60 research outputs found
Heterologous prime-boost vaccination with H3N2 influenza viruses of swine favors cross-clade antibody responses and protection
The emergence of multiple novel lineages of H1 and H3 influenza A viruses in swine has confounded control by inactivated vaccines. Because of substantial genetic and geographic heterogeneity among circulating swine influenza viruses, one vaccine strain per subtype cannot be efficacious against all of the current lineages. We have performed vaccination-challenge studies in pigs to examine whether priming and booster vaccinations with antigenically distinct H3N2 swine influenza viruses could broaden antibody responses and protection. We prepared monovalent whole inactivated, adjuvanted vaccines based on a European and a North American H3N2 swine influenza virus, which showed 81.5% aa homology in the HA1 region of the hemagglutinin and 83.4% in the neuraminidase. Our data show that (i) Priming with European and boosting with North American H3N2 swine influenza virus induces antibodies and protection against both vaccine strains, unlike prime-boost vaccination with a single virus or a single administration of bivalent vaccine. (ii) The heterologous prime-boost vaccination enhances hemagglutination inhibiting, virus neutralizing and neuraminidase inhibiting antibody responses against H3N2 viruses that are antigenically distinct from both vaccine strains. Antibody titers to the most divergent viruses were higher than after two administrations of bivalent vaccine. (iii) However, it does not induce antibodies to the conserved hemagglutinin stalk or to other hemagglutinin subtypes. We conclude that heterologous prime-boost vaccination might broaden protection to H3N2 swine influenza viruses and reduce the total amount of vaccine needed. This strategy holds potential for vaccination against influenza viruses from both humans and swine and for a better control of (reverse) zoonotic transmission of influenza viruses
A role of SCN9A in human epilepsies, as a cause of febrile seizures and as a potential modifier of Dravet syndrome
A follow-up study of a large Utah family with significant linkage to chromosome 2q24 led us to identify a new febrile seizure (FS) gene, SCN9A encoding Na(v)1.7. In 21 affected members, we uncovered a potential mutation in a highly conserved amino acid, p.N641Y, in the large cytoplasmic loop between transmembrane domains I and II that was absent from 586 ethnically matched population control chromosomes. To establish a functional role for this mutation in seizure susceptibility, we introduced the orthologous mutation into the murine Scn9a ortholog using targeted homologous recombination. Compared to wild-type mice, homozygous Scn9a(N641Y/N641Y) knockin mice exhibit significantly reduced thresholds to electrically induced clonic and tonic-clonic seizures, and increased corneal kindling acquisition rates. Together, these data strongly support the SCN9A p.N641Y mutation as disease-causing in this family. To confirm the role of SCN9A in FS, we analyzed a collection of 92 unrelated FS patients and identified additional highly conserved Na(v)1.7 missense variants in 5% of the patients. After one of these children with FS later developed Dravet syndrome (severe myoclonic epilepsy of infancy), we sequenced the SCN1A gene, a gene known to be associated with Dravet syndrome, and identified a heterozygous frameshift mutation. Subsequent analysis of 109 Dravet syndrome patients yielded nine Na(v)1.7 missense variants (8% of the patients), all in highly conserved amino acids. Six of these Dravet syndrome patients with SCN9A missense variants also harbored either missense or splice site SCN1A mutations and three had no SCN1A mutations. This study provides evidence for a role of SCN9A in human epilepsies, both as a cause of FS and as a partner with SCN1A mutations
A Dravet-szindrĂłma klinikai Ă©s genetikai diagnosztikĂĄjĂĄrĂłl hĂșsz esetĂŒnk kapcsĂĄn = Clinical and genetic diagnosis of Dravet syndrome: report of 20 cases
OBJECTIVE AND BACKGROUND: Severe myoclonic epilepsy in infancy (SMEI; Dravet's syndrome) is a malignant epilepsy syndrome characterized by prolonged febrile hemiconvulsions or generalized seizures starting in the first year of life. Later on myoclonic, atypical absence, and complex partial seizures appear. When one of these seizure forms is lacking the syndrome of borderline SMEI (SMEB) is defined. Psychomotor delay resulting in mental retardation is observed during the second year of life. In most patients a de novo sodium channel alpha-1 subunit (SCN1A) mutation can be identified. By reviewing the clinical, laboratory, and neuroimaging data of our SMEI patients diagnosed between 2000 and 2008, we would like to share our experiences in this rare but challenging syndrome. Our results will facilitate the earlier and better diagnosis of Hungarian children with SMEI. PATIENTS AND METHODS: Clinical, EEG, MRI and DNA mutation data of 20 SMEI patients treated in the Bethesda Children's Hospital (Budapest) were reviewed. RESULTS: The first seizure appeared at age 6.3+/-3.0 months. At least one of the first two seizures were complex febrile seizures in 19/20 and unilateral seizures in 12/20 children. All children except for one showed hemiconvulsions at least once; all children had seizures lasting longer than 15 minutes. Eight of twenty patients had SMEB. DNA diagnostics identified an SCN1A mutation in 17 patients (6 missense, 4 nonsense, 4 frameshift, 2 splice site, 1 deletion) while 3 children had no mutation. CONCLUSION: Early diagnosis of SMEI is important for the avoiding unnecessary examinations and false therapies as well as for genetic counselling. Typical symptoms of SMEI are early and prolonged febrile hemiconvulsions with neurological symptoms, mental retardation and secondary seizure types later on. The presence of an SCN1A mutation supports the diagnosis. We propose the availability of molecular diagnostics and stiripentol therapy for SMEI children in Hungar
16p11.2 600 kb Duplications confer risk for typical and atypical Rolandic epilepsy
Rolandic epilepsy (RE) is the most common idiopathic focal childhood epilepsy. Its molecular basis is largely unknown and a complex genetic etiology is assumed in the majority of affected individuals. The present study tested whether six large recurrent copy number variants at 1q21, 15q11.2, 15q13.3, 16p11.2, 16p13.11 and 22q11.2 previously associated with neurodevelopmental disorders also increase risk of RE. Our association analyses revealed a significant excess of the 600 kb genomic duplication at the 16p11.2 locus (chr16: 29.5-30.1 Mb) in 393 unrelated patients with typical (n = 339) and atypical (ARE; n = 54) RE compared with the prevalence in 65 046 European population controls (5/393 cases versus 32/65 046 controls; Fisher's exact test P = 2.83 Ă 10â6, odds ratio = 26.2, 95% confidence interval: 7.9-68.2). In contrast, the 16p11.2 duplication was not detected in 1738 European epilepsy patients with either temporal lobe epilepsy (n = 330) and genetic generalized epilepsies (n = 1408), suggesting a selective enrichment of the 16p11.2 duplication in idiopathic focal childhood epilepsies (Fisher's exact test P = 2.1 Ă 10â4). In a subsequent screen among children carrying the 16p11.2 600 kb rearrangement we identified three patients with RE-spectrum epilepsies in 117 duplication carriers (2.6%) but none in 202 carriers of the reciprocal deletion. Our results suggest that the 16p11.2 duplication represents a significant genetic risk factor for typical and atypical R
Retinal Ganglion Cells: Global Number, Density and Vulnerability to Glaucomatous Injury in Common Laboratory Mice
How many RBPMS+ retinal ganglion cells (RGCs) does a standard C57BL/6 laboratory mouse have on average and is this number substrain- or sex-dependent? Do RGCs of (European) C57BL/6J and -N mice show a different intrinsic vulnerability upon glaucomatous injury? Global RGC numbers and densities of common laboratory mice were previously determined via axon counts, retrograde tracing or BRN3A immunohistochemistry. Here, we report the global RGC number and density by exploiting the freely available tool RGCode to automatically count RGC numbers and densities on entire retinal wholemounts immunostained for the pan-RGC marker RBPMS. The intrinsic vulnerability of RGCs from different substrains to glaucomatous injury was evaluated upon introduction of the microbead occlusion model, followed by RBPMS counts, retrograde tracing and electroretinography five weeks post-injury. We demonstrate that the global RGC number and density varies between substrains, yet is not sex-dependent. C57BL/6J mice have on average 46K ± 2K RBPMS+ RGCs per retina, representing a global RGC density of 3268 ± 177 RGCs/mm2. C57BL/6N mice, on the other hand, have on average less RBPMS+ RGCs (41K ± 3K RGCs) and a lower density (3018 ± 189 RGCs/mm2). The vulnerability of the RGC population of the two C57BL/6 substrains to glaucomatous injury did, however, not differ in any of the interrogated parameters
Target-Derived Neurotrophic Factor Deprivation Puts Retinal Ganglion Cells on Death Row: Cold Hard Evidence and Caveats
Glaucoma and other optic neuropathies are characterized by axonal transport deficits. Axonal cargo travels back and forth between the soma and the axon terminus, a mechanism ensuring homeostasis and the viability of a neuron. An example of vital molecules in the axonal cargo are neurotrophic factors (NTFs). Hindered retrograde transport can cause a scarcity of those factors in the retina, which in turn can tilt the fate of retinal ganglion cells (RGCs) towards apoptosis. This postulation is one of the most widely recognized theories to explain RGC death in the disease progression of glaucoma and is known as the NTF deprivation theory. For several decades, research has been focused on the use of NTFs as a novel neuroprotective glaucoma treatment. Until now, results in animal models have been promising, but translation to the clinic has been highly disappointing. Are we lacking important knowledge to lever NTF therapies towards the therapeutic armamentarium? Or did we get the wrong end of the stick regarding the NTF deprivation theory? In this review, we will tackle the existing evidence and caveats advocating for and against the target-derived NTF deprivation theory in glaucoma, whilst digging into associated therapy efforts.status: Published onlin
The DREADDful Hurdles and Opportunities of the Chronic Chemogenetic Toolbox
The chronic character of chemogenetics has been put forward as one of the assets of the technique, particularly in comparison to optogenetics. Yet, the vast majority of chemogenetic studies have focused on acute applications, while repeated, long-term neuromodulation has only been booming in the past few years. Unfortunately, together with the rising number of studies, various hurdles have also been uncovered, especially in relation to its chronic application. It becomes increasingly clear that chronic neuromodulation warrants caution and that the effects of acute neuromodulation cannot be extrapolated towards chronic experiments. Deciphering the underlying cellular and molecular causes of these discrepancies could truly unlock the chronic chemogenetic toolbox and possibly even pave the way for chemogenetics towards clinical application. Indeed, we are only scratching the surface of what is possible with chemogenetic research. For example, most investigations are concentrated on behavioral read-outs, whereas dissecting the underlying molecular signature after (chronic) neuromodulation could reveal novel insights in terms of basic neuroscience and deregulated neural circuits. In this review, we highlight the hurdles associated with the use of chemogenetic experiments, as well as the unexplored research questions for which chemogenetics offers the ideal research platform, with a particular focus on its long-term application
- âŠ