Evidence for the Role of B Cells and Immunoglobulins in the Pathogenesis of Multiple Sclerosis

The pathogenesis of multiple sclerosis (MS) remains elusive. Recent reports advocate greater involvement of B cells and immunoglobulins in the initiation and propagation of MS lesions at different stages of their ontogeny. The key role of B cells and immunoglobulins in pathogenesis was initially identified by studies in which patients whose fulminant attacks of demyelination did not respond to steroids experienced remarkable functional improvement following plasma exchange. The positive response to Rituximab in Phase II clinical trials of relapsing-remitting MS confirms the role of B cells. The critical question is how B cells contribute to MS. In this paper, we discuss both the deleterious and the beneficial roles of B cells and immunoglobulins in MS lesions. We provide alternative hypotheses to explain both damaging and protective antibody responses

Genome-wide analysis of the human Alu Yb-lineage.

The Alu Yb-lineage is a \u27young\u27 primarily human-specific group of short interspersed element (SINE) subfamilies that have integrated throughout the human genome. In this study, we have computationally screened the draft sequence of the human genome for Alu Yb-lineage subfamily members present on autosomal chromosomes. A total of 1,733 Yb Alu subfamily members have integrated into human autosomes. The average ages of Yb-lineage subfamilies, Yb7, Yb8 and Yb9, are estimated as 4.81, 2.39 and 2.32 million years, respectively. In order to determine the contribution of the Alu Yb-lineage to human genomic diversity, 1,202 loci were analysed using polymerase chain reaction (PCR)-based assays, which amplify the genomic regions containing individual Yb-lineage subfamily members. Approximately 20 percent of the Yb-lineage Alu elements are polymorphic for insertion presence/absence in the human genome. Fewer than 0.5 percent of the Yb loci also demonstrate insertions at orthologous positions in non-human primate genomes. Genomic sequencing of these unusual loci demonstrates that each of the orthologous loci from non-human primate genomes contains older Y, Sg and Sx Alu family members that have been altered, through various mechanisms, into Yb8 sequences. These data suggest that Alu Yb-lineage subfamily members are largely restricted to the human genome. The high copy number, level of insertion polymorphism and estimated age indicate that members of the Alu Yb elements will be useful in a wide range of genetic analyses

Vaccination with Human Hookworm Vaccine Necator americanus Aspartic Protease-1 M74 Generates Neutralizing Antibodies and a Potent Immune Response in BALB/c Mice

Backgound: Human Hookworm Infection, a neglected tropical disease infects more than 600 million people around the world. Hookworms ingest hemoglobin containing erythrocytes and Necator americanus Aspartic Protease-1 wild type (Na-APR-1wt) a hemoglobinase cleaves hemoglobin to form Heme and Globin. Globin is further digested by other gut enzymes and the nutritional end products are absorbed by the hookworm’s gut wall. Also, Heme which is toxic to hookworm is detoxified by the Necator americanus Glutathione Transferase-1 (Na-GST-1) a detoxification enzyme secreted by the gut of the hookworm. Necator americanus Aspartic Protease-1 M74 (Na-APR-1 M74) is the new vaccine for the Human Hookworm Infection which is currently under pre-clinical development. Na-APR-1 M74 vaccine is an Alhydrogel® adjuvanted vaccine containing the mutant form of the Na-APR-1wt. Neutralizing Na-APR-1wt by potent antibodies (IgG) in the vaccinees will block the initiation of the hemoglobin digestion cascade and starve the hookworms from essential nutrition, leading to their death. Here, we report the results of the neutralizing capacity of antibodies and potency (immunogenicity) of Na-APR-1 M74 vaccine in BALB/c mice. Methods: Serum for IgG was generated by vaccinating BALB/c mice twice subcutaneously with Na-APR-1 M74 an enzymatically inactive mutant form of Na-APR-1wt formulated with Alhydrogel®. Assessment of neutralizing capacity of IgG was performed using the standard Cathepsin-D protease assay using MOCAc substrate. Dose response (% Inhibition vs Dose) was assessed using linear regression analysis. Potency testing of the Na-APR-1M74 clinical drug product was performed by standard bioassay. Median Effective Dose 50 (ED50) with the 95% fiducial limits (95%FL) was estimated using Probit Analysis (SAS® 9.3). Also, Relative Potency (RP) was estimated by the methods described in European Pharmacopeia\u27s Chapter 5.3. Results: Five microgram of IgG neutralized 51.06% of the enzymatic activity of 250ng of Na-APR-1wt. An excellent dose response was also observed. ED50 of 14.15μg (95%FL = 10.47μg -- 18.93μg) and 11.46μg (95%FL = 4.86μg --27.42μg) was estimated for time 1 and 7 month post manufacture respectively. RP at 7 months was found to be 1.23 (95%FL = 0.792--1.917). Conclusion: These preclinical results of the Na-APR-1 M74 vaccine lay the foundation for a Phase 1 Clinical Trial in USA and Brazil. This Na-APR-1 M74 vaccine will be subsequently combined with Necator americanus Glutathione transferase-1 (Na-GST-1) vaccine to form a multivalent human hookworm vaccine

Characterization of a recurrent missense mutation in the forkhead DNA-binding domain of \u3ci\u3eFOXP1\u3c/i\u3e

Haploinsufficiency of Forkhead box protein P1 (FOXP1), a highly conserved transcription factor, leads to developmental delay, intellectual disability, autism spectrum disorder, speech delay, and dysmorphic features. Most of the reported FOXP1 mutations occur on the C-terminus of the protein and cluster around to the forkhead domain. All reported FOXP1 pathogenic variants result in abnormal cellular localization and loss of transcriptional repression activity of the protein product. Here we present three patients with the same FOXP1 mutation, c.1574G\u3eA (p.R525Q), that results in the characteristic loss of transcription repression activity. This mutation, however, represents the first reported FOXP1 mutation that does not result in cytoplasmic or nuclear aggregation of the protein but maintains normal nuclear localization

APACHE III outcome prediction in patients admitted to the intensive care unit after liver transplantation: a retrospective cohort study

<p>Abstract</p> <p>Background</p> <p>The Acute Physiology and Chronic Health Evaluation (APACHE) III prognostic system has not been previously validated in patients admitted to the intensive care unit (ICU) after orthotopic liver transplantation (OLT). We hypothesized that APACHE III would perform satisfactorily in patients after OLT</p> <p>Methods</p> <p>A retrospective cohort study was performed. Patients admitted to the ICU after OLT between July 1996 and May 2008 were identified. Data were abstracted from the institutional APACHE III and liver transplantation databases and individual patient medical records. Standardized mortality ratios (with 95% confidence intervals) were calculated by dividing the observed mortality rates by the rates predicted by APACHE III. The area under the receiver operating characteristic curve (AUC) and the Hosmer-Lemeshow C statistic were used to assess, respectively, discrimination and calibration of APACHE III.</p> <p>Results</p> <p>APACHE III data were available for 918 admissions after OLT. Mean (standard deviation [SD]) APACHE III (APIII) and Acute Physiology (APS) scores on the day of transplant were 60.5 (25.8) and 50.8 (23.6), respectively. Mean (SD) predicted ICU and hospital mortality rates were 7.3% (15.4) and 10.6% (18.9), respectively. The observed ICU and hospital mortality rates were 1.1% and 3.4%, respectively. The standardized ICU and hospital mortality ratios with their 95% C.I. were 0.15 (0.07 to 0.27) and 0.32 (0.22 to 0.45), respectively.</p> <p>There were statistically significant differences in APS, APIII, predicted ICU and predicted hospital mortality between survivors and non-survivors. In predicting mortality, the AUC of APACHE III prediction of hospital death was 0.65 (95% CI, 0.62 to 0.68). The Hosmer-Lemeshow C statistic was 5.288 with a p value of 0.871 (10 degrees of freedom).</p> <p>Conclusion</p> <p>APACHE III discriminates poorly between survivors and non-survivors of patients admitted to the ICU after OLT. Though APACHE III has been shown to be valid in heterogenous populations and in certain groups of patients with specific diagnoses, it should be used with caution – if used at all – in recipients of liver transplantation.</p

DHODH modulates transcriptional elongation in the neural crest and melanoma

Melanoma is a tumour of transformed melanocytes, which are originally derived from the embryonic neural crest. It is unknown to what extent the programs that regulate neural crest development interact with mutations in the BRAF oncogene, which is the most commonly mutated gene in human melanoma1. We have used zebrafish embryos to identify the initiating transcriptional events that occur on activation of human BRAF(V600E) (which encodes an amino acid substitution mutant of BRAF) in the neural crest lineage. Zebrafish embryos that are transgenic for mitfa:BRAF(V600E) and lack p53 (also known as tp53) have a gene signature that is enriched for markers of multipotent neural crest cells, and neural crest progenitors from these embryos fail to terminally differentiate. To determine whether these early transcriptional events are important for melanoma pathogenesis, we performed a chemical genetic screen to identify small-molecule suppressors of the neural crest lineage, which were then tested for their effects on melanoma. One class of compound, inhibitors of dihydroorotate dehydrogenase (DHODH), for example leflunomide, led to an almost complete abrogation of neural crest development in zebrafish and to a reduction in the self-renewal of mammalian neural crest stem cells. Leflunomide exerts these effects by inhibiting the transcriptional elongation of genes that are required for neural crest development and melanoma growth. When used alone or in combination with a specific inhibitor of the BRAF(V600E) oncogene, DHODH inhibition led to a marked decrease in melanoma growth both in vitro and in mouse xenograft studies. Taken together, these studies highlight developmental pathways in neural crest cells that have a direct bearing on melanoma formation

Comparison of MRI lesion evolution in different central nervous system demyelinating disorders

Background and Objective: There are few studies that compare lesion evolution across different CNS demyelinating diseases, yet knowledge of this may be important for diagnosis and understanding differences in disease pathogenesis. We sought to compare MRI T2-lesion evolution in myelin-oligodendrocyte-glycoprotein-IgG-associated disorder (MOGAD), aquaporin-4-IgG-positive neuromyelitis optica spectrum disorder (AQP4-IgG-NMOSD), and multiple sclerosis (MS). Methods: In this descriptive study, we retrospectively identified Mayo Clinic patients with MOGAD, AQP4-IgG-NMOSD, or MS and: 1) brain or myelitis attack; 2) available attack MRI within 6 weeks; and 3) follow-up MRI beyond 6 months without interval relapses in that region. Two neurologists identified the symptomatic or largest T2-lesion for each patient (index lesion). MRIs were then independently reviewed by two neuroradiologists blinded to diagnosis to determine resolution of T2-lesions by consensus. The index T2-lesion area was manually outlined acutely and at follow-up to assess variation in size. Results: We included 156 patients (MOGAD, 38; AQP4-IgG-NMOSD, 51; MS, 67) with 172 attacks (brain, 81; myelitis, 91). The age (median [range]) differed between MOGAD (25 [2-74]), AQP4-IgG-NMOSD (53 [10-78]) and MS (37 [16-61]) (p&lt;0.01) and female sex predominated in the AQP4-IgG-NMOSD (41/51 [80%]) and MS (51/67 [76%]) groups but not among those with MOGAD (17/38 [45%]). Complete resolution of the index T2-lesion was more frequent in MOGAD (brain, 13/18[72%]; spine, 22/28[79%]) than AQP4-IgG-NMOSD (brain, 3/21[14%]; spine, 0/34[0%]) and MS (brain, 7/42[17%]; spine, 0/29[0%]), p&lt;0.001. Resolution of all T2-Lesions occurred most often in MOGAD (brain, 7/18[39%]; spine, 22/28[79%]) than AQP4-IgG-NMOSD (brain, 2/21[10%]; spine, 0/34[0%]), and MS (brain, 2/42[5%]; spine, 0/29[0%]), p&lt; 0.01. There was a larger median (range) reduction in T2-lesion area in mm2 on follow-up axial brain MRI with MOGAD (213[55-873]) than AQP4-IgG-NMOSD (104[0.7-597]) (p=0.02) and MS, 36[0-506]) (p&lt; 0.001) and the reductions in size on sagittal spine MRI follow-up in MOGAD (262[0-888]) and AQP4-IgG-NMOSD (309[0-1885]) were similar (p=0.4) and greater than MS (23[0-152]) (p&lt;0.001)

Vaccination with DNA plasmids expressing Gn coupled to C3d or alphavirus replicons expressing Gn protects mice against rift valley fever virus

Background: Rift Valley fever (RVF) is an arthropod-borne viral zoonosis. Rift Valley fever virus (RVFV) is an important biological threat with the potential to spread to new susceptible areas. In addition, it is a potential biowarfare agent. Methodology/Principal Findings: We developed two potential vaccines, DNA plasmids and alphavirus replicons, expressing the Gn glycoprotein of RVFV alone or fused to three copies of complement protein, C3d. Each vaccine was administered to mice in an all DNA, all replicon, or a DNA prime/replicon boost strategy and both the humoral and cellular responses were assessed. DNA plasmids expressing Gn-C3d and alphavirus replicons expressing Gn elicited high titer neutralizing antibodies that were similar to titers elicited by the live-attenuated MP12 virus. Mice vaccinated with an inactivated form of MP12 did elicit high titer antibodies, but these antibodies were unable to neutralize RVFV infection. However, only vaccine strategies incorporating alphavirus replicons elicited cellular responses to Gn. Both vaccines strategies completely prevented weight loss and morbidity and protected against lethal RVFV challenge. Passive transfer of antisera from vaccinated mice into naïve mice showed that both DNA plasmids expressing Gn-C3d and alphavirus replicons expressing Gn elicited antibodies that protected mice as well as sera from mice immunized with MP12. Conclusion/Significance: These results show that both DNA plasmids expressing Gn-C3d and alphavirus replicons expressing Gn administered alone or in a DNA prime/replicon boost strategy are effective RVFV vaccines. These vaccine strategies provide safer alternatives to using live-attenuated RVFV vaccines for human use. © 2010 Bhardwaj et al