesiVax Conjugatable Adjuvant Lipid Vesicles (CALV) containing one of four toll-like-receptor (TLR) ligands, each activating a receptor with distinct cellular localization and downstream pathways. C57BL/6 mice were vaccinated by intranasal prime followed by two sub-cheek boosts and their sera immunoglobulin and neutralizing potency were measured over a duration of 3months after vaccination. PBS control, VLPs alone, CALV+VLPs, and VLPs complexed with CALV and ligands for TLR2 (PAM3CAG), TLR3 (dsRNA), TLR4 (MPLA), or TLR7/8 (resiquimod) were evaluated based on antibody titer, IgG1 and IgG2c class switching, germinal center formation, T follicular cells and potency of neutralizing antibodies. Consistently, the TLR3 ligand dsRNA complexed to CALV and in combination with VLPs (CALV(dsRNA)+VLPs) induced the strongest response. CALV(dsRNA)+VLPs induced the highest titers against the recombinant vaccine antigens clade B Bal gp120 and pr55 Gag. Additionally, CALV(dsRNA)+VLPs induced cross-clade antibodies, represented by high titers of antibody to clade c 96ZM651 gp120. CALV(dsRNA)+VLPs induced predominantly IgG2c over IgG1, a response associated with T helper type 1 (Th1)-like cytokines. In turn, CALV(dsRNA)+VLP immunized mice generated the most potent neutralizing antibodies against HIV strain MN.3. Finally, at time of sacrifice, a significant increase in germinal center B cells and T follicular cells was detected in mice which received CALV(dsRNA)+VLPs compared to PBS. Our results indicate that CALV(dsRNA) is a superior adjuvant for HIV VLPs in generating a Th1-like immunoglobulin profile, while prolonging lymph node germinal centers, T follicular cells and generating neutralizing antibodies to a highly sensitive tier 1A variant of HIV.

HIV virus-like particles (VLPs) present the HIV envelope protein in its native conformation, providing an ideal vaccine antigen. To enhance the immunogenicity of the VLP vaccine, we sought to improve upon two components; the route of administration and the additional adjuvant. Using HIV VLPs, we evaluated sub-cheek as a novel route of vaccine administration when combined with other conventional routes of immunization. Of five combinations of distinct prime and boost sequences, which included sub-cheek, intranasal, and intradermal routes of administration, intranasal prime and sub-cheek boost (IN+SC) resulted in the highest HIV-specific IgG titers among the groups tested. Using the IN+SC regimen we tested the adjuvant VesiVax Conjugatable Adjuvant Lipid Vesicles (CALV) + monophosphoryl lipid A (MPLA) at MPLA concentrations of 0, 7.5, 12.5, and 25 μg/dose in combination with our VLPs. Mice that received 12.5 or 25 μg/dose MPLA had the highest concentrations of Env-specific IgG2c (20.7 and 18.4 μg/ml respectively), which represents a Th1 type of immune response in C57BL/6 mice. This was in sharp contrast to mice which received 0 or 7.5 μg MPLA adjuvant (6.05 and 5.68 μg/ml of IgG2c respectively). In contrast to IgG2c, MPLA had minor effects on Env-specific IgG1; therefore, 12.5 and 25 μg/dose of MPLA induced the optimal IgG1/IgG2c ratio of 1.3. Additionally, the percentage of germinal center B cells increased significantly from 15.4% in the control group to 31.9% in the CALV + 25 μg MPLA group. These mice also had significantly more IL-2 and less IL-4 Env-specific CD8+ T cells than controls, correlating with an increased percentage of Env-specific central memory CD4+ and CD8+ T cells. Our study shows the strong potential of IN+SC as an efficacious route of administration and the effectiveness of VLPs combined with MPLA adjuvant to induce Env specific Th1-oriented HIV-specific immune responses.

Super bioavailability (SUBA) itraconazole (S-ITZ), which releases drug in the duodenum, and conventional itraconazole (C-ITZ), which releases drug in the stomach, were compared in two pharmacokinetic (PK) studies: a 3-day loading dose study and a 15-day steady-state administration study. These were crossover oral bioequivalence studies performed under fed conditions in healthy adult volunteers. In the loading dose study, C-ITZ (two doses of 100 mg each) and S-ITZ (two doses of 65 mg each) were administered three times daily for 3 days and once on day 4 (n = 15). For the steady-state administration study, C-ITZ (two doses of 100 mg each) and S-ITZ (two doses of 65 mg each) were administered twice daily for 14 days and a last dose was administered 30 min after a meal on day 15 (n = 16). Blood samples collected throughout both studies were analyzed for ITZ and hydroxy-ITZ (OH-ITZ) levels. Least-squares geometric means were used to compare the maximum peak concentration of drug after administration at steady state prior to administration of the subsequent dose (Cmax_ss), the minimum drug level after administration prior to the subsequent dose (Ctrough), and the area under the curve over the dosing interval (AUCtau) of each formulation. The ratios of itraconazole (ITZ) and OH-ITZ for S-ITZ to C-ITZ were between 107% and 118% in both studies for Cmax_ss, Ctrough, and AUCtau, which were within the U.S. FDA-required bioequivalence range of 80% to 125%. At the end of the steady-state administration study, 13 of 16 volunteers obtained higher mean ITZ blood Ctrough levels of >1,000 ng/ml when they were administered S-ITZ (81%) than when they were administered C-ITZ (44%). The study drugs were well tolerated in both studies, with similar adverse events (AEs). All treatment-emergent AEs resolved after study completion. One volunteer receiving C-ITZ discontinued due to a treatment-unrelated AE in the steady-state administration study. No serious AEs were reported. Total, trough, and peak ITZ and OH-ITZ exposures were similar between the two formulations. Therefore, SUBA-ITZ, which has 35% less drug than C-ITZ, was bioequivalent to C-ITZ in healthy adult volunteers and exhibited a safety profile similar to that of C-ITZ.

Conventional itraconazole (C-ITZ) suffers from absorption variability. SUBA-itraconazole (S-ITZ) is more bioavailable than C-ITZ at steady-state in a fed condition, but there is no data comparing them under a fasted state. An open-label, single-dose, randomized, bioequivalence study was performed comparing S-ITZ to C-ITZ capsules under fasted and fed conditions in healthy adults measuring itraconazole and hydroxyitraconazole plasma levels. This study demonstrated less variability of S-ITZ compared to C-ITZ capsules under fasted conditions.

Studies have shown that blockade of CTLA-4 promoted the expansion of germinal center B-cells in viral infection or immunization with model antigens. Few studies have evaluated the immunological consequences of CTLA-4 blockade during immunization against relevant vaccine candidates. Here, we investigated the effects of CTLA-4 blockade on HIV virus-like particles (VLPs) vaccination in a C57BL/6J mouse model. We found that CTLA-4 blockade during HIV VLP immunization resulted in increased CD4+ T-cell activation, promoted the expansion of HIV envelope (Env)-specific follicular helper T cell (Tfh) cells, and significantly increased HIV Gag- and Env-specific IgG with higher avidity and antibody-dependent cellular cytotoxicity (ADCC) capabilities. Furthermore, after only a single immunization, CTLA-4 blockade accelerated T-cell dependent IgG class switching and the induction of significantly high serum levels of the B-cell survival factor, A proliferation-inducing ligand (APRIL). Although no significant increase in neutralizing antibodies was observed, increased levels of class-switched Env- and Gag-specific IgG are indicative of increased polyclonal B-cell activation, which demonstrated the ability to mediate and enhance ADCC in this study. Altogether, our findings show that CTLA-4 blockade can increase the levels of HIV antigen-specific B-cell and antigen-specific Tfh cell activity and impact humoral immune responses when combined with a clinically relevant HIV VLP-based vaccine.

The Near East North Africa (NENA) region is exposed to a series of interconnected challenges that impede agriculture and therefore food security and poverty reduction. The economic growth rate in the NENA region has stagnated at two percent per year since 1990. Meanwhile, unemployment rates remain high, especially amongst youth with 28.2 percent unemployment in the Middle East and 30.5 percent in North Africa. These trends present challenges for the region, especially given its high population growth rate, which is above the global average, at 2 percent per year compared with 1.2 percent globally. While the population is growing, the unemployment rates suggest that the transition towards inclusive economic growth has not taken hold. Around 43 percent of the NENA region’s population live in rural areas, which in turn are highly affected by the poverty that results from exclusion from the region’s economic growth; 70 percent of the region’s poor currently live in rural areas and are largely dependent on agriculture for their livelihoods. Many of these are small-scale family farmers. The region, in turn, is even more dependent on small-scale farmers who generate 80 percent of the region’s agricultural production. They are therefore essential to NENA’s pathway out of food insecurity and poverty.

BackgroundConventional itraconazole (CI) absorption from capsules even under fed conditions is suboptimal (~55%), let alone when fasted. SUBA-itraconazole (SI) is ~1.8x’s more bioavailable than CI at steady-state in a fed condition. There are, however, no data comparing these formulations under a fasted state. A single-dose PK study was performed comparing bioavailability of 65mg SI to 100mg CI under fasted or fed conditions.MethodsThis was an open-label, single-dose, randomized, four-period, four-treatment, four-sequence, crossover bioequivalence study under fasted and fed conditions in healthy adults. Subjects were administered a single dose of SI (1 × 65 mg) and CI (1 × 100 mg). Under fasted condition, subjects were administered SI or CI following an overnight fast of at least 10 hours. Subjects under fed condition were administered SI or CI after 30 minutes of consuming a standardized high fat breakfast preceded by an overnight fast of at least 10 hours. After dosing, all subjects fasted for at least 4 hours post-dose in all periods. Blood samples were collected prior to dosing and then from 1 to 120 hours. Analysis of itraconazole (IZ) and hydoxyitraconazole (HIZ) serum levels was by least-squares-geometric means of PK parameters.ResultsUnder fasted condition, Cmax and AUCtau of IZ for SI were substantially higher compared with CI (Table, Figure 1). Under fed conditions, however, the Cmax and AUCtau of IZ for SI was 20% and 10% lower, respectively (table, Figure 2). Similar results were found for HIZ. The Tmax for IZ and HIZ of SI and CI were similar under a fasted condition but extended by over 2 hours for SI vs. CI under fed conditions. Study drugs were well-tolerated under fasted and fed conditions. All TEAEs were mild and resolved at the end of the study. Fifty of 52 subjects enrolled completed the study. Two subjects did not complete the study due to not being able to finish a high fat meal and noncompliance. No SAEs were reported.ConclusionTotal and peak IZ/HIZ exposure was substantially higher for SI under fasted conditions compared with CI, but slightly lower under fed conditions with similar safety profiles. This study demonstrates the unique nature of the SI formulation compared with CI under fasted conditions and may lead to less variability if patients are not adherent to dietary requirements when taking itraconazole. Disclosures All authors: No reported disclosures.

This is an open access journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms.