The inactive X chromosome in the human female is enriched in 5-methylcytosine to an unusual degree and appears to contain more of this modified nucleotide than the remainder of the genome

By employing a procedure that combines ELISA and photoacoustic spectroscopy, we have examined the content of 5-methylcytosine (m5C) in DNA of individuals who differed from one another in the number of X chromosomes in their genomes. The results show that the human inactive X chromosome (Xi) contains very high amounts of this modified nucleotide. We estimate that in the 46,XX female there is more m5C in Xi (~3.6 × 107) than in all the remaining chromosomes put together (~2.1 × 107). Our results also suggest that nearly one-fifth of all cytosines in Xi are methylated and that, in addition to CpG methylation, there is extensive non-CpG methylation as well

Intranasal Mice Model to Study the role of Bordetella pertussis antigens in Immunity

699-702Pertussis known as whooping cough is a highly contagious disease. Whole cell pertussis vaccine is the most economical and effective strategy for preventing and controlling pertussis. The efficacy of whole cell vaccine is ascertained most commonly by intracerebral challenge assay, but it does not reflect the true efficacy of vaccine as Pertussis essentially is a respiratory disease. Therefore, in order to mimic the natural infection, intranasal challenge model in mice was developed. In intranasal challenge assay mice were immunized with vaccine and challenged through intranasal route. Mice lungs were dissected and examined for bacterial count. The degree of count was related to efficacy of vaccine, higher count indicated low efficacy and low count pointed to better efficacy

Characterisation of Inactivation Domains and Evolutionary Strata in Human X Chromosome through Markov Segmentation

Markov segmentation is a method of identifying compositionally different subsequences in a given symbolic sequence. We have applied this technique to the DNA sequence of the human X chromosome to analyze its compositional structure. The human X chromosome is known to have acquired DNA through distinct evolutionary events and is believed to be composed of five evolutionary strata. In addition, in female mammals all copies of X chromosome in excess of one are transcriptionally inactivated. The location of a gene is correlated with its ability to undergo inactivation, but correlations between evolutionary strata and inactivation domains are less clear. Our analysis provides an accurate estimate of the location of stratum boundaries and gives a high–resolution map of compositionally different regions on the X chromosome. This leads to the identification of a novel stratum, as well as segments wherein a group of genes either undergo inactivation or escape inactivation in toto. We identify oligomers that appear to be unique to inactivation domains alone

Prolidase deficiency causes spontaneous T cell activation and lupus-like autoimmunity

Prolidase deficiency (PD) is a multisystem disorder caused by mutations in the PEPD gene, which encodes a ubiquitously expressed metallopeptidase essential for the hydrolysis of dipeptides containing C-terminal proline or hydroxyproline. PD typically presents in childhood with developmental delay, skin ulcers, recurrent infections, and, in some patients, autoimmune features that can mimic systemic lupus erythematosus. The basis for the autoimmune association is uncertain, but might be due to self-antigen exposure with tissue damage, or indirectly driven by chronic infection and microbial burden. In this study, we address the question of causation and show that Pepd-null mice have increased antinuclear autoantibodies and raised serum IgA, accompanied by kidney immune complex deposition, consistent with a systemic lupus erythematosus–like disease. These features are associated with an accumulation of CD4 and CD8 effector T cells in the spleen and liver. Pepd deficiency leads to spontaneous T cell activation and proliferation into the effector subset, which is cell intrinsic and independent of Ag receptor specificity or antigenic stimulation. However, an increase in KLRG1+ effector CD8 cells is not observed in mixed chimeras, in which the autoimmune phenotype is also absent. Our findings link autoimmune susceptibility in PD to spontaneous T cell dysfunction, likely to be acting in combination with immune activators that lie outside the hemopoietic system but result from the abnormal metabolism or loss of nonenzymatic prolidase function. This knowledge provides insight into the role of prolidase in the maintenance of self-tolerance and highlights the importance of treatment to control T cell activation

Themis2 lowers the threshold for B cell activation during positive selection

The positive and negative selection of lymphocytes by antigen is central to adaptive immunity and self-tolerance, yet how this is determined by different antigens is incompletely understood. Here we report that Themis2 increased the positive selection of B1 cells and germinal center B cells by self and foreign antigens. We found that Themis2 lowered the threshold for B cell activation by low but not high avidity antigens. Themis2 constitutively bound the adaptor protein Grb2, src-kinase Lyn and signal transducer PLCγ2, and increased activation of PLCγ2 and its downstream pathways following B cell receptor stimulation. These findings identify a unique function for Themis2 in differential signaling and provide insight into how B cells discriminate between antigens of different quantity and quality

The Pan-University Network for Global Health: framework for collaboration and review of global health needs

In the current United Nations efforts to plan for post 2015-Millennium Development Goals, global partnership to address non-communicable diseases (NCDs) has become a critical goal to effectively respond to the complex global challenges of which inequity in health remains a persistent challenge. Building capacity in terms of wellequipped local researchers and service providers is a key to bridging the inequity in global health. Launched by Penn State University in 2014, the Pan University Network for Global Health responds to this need by bridging researchers at more than 10 universities across the globe. In this paper we outline our framework for international and interdisciplinary collaboration, as well the rationale for our research areas, including a review of these two themes. After its initial meeting, the network has established two central thematic priorities: 1) urbanization and health and 2) the intersection of infectious diseases and NCDs. The urban population in the global south will nearly double in 25 years (approx. 2 billion today to over 3.5 billion by 2040). Urban population growth will have a direct impact on global health, and this growth will be burdened with uneven development and the persistence of urban spatial inequality, including health disparities. The NCD burden, which includes conditions such as hypertension, stroke, and diabetes, is outstripping infectious disease in countries in the global south that are considered to be disproportionately burdened by infectious diseases. Addressing these two priorities demands an interdisciplinary and multi-institutional model to stimulate innovation and synergy that will influence the overall framing of research questions as well as the integration and coordination of research

The Genome of the Stick Insect Medauroidea extradentata Is Strongly Methylated within Genes and Repetitive DNA

BACKGROUND: Cytosine DNA methylation has been detected in many eukaryotic organisms and has been shown to play an important role in development and disease of vertebrates including humans. Molecularly, DNA methylation appears to be involved in the suppression of initiation or of elongation of transcription. Resulting organismal functions are suggested to be the regulation of gene silencing, the suppression of transposon activity and the suppression of initiation of transcription within genes. However, some data concerning the distribution of methylcytosine in insect species appear to contradict such roles. PRINCIPAL FINDINGS: By comparison of MspI and HpaII restriction patterns in genomic DNA of several insects we show that stick insects (Phasmatodea) have highly methylated genomes. We isolated methylated DNA fragments from the Vietnamese Walking Stick Medauroidea extradentata (formerly known as Baculum extradentatum) and demonstrated that most of the corresponding sequences are repetitive. Bisulfite sequencing of one of these fragments and of parts of conserved protein-coding genes revealed a methylcytosine content of 12.6%, mostly found at CpG, but also at CpT and CpA dinucleotides. Corresponding depletions of CpG and enrichments of TpG and CpA dinucleotides in some highly conserved protein-coding genes of Medauroidea reach a similar degree as in vertebrates and show that CpG methylation has occurred in the germline of these insects. CONCLUSIONS: Using four different methods, we demonstrate that the genome of Medauroidea extradentata is strongly methylated. Both repetitive DNA and coding genes appear to contain high levels of methylcytosines. These results argue for similar functions of DNA methylation in stick insects as those already known for vertebrates

<i>Drosophila melanogaster</i> as a model host to study arbovirus–vector interaction

ABSTRACTArboviruses cause the most devastating diseases in humans and animals worldwide. Several hundred arbovirus are transmitted by mosquitoes, sand flies or ticks and are responsible for more than million deaths annually. Development of a model system is essential to extrapolate the molecular events occurring during infection in the human and mosquito host. Virus overlay protein binding assay (VOPBA) combined with MALDI TOF/TOF MS revealed that Dengue-2 virus (DENV-2) exploits similar protein molecules in Drosophila melanogaster and Aedes aegypti for its infection. Furthermore, the virus susceptibility studies revealed that DENV-2 could propagate in D. melanogaster, and DENV-2 produced in fruit fly is equally infectious to D. melanogaster and Ae. aegypti. Additionally, real time PCR analysis revealed that RNAi coupled with JAK-STAT and Toll pathway constitutes an effector mechanism to control the DENV-2 infection in flies. These observations point out that D. melanogaster harbors all necessary machineries to support the growth of arboviruses. With the availability of well-established techniques for genetic and developmental manipulations, D. melanogaster, offers itself as the potential model system for the study of arbovirus-vector interactions.</jats:p