Genetic Deletion of a Single Immunodominant T-cell Response Confers Susceptibility to Virus-induced Demyelination

An important question in neuropathology involves determining the antigens that are targeted during demyelinating disease. Viral infection of the central nervous system (CNS) leads to T-cell responses that can be protective as well as pathogenic. In the Theiler’s murine encephalomyelitis virus (TMEV) model of demyelination it is known that the immune response to the viral capsid protein 2 (VP2) is critical for disease pathogenesis. This study shows that expressing the whole viral capsid VP2 or the minimal CD8-specific peptide VP2(121-130) as “self” leads to a loss of VP2-specific immune responses. Loss of responsiveness is caused by T cell-specific tolerance, as VP2-specific antibodies are generated in response to infection. More importantly, these mice lose the CD8 T-cell response to the immunodominant peptide VP2(121-130), which is critical for the development of demyelinating disease. The transgenic mice fail to clear the infection and develop chronic demyelinating disease in the spinal cord white matter. These findings demonstrate that T-cell responses can be removed by transgenic expression and that lack of responsiveness alters viral clearance and CNS pathology. This model will be important for understanding the mechanisms involved in antigen-specific T-cell deletion and the contribution of this response to CNS pathology

Serious fungal infections in Thailand

The burden of serious fungal infection in Thailand is increasing but data regarding its incidence and prevalence are lacking. In this study we aimed to estimate the burden of serious fungal diseases in Thailand based on the size of the populations at risk and available epidemiological databases. Data derived from The Bureau of Epidemiology, Department of Disease Control, Thai Ministry of Public Health, World Health Organisation, international and local reports, and some unreported data were used. When no data existed, risk populations were used to estimate frequencies of fungal infections, using previously described methodology by LIFE. Recurrent vulvovaginal candidiasis (>4 episodes per year) is estimated to occur in 3,310 per 100,000 population. Using a previously described rate that 14/10,000 admissions are with fungaemia and 94% of those are Candida, we estimated 8,650 patients with candidaemia. The prevalence of chronic pulmonary aspergillosis is relatively high with a total of 19,044, approximately half subsequent to pulmonary tuberculosis. Invasive aspergillosis is estimated to affect 941 patients following leukaemia therapy, transplantations, and chronic obstructive pulmonary disease, approximately 1.4/100,000. In addition, allergic bronchopulmonary aspergillosis and severe asthma with fungal sensitisation were estimated at approximately 58.4/100,000 and 77/100,000, respectively. Given approximately 8,134 new cases of AIDS annually, cryptococcal meningitis, Pneumocystis pneumonia, and Talaromyces marneffei infection are estimated at 1.9/100,000, 2.6/100,000, and 0.3/100,000, respectively. The present study indicates that about 1.93% (1,254,562) of the population is affected by serious fungal infections. Owing to the lack of data, reports, and statistics, the number of patients with mycoses in Thailand can only be estimated

An Autopsy Study Describing Causes of Death and Comparing Clinico-Pathological Findings among Hospitalized Patients in Kampala, Uganda

Background: Information on causes of death in HIV-infected patients in Sub-Saharan Africa is mainly derived from observational cohort and verbal autopsy studies. Autopsy is the gold standard to ascertain cause of death. We conducted an autopsy study to describe and compare the clinical and autopsy causes of death and contributory findings in hospitalized HIV-infected and HIV-uninfected patients in Uganda. Methods: Between May and September 2009 a complete autopsy was performed on patients that died on a combined infectious diseases gastroenterology ward in Mulago Hospital in Kampala, Uganda. Autopsy cause of death and contributing findings were based on the macro- and microscopic post-mortem findings combined with clinical information. Clinical diagnoses were reported by the ward doctor and classified as confirmed, highly suspected, considered or not considered, based on information derived from the medical chart. Results are reported according to HIV serostatus. Results: Fifty-three complete autopsies were performed in 66 % HIV-positive, 21 % HIV-negative and 13 % patients with an unknown HIV serological status. Infectious diseases caused death in 83 % of HIV-positive patients, with disseminated TB as the main diagnosis causing 37 % of deaths. The spectrum of illness and causes of death were substantially different betwee

Mission impossible? The paradoxes of stretch goal setting

© 2016, © The Author(s) 2016. Stretch goal setting is a process involving multiple and nested paradoxes. The paradoxical side of stretch is attractive because it holds great promise yet dangerous because it triggers processes that are hard to control. Paradoxes are not readily managed by assuming a linear relation between the here and now and the intended future perfect. Before adopting stretch goal setting, managers should thus be prepared for the tensions and contradictions created by nested or interwoven paradoxes. Achieving stretch goals can be as difficult for the managers seeking to direct the process as for designated delegates. While the increasing popularity of stretch goal setting is understandable, its unexpected consequences must be taken into account. The inadequate use of stretch goals can jeopardize the social sustainability of organizations as well as their societal support systems

Drosophila Dynein Intermediate Chain Gene, Dic61B, Is Required for Spermatogenesis

This study reports the identification and characterization of a novel gene, Dic61B, required for male fertility in Drosophila. Complementation mapping of a novel male sterile mutation, ms21, isolated in our lab revealed it to be allelic to CG7051 at 61B1 cytogenetic region, since two piggyBac insertion alleles, CG7051c05439 and CG7051f07138 failed to complement. CG7051 putatively encodes a Dynein intermediate chain. All three mutants, ms21, CG7051c05439 and CG7051f07138, exhibited absolute recessive male sterility with abnormally coiled sperm axonemes causing faulty sperm individualization as revealed by Phalloidin staining in Don Juan-GFP background. Sequencing of PCR amplicons uncovered two point mutations in ms21 allele and confirmed the piggyBac insertions in CG7051c05439 and CG7051f07138 alleles to be in 5′UTR and 4th exon of CG7051 respectively, excision of which reverted the male sterility. In situ hybridization to polytene chromosomes demonstrated CG7051 to be a single copy gene. RT-PCR of testis RNA revealed defective splicing of the CG7051 transcripts in mutants. Interestingly, expression of cytoplasmic dynein intermediate chain, α, β, γ tubulins and α-spectrin was normal in mutants while ultra structural studies revealed defects in the assembly of sperm axonemes. Bioinformatics further highlighted the homology of CG7051 to axonemal dynein intermediate chain of various organisms, including DNAI1 of humans, mutations in which lead to male sterility due to immotile sperms. Based on these observations we conclude that CG7051 encodes a novel axonemal dynein intermediate chain essential for male fertility in Drosophila and rename it as Dic61B. This is the first axonemal Dic gene of Drosophila to be characterized at molecular level and shown to be required for spermatogenesis

The effect Akt2 deletion on tumor development in Pten+/− mice

The serine/threonine kinase Akt is frequently activated in human cancers and is considered an attractive therapeutic target. However, the relative contributions of the different Akt isoforms to tumorigenesis, and the effect of their deficiencies on cancer development are not well understood. We had previously shown that Akt1 deficiency is sufficient to markedly reduce the incidence of tumors in Pten+/− mice. Particularly, Akt1 deficiency inhibits endometrial carcinoma and prostate neoplasia in Pten+/− mice. Here, we analyzed the effect of Akt2 deficiency on the incidence of tumors in Pten+/− mice. Relative to Akt1, Akt2 deficiency had little-to-no effect on the incidence of prostate neoplasia, endometrial carcinoma, intestinal polyps and adrenal lesions in Pten+/− mice. However, Akt2 deficiency significantly decreased the incidence of thyroid tumors in Pten+/−, which correlates with the relatively high level of Akt2 expression in the thyroid. Thus, unlike Akt1 deletion, Akt2 deletion is not sufficient to markedly inhibit tumorigenesis in Pten+/− mice in most tested tissues. The relatively small effect of Akt2 deletion on the inhibition of tumorigenesis in Pten+/− mice could be explained, in part, by an insufficient decrease in total Akt activity, due to the relatively lower Akt2 versus Akt1 expression, and relatively high blood insulin levels in Pten+/−Akt2−/− mice. The relatively high blood insulin levels in Pten+/−Akt2−/− mice may elevate the activity of Akt1, and possibly Akt3, thus, limiting the reduction of total Akt activity and preventing this activity from dropping to a threshold level required to inhibit tumorigenesis

Theiler's Murine Encephalomyelitis Virus as a Vaccine Candidate for Immunotherapy

The induction of sterilizing T-cell responses to tumors is a major goal in the development of T-cell vaccines for treating cancer. Although specific components of anti-viral CD8+ immunity are well characterized, we still lack the ability to mimic viral CD8+ T-cell responses in therapeutic settings for treating cancers. Infection with the picornavirus Theiler's murine encephalomyelitis virus (TMEV) induces a strong sterilizing CD8+ T-cell response. In the absence of sterilizing immunity, the virus causes a persistent infection. We capitalized on the ability of TMEV to induce strong cellular immunity even under conditions of immune deficiency by modifying the virus to evaluate its potential as a T-cell vaccine. The introduction of defined CD8+ T-cell epitopes into the leader sequence of the TMEV genome generates an attenuated vaccine strain that can efficiently drive CD8+ T-cell responses to the targeted antigen. This virus activates T-cells in a manner that is capable of inducing targeted tissue damage and glucose dysregulation in an adoptive T-cell transfer model of diabetes mellitus. As a therapeutic vaccine for the treatment of established melanoma, epitope-modified TMEV can induce strong cytotoxic T-cell responses and promote infiltration of the T-cells into established tumors, ultimately leading to a delay in tumor growth and improved survival of vaccinated animals. We propose that epitope-modified TMEV is an excellent candidate for further development as a human T-cell vaccine for use in immunotherapy

A Young Drosophila Duplicate Gene Plays Essential Roles in Spermatogenesis by Regulating Several Y-Linked Male Fertility Genes

Gene duplication is supposed to be the major source for genetic innovations. However, how a new duplicate gene acquires functions by integrating into a pathway and results in adaptively important phenotypes has remained largely unknown. Here, we investigated the biological roles and the underlying molecular mechanism of the young kep1 gene family in the Drosophila melanogaster species subgroup to understand the origin and evolution of new genes with new functions. Sequence and expression analysis demonstrates that one of the new duplicates, nsr (novel spermatogenesis regulator), exhibits positive selection signals and novel subcellular localization pattern. Targeted mutagenesis and whole-transcriptome sequencing analysis provide evidence that nsr is required for male reproduction associated with sperm individualization, coiling, and structural integrity of the sperm axoneme via regulation of several Y chromosome fertility genes post-transcriptionally. The absence of nsr-like expression pattern and the presence of the corresponding cis-regulatory elements of the parental gene kep1 in the pre-duplication species Drosophila yakuba indicate that kep1 might not be ancestrally required for male functions and that nsr possibly has experienced the neofunctionalization process, facilitated by changes of trans-regulatory repertories. These findings not only present a comprehensive picture about the evolution of a new duplicate gene but also show that recently originated duplicate genes can acquire multiple biological roles and establish novel functional pathways by regulating essential genes

Structural basis for inhibition of homologous recombination by the RecX protein

The RecA/RAD51 nucleoprotein filament is central to the reaction of homologous recombination (HR). Filament activity must be tightly regulated in vivo as unrestrained HR can cause genomic instability. Our mechanistic understanding of HR is restricted by lack of structural information about the regulatory proteins that control filament activity. Here, we describe a structural and functional analysis of the HR inhibitor protein RecX and its mode of interaction with the RecA filament. RecX is a modular protein assembled of repeated three-helix motifs. The relative arrangement of the repeats generates an elongated and curved shape that is well suited for binding within the helical groove of the RecA filament. Structure-based mutagenesis confirms that conserved basic residues on the concave side of RecX are important for repression of RecA activity. Analysis of RecA filament dynamics in the presence of RecX shows that RecX actively promotes filament disassembly. Collectively, our data support a model in which RecX binding to the helical groove of the filament causes local dissociation of RecA protomers, leading to filament destabilisation and HR inhibition

Combination leflunomide and methotrexate (MTX) therapy for patients with active rheumatoid arthritis failing MTX monotherapy: open-label extension of a randomized, double-blind, placebo controlled trial

P e r s o n a l n o n -c o m m e r c i a l u s e o n l y . T h e J o u r n a l o f R h e u m a t o l o g y . C o p y r i g h t © 2 0 0 4 . A l l r i g h t s r e s e r v e d Conclusion. Response to therapy was maintained to 48 weeks of treatment in patients who continued to receive LEF and MTX during the extension. Importantly, ACR20 response rates after 24 weeks of LEF therapy were similar between patients switched from PLA to LEF without loading dose, and those who received a loading does of LEF (100 mg/day × 2 days) at randomization. Fewer adverse events were reported in patients switched to LEF without a loading dose. (J Rheumatol 2004;31:1521-31