Immune surveillance of nasopharyngeal carcinoma (NpC)

In the U.S., nasopharyngeal carcinoma (NpC) kills >7,600 each year. Deaths are predominantly among adult men, and in most cases, early detection and treatment can save lives. Despite the annual spending of approximately 3.2 billion dollars on head and neck cancer research, NpC remains a neglected disease since its fatality rates are among the lowest nation wide. The relative survival rates from NpC have not improved in the U.S. in the last 20 years. Infection with Epstein Barr Virus (EBV) is an important co-factor in the etiology of NpC. In other regions of the word (e.g., South-East Asia, Latin America), EBV infection and NpCrelated prevalence and mortality are substantially higher and more alarming. Epidemiological data indicate high prevalence of EBV infection and increased risk for NpC among Central and South American and Asian immigrants in the U.S., and also predict a sharp increase in NpC incidence in the next decade. To face this emerging threat, it is important to develop and validate novel modes of detection and intervention for NpC. To this end, we characterized the proteomic signature of NpC, and of the tumor infiltrating lymphocytes of the CD8+, activated (CD38+, mTOR+) and regulatory immune cell (FoxP3+) phenotype. Paraffinized biopsies were processed, and tissue microarrays constructed and tested by immunohistochemistry and triimmunohistofluorescence for a battery of signaling markers, including AKT and PI3K, in conjunction with EBV status and ANKRD11, an NpC susceptibility biomarker. Microphotographs, analyzed and quantified by confocal microscopy and fractal analysis, suggest new avenues for immunotherapies of NpC.     

The role of the microenvironment in tumor immune surveillance

The evidence appears compelling that the microenvironment, and associated biological cellular and molecular factors, may contribute to the progression of a variety of tumors. The effects of the microenvironment may directly influence the plasticity of T cell lineages, which was recently discussed (O''Shea & Paul, 2010 [4]). To review the putative role of the microenvironment in modulating the commitment of tumor immune surveillance, we use the model of oral premalignant lesions.     

Molecular Characterization of Notch1 Positive Progenitor Cells in the Developing Retina

The oscillatory expression of Notch signaling in neural progenitors suggests that both repressors and activators of neural fate specification are expressed in the same progenitors. Since Notch1 regulates photoreceptor differentiation and contributes (together with Notch3) to ganglion cell fate specification, we hypothesized that genes encoding photoreceptor and ganglion cell fate activators would be highly expressed in Notch1 receptor-bearing (Notch1⁺) progenitors, directing these cells to differentiate into photoreceptors or into ganglion cells when Notch1 activity is diminished. To identify these genes, we used microarray analysis to study expression profiles of whole retinas and isolated from them Notch1⁺ cells at embryonic day 14 (E14) and postnatal day 0 (P0). To isolate Notch1⁺ cells, we utilized immunomagnetic cell separation. We also used Notch3 knockout (Notch3KO) animals to evaluate the contribution of Notch3 signaling in ganglion cell differentiation. Hierarchical clustering of 6,301 differentially expressed genes showed that Notch1⁺ cells grouped near the same developmental stage retina cluster. At E14, we found higher expression of repressors (Notch1, Hes5) and activators (Dll3, Atoh7, Otx2) of neuronal differentiation in Notch1⁺ cells compared to whole retinal cell populations. At P0, Notch1, Hes5, and Dll1 expression was significantly higher in Notch1⁺ cells than in whole retinas. Otx2 expression was more than thirty times higher than Atoh7 expression in Notch1⁺ cells at P0. We also observed that retinas of wild type animals had only 14% (P < 0.05) more ganglion cells compared to Notch3KO mice. Since this number is relatively small and Notch1 has been shown to contribute to ganglion cell fate specification, we suggested that Notch1 signaling may play a more significant role in RGC development than the Notch3 signaling cascade. Finally, our findings suggest that Notch1⁺ progenitors—since they heavily express both pro-ganglion cell (Atoh7) and pro-photoreceptor cell (Otx2) activators—can differentiate into either ganglion cells or photoreceptors.     

Possible cause of allergy for the librarians: books manipulation and ventilation as sources of fungus spores spreading

The objective of this study was to investigate the airborne viable spore concentrations and identify the fungal species in all indoor spaces from the lending library at the Technical University “Gheorghe Asachi” Iaşi, Romania. Samples were collected using the settle plate method and swab samples from PC cooler fan grids as well as from the wall in it’s vicinity and from paper/wood fragments. There were no air conditioning systems in the library rooms. The heating systems were standard with an environmental temperature of 20°C in winter, except for the storage area of old/rare books stacks II, where the temperature was below 15°C and the humidity was very high due to water infiltrations in the walls and poor maintenance. More than 296 fungal colonies from over 78 samples were identified, enumerated, and reported. Indoor airborne fungal spore deposition rates were within the range of 419–1,677 CFU/m², with the predominance of genera being Aspergillus spp., Penicillium spp., Cladosporium spp., Alternaria spp. and Chaetomium spp. Approximately ten fungal colonies could not be identified. The PC fans move particles from the low levels (floor) to the air, and are thus responsible for maintaining a constant air velocity and contribute to fungal-spore aerosolization, transport, deposition and resuspension. Book paper and wood furniture are known to be suitable substrates for cellulose degrading fungi.     

A Modular BAM Complex in the Outer Membrane of the α-Proteobacterium Caulobacter crescentus

Mitochondria are organelles derived from an intracellular α-proteobacterium. The biogenesis of mitochondria relies on the assembly of β-barrel proteins into the mitochondrial outer membrane, a process inherited from the bacterial ancestor. Caulobacter crescentus is an α-proteobacterium, and the BAM (β-barrel assembly machinery) complex was purified and characterized from this model organism. Like the mitochondrial sorting and assembly machinery complex, we find the BAM complex to be modular in nature. A ∼150 kDa core BAM complex containing BamA, BamB, BamD, and BamE associates with additional modules in the outer membrane. One of these modules, Pal, is a lipoprotein that provides a means for anchorage to the peptidoglycan layer of the cell wall. We suggest the modular design of the BAM complex facilitates access to substrates from the protein translocase in the inner membrane.     

Protein secretion and outer membrane assembly in Alphaproteobacteria

The assembly of beta-barrel proteins into membranes is a fundamental process that is essential in Gram-negative bacteria, mitochondria and plastids. Our understanding of the mechanism of beta-barrel assembly is progressing from studies carried out in Escherichia coli and Neisseria meningitidis. Comparative sequence analysis suggests that while many components mediating beta-barrel protein assembly are conserved in all groups of bacteria with outer membranes, some components are notably absent. The Alphaproteobacteria in particular seem prone to gene loss and show the presence or absence of specific components mediating the assembly of beta-barrels: some components of the pathway appear to be missing from whole groups of bacteria (e.g. Skp, YfgL and NlpB), other proteins are conserved but are missing characteristic domains (e.g. SurA). This comparative analysis is also revealing important structural signatures that are vague unless multiple members from a protein family are considered as a group (e.g. tetratricopeptide repeat (TPR) motifs in YfiO, beta-propeller signatures in YfgL). Given that the process of the beta-barrel assembly is conserved, analysis of outer membrane biogenesis in Alphaproteobacteria, the bacterial group that gave rise to mitochondria, also promises insight into the assembly of beta-barrel proteins in eukaryotes.     

Gastrointestinal complications of mitochondrial disease

The clinical presentation of mitochondrial disease can involve a number of organ systems which are seemingly unrelated. Gastrointestinal manifestations are often an early presentation of mitochondrial disorders. Dysphagia, feeding difficulties, gastroesophageal reflux, dysmotility with delayed gastric emptying, intestinal pseudo-obstruction, diarrhea and pancreatic exocrine insufficiency are amongst the major complications. Neuromuscular dysfunction affecting peristalsis is a common pathophysiologic mechanism causing many of these symptoms and treatment is primarily supportive.