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Recurrent urinary tract infections (rUTI) are a serious disease associated with morbidities and mortality. Resistance to the standard of care antibiotics is now widespread because of the continued use of antibiotics among people who suffer from rUTI. We are therefore developing a vaccine to prevent recurrences among patients with rUTI. The antigen of the vaccine is FimH, a bacterial adhesin protein, and the vaccine is adjuvanted with a TLR-4 agonist. In a Phase 1 clinical study evaluating the vaccine, immunized individuals produced FimH-binding antibodies. Here we describe the optimization, qualification, and use of an assay to assess the functionality of these anti-FimH antibodies. The suitability of the assay for its intended purpose was demonstrated by selectivity, specificity, sensitivity, and intra-assay and inter-assay precision. The acceptance criteria were achieved for all parameters including intra-assay precision with ≤10% relative standard deviations and inter-assay precision with ≤25% relative standard deviations. The results presented herein suggest this functional assay will be important for supporting the vaccine’s efficacy in future human studies. Furthermore and of great significance, these results prove that vaccine-induced functional antibodies can be elicited in rUTI patients against an essential virulence factor, FimH.

BackgroundPreviously we demonstrated that the resection of primary 4T1 tumors only slightly prolongs mouse survival, but importantly, creates a "window of opportunity" with attenuated suppressor cell and increased activated T cell populations. This suggests that additional activation of the immune system by immunostimulatory agents during this period may enhance anti-tumor immunity and potentially eradicate micro-metastatic disease in this stringent model. We hypothesized that the immunostimulator Immunomax®, which is comprised of a plant-derived polysaccharide, is non-toxic in humans and stimulates immune defense during the infectious diseases treatment, may have also anti-tumor activity and be beneficial in the adjuvant setting when endogenous anti-tumor responses are present and during the "window of opportunity" in post-resection metastatic breast cancer model. Here we provide the initial report that Immunomax® demonstrates the capacity to eliminate micro-metastatic disease in the post-resection, 4T1 mouse model of breast cancer.MethodsThe efficacy of Immunomax® was evaluated by analyzing survival rate and the number of spontaneous clonogenic tumor cells in the lung homogenates of mice. The frequencies of activated NK, CD4(+) and CD8(+) cells as well as myeloid-derived suppressor cells and Treg cells were evaluated using flow cytometry. Highly purified mouse and human dendritic and NK cells were sorted and the effect of Immunomax® on activation status of these cells was assessed by flow cytometry. The property of Immunomax® as TLR-4 agonist was determined by NF-κB/SEAP reporter gene assay, WB, RT-PCR.ResultsImmunomax® injections significantly prolonged overall survival and cured 31% of mice. This immunostimulator activates DCs via the TLR-4, which in turn stimulates tumoricidal NK cells and in vitro, completely inhibits growth of 4T1 cells. Incubation of PBMC from healthy donors with Immunomax® activates NK cells via activation of plasmacytoid DC leading significantly higher efficacy in killing of human NK-target cells K562 compared with non-treated cells.ConclusionThis is the first demonstration that Immunomax® is a TLR-4 agonist and the first report of a documented role for this pharmaceutical grade immunostimulator in augmenting anti-tumor activity, suggesting that incorporation of Immunomax® into developing breast cancer therapeutic strategies may be beneficial and with less potential toxicity than checkpoint inhibitors.

Cancer immunotherapy is a powerful approach for cancer treatment, but its clinical effects rely on the tumor's immune conditions. In particular, low response rates to PD-1 blockades are highly correlated with impaired T cell priming. Here, we demonstrate that E. coli-derived monophosphoryl lipid A (EcML) activates dendritic cells in a toll-like receptor-4 (TLR-4)-dependent manner and increases the sensitivity of cancer cells to anti-PD-1 immunotherapy. EcML is a mixture of 4'-monophosphoryl lipids A (MPLAs) produced directly by an engineered Escherichia coli strain; it has a unique congener composition that differentiates it from the well-established MPLA adjuvants, 3-O-desacyl-4'-monophosphoryl lipid A and glucopyranosyl lipid A. Given that active dendritic cells initiate adaptive immune responses, we investigated the anti-tumor activity of an aqueous formulation of EcML. Upon sensing EcML via TLR-4, dendritic cells matured into powerful antigen-presenting cells that could stimulate naïve T cells. EcML reduced tumor growth in the B16F10 mouse model via dendritic cell activation and potentiated PD-1 blockade therapy in the B16F10-OVA melanoma model. These data identify EcML as a promising TLR-4 agonist that can induce anti-tumor immune responses and potentiate PD-1 blockade therapy against tumors. [ABSTRACT FROM AUTHOR]

Transcutaneous immunization is the administration of a vaccine on the skin to generate efficient systemic and mucosal immune responses against an antigen. In the present study, reconstituted hepatitis B surface antigen vesicles (HBsAg-REVs) integrated with monophosphoryl lipid A were prepared by the delipidation-reconstitution method and tested as built-in adjuvanted vaccine, system for transcutaneous immunization using a combined approach of tape strippings, and enhanced antigen skin contact time. Prepared vesicles were extensively characterized for size, shape, zeta potential, and antigen protein loading efficiency. Following topical application, HBsAg-REVs skin permeation on isolated rat skin and cell uptake by bone marrow–derived dendritic cells were determined by confocal laser scanning microscopy and flow cytometry, respectively. The humoral and cellular immune responses elicited by HBsAg-REVs via transcutaneous immunization were comparable to the marketed intramuscular hepatitis B vaccine formulation with predefined immunization protocols. This study supports that delivery of reconstituted HBsAg vesicles via transcutaneous route may open a new vista for designing topical vaccines with possible immune protection against hepatitis B in future. [ABSTRACT FROM AUTHOR]

Lymphatic filariasis (LF) affects 120 million people around the world and another 856 million people are at risk of acquiring the infection. Mass Drug Administration (MDA) spearheaded by the World Health Organization is the only current strategy to control this infection. Recent reports suggest that despite several rounds of MDA, elimination has not been achieved and there is a need for more stringent control strategies for control of LF. An effective prophylactic vaccine combined with MDA has significant potential. Initial trials using a prophylactic trivalent recombinant Brugia malayi heat shock protein 12.6, abundant larval transcript -2 and tetraspanin large extra-cellular loop (r Bm HAT) vaccine developed in our laboratory conferred only 35% protection in macaques. Therefore, the focus of the present study was to improve the current vaccine formulation to obtain better protection in non-human primates. We made two modifications to the current formulation: (i) the addition of another antigen, thioredoxin peroxidase-2 (TPX-2) to make it a tetravalent vaccine (r Bm HAXT) and (ii) the inclusion of an adjuvant; AL019 (alum plus glucopyranosyl lipid adjuvant-stable emulsion) that is known to promote a balanced Th1/Th2 response. A double-blinded vaccination trial was performed with 40 macaques that were divided into three treatment groups and one control group ( n  = 10/group). Vaccinated animals received 4 immunisations at 1 month intervals with 150 µg/ml of r Bm HAT plus alum, r Bm HAT plus AL019 or r Bm HAXT plus AL019. Control animals received AL019 only. All vaccinated macaques developed significant ( P  ≤ 0.003) titers of antigen-specific IgG antibodies (1:20,000) compared with the controls. One month after the last dose, all macaques were challenged s.c. with 130–180 B. malayi L3s. Our results showed that seven out of 10 (70%) of macaques given the improved r Bm HAXT vaccine did not develop the infection compared with AL019 controls, of which seven out of 10 macaques developed the infection. Titers of antigen-specific IgG1 and IgG2 antibodies were significantly ( P  ≤ 0.01) higher in vaccinated animals and there was an increase in the percentage of IL-4 and IFN-γ secreting antigen-responding memory T cells. These studies demonstrated that the improved formulation (r Bm HAXT plus AL019) is a promising vaccine candidate against human lymphatic filariasis. [ABSTRACT FROM AUTHOR]

Malaria infection is the severe health concern for a long time. As per the WHO reports, the malarial infection causes huge mortality all around the world and is incomparable with any other infectious diseases. The absence of effective treatment options and increasing drug resistance to the available therapeutics like artemisinin and other derivatives demand an efficient alternative to overcome this death burden. Here, we performed the literature survey and sorted the Plasmodium falciparum secretory and membrane proteins to design multi-epitope subunit vaccine using an adjuvant, B-cell- and T-cell epitopes. Every helper T-lymphocyte (HTL) epitope was IFN-γ positive and IL-4 non-inducer. The physicochemical properties, allergenicity, and antigenicity of designed vaccine were analyzed for the safety concern. Homology modeling and refinement were performed to obtain the functional tertiary structure of vaccine protein followed by its molecular docking with the toll-like receptor-4 (TLR-4) immune receptor. Molecular dynamics simulation was performed to check the interaction and stability of the receptor-ligand complex. Lastly, in silico cloning was performed to generate the restriction clone of designed vaccine for the futuristic expression in a microbial expression system. This way, we designed the multi-epitope subunit vaccine to serve the people living in the global endemic zone. [ABSTRACT FROM AUTHOR]

Mass drug administration (MDA) is the current strategy for interrupting the transmission of lymphatic filariasis (LF) infection and control of the disease in endemic areas. However, subject non-compliance has resulted in the presence of several 'transmission hotspots' in the endemic regions threatening the reemergence of LF. This situation is further complicated by the fact that the drugs used in MDA are not effective against adult LF worms, a major concern for the control strategy. Thus, there is clearly a need for an effective and sustainable approach to control LF. Prophylactic vaccine combined with targeted treatment of infected patients and vector control is suggested as a more sustainable strategy to eliminate LF infection from endemic regions. A multivalent vaccine (r BmHAT) developed in our laboratory conferred about 90% protection in rodents. However, when we tested the r BmHAT vaccine along with alum in rhesus macaques, only about 40% protection was achieved and the immune response obtained was Th2 biased. In an attempt to improve the vaccine, in this study, we tested two vaccine antigens (r BmHAT and r BmHAX) along with two adjuvant formulations [alum + GLA (AL019) and mannosylated chitosan (MCA)] in a mouse model. Our results show that r BmHAT is a better vaccine antigen than r BmHAX. Combination of r BmHAT with AL019 or MCA adjuvants gave 94 and 88% protection, respectively, against challenge infections. Immunized animals developed antigen-specific memory T cells that secreted significant levels of IL-4, IFN-γ, and IL-17 suggesting the generation of a balanced Th1/Th2 responses following immunization. A major advantage of MCA adjuvant is that the vaccine booster doses can be administered orally. These studies thus showed that r BmHAT is a better vaccine antigen and can be given in combination with AL019 or MCA adjuvant to obtain excellent results. [ABSTRACT FROM AUTHOR]

Highlights: [•] rBmHAT is an excellent multivalent vaccine candidate for lymphatic filariasis. [•] However, rBmHSP12.6, a component of rBmHAT was shown to bind to human IL-10R. [•] Deletion mutant of BmHSP12.6 was created to remove the IL-10R binding region. [•] Multivalent vaccine formulated with the BmHSPαc deletion mutant was 40% less effective. [•] Including alum or alum plus TLR-4 agonist adjuvant regained the vaccine efficacy of rBmHATαc to 95%. [ABSTRACT FROM AUTHOR]

Abstract: Inefficiency of cancer chemotherapy to improve life expectancy in majority of patients raises serious concern and warrants development of novel therapeutic strategies. Immunotherapy in combination with chemotherapy has shown promising outcomes in recent years. Herein, we report better tumor regression and enhancement of antitumor immune response at the tumor microenvironment by co-delivery of paclitaxel and a TLR4 agonist through a PLGA based nanoparticle preparation (TLNP). Particle characterization showed high encapsulation of both components and retention of their biological activities. In vivo tumor regression studies demonstrated clear benefit of TLNP over the paclitaxel. The mean tumor volume of the TLNP treated animals was found to be 40% less than that of the Paclitaxel treated animals. Flow cytometric analysis of tumor infiltrating immune cells indicated activation of antigen presenting cells and T-cells providing evidence of Th1 immune response. In vivo results are promising and could pave way for novel chemo-immunotherapeutic treatment modality. [Copyright &y& Elsevier]

Recurrent urinary tract infections (rUTI) are a serious disease associated with morbidities and mortality. Resistance to the standard of care antibiotics is now widespread because of the continued use of antibiotics among people who suffer from rUTI. We are therefore developing a vaccine to prevent recurrences among patients with rUTI. The antigen of the vaccine is FimH, a bacterial adhesin protein, and the vaccine is adjuvanted with a TLR-4 agonist. In a Phase 1 clinical study evaluating the vaccine, immunized individuals produced FimH-binding antibodies. Here we describe the optimization, qualification, and use of an assay to assess the functionality of these anti-FimH antibodies. The suitability of the assay for its intended purpose was demonstrated by selectivity, specificity, sensitivity, and intra-assay and inter-assay precision. The acceptance criteria were achieved for all parameters including intra-assay precision with ≤10% relative standard deviations and inter-assay precision with ≤25% relative standard deviations. The results presented herein suggest this functional assay will be important for supporting the vaccine's efficacy in future human studies. Furthermore and of great significance, these results prove that vaccine-induced functional antibodies can be elicited in rUTI patients against an essential virulence factor, FimH.

This is the second phase 1 study of a respiratory syncytial virus (RSV) vaccine containing RSV fusion protein (sF) adjuvanted with glucopyranosyl lipid A (GLA) in a squalene-based 2% stable emulsion (GLA-SE). In this randomized, double-blind study, 261 subjects aged ≥60 years received inactivated influenza vaccine (IIV), a vaccine containing 120 μg sF with escalating doses of GLA (1, 2.5, or 5 μg) in SE, or a vaccine containing 80 μg sF with 2.5 μg GLA in SE. Subjects receiving 120 μg sF with 2.5 or 5 μg GLA were also randomized to receive IIV or placebo. Immunity to RSV was assessed by detection of microneutralizing, anti-F immunoglobulin G, and palivizumab-competitive antibodies and F-specific gamma interferon enzyme-linked immunosorbent spot assay T-cell responses. Higher adjuvant doses increased injection site discomfort, but at the highest dose, the reactogenicity was similar to that of IIV. Significant humoral and cellular immune responses were observed. The 120 μg sF plus 5.0 μg GLA formulation resulted in the highest responses in all subjects and in older subjects. These results confirm previous observations of vaccine tolerability, safety, and immunogenicity and were used to select the 120 μg sF plus 5.0 μg GLA formulation for phase 2 evaluation. (This study has been registered at ClinicalTrials.gov under registration no. NCT02289820.)., (Copyright © 2017 Falloon et al.)