Biosynthesis of HLA-C heavy chains in melanoma cells with multiple defects in the expression of HLA-A, -B, -C molecules

Recent investigations have shown that malignant transformation may down-regulate the expression of class I HLA molecules, beta(2)-microglobulin (beta(2)m) and members of the antigen-processing machinery. In the present study, we HLA-genotyped and identified at a biochemical level the three (HLA-A25, -B8, -Cw7) class I alleles expressed by the previously described [D'Urso CM et al (1992) J Clin Invest 87: 284-292] beta(2)m-defective human melanoma FO-1 cell line and tested their ability to interact with calnexin, calreticulin and the TAP (transporter associated with antigen processing) complex. Ail these alleles were found to bind calnexin, but not calreticulin or the poorly expressed TAP complex, both in parental and beta(2)m-transfected FO-1 cells, demonstrating a complex defect of class I expression in FO-1 cells. In these conditions, Cw7 heavy chains interacted with calnexin more strongly than A25 and B8, and preferentially accumulated in the endoplasmic reticulum, in both a calnexin-associated and a calnexin-free form. In addition, they could be transported to the cell surface at low levels even in the absence of beta(2)m, without undergoing terminal glycosylation. These results establish a parallel between HLA-C and the murine D-b and L-d molecules which have been found to be surface expressed and functional in beta(2)m-defective cells. They also demonstrate distinctive features of HLA-C molecules. We propose that the accumulation of several assembly intermediates of HLA-C might favour the binding of peptide antigens not readily bound by HLA-A and -B molecules in neoplastic cells with suboptimal class I expression

Spherical Lactic Acid Bacteria Activate Plasmacytoid Dendritic Cells Immunomodulatory Function via TLR9-Dependent Crosstalk with Myeloid Dendritic Cells

Plasmacytoid dendritic cells (pDC) are a specialized sensor of viral and bacterial nucleic acids and a major producer of IFN-α that promotes host defense by priming both innate and acquired immune responses. Although synthetic Toll-like receptor (TLR) ligands, pathogenic bacteria and viruses activate pDC, there is limited investigation of non-pathogenic microbiota that are in wide industrial dietary use, such as lactic acid bacteria (LAB). In this study, we screened for LAB strains, which induce pDC activation and IFN-α production using murine bone marrow (BM)-derived Flt-3L induced dendritic cell culture. Microbial strains with such activity on pDC were absent in a diversity of bacillary strains, but were observed in certain spherical species (Lactococcus, Leuconostoc, Streptococcus and Pediococcus), which was correlated with their capacity for uptake by pDC. Detailed study of Lactococcus lactis subsp. lactis JCM5805 and JCM20101 revealed that the major type I and type III interferons were induced (IFN-α, -β, and λ). IFN-α induction was TLR9 and MyD88-dependent; a slight impairment was also observed in TLR4-/- cells. While these responses occurred with purified pDC, IFN-α production was synergistic upon co-culture with myeloid dendritic cells (mDC), an interaction that required direct mDC-pDC contact. L. lactis strains also stimulated expression of immunoregulatory receptors on pDC (ICOS-L and PD-L1), and accordingly augmented pDC induction of CD4+CD25+FoxP3+ Treg compared to the Lactobacillus strain. Oral administration of L. lactis JCM5805 induced significant activation of pDC resident in the intestinal draining mesenteric lymph nodes, but not in a remote lymphoid site (spleen). Taken together, certain non-pathogenic spherical LAB in wide dietary use has potent and diverse immunomodulatory effects on pDC potentially relevant to anti-viral immunity and chronic inflammatory disease

A Second-Generation Device for Automated Training and Quantitative Behavior Analyses of Molecularly-Tractable Model Organisms

A deep understanding of cognitive processes requires functional, quantitative analyses of the steps leading from genetics and the development of nervous system structure to behavior. Molecularly-tractable model systems such as Xenopus laevis and planaria offer an unprecedented opportunity to dissect the mechanisms determining the complex structure of the brain and CNS. A standardized platform that facilitated quantitative analysis of behavior would make a significant impact on evolutionary ethology, neuropharmacology, and cognitive science. While some animal tracking systems exist, the available systems do not allow automated training (feedback to individual subjects in real time, which is necessary for operant conditioning assays). The lack of standardization in the field, and the numerous technical challenges that face the development of a versatile system with the necessary capabilities, comprise a significant barrier keeping molecular developmental biology labs from integrating behavior analysis endpoints into their pharmacological and genetic perturbations. Here we report the development of a second-generation system that is a highly flexible, powerful machine vision and environmental control platform. In order to enable multidisciplinary studies aimed at understanding the roles of genes in brain function and behavior, and aid other laboratories that do not have the facilities to undergo complex engineering development, we describe the device and the problems that it overcomes. We also present sample data using frog tadpoles and flatworms to illustrate its use. Having solved significant engineering challenges in its construction, the resulting design is a relatively inexpensive instrument of wide relevance for several fields, and will accelerate interdisciplinary discovery in pharmacology, neurobiology, regenerative medicine, and cognitive science

Landscape of somatic mutations in 560 breast cancer whole-genome sequences.

We analysed whole-genome sequences of 560 breast cancers to advance understanding of the driver mutations conferring clonal advantage and the mutational processes generating somatic mutations. We found that 93 protein-coding cancer genes carried probable driver mutations. Some non-coding regions exhibited high mutation frequencies, but most have distinctive structural features probably causing elevated mutation rates and do not contain driver mutations. Mutational signature analysis was extended to genome rearrangements and revealed twelve base substitution and six rearrangement signatures. Three rearrangement signatures, characterized by tandem duplications or deletions, appear associated with defective homologous-recombination-based DNA repair: one with deficient BRCA1 function, another with deficient BRCA1 or BRCA2 function, the cause of the third is unknown. This analysis of all classes of somatic mutation across exons, introns and intergenic regions highlights the repertoire of cancer genes and mutational processes operating, and progresses towards a comprehensive account of the somatic genetic basis of breast cancer

ATHENA detector proposal - a totally hermetic electron nucleus apparatus proposed for IP6 at the Electron-Ion Collider

ATHENA has been designed as a general purpose detector capable of delivering the full scientific scope of the Electron-Ion Collider. Careful technology choices provide fine tracking and momentum resolution, high performance electromagnetic and hadronic calorimetry, hadron identification over a wide kinematic range, and near-complete hermeticity.This article describes the detector design and its expected performance in the most relevant physics channels. It includes an evaluation of detector technology choices, the technical challenges to realizing the detector and the R&D required to meet those challenges

Conformation of human leucocyte antigen-C molecules at the surface of human trophoblast cells

Human leucocyte antigen (HLA)-C is expressed at lower levels than other classical HLA-I molecules on somatic cells. Surface HLA-C proteins can occur as conventionally β2-microglobulin (β2m)-associated complexes or as open conformers dissociated from peptide and/or β2m. We investigated the conformation of HLA-C molecules on normal human trophoblast cells, which invade the maternal decidua during placentation. A panel of monoclonal antibodies to different conformations of HLA-I molecules was used in flow cytometry and surface immunoprecipitation experiments. On the surface of trophoblast cells only β2m-associated complexes of HLA-C molecules were detected. In contrast, both open conformers and β2m-associated HLA-C could be detected on other cells from the decidua, HLA-C-transfectants and cell lines. The levels of HLA-C expressed on primary trophoblast cells could be detected by antibodies specific to non-β2m-associated conformations because binding was seen after acid-induced denaturation of surface proteins. In contrast to HLA-G molecules on trophoblasts, we found no evidence for the presence of disulphide-linked multimers of HLA-C complexes. These results show that most HLA-C molecules present at the trophoblast cell surface are in the conventional β2m-associated conformation. These findings have implications regarding the stability of trophoblast HLA-C molecules and how they interact with receptors on decidual leucocytes during placentation

Comparison of infant sleep practices in African-American and U.S. Hispanic families: Implications for sleep-related infant death

BACKGROUND: African-American and Hispanic families share similar socioeconomic profiles. Hispanic rates of sleep-related infant death are four times lower than African-American rates. METHODS: Cross-sectional, multi-modal (surveys, qualitative interviews) study to compare infant care practices that impact risk for sleep-related infant death in African-American and Hispanic families. RESULTS: We surveyed 422 African-American and 90 Hispanic mothers. Eighty-three African-American and 6 Hispanic mothers participated in qualitative interviews. African-American infants were more likely to be placed prone (p<0.001), share the bed with the parent (p<0.001), and to be exposed to smoke (p<0.001). Hispanic women were more likely to breastfeed (p<.001), while African-American women were more knowledgeable about SIDS. Qualitative interviews indicate that, although African-American and Hispanic parents had similar concerns, behaviors differed. DISCUSSION: Although the rationale for infant care decisions was similar for African-American and Hispanic families, practices differed. This may help to explain the racial/ethnic disparity seen in sleep-related infant deaths

BRIEF REPORT: Gender and Total Knee/Hip Arthroplasty Utilization Rate in the VA System

OBJECTIVE: Osteoarthritis (OA) is a leading cause of disability and is more prevalent in women than men. Total joint arthroplasty is an effective treatment option for end-stage OA. We examined gender differences in utilization rates of total knee/hip arthroplasty in the Veterans Administration (VA) system. METHODS: The sample consisted of all VA patients for fiscal year (FY) 1999, 50 years of age or older, with or without the diagnosis of OA in any joint. We calculated the odds of patients undergoing total knee/hip arthroplasty adjusting for age, comorbidities, and presence of OA. We included the hospital site as a random effects variable to adjust for clustering. RESULTS: Of the 1,968,093 (2.3% women) VA patients in FY 1999 who were 50 years of age or older, 329,461 (2.9% women) patients carried a diagnosis of OA. For women, 2-year adjusted odds of undergoing total knee or hip arthroplasty were 0.97 (0.83 to 1.14) and 1.00 (0.79 to 1.27), respectively. CONCLUSION: Among patients potentially at risk for the procedure, men and women in the VA system were equally likely to undergo knee/hip arthroplasty

Transcriptomic variation of pharmacogenes in multiple human tissues and lymphoblastoid cell lines.

Variation in the expression level and activity of genes involved in drug disposition and action ('pharmacogenes') can affect drug response and toxicity, especially when in tissues of pharmacological importance. Previous studies have relied primarily on microarrays to understand gene expression differences, or have focused on a single tissue or small number of samples. The goal of this study was to use RNA-sequencing (RNA-seq) to determine the expression levels and alternative splicing of 389 Pharmacogenomics Research Network pharmacogenes across four tissues (liver, kidney, heart and adipose) and lymphoblastoid cell lines, which are used widely in pharmacogenomics studies. Analysis of RNA-seq data from 139 different individuals across the 5 tissues (20-45 individuals per tissue type) revealed substantial variation in both expression levels and splicing across samples and tissue types. Comparison with GTEx data yielded a consistent picture. This in-depth exploration also revealed 183 splicing events in pharmacogenes that were previously not annotated. Overall, this study serves as a rich resource for the research community to inform biomarker and drug discovery and use