Chronically inflamed human tissues are infiltrated by highly differentiated Th17 lymphocytes

Chronic inflammatory diseases are characterized by local tissue injury caused by immunocompetent cells, in particular CD4(+) T lymphocytes, that are involved in the pathogenesis of these disorders via the production of distinctive sets of cytokines. Here, we have characterized single CD4(+) T cells that infiltrate inflamed tissue taken from patients with psoriasis, Crohn's disease, rheumatoid arthritis, or allergic asthma. Results from a cytokine production and gene profile analysis identified a population of in vivo differentiatedretinoid-related orphan receptor gamma-expressing T cells, producing high levels of IL-17, that can represent up to 30% of infiltrating T lymphocytes. Activated Th17 cells produced IL-26, TNF-alpha, lymphotoxin-beta, and IL-22. IL-17 and IL-22 concentrations secreted by tissue infiltrating Th17 cells could reach up to 100 nM and were inversely correlated with the production of Th1- and Th2-associated cytokines. In addition, tissue-infiltrating Th17 cells are also characterized by high cell surface expression of CCR6, a chemokine receptor that was not expressed by Th1 and Th2 cells, isolated from the same lesions, and by the production of CCL20/MIP3alpha, a CCR6 ligand, associated with tissue infiltration. Culture supernatants of activated Th17 cells, isolated from psoriatic lesions, induced the expression of gene products associated with inflammation and abnormal keratinocyte differentiation in an IL-17 and IL-22-dependent manner. These results show that tissue-infiltrating Th17 cells contribute to human chronic inflammatory disease via the production of several inflammatory cytokines and the creation of an environment contributing to their migration and sequestration at sites of inflammation.     

Anticonvulsant hypersensitivity syndrome after phenytoin administration in an adolescent patient: a case report and review of literature

Background

Hypersensitivity is a rare adverse drug reaction (ADR) associated with anti-epileptic medications. Phenytoin is one of the commonly used drugs for treatment of epilepsy that encounters a hypersensitivity reaction. This reaction can be ranged from mild cutaneous rash to anticonvulsant hypersensitivity syndrome (AHS) or drug reaction with eosinophilia and systemic symptoms (DRESS) that includes fever, rash, eosinophilia and involvement of multiple internal organs.

Case presentation

A 15 year old middle eastern female patient from Gaza strip with free past medical and allergic history. She presented to An-Najah National University Hospital (NNUH) in Nablus with intermittent high grade fever, jaundice, rash and skin peeling. On examination, she had axillary and inguinal lymphadenopathy, moderate splenomegaly and diffuse maculopapular rash. The patient was on phenytoin which started 1 month prior to her presentation as a seizure prophylaxis due to previous head injury. Eventually, the patient was diagnosed with AHS/DRESS.

Conclusions

AHS is a diagnosis of exclusion and it is significantly underreported that requires a high index of suspicion. We liked to share this case and shed the light in more details on AHS/DRESS. Our goal was to help making AHS more reported in the literature in adolescent patients, as well as to make physicians more alert of this condition’s seriousness when they prescribe antiepileptic medications in particular. In this report, we included the first case of AHS which was reported in an adolescent patient in Palestine. Moreover, we reviewed the available literature for a better understanding of the pathophysiology and management of AHS. We still believe that the full understanding of the pathogenesis of AHS is lacking, and also we are lacking a clinical tool or scoring system to determine the severity of AHS/DRESS.

     

Apurinic/apyrimidinic endonuclease1/redox factor-1 (Ape1/Ref-1) is essential for IL-21-induced signal transduction through ERK1/2 pathway

IL-21 is a pleiotropic cytokine that regulates T-cell and B-cell differentiation, NK-cell activation, and dendritic cell functions. IL-21 activates the JAK-STAT, ERK, and PI3K pathways. We report here that Ape1/Ref-1 has an essential role in IL-21-induced cell growth signal transduction. Overexpression of Ape1/Ref-1 enhances IL-21-induced cell proliferation, but it is suppressed by overexpressing an N-terminal deletion mutant of Ape1/Ref-1 that lacks the redox domain. Furthermore, knockdown of the Ape1/Ref-1 mRNA dramatically compromises IL-21-induced ERK1/2 activation and cell proliferation with increasing cell death. These impaired activities are recovered by the re-expression of Ape1/Ref-1 in the knockdown cells. Our findings are the first demonstration that Ape1/Ref-1 is an indispensable molecule for the IL-21-mediated signal transduction through ERK1/2 activation.     

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO₂ drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy.     

NtLRP1, a tobacco leucine-rich repeat gene with a possible role as a modulator of the hypersensitive response

Plant defense responses against pathogens often involve the restriction of the pathogen to its site of penetration achieved through the combined effects of the hypersensitive response (HR) and its tightly connected localized acquired resistance (LAR). The tobacco DD9-3 expressed sequence tag was previously isolated from a screen designed to isolate genes induced early during the HR, thus potentially involved in the induction/regulation of the HR or LAR. Translation of the open reading frame of DD9-3 revealed a leucine-rich repeat (LRR) domain highly homologous with the receptor domain of a receptor kinase, suggesting a potential function in signaling pathways. The full-length cDNA was cloned. It encodes a small (232 amino acids) LRR protein, designated Nicotiana tabacum leucine-rich protein 1 (NtLRP1), containing a signal peptide, four leucine zipper repeats, five LRR repeats, and a C-terminal domain rich in proline. NtLRP1 expression is induced early during the HR initiated by elicitins, Ralstonia solanacearum, or Tobacco mosaic virus. NtLRP1 coupled with the green fluorescent protein localizes to the endoplasmic reticulum (ER). Loss-of-function through virus-induced gene silencing or through RNA interference did not modify the elicitin-induced HR or LAR. Gain-of-function experiments through transient Agrobacterium tumefaciens-mediated NtLRP1 expression in tobacco leaves caused the suppression of the HR induced by 2 nM elicitin and delayed the HR when the elicitin was applied at higher concentrations. The results suggest that NtLRP1 acts as a modulator of the HR and that retention in the ER is essential for its function.     

Impaired IL-7 signaling may explain a case of atypical JAK3-SCID

Janus kinase 3-severe combined immunodeficiency (JAK3-SCID) is an autosomal recessive immunodeficiency disease caused by various mutations in the JAK3 gene. Typical JAK3-SCID is characterized by a phenotype in which B cells are present but T and NK cells are not, the T^?B⁺NK^? phenotype, and by impaired signaling through cytokine receptors that use the common gamma chain (γc) subunit. An atypical JAK3-SCID case carrying a single glutamate to glycine substitution mutation (E481G) in the JH3 domain of one JAK3 allele, and a deletion mutation (del482-596) in the JH3 and JH2 domains of the other allele was reported previously. Although this patient had CD4⁺ T cells and NK cells unlike typical cases, the CD4⁺ T cells were functionally impaired. We report here that the JAK3-E481G mutant transduced IL-2-, IL-4-, IL-15-, and IL-21-induced signals as efficiently as wild-type JAK3. However, this mutant failed to respond to IL-7 by phosphorylating JAK1, JAK3, or STAT5. The other mutant JAK3, JAK3-del482-596, was non-functional. Thus, an impaired IL-7 signal may cause SCID and compromise T-cell differentiation, even if the IL-15 signal is preserved and supports NK-cell development, as in this patient.     

Incubation temperature and hemoglobin dielectric of chicken embryos incubated under the influence of electric field

Eggs from a layer-type breeder flock (Baladi, King Saud University) between 61 and 63 weeks of age were used in 3 trials to study the effects of electric field (EF) during incubation on the internal temperature of incubation, and eggs and hemoglobin (Hb) dielectric of chicken embryos at 18 days of age. Dielectric relative permittivity (epsilon') and conductivity (sigma) of Hb were examined in the range of frequency from 20 to 100 kHz. The values of dielectric increment (Deltaepsilon') and the relaxation times (tau) of Hb molecules were calculated. The internal temperature of eggs was measured in empty (following the removal of egg contents) and fertilized eggs in trials 1 and 2, respectively. The level of the EF was 30 kV/m, 60 Hz. EF incubation of embryos influenced the temperature of incubation and electrical properties of Hb molecules and did not influence the temperature of incubation and internal environment of eggs when empty eggs were incubated. EF incubation of fertilized eggs significantly raised the temperature of incubation, egg air cell, and at the surface of the egg yolk by approximately 0.09, 0.60, and 0.61 degrees F, respectively and Hb epsilon', sigma, Deltaepsilon', and tau as a function of the range of frequency of 20 to 100 kHz when compared with their counterparts of the control group. It was concluded that the exposure of fertilized chicken eggs to EF of 30 kV/m, 60 Hz, during incubation altered dielectric properties of Hb and that probably affected cell to cell communication and created the right environment for enhancing the growing process and heat production of embryos consequently increasing the temperature of the internal environment of the egg, and incubation.     

Phylogenetic diversity and biotechnological potentials of marine bacteria from continental slope of eastern Arabian Sea

Marine environments are substantially untapped source for the isolation of bacteria with the capacity to produce various extracellular hydrolytic enzymes, which have important ecological roles and promising biotechnological applications. Hydrolases constitute a class of enzymes widely distributed in nature from bacteria to higher eukaryotes. Marine microbial communities are highly diverse and have evolved during extended evolutionary processes of physiological adaptations under the influence of a variety of ecological conditions and selection pressures. A number of marine hydrolases have been described, including amylases, lipases and proteases, which are being used extensively for biotechnological applications. The present study was carried out to isolate marine bacteria from continental slope sediments of the eastern Arabian Sea and explore their biotechnological potential. Among the 119 isolates screened, producers of amylases (15%), caseinases (40%), cellulases (40%), gelatinases (60%), lipases (26%), ligninases (33%), phytase (11%) and Malachite Green dye degraders (16%) were detected. Phylogenetic analysis based on 16S rRNA gene sequencing showed that predominant marine sediment bacteria possessing more than four enzymatic activities belonged to the phyla Firmicutes and Proteobacteria, was assigned to the genera Bacillus, Planococcus, Staphylococcus, Chryseomicrobium, Exiguobacterium and Halomonas. Biodegradation of the dye Malachite Green using the liquid decolorization assay showed that both the individual cultures (Bacillus vietnamensis, Planococcus maritimus and Bacillus pumilus) and their consortium were able to decolorize more than 70% of dye within 24?h of incubation. This is the first report on diversity and extracellular hydrolytic enzymatic activities and bioremediation properties of bacteria from continental slope sediment of eastern Arabian Sea.