Fever-like thermal conditions regulate the activation of maturing dendritic cells

Fever is one of the most frequent clinical signs encountered in pathology, especially with respect to infectious diseases. It is currently thought that the role of fever on immunity is limited to activation of innate immunity; however, its relevance to activation of adaptive immunity remains unclear. Dendritic cells (DCs) that behave as sentinels of the immune system provide an important bridge between innate and adaptive immunity. To highlight the role of fever on adaptive immunity, we exposed murine bone marrow-derived lipopolysaccharide (LPS)- or live bacteria-maturing DCs over a 3-h period to 37 degrees C or to fever-like thermal conditions (39 degrees C or 40 degrees C). At these three temperatures, we measured the kinetics of cytokine production and the ability of DCs to induce an allogeneic mixed lymphocyte reaction. Our results show that short exposure of DCs to temperatures of 39 degrees C or 40 degrees C differentially increased the secretion of interleukin (IL)-12p70 and decreased the secretion of IL-10 and tumor necrosis factor alpha by maturing DCs. These fever-like conditions induced a regulation of cytokine production at the single-cell level. In addition, short-term exposed LPS-maturing DCs to 39 degrees C induced a stronger reaction with allogeneic CD4(+) T cells than maturing DCs incubated at 37 degrees C. These results provide evidence that temperature regulates cytokine secretion and DC functions, both of which are of particular importance in bacterial diseases.     

Brain structure in asymptomatic FMR1 premutation carriers at risk for fragile X-associated tremor/ataxia syndrome

Fragile X-associated tremor/ataxia syndrome (FXTAS), a late-onset movement disorder affecting FMR1 premutation carriers, is associated with cerebral and cerebellar lesions. The aim of this study was to test whether computational anatomy can detect similar patterns in asymptomatic FMR1 premutation carriers (mean age 46.7 years) with qualitatively normal -appearing grey and white matter on brain MRI. We used a multimodal imaging protocol to characterize brain anatomy by automated assessment of gray matter volume and white matter properties. Structural changes in the hippocampus and in the cerebellar motor network with decreased gray matter volume in lobule VI and white matter alterations of the corresponding afferent projections through the middle cerebellar peduncles are demonstrated. Diffuse subcortical white matter changes in both hemispheres, without corresponding gray matter alterations, are only identified through age × group interactions. We interpret the hippocampal fimbria and cerebellar changes as early alterations with a possible neurodevelopmental origin. In contrast, progression of the diffuse cerebral hemispheric white matter changes suggests a neurodegenerative process, leading to late-onset lesions, which may mark the imminent onset of FXTAS.     

Harnessing CRISPR-Cas system diversity for gene editing technologies

The discovery and utilization of RNA-guided surveillance complexes,such as CRISPR-Cas9,for sequencespecific DNA or RNA cleavage,has revolutionised the process of gene modification or knockdown.To optimise the use of this technology,an exploratory race has ensued to discover or develop new RNA-guided endonucleases with the most flexible sequence targeting requirements,coupled with high cleavage efficacy and specificity.Here we review the constraints of existing gene editing and assess the merits of exploiting the diversity of CRISPR-Cas effectors as a methodology for surmounting these limitations.     

Nonsyndromic X‐linked intellectual deficiency in three brothers with a novel MED12 missense mutation [c.5922G>T (p.Glu1974His)]

X‐linked intellectual deficiency (XLID) is a large group of genetic disorders. MED12 gene causes syndromic and nonsyndromic forms of XLID. Only seven pathological mutations have been identified in this gene. Here, we report a novel mutation segregating with XLID phenotype. This mutation could be in favor of genotype–phenotype correlations.     

The psychological impact of cryptic chromosomal abnormalities diagnosis announcement

This qualitative study aims to describe the psychological impact of the diagnosis announcement of pathogenic Copy Number Variations (pCNVs). We performed semi-structured interviews of 60 parents of 41 affected children and 5 geneticists who announced the diagnoses. The diagnosis of the best characterized microdeletion syndromes, often defined by patronymic names (e.g. Williams syndrome), is generally made on a clinical basis by geneticists and confirmed by fluorescence in situ hybridization analysis. Chromosomal microarray, on the contrary, can allow the disclosure of rare pCNVs named after cytogenetic formulas, with poorly known clinical consequences: this makes doctors feel less confident with these diagnosis announcements. The disclosure of pCNVs named after cytogenetic formulas does not facilitate the parental mental representation of the disease, leading some parents to call into question the genotype-phenotype correlation or the very notion of a diagnosis. The announcement of inherited pCNVs can increase the feeling of parental guilt; the disclosure of de novo pCNVs can induce a feeling of “breakage” in the mental representation of the parent-child vertical transmission. In conclusion, our study shows that the disclosure of pCNVs has a significant psychological impact: a multidisciplinary approach to the diagnosis announcement, including a psychological support, should be systematically warranted.     

Recent studies of the human chromosome 9p21 locus, which is associated with atherosclerosis in human populations

The chromosome 9p21 (Chr9p21) locus was discovered in 2007 by independent genome-wide association studies for coronary artery disease. Since then, the locus has been replicated numerous times and can be considered the most robust genetic marker of coronary artery disease today. Subsequent work has shown associations of Chr9p21 with a number of additional cardiovascular disease traits, such as carotid artery plaque, stroke, aneurysms, peripheral artery disease, heart failure, and cardiovascular mortality, suggesting a more general role in vascular pathology. Importantly, Chr9p21 lacks associations with common cardiovascular risk factors, such as lipids and hypertension, indicating that the locus exerts its effect through a completely novel mechanism. One of the challenges is that the core haplotype block at Chr9p21 resides in a region of the genome devoid of protein-coding genes. Recent progress has been made by functional studies focusing on differential expression of antisense noncoding RNA in the INK4 locus (ANRIL), which is transcribed from the Chr9p21 locus, as well as neighboring protein-coding genes at the INK4/ARF locus. The emerging concept suggests that ANRIL might constitute a regulator of epigenetic modification and thus modulate cardiovascular risk. Here, we review the current clinical, mechanistic, and diagnostic implications of the Chr9p21 locus in cardiovascular disease.