Pharmacokinetics of α-Pyrrolidinovalerophenone in Male Rats with and without Vaccination with an α-Pyrrolidinovalerophenone Vaccine.

PURPOSE: α-Pyrrolidinovalerophenone (α-PVP) is a second-generation synthetic cathinone which acts as an inhibitor at the dopamine and norepinephrine transporters in the brain. These novel studies determined the pharmacokinetics (PK) of α-PVP in rats and then evaluated the effects of an α-PVP vaccine on the PK profile. METHODS: Adult male Sprague-Dawley rats were randomly divided into treatment groups (n = 24/group) in which the vaccinated rats received an initial and two booster immunizations of the α-PVP vaccine at 0, 3, and 9 wks. Control rats received saline injections. α-PVP (0.56, 1, 3 mg/kg, sc) was then administered to both groups between 11-12 weeks and serum samples were collected for determination of α-PVP serum concentrations by LC-MS/MS (n=6 rats/treatment/time). At 13 weeks, brain, heart and kidney concentrations of α-PVP were determined by LC-MS/MS after administration of 1 mg/kg α-PVP (n=4-5 rats/treatment/time). RESULTS: PK values in control rats showed dose-dependent increases in maximum serum concentrations (Cmax) and area under the curve (AUCinf) values with an elimination half-life (t1/2) of approximately 2.1 h. α-PVP exhibited linear PK profile in control rats. Vaccinated rats had significantly (p<0.05) higher serum Cmax and AUCinf values than controls, and significantly reduced total body clearance, volume of distribution and t1/2 values. Vaccinated rats had significantly lower α-PVP concentrations in the brain, heart, and kidney in comparison to control rats at early time points. CONCLUSION: Vaccination with the novel α-PVP vaccine significantly altered serum PK leading to a time-dependent reduction in brain, kidney and heart concentrations of α-PVP compared to controls.

Post-Chemotherapy Titer Status and Need for Revaccination After Treatment for Childhood Cancer.

Objectives. To evaluate the strategy of checking vaccine titers after completion of chemotherapy. Study Design. Retrospective review of pediatric oncology patients who completed chemotherapy. Demographics, post-chemotherapy titers, and absolute lymphocyte counts (ALCs) were analyzed. Results. Ninety patients met inclusion criteria, and 87% of patients had at least one titer checked. Comparing patients <7 years and those ≥7 years at diagnosis, there was no difference in incidence of negative titers except mumps; those <7 years old were more likely to have negative titers (58% vs 20%, P = .003). Comparing those <13 years old to ≥13 years old, there was no difference in negative titers except mumps (45% vs 19%, P = .02) and tetanus (44% vs 0%, P = .002). No patient maintained all protective titers after completion of chemotherapy. Time to ALC recovery was not predictive of positive titers. Conclusion. Checking titers after chemotherapy is not recommended. Providers should assume loss of immunity.

Antibody production and pharmacokinetics of METH in rats following vaccination with the METH vaccine, IXT-v100, adjuvanted with GLA-SE.

BACKGROUND: Methamphetamine use disorder continues to be inadequately treated, but improvements are being made in the field of immunotherapeutics, including vaccines, which could provide new options for treatment. Cocaine and nicotine vaccines have been tested clinically, but have yet to elicit the necessary antibody concentrations required to be effective. Methamphetamine vaccines have been tested in multiple nonclinical models and appear promising. Improved adjuvants have the potential to further stimulate the immune system to reach effective levels of antibodies. Previously, the methamphetamine vaccine IXT-v100 was administered with GLA-SE, a toll-like receptor 4 agonist, in mice to produce higher levels of antibodies than when it was administered with two other widely used adjuvants, Alhydrogel and Sigma Adjuvant System. METHODS: The purpose of this research was to evaluate IXT-v100, given in combination with the adjuvant GLA-SE, to determine its efficacy in antagonizing methamphetamine disposition in a rat pharmacokinetic study. Additional rat studies were conducted to compare the ability of IXT-v100 manufactured with greater hapten densities to elicit higher antibody levels. RESULTS: As expected based on prior studies with anti-methamphetamine monoclonal antibodies, the antibodies resulting from vaccination with IXT-v100 altered methamphetamine pharmacokinetics by increasing serum concentrations and extending the half-life. Furthermore, intentional variations in the ratio of components during manufacturing led to production of vaccines with higher hapten densities. The higher hapten densities resulted in production of antibodies that maintained the ability to bind methamphetamine with high affinity. CONCLUSIONS: The results support continued development of IXT-v100 for the treatment of methamphetamine use disorder.

Vesicle-based secretion in schistosomes: Analysis of protein and microRNA (miRNA) content of exosome-like vesicles derived from Schistosoma mansoni.

Exosomes are small vesicles of endocytic origin, which are released into the extracellular environment and mediate a variety of physiological and pathological conditions. Here we show that Schistosoma mansoni releases exosome-like vesicles in vitro. Vesicles were purified from culture medium by sucrose gradient fractionation and fractions containing vesicles verified by western blot analyses and electron microscopy. Proteomic analyses of exosomal contents unveiled 130 schistosome proteins. Among these proteins are common exosomal markers such as heat shock proteins, energy-generating enzymes, cytoskeletal proteins, and others. In addition, the schistosome extracellular vesicles contain proteins of potential importance for host-parasite interaction, notably peptidases, signaling proteins, cell adhesion proteins (e.g., integrins) and previously described vaccine candidates, including glutathione-S-transferase (GST), tetraspanin (TSP-2) and calpain. S. mansoni exosomes also contain 143 microRNAs (miRNA), of which 25 are present at high levels, including miRNAs detected in sera of infected hosts. Quantitative PCR analysis confirmed the presence of schistosome-derived miRNAs in exosomes purified from infected mouse sera. The results provide evidence of vesicle-mediated secretion in these parasites and suggest that schistosome-derived exosomes could play important roles in host-parasite interactions and could be a useful tool in the development of vaccines and therapeutics.

Rational incorporation of molecular adjuvants into a hybrid nanoparticle-based nicotine vaccine for immunotherapy against nicotine addiction.

Current clinically-tested nicotine vaccines have yet shown enhanced smoking cessation efficacy due to their low immunogenicity. Achieving a sufficiently high immunogenicity is a necessity for establishing a clinically-viable nicotine vaccine. This study aims to facilitate the immunogenicity of a hybrid nanoparticle-based nicotine vaccine by rationally incorporating toll-like receptor (TLR)-based adjuvants, including monophosphoryl lipid A (MPLA), Resiquimod (R848), CpG oligodeoxynucleotide 1826 (CpG ODN 1826), and their combinations. The nanoparticle-delivered model adjuvant was found to be taken up more efficiently by dendritic cells than the free counterpart. Nanovaccine particles were transported to endosomal compartments upon cellular internalization. The incorporation of single or dual TLR adjuvants not only considerably increased total anti-nicotine IgG titers but also significantly affected IgG subtype distribution in mice. Particularly, the nanovaccines carrying MPLA+R848 or MPLA+ODN 1826 generated a much higher anti-nicotine antibody titer than those carrying none or one adjuvant. Meanwhile, the anti-nicotine antibody elicited by the nanovaccine adjuvanted with MPLA+R848 had a significantly higher affinity than that elicited by the nanovaccine carrying MPLA+ODN 1826. Moreover, the incorporation of all the selected TLR adjuvants (except MPLA) reduced the brain nicotine levels in mice after nicotine challenge. Particularly, the nanovaccine with MPLA+R848 exhibited the best ability to reduce the level of nicotine entering the brain. Collectively, rational incorporation of TLR adjuvants could enhance the immunological efficacy of the hybrid nanoparticle-based nicotine vaccine, making it a promising next-generation immunotherapeutic candidate for treating nicotine addiction.

Effects on the anti-ABO titers of military blood donors from a predeployment vaccination program.

BACKGROUND: The use of blood group O as "universal blood" for emergency whole blood transfusions carries the risk for a hemolytic transfusion reaction mediated by incompatible A/B antibodies. This risk can be minimized by assuring that the donor has a low titer of anti-A and anti-B. The level of these naturally occurring antibodies has been shown to be increased by vaccination with most biologically derived vaccines. This boostering effect has been investigated for the new generation of vaccines. METHODS: The 120 crew members of a Swedish naval ship deployed for 7 months to the Indian Ocean were tested for anti-A and anti-B before their predeployment vaccination program and after returning to Sweden. The vaccination program contained vaccines against cholera, diphtheria, hepatitis A and B, influenza, measles, meningitis, mumps, pertussis, polio, rubella, TBE virus, tetanus, typhus and yellow fever. Paired antibody titrations were performed for both IgM and IgG using microtube gelcards (Diamed GMBH). RESULTS: No crew member, including the six belonging to the "high titer" group, showed a sign of a booster effect by any of the used vaccines. CONCLUSION: The earlier reported boostering effects mediated by different vaccines cannot be replicated with the new vaccines of today. This is probably a result of the new manufacturing techniques resulting in much purer vaccines. LEVEL OF EVIDENCE: Therapeutic/care management study, level II.

An Advance in Prescription Opioid Vaccines: Overdose Mortality Reduction and Extraordinary Alteration of Drug Half-Life.

Prescription opioids (POs) such as oxycodone and hydrocodone are highly effective medications for pain management, yet they also present a substantial risk for abuse and addiction. The consumption of POs has been escalating worldwide, resulting in tens of thousands of deaths due to overdose each year. Pharmacokinetic strategies based upon vaccination present an attractive avenue to suppress PO abuse. Herein, the preparation of two active PO vaccines is described that were found to elicit high-affinity antiopioid antibodies through a structurally congruent drug-hapten design. Administration of these vaccines resulted in a significant blockade of opioid analgesic activity, along with an unprecedented increase in drug serum half-life and protection against lethal overdose.

Novel Ricin Subunit Antigens With Enhanced Capacity to Elicit Toxin-Neutralizing Antibody Responses in Mice.

RiVax is a candidate ricin toxin subunit vaccine antigen that has proven to be safe in human phase I clinical trials. In this study, we introduced double and triple cavity-filling point mutations into the RiVax antigen with the expectation that stability-enhancing modifications would have a beneficial effect on overall immunogenicity of the recombinant proteins. We demonstrate that 2 RiVax triple mutant derivatives, RB (V81L/C171L/V204I) and RC (V81I/C171L/V204I), when adsorbed to aluminum salts adjuvant and tested in a mouse prime-boost-boost regimen were 5- to 10-fold more effective than RiVax at eliciting toxin-neutralizing serum IgG antibody titers. Increased toxin neutralizing antibody values and seroconversion rates were evident at different antigen dosages and within 7 days after the first booster. Quantitative stability/flexibility relationships analysis revealed that the RB and RC mutations affect rigidification of regions spanning residues 98-103, which constitutes a known immunodominant neutralizing B-cell epitope. A more detailed understanding of the immunogenic nature of RB and RC may provide insight into the fundamental relationship between local protein stability and antibody reactivity.

Imunização de cães com produtos oriundos de Lutzomyia Longipalpis em duas diferentes abordagens: Canarypoxvirus sp. Expressando o gene que codifica para a proteína salivar LJM17 e/ou LJL143, e a proteína do intestino médio luloper1 como vacina bloqueadora de transmissão / dog immunization with products from Lutzomyia longipalpis in two different approaches: Canarypoxvirus sp. Expressing the gene that encodes the protein salivary LJM17 and / or LJL143 and the midgut protein luloper1 as a transmission blocking vaccine

As interações entre flebótomo, parasita e hospedeiro desempenham um papel importante na transmissão da leishmaniose. As moléculas provenientes do vetor são relevantes para estas interações e incluem as proteínas da saliva e do intestino médio. Nos flebótomos, as Leishmanias passam por um ciclo de desenvolvimento complexo dentro do intestino médio sob a proteção da matriz peritrófica, necessário para a geração de formas metacíclicas infectantes. As Leishmanias são transmitidas pelos flebótomos que co-injetam parasitas juntamente com a saliva, na derme do hospedeiro. Estudos anteriores demonstraram que a imunização de cães com duas proteínas salivares (LJM17 ou LJL143) de L. longipalpis, resultaram em uma imunidade mediada por células Th1 sistêmica e local afetando a sobrevivência do parasita in vitro. Assim, o objetivo deste trabalho foi avaliar a imunidade conferida pela imunização de cães com DNA e rCanarypoxvirus expressando o gene que codifica para as proteínas salivares de L. longipalpis (LJM17 e/ou LJL143)...

Sand fly, parasite, host interactions play an important role in the transmission of leishmaniasis. Vector molecules are relevant for such interactions and include midgut and salivary proteins. In vector sand fly species, Leishmania parasites undergo a complex developmental cycle within the midgut, protected by the peritrophic matrix that is necessary for generation of infectious metacyclics. Leishmania parasites are transmitted by sand flies that co-inject parasites and saliva, in the host’s skin. Previous studies showed immunization of dogs with two proteins (LJM17 or LJL143) from Lutzomyia longipalpis, resulted in a systemic and local Th1 cell-mediated immunity affecting parasite survival in vitro. In this work we evaluated the immunity conferredbyimmunization of dogs with DNA and recombinant Canarypoxvírusexpressing the gene encoding the salivary ofL.longipalpis (LJM17and/orLJL143). Immunization with both LJL143 and LJM17...

Enzyme-linked immunospot assays for direct ex vivo measurement of vaccine-induced human humoral immune responses in blood.

The enzyme-linked immunospot (ELISPOT) assay was originally developed to enumerate antigen-specific antibody-secreting cells (ASCs), and has subsequently been adapted for various applications, including the detection cytokine-secreting cells. Owing to its exceptionally high sensitivity, the ELISPOT has proven to be especially useful for detecting discrete populations of active cells (e.g., antigen-specific cells). Because of its versatility, the ELISPOT assay is used for a wide range of applications, including clonal analyses of immune responses after vaccination or after immunotherapy. Here we describe standard protocols for the detection of human ASCs specific to virtually any vaccine antigen after enrichment of circulating plasmablasts. In addition, a protocol is described for the measurement of mucosal ASC responses after prior immunomagnetic enrichment of mucosally derived blood lymphocytes. The protocols described allow rapid (~6-8 h) detection of specific ASCs in small (1-2 ml) samples of blood and can be performed in resource-poor settings.

Immobilisation of vaccines onto micro-crystals for enhanced thermal stability.

The thermal instability of many vaccines leads to the wastage of half of all supplied vaccines. In this note, we report the application of a novel technology: protein-coated micro-crystals (PCMC) to improve the thermostability of a model vaccine (diphtheria toxoid, DT). The latter was immobilised onto the surface of a crystalline material (L-glutamine) via a rapid dehydration method, resulting in the production of a fine free-flowing powder. The PCMC consisted of thin, flat crystals with an antigen loading of 3.95% (w/w). The DT-coated glutamine crystals and free DT (the controls) were incubated at different temperatures for a defined time period (4 degrees C, RT and 37 degrees C for 2 weeks and 45 degrees C for 2 days), after which the crystals were suspended in buffer and intramuscularly administered to mice. Incubation of DT (free and crystal-coated) at room temperature and at 37 degrees C for 2 weeks did not result in any change in the antibody response compared to DT that had always been stored properly (i.e. in the refrigerator). In contrast, incubation of free DT at 45 degrees C resulted in a reduced IgG response, indicating thermal instability of free DT at that temperature. The antibody response was not reduced, however, with the crystal-coated DT. These preliminary studies show that PCMC is a promising technology for the thermal stabilisation of vaccines.