Dataset Information

Investigating hapten clustering as a strategy to enhance vaccines against drugs of abuse.

ABSTRACT: Vaccines for drugs of abuse have yet to achieve full clinical relevance, largely due to poor/inconsistent immune responses in patients. The use of multivalent scaffolding as a means to tailor drug-hapten density and clustering was examined in the context of drug-immune response modulation. A modular trivalent hapten containing a diglycine spacer, triAM1(Gly)2, was synthesized and shown to elicit anti-nicotine antibodies at equivalent affinity and concentration to the monovalent AM1 analog, despite in this instance having a lower effective hapten density. Augmenting this data, the corresponding monovalent hapten AM1(Gly)2 resulted in enhanced antibody affinity and concentration. Drug-hapten clustering represents a new vaccine paradigm, and, while examined only in the context of nicotine, it should be readily translatable to other drugs of abuse.

SUBMITTER: Collins KC

PROVIDER: S-EPMC3983143 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Investigating hapten clustering as a strategy to enhance vaccines against drugs of abuse.

Collins Karen C KC Janda Kim D KD

Bioconjugate chemistry 20140225 3

Vaccines for drugs of abuse have yet to achieve full clinical relevance, largely due to poor/inconsistent immune responses in patients. The use of multivalent scaffolding as a means to tailor drug-hapten density and clustering was examined in the context of drug-immune response modulation. A modular trivalent hapten containing a diglycine spacer, triAM1(Gly)2, was synthesized and shown to elicit anti-nicotine antibodies at equivalent affinity and concentration to the monovalent AM1 analog, despi ...[more]

PMID: 24521489

Similar Datasets

Project description:The accurate analytical measurement of binding affinities of polyclonal antibody in sera to heroin, 6-acetylmorphine (6-AM), and morphine has been a challenging task. A simple nonradioactive method that uses deuterium-labeled drug tracers and equilibrium dialysis (ED) combined with ultra performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) to measure the apparent dissociation constant (K d) of antibodies to 6-AM and morphine is described. The method can readily detect antibodies with K d in the low nanomolar range. Since heroin is rapidly degraded in sera, esterase inhibitors were included in the assay, greatly reducing heroin hydrolysis. MS/MS detection directly measured the heroin in the assay after overnight ED, thereby allowing the quantitation of % bound heroin in lieu of K d as an alternative measurement to assess heroin binding to polyclonal antibody sera. This is the first report that utilizes a solution-based assay to quantify heroin-antibody binding without being confounded by the presence of 6-AM and morphine and to measure K d of polyclonal antibody to 6-AM. Hapten surrogates 6-AcMorHap, 6-PrOxyHap, MorHap, DiAmHap, and DiPrOxyHap coupled to tetanus toxoid (TT) were used to generate high affinity antibodies to heroin, 6-AM, and morphine. In comparison to competition ED-UPLC/MS/MS which gave K d values in the nanomolar range, the commonly used competition enzyme-linked immunosorbent assay (ELISA) measured the 50% inhibition concentration (IC50) values in the micromolar range. Despite the differences in K d and IC50 values, similar trends in affinities of hapten antibodies to heroin, 6-AM, and morphine were observed by both methods. Competition ED-UPLC/MS/MS revealed that among the five TT-hapten bioconjugates, TT-6-AcMorHap and TT-6-PrOxyHap induced antibodies that bound heroin, 6-AM, and morphine. In contrast, TT-MorHap induced antibodies that poorly bound heroin, while TT-DiAmHap and TT-DiPrOxyHap induced antibodies either did not bind or poorly bound to heroin, 6-AM, and morphine. This simple and nonradioactive method can be extended to other platforms, such as oxycodone, cocaine, nicotine, and methamphetamine for the selection of the lead hapten design during substance abuse vaccine development.

Project description:Three sets of in silico experiments have been conducted to elucidate the binding mechanics of two drugs, (+)-methamphetamine (METH) and amphetamine (AMP) to the single-chain variable fragment (scFv) recently engineered from anti-METH monoclonal antibody mAb6H4 (IgG, κlight chain, K(d)=11nM). The first set of in silico experiments are long time equilibration runs of scFv:drug complexes and of drug-free scFv both in the solution. They demonstrate how the solution structures of scFv deviate from its crystallographic form with or without drug molecules bound to it. They lead to the prediction that the Arrhenius activation barrier is nearly zero for transitions from the dissociated state to the bound state. The second set of in silico experiments are nonequilibrium dynamics of pulling the drug molecules out of the binding pocket of scFv and the equilibration runs for drugs to fall back into the binding pocket. They demonstrate that extra water molecules (in addition to the two crystallographic waters) exist inside the binding pocket, underneath the drug molecules. These extra waters must have been evaporated from the binding pockets during the crystallization process of the in vitro experiments of structural determination. The third set of in silico experiments are nonequilibrium steered molecular dynamics simulations to determine the absolute binding free energies of METH and AMP to scFv. The center of mass of a drug molecule (METH or AMP) is steered (pulled) towards (forward) and away from (reverse) the binding site, sampling forward and reverse pulling paths. Mechanic work is measured along the pulling paths. The work measurements are averaged through the Brownian dynamics fluctuation dissipation theorem to produce the free-energy profiles of the scFv:drug complexes as a function of the drug-scFv separation. These experiments lead to the theoretical prediction of absolute binding energies of METH and AMP that are in agreement with the in vitro experimental results.

Project description:In summary, we characterized genomic signatures of response to drugs of abuse and we found positive correlations between the drug-induced expression and various behavioral effects. These signatures are formed by two dynamically inducible transcriptional networks: (1) CREB/SRF-dependent gene pattern that appears to be related to drug-induced neuronal activity, (2) the pattern of genes controlled at least in part via release of glucocorticoids and androgens that are associated with rewarding and harmful drug effects. The discovery of co-expressed networks of genes allowed for the identification of master-switch controlling factors involved in molecular response to the drugs. Finally, using the pharmacological tools we were able to dissect and inhibit particular gene expression patterns from genomic profile. Type: Drug response, Time-course, Gene expression profiling with Illumina Microarrays Keywords: Addiction, Drugs of abuse, Time-course, Immediate Early Genes, Glucocorticoid receptor dependent genes, Cocaine, Heroin, Nicotine, Ethanol, Morphine, Methamphetamine The microarray experiment was performed to analyze time-course of drug-induced transcriptional response in C57BL/6J mouse striatum. Six the most addictive and harming drugs of abuse (morphine 20 mg/kg, heroin 10 mg/kg, ethanol 2 g/kg, nicotine 1 mg/kg, methamphetamine 2 mg/kg or cocaine 25 mg/kg, i.p.) were selected for the comparison. Drug doses were previously reported as rewarding in mice and further tested in our laboratory. To analyze dynamics of early, intermediate and relatively late changes of mRNA abundance the experiment was performed in four time points (1, 2, 4 and 8h after drug administration). To exclude influence of drug injection and circadian rhythm on gene expression profile, control groups of saline treated and naïve animals were prepared for each time point. Design of the experiment assumed pooling of two animals per each array and using of three independent arrays per group. To provide appropriate balance in the whole dataset groups were equally divided between the array hybridization batches. 'Complete' normalized data and non-normalized data (containing control rows not represented in Platform GPL6105) are linked below as supplementary files.

Dataset Information

Investigating hapten clustering as a strategy to enhance vaccines against drugs of abuse.

Publications

Investigating hapten clustering as a strategy to enhance vaccines against drugs of abuse.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure