Composition of children pharyngeal microbiome by 16S rRNA deep sequencing

<p>The upper respiratory tract (URT) is colonised by a large variety of bacteria that constitute the respiratory microbiota. Most do not have a role and may even be protective. The aim of the present study was to analyse the microbiome and characterize the relative abundance of microbial communities of the pharynx by next generation sequencing of the 16S rRNA gene of bacteria in healthy children and children with a respiratory infection. Ten phyla were identified in the 8 study subjects. The most abundant phyla detected, were Firmicutes, Proteobacteria and Bacteroidetes, while the relative abundance of each was highly variable across the subjects. At the family, genus and species level, 24 families, 19 genera and 71 species respectively were common both in patients and healthy subjects, while some (28 families and 24 genera) were identified only in healthy subjects and few (7 families, 8 genera and 9 species) were identified only in patients. No statistically significant differences were observed in relation to the age or gender of the subjects. Interestingly, the most abundant bacteria detected in healthy children were Streptococcus, Prevotella, Moraxella, Veillonella and leptotrichia, while in young patients Moraxellawas not detected among the most prevalent bacteria, supporting the notion that it may play a protective role in infection. Protective and pathogenic bacteria have been identified in healthy children and in patients. Such studies can form the basis for new approaches to fight diseases responding poorly to traditional interventions.</p&gt

Humoral response in experimental autoimmune encephalomyelitis targets neural precursor cells in the central nervous system of naive rodents

Background: Neural precursor cells (NPCs) located in the subventricular zone (SVZ), a well-defined NPC niche, play a crucial role in central nervous system (CNS) homeostasis. Moreover, NPCs are involved in the endogenous reparative process both in multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). However, the possibility that NPCs may be vulnerable to immune-related components may not be ruled out. Therefore, we investigated the potential affinity of myelin oligodendrocyte glycoprotein (MOG)-induced humoral response(s) to NPCs. Methods: MOG35-55-EAE was induced in C57BL/6 mice; blood-sampling was performed on days 17-21 (acute phase) along with a naive group and corresponding antisera (AS) were collected (EAE-AS, NAIVE-AS). The presence of anti-CNS autoantibodies was examined with western blotting. Furthermore, using the collected antisera and anti-MOG antibody (as positive control), immunohistochemistry and double immunofluorescence were implemented on normal neonatal, postnatal, and adult mouse brain sections. Targeted NPCs were identified with confocal microscopy. In vitro immunoreactivity assessment on NPCs challenged with autoantibodies was evaluated for apoptotic/autophagic activity. Results: Western blotting verified the existence of autoantibodies in EAE mice and demonstrated bands corresponding to yet unidentified NPC surface epitopes. A dominant selective binding of EAE-AS in the subventricular zone in all age groups compared to NAIVE-AS (p<0.001) was observed. Additionally, anti-BrdU+/EAE-AS+ colocalization was significantly higher than anti-BrdU+/anti-MOG+, a finding suggesting that the EAE humoral response colocalized with NPCs(BrdU+), cells that do not express MOG. Well-established NPC markers (Nestin, m-Musashi-1, Sox2, DCX, GFAP, NG2) were used to identify the distinct cell types which exhibited selective binding with EAE-AS. The findings verified that EAE-AS exerts cross-reactivity with NPCs which varies throughout the neonatal to adult stage, with a preference to cells of early developmental stages. Finally, increased expressions of Caspase 3 and Beclin 1 on NPCs were detected. Conclusion: We provide evidence for the first time that MOG35-55 EAE induces production of antibodies with affinity to SVZ of naive mice in three different age groups. These autoantibodies target lineage-specific NPCs as brain develops and have the potential to trigger apoptotic pathways. Thus, our findings provide indication that cross-talk between immunity and NPCs may lead to functional alteration of NPCs regarding their viability and potentially oligodendrogenesis and effective remyelination. © 2017 The Author(s)