Polymorphism of sheep MHC Class IIb gene TAPASIN

The Major Histocompatibility Complex (MHC) is one of the most gene dense regions in the genome and studies in several species have shown significant associations between the MHC and disease. The endoplasmic reticular glycoprotein, tapasin, is involved in the MHC class I antigen presentation pathway. Sheep TAPASIN is located in the class IIb region of the MHC. Sheep TAPASIN was subcloned from BAC and cosmid genomic clones and DNA sequenced. TAPASIN is 9549 bp in length and encodes a protein of 447 amino acids. The structure of sheep TAPASIN was similar to other mammals and consisted of eight exons with a distinctively larger intron between exon three and four. Sheep TAPASIN gene had high sequence identity with other mammalian TAPASINs. The TAPASIN gene sequence is conserved across many mammalian species and is possibly maintained through purifying selection with the average ratio of ds/dn of 3.9. Twenty-six SNPs in sheep TAPASIN were identified

The genetic architecture of the MHC class II region in British Texel sheep

Understanding the structure of the major histocompatibility complex, especially the number and frequency of alleles, loci and haplotypes, is crucial for efficient investigation of the way in which the MHC influences susceptibility to disease. Nematode infection is one of the most important diseases suffered by sheep, and the class II region has been repeatedly associated with differences in susceptibility and resistance to infection. Texel sheep are widely used in many different countries and are relatively resistant to infection. This study determined the number and frequency of MHC class II genes in a small flock of Texel sheep. There were 18 alleles at DRB1, 9 alleles at DQA1, 13 alleles at DQB1, 8 alleles at DQA2 and 16 alleles at DQB2. Several haplotypes had no detectable gene products at DQA1, DQB1 or DQB2, and these were defined as null alleles. Despite the large numbers of alleles, there were only 21 distinct haplotypes in the population. The relatively small number of observed haplotypes will simplify finding disease associations because common haplotypes provide more statistical power but complicate the discrimination of causative mutations from linked marker loci

Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same regio

Predictive mutational bioinformatic analysis of variation in the skin and wool associated corneodesmosin (CDSN) gene in sheep

Corneodesmosin (CDSN) is an important component of the desmosome in the epidermal cornified stratum and inner root sheath of hair follicles. DNA from a sheep BAC clone previously identified by us to contain CDSN was PCR amplified using cattle-derived primers and the product sequenced. A region of 4579bp containing CDSN was shown to contain two exons separated by one intron and spanning 3683bp. The DNA encodes a predicted protein of 546 amino acids. Phylogenetic analysis shows that sheep CDSN falls within a clade containing cattle and other ruminant-like species. Comparison of sequences generated from 12 unrelated merino sheep and the International Sheep Genome Consortium (ISGC) data identified 58 single nucleotide polymorphisms (SNPs) within the 4579bp region of which 16 are contained within coding sequences (1 in 80bp). The SNPs identified in this study will add to the Major Histocompatibility Complex (MHC) SNP panel, which will allow extensive haplotyping of the sheep MHC in future studies

A Randomized Phase 2 Trial of Nivolumab and Stereotactic Ablative Body Radiotherapy (SABR) in Advanced Non-Small Cell Lung Cancer, Progressing After First- or Second-Line Chemotherapy (NIVORAD)

PURPOSE/OBJECTIVE(S): Synergy and abscopal phenomena have been observed with radiation and immunotherapy in pre-clinical and early clinical studies. Nivolumab, a PD-1 receptor antibody, improved overall survival in advanced NSCLC progressing after chemotherapy. We hypothesized that the addition of SABR might increase the activity of nivolumab. The aim of NIVORAD was to determine the activity and safety of treating a site of disease with a single fraction of SABR during therapy with nivolumab in advanced NSCLC progressing after 1 or 2 lines of chemotherapy. MATERIALS/METHODS: Adults with metastatic NSCLC progressing after 1 or 2 lines of chemotherapy and a disease site suitable for SABR were randomly assigned (2:1) to either nivolumab 240mg 2-weekly until disease progression or prohibitive toxicity given together with a single fraction of SABR (18-20 Gy on day 8-14 of cycle 1); or, the same regimen of nivolumab without SABR. The primary endpoint was progression-free survival (PFS) at 6 months. Secondary endpoints included objective tumor response rate (OTRR), overall survival (OS), PFS at 1 year and 2 years, and adverse events (AEs). The planned sample size of 120 provided 80% power with a 1-sided type 1 error rate of 5% to distinguish the observed proportions alive and progression free at 6 months from benchmarks of 50% (worthy of pursuit) versus 35%. The study was closed early because of slow accrual. RESULTS: Fifty of the planned 120 participants were recruited from MAR2017 to JUN2019 (median age 66 years; male 58%; ECOG PS 0 32%, PS 1 68%; current smoker 30%) and randomly assigned to either nivolumab plus SABR (n = 34) or nivolumab alone (n = 16). Median follow-up was 25 months. PFS was similar among those assigned nivolumab plus SABR versus nivolumab alone (HR = 0.82, 95% CI 0.44 to 1.54, P = 0.6; PFS at 6mo 44% vs 43%, at 1y 27% vs 19%, and at 2y 16% vs 6%, respectively). OTRR (8/34 [24%] vs 4/16 [25%]) and OS (HR 0.94, P = 0.9) were also similar in the two treatment groups, as were the numbers of participants with grade 3-4 AEs: 24/30 (80%) vs 12/16 (75%) respectively. There were no treatment-related deaths in either arm. CONCLUSION: Nivolumab plus SABR demonstrated similar activity and safety to nivolumab alone in NSCLC progressing after 1 or 2 lines of chemotherapy, with a potential signal of long-term efficacy, although the study was underpowered to detect this. Research should focus on identifying more active regimens of SABR and immunotherapy worthy of further evaluation.</p

Synthesis of 2,6-Di(pyrazol-1-yl)pyrazine derivatives and the spin-state behavior of their iron(II) complexes

Chlorination of 2,6-bis(pyrazol-1-yl)pyrazine (bppz) with Na- ClO in acetic acid afforded 2,6-bis(4-chloropyrazol-1-yl)pyrazine (LCl). 2,6-Bis(4-bromopyrazol-1-yl)pyrazine (LBr), 2,6-bis(4-iodopyrazol-1- yl)pyrazine (LI), 2,6-bis(4-methylpyrazol- 1-yl)pyrazine (L Me), and 2,6-bis(4-nitropyrazol-1- yl)pyrazine (LNO ) were also prepared by reactions of the preformed 4-substituted pyrazoles with 2,6-dichloropyrazine. The reduction of LNO with iron powder gave 2,6-bis(4- aminopyrazol-1-yl)pyrazine (L NH) and LI was converted into 2,6-bis[4-(phenylethynyl)pyrazol-1-yl]pyrazine (LCCPh) by a Sonogashira coupling reaction. The salts [Fe(LMe)]X (X- = BF - and ClO -) underwent thermal spin-crossover abruptly at around 200 K in one and two steps, respectively. The [Fe(LMe)]X salts exhibited dif- ferent light-induced excited spin-state trapping (LIESST) behavior; the BF - salt behaves classically [T(LIESST) = 93 K], but the ClO - salt undergoes a multistep LIESST relaxation. In contrast, solid [Fe(L Cl)][BF]2 adopts a fixed 2:1 high/ low-spin-state population that does not change with temperature below 300 K, whereas [Fe(LBr)][BF]2 and [Fe(L I)][BF]2 form low-spin solvated crystals that are transformed into high-spin powders on drying. The pyrazinyl group in the LR ligands slightly stabilizes the low-spin state of the complexes, as determined by solution-phase magnetic measurements. The crystal structure of [Fe(LCCPh)(OH)z]- [BF]2 contains a disordered mixture of six- (z = 3) and sevencoordinate (z = 4) iron centers