The safety and immunogenicity of a bivalent conjugate vaccine against Salmonella enterica Typhi and Paratyphi A in healthy Indian adults: a phase 1, randomised, active-controlled, double-blind trial.

BACKGROUND: Enteric fever caused by Salmonella enterica Typhi and Salmonella Paratyphi A is an important public health problem, especially in low-income and middle-income countries with limited access to safe water and sanitation. We present results from, to our knowledge, the first ever human study of a bivalent paratyphoid A-typhoid conjugate vaccine (Sii-PTCV). METHODS: In this double-blind phase 1 study, 60 healthy Indian adults were randomly assigned (1:1) to receive a single intramuscular dose of either Sii-PTCV or typhoid conjugate vaccine (Typbar-TCV). Safety was assessed by observing solicited adverse events for 1 week, unsolicited events for 1 month, and serious adverse events (SAEs) over 6 months. Immunogenicity at 1 month and 6 months was assessed by measuring anti-capsular polysaccharide antigen Vi (anti-Vi) IgG and IgA against Salmonella Typhi and anti-lipopolysaccharide (LPS) IgG against Salmonella Paratyphi A by ELISA, and functional antibodies using serum bactericidal assay (SBA) against Salmonella Paratyphi A. This study is registered with Clinical Trial Registry-India (CTRI/2022/06/043608) and is completed. FINDINGS: 60 participants were enrolled. Of these 60 participants, 57 (95%) participants were male and three (5%) participants were female. Solicited adverse events were observed in 27 (90%) of 30 participants who received Sii-PTCV and 26 (87%) of 30 participants who received Typbar-TCV. The most common local solicited event was pain in 27 (90%) participants who received Sii-PTCV and in 23 (77%) participants who received Typbar-TCV. The most common solicited systemic event was myalgia in five (17%) participants who received Sii-PTCV, whereas four (13%) participants who received Typbar-TCV had myalgia and four (13%) had headache. No vaccine-related unsolicited adverse events or SAEs were reported. The seroconversion rates on day 29 were 96·7% (95% CI 82·8-99·9) with Sii-PTCV and 100·0% (88·4-100·0) with Typbar-TCV for anti-Vi IgG; 93·3% (77·9-99·2) with Sii-PTCV and 100·0% (88·4-100·0) with Typbar-TCV for anti-Vi IgA; 100·0% (88·4-100·0) with Sii-PTCV and 3·3% (0·1-17·2) with Typbar-TCV for anti-LPS (paratyphoid); and 93·3% (77·9-99·2) with Sii-PTCV and 0% (0·0-11·6) with Typbar-TCV for SBA titres (paratyphoid). Paratyphoid anti-LPS immune responses were sustained at day 181. INTERPRETATION: Sii-PTCV was safe and immunogenic for both typhoid and paratyphoid antigens indicating its potential for providing comprehensive protection against enteric fever. FUNDING: Serum Institute of India.

An observer-blind, randomised, placebo-controlled, phase 1, single ascending dose study of dengue monoclonal antibody in healthy adults in Australia.

BACKGROUND: Dengue is highly prevalent in Asia and Latin America and has no specific dengue antiviral treatment. A recombinant monoclonal antibody (VIS513) that neutralises all four serotypes of the dengue virus has been developed in India. After confirmation of safety and efficacy in preclinical studies, it was tested in a first-in-human study to assess the safety and pharmacokinetics. METHODS: This was a partially blind (observer-blind), randomised, placebo-controlled, phase 1, single ascending dose study in Australia. Participants were dengue naive, healthy adults (aged 18-45 years) with no clinically significant disorders or immunosuppressive conditions. Four dose levels of dengue monoclonal antibody (ie, 1 mg/kg, 3 mg/kg, 7 mg/kg, and 12 mg/kg; n=4 for 1 mg/kg and n=10 each for 3 mg/kg, 7 mg/kg, and 12 mg/kg doses) were assessed in a dose-ascending way with a placebo control (n=2 for each dose cohort, total n=6) for each cohort except for 1 mg/kg. Within each cohort, participants were first randomly assigned (1:1) in a sentinel sub-cohort and then randomly assigned (9:1) in an expansion sub-cohort to dengue monoclonal antibody or placebo except for the 1 mg/kg cohort. Participants, investigators, and outcome assessors were masked and treatment administrators were not masked. 40 participants received a single intravenous injection or infusion of either dengue monoclonal antibody or placebo over a period of 3 min to 2 h and were followed up until day 85. The primary outcomes were proportion of participants with adverse events and serious adverse events (SAEs) up to 84 days after dosing whereas the secondary outcomes were to assess the pharmacokinetic profile of dengue monoclonal antibody and to assess the presence of anti-drug antibody (ADA) to dengue monoclonal antibody. All participants were included in the safety analysis and the pharmacokinetic population involved participants receiving dengue monoclonal antibody. This study is registered with ClinicalTrials.gov, NCT03883620. FINDINGS: Between March 22 and Dec 23, 2019, 40 healthy adults were randomly assigned and all completed the study. There were no SAEs reported. None of the placebo recipients (n=6) reported any adverse events. 31 (91%) of 34 participants receiving dengue monoclonal antibody reported 143 adverse events (1 mg/kg: four [100%] of four participants; 3 mg/kg: ten [100%] of ten participants; 7 mg/kg: seven [70%] of ten participants; 12 mg/kg: ten [100%] of ten participants). Of these 143 adverse events, 80 were treatment-related adverse events in 28 (82%) of 34 participants. Headache (16 [47%] of 34), infusion reaction (11 [32%] of 34), lymphopenia (seven [21%] of 34), fatigue (five [15%] of 34), and pyrexia (four [12%] of 34) were the most common reactions. Infusion reactions were reduced in the 7 mg/kg (two [20%] of ten participants) and 12 mg/kg (three [30%] of ten) cohorts with paracetamol premedication compared with the 3 mg/kg cohort (five [50%] of ten). The majority of adverse events were grade 1 or grade 2 in severity, and resolved completely. Median maximum serum concentrations ranged from 28 µg/mL (1 mg/kg) to 525 µg/mL (12 mg/kg). The median elimination half-life ranged from 775 h (1 mg/kg) to 878 h (12 mg/kg). No ADA against dengue monoclonal antibody was detected. INTERPRETATION: Dengue monoclonal antibody was safe and well tolerated. It showed a dose-proportionate increase in pharmacokinetic exposure. These data support further evaluation of dengue monoclonal antibody in patients with dengue for safety and efficacy. FUNDING: Serum Institute of India.

Antioxidants in central nervous system diseases: preclinical promise and translational challenges.

Oxidative damage is strongly implicated in the pathogenesis of neurodegenerative diseases including Alzheimer's disease, amyotrophic lateral sclerosis, Huntington's disease, Parkinson's disease and stroke (brain ischemia/reperfusion injury). The availability of transgenic and toxin-inducible models of these conditions has facilitated the preclinical evaluation of putative antioxidant agents ranging from prototypic natural antioxidants such as vitamin E (alpha-tocopherol) to sophisticated synthetic free radical traps and catalytic oxidants. Literature review shows that antioxidant therapies have enjoyed general success in preclinical studies across disparate animal models, but little benefit in human intervention studies or clinical trials. Recent high-profile failures of vitamin E trials in Parkinson's disease, and nitrone therapies in stroke, have diminished enthusiasm to pursue antioxidant neuroprotectants in the clinic. The translational disappointment of antioxidants likely arises from a combination of factors including failure to understand the drug candidate's mechanism of action in relationship to human disease, and failure to conduct preclinical studies using concentration and time parameters relevant to the clinical setting. This review discusses the rationale for using antioxidants in the prophylaxis or mitigation of human neurodiseases, with a critical discussion regarding ways in which future preclinical studies may be adjusted to offer more predictive value in selecting agents for translation into human trials.

A survey of sesamin and composition of tocopherol variability from seeds of eleven diverse sesame (Sesamum indicum L.) genotypes using HPLC-PAD-ECD.

The objective of this study was to determine the composition and content of sesamin and desmethyl tocopherols such as alpha-tocopherol (alphaT), delta-tocopherol (deltaT) and gamma-tocopherol (gammaT) in seeds of sesame (Sesamum indicum L.) for 11 genotypes conserved in the United States Department of Agriculture (USDA), Agricultural Research Service (ARS) and Plant Genetic Resources Conservation Unit (PGRCU) in Griffin, Georgia, USA. Seed accessions studied were collections from eight countries worldwide, including one landrace from Thailand and two cultivars from Texas, USA. Novel methodologies and analytical techniques described herein consisted of reverse-phase high-performance liquid chromatography (HPLC) connected in series with two detection systems specific for each analyte class. Photodiode array detection was employed for sesamin analysis and electrochemical array detection was used in the determination of tocopherols. A preliminary study was conducted to assess sesamin levels in 2003 and tocopherol levels in 2004 from sesame seed samples conserved at the USDA, ARS and PGRCU. In 2005, sesame seed samples were grown, harvested and evaluated for sesamin as well as tocopherol levels. The overall results (n = 3) showed that sesamin, alphaT, deltaT and gammaT levels were 0.67-6.35 mg/g, 0.034-0.175 microg/g, 0.44-3.05 microg/g and 56.9-99.3 microg/g respectively, indicating that the sesame seed accessions contained higher levels of sesamin and gammaT compared with alphaT and deltaT. Statistical analysis was conducted and significant differences were observed among the 11 different sesame genotypes. This suggests that genetic, environmental and geographical factors influence sesamin and desmethyl tocopherol content.

Mutant p53 facilitates pro-angiogenic, hyperproliferative phenotype in response to chronic relative hypoxia.

There is much controversy in the literature regarding the role of p53 status response on hypoxia inducible factor (HIF) signaling in response to chronic relative hypoxia (CRH). The goal of this paper was to methodically examine this response in isogenically matched tumor cells. We report that p53-mutant (MUT) cells, versus p53-wild-type (WT) cells, showed decreased apoptosis, increased cell proliferation with higher basal HIF-1alpha levels in response to CRH. In addition, we found increased HIF-mediated transactivation and increased VEGF release with decreased HIF-1alpha/p53 and HIF-1alpha/MDM-2 partnering in p53-MUT versus p53-WT cells in response to CRH.

A long-term "memory" of HIF induction in response to chronic mild decreased oxygen after oxygen normalization.

BACKGROUND: Endothelial dysfunction (ED) is functionally characterized by decreased vasorelaxation, increased thrombosis, increased inflammation, and altered angiogenic potential, has been intimately associated with the progression and severity of cardiovascular disease. Patients with compromised cardiac function oftentimes have a state of chronic mild decreased oxygen at the level of the vasculature and organs, which has been shown to exacerbate ED. Hypoxia inducible factor (HIF) is a transcription factor complex shown to be the master regulator of the cellular response to decreased oxygen levels and many HIF target genes have been shown to be associated with ED. METHODS: Human endothelial and aortic smooth muscle cells were exposed either to A) normoxia (21% O2) for three weeks, or to B) mild decreased oxygen (15% O2) for three weeks to mimic blood oxygen levels in patients with heart failure, or to C) mild decreased oxygen for two weeks followed by one week of normoxia ("memory" treatment). Levels of HIF signaling genes (HIF-1alpha, HIF-2alpha, VEGF, BNIP3, GLUT-1, PAI-1 and iNOS) were measured both at the protein and mRNA levels. RESULTS: It was found that chronic exposure to mild decreased oxygen resulted in significantly increased HIF signaling. There was also a "memory" of HIF-1alpha and HIF target gene induction when oxygen levels were normalized for one week, and this "memory" could be interrupted by adding a small molecule HIF inhibitor to the last week of normalized oxygen. Finally, levels of ubiquitylated HIF-1alpha were reduced in response to chronic mild decreased oxygen and were not full restored after oxygen normalization. CONCLUSION: These data suggest that HIF signaling may be contributing to the pathogenesis of endothelial dysfunction and that normalization of oxygen levels may not be enough to reduce vascular stress.

A novel multidrug resistance phenotype of bladder tumor cells grown on Matrigel or SIS gel.

We have previously shown that growth of bladder carcinoma cell lines onto matrices such as Matrigel and small intestinal submucosal (SIS) gel cause distinct changes in cellular morphology and motility. In these studies, we found that bladder cells grown on Matrigel showed increased resistance to either doxorubicin or mitomycin-C whereas growth of cells in SIS gel caused either significant increases or little difference in drug resistance, depending on both the cells and the drug. Finally, it was found that this altered drug sensitivity is reversible with a finite half-life and is likely due to altered drug accumulation and/or cell cycle kinetics.

Role of HIF signaling on tumorigenesis in response to chronic low-dose arsenic administration.

Trivalent inorganic arsenic (arsenite, arsenic trioxide, As(III)) is a primary contaminant of groundwater supplies worldwide. As(III), marketed as trisenox, is also an FDA-approved agent to treat cancer It has been previously shown by our laboratory that As(III) administered at doses lower than a therapeutic anticancer dose results in an increase in tumor formation and blood vessel density of tumors. In this work it was found that chronic administration of As(III) approaching the EPA action level of 10 ppb, given in the drinking water of mice 5 weeks prior to B16-F10 melanoma implantation, increased the growth rate of primary tumors and the number of metastases to the lung. Further, levels of arsenic in the tumor and lung were found to be much greater than those in the blood and similar to pro-angiogenic As(III) doses. Levels of hypoxia inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) surrounding the blood vessels in the tumors of the As(III)-treated mice were also found to be increased. Exposure of isolated B16-F10 tumor cells to chronic (3 or 7 day) but not acute (4 h) low-dose As(III) was found to increase HIF-1alpha expression and secretion of VEGF. Finally, coadministration of an inhibitor of HIF (YC-1) or a VEGFR-2 kinase inhibitor (SU5416) was found to antagonize the pro-angiogenic effects of low-dose As(III). Together, these results suggest that chronic exposure to low-dose As(III) could stimulate growth of tumors through a HIF-dependent stimulation of angiogenesis.

A DNA Hypomethylation Signature Predicts Antitumor Activity of LSD1 Inhibitors in SCLC.

Epigenetic dysregulation has emerged as an important mechanism in cancer. Alterations in epigenetic machinery have become a major focus for targeted therapies. The current report describes the discovery and biological activity of a cyclopropylamine containing inhibitor of Lysine Demethylase 1 (LSD1), GSK2879552. This small molecule is a potent, selective, orally bioavailable, mechanism-based irreversible inactivator of LSD1. A proliferation screen of cell lines representing a number of tumor types indicated that small cell lung carcinoma (SCLC) is sensitive to LSD1 inhibition. The subset of SCLC lines and primary samples that undergo growth inhibition in response to GSK2879552 exhibit DNA hypomethylation of a signature set of probes, suggesting this may be used as a predictive biomarker of activity.

Arsenic stimulates angiogenesis and tumorigenesis in vivo.

Trivalent inorganic arsenic (arsenite, arsenic trioxide, As[III]) is currently being used to treat hematologic tumors and is being investigated for treating solid tumors. However, low concentrations of As(III) stimulate vascular cell proliferation in cell culture, although this has not been confirmed in vivo. Therefore, the hypothesis that As(III) enhances blood vessel growth (angiogenesis) and tumorigenesis was tested in two in vivo models of angiogenesis and a model of tumor growth. In the first, arsenite caused a dose-dependent increase in vessel density in a chicken chorioallantoic-membrane (CAM) assay. The threshold As(III) concentration for this response was 0.033 microM and inhibition of vessel growth was observed at concentrations greater than 1 microM. Mouse Matrigel implants were used to test the angiogenic effects of As(III) in an adult mammalian system. Mice were injected with 0.8-80 microg/kg As(III)/day over a three-week period. During the last two weeks, Matrigel plugs were placed on the abdominal wall. Low and high doses of As(III) were synergistic with fibroblast growth factor-2 (FGF-2) in increasing vessel density in the Matrigel assay, while a middle dose had no effect. To test the effects of As(III) on tumor growth, GFP-labeled B16-F10 mouse melanoma cells were implanted in nude mice, which subsequently received biweekly injections of 0.5-5.0 mg/kg As(III). Significant tumor growth and lung metastasis was seen in all animals, with the largest tumors occurring in animals treated with lower doses of As(III). These studies support the hypothesis and indicate that induction of angiogenesis, enhanced tumor growth, and metastasis are potential dose-dependent toxic side effects of arsenic therapies.

Poly(ß-amino ester) nanoparticle delivery of TP53 has activity against small cell lung cancer in vitro and in vivo.

Small cell lung cancer (SCLC) is an aggressive disease with one of the highest case-fatality rates among cancer. The recommended therapy for SCLCs has not changed significantly over the past 30 years; new therapeutic approaches are a critical need. TP53 is mutated in the majority of SCLC cases and its loss is required in transgenic mouse models of the disease. We synthesized an array of biodegradable poly(ß-amino ester) (PBAE) polymers that self-assemble with DNA and assayed for transfection efficiency in the p53-mutant H446 SCLC cell line using high-throughput methodologies. Two of the top candidates were selected for further characterization and TP53 delivery in vitro and in vivo. Nanoparticle delivery of TP53 resulted in expression of exogenous p53, induction of p21, induction of apoptosis, and accumulation of cells in sub-G1 consistent with functional p53 activity. Intratumoral injection of subcutaneous H446 xenografts with polymers carrying TP53 caused marked tumor growth inhibition. This is the first demonstration of TP53 gene therapy in SCLC using nonviral polymeric nanoparticles. This technology may have general applicability as a novel anticancer strategy based on restoration of tumor suppressor gene function.