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John Trowsdale

Bio: John Trowsdale is an academic researcher from University of Cambridge. The author has contributed to research in topics: Human leukocyte antigen & Major histocompatibility complex. The author has an hindex of 58, co-authored 112 publications receiving 19830 citations. Previous affiliations of John Trowsdale include University College London & University of Pennsylvania.


Papers
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Journal ArticleDOI
TL;DR: This report documents the additions and revisions to the nomenclature of HLA specificities following the principles established in previous reports.
Abstract: The WHO Nomenclature Committee for Factors of the HLA System met following the 14th International HLA and Immunogenetics Workshop in Melbourne, Australia in December 2005 and Buzios, Brazil during the 15th International HLA and Immunogenetics Workshop in September 2008. This report documents the additions and revisions to the nomenclature of HLA specificities following the principles established in previous reports (1–18).

2,390 citations

Journal ArticleDOI
TL;DR: The strongest synergistic effect of these loci was on progression to depletion of CD4+ T cells, which suggests that a protective response of NK cells involving KIR3DS1 and its HLA class I ligands begins soon after HIV-1 infection.
Abstract: Natural killer (NK) cells provide defense in the early stages of the innate immune response against viral infections by producing cytokines and causing cytotoxicity1. The killer immunoglobulin-like receptors (KIRs) on NK cells regulate the inhibition and activation of NK-cell responses through recognition of human leukocyte antigen (HLA) class I molecules on target cells2 KIR and HLA loci are both highly polymorphic, and some HLA class I products bind and trigger cell-surface receptors specified by KIR genes. Here we report that the activating KIR allele KIR3DS1, in combination with HLA-B alleles that encode molecules with isoleucine at position 80 (HLA-B Bw4-80Ile), is associated with delayed progression to AIDS in individuals infected with human immunodeficiency virus type 1 (HIV-1). In the absence of KIR3DS1, the HLA-B Bw4-80Ile allele was not associated with any of the AIDS outcomes measured. By contrast, in the absence of HLA-B Bw4-80Ile alleles, KIR3DS1 was significantly associated with more rapid progression to AIDS. These observations are strongly suggestive of a model involving an epistatic interaction between the two loci. The strongest synergistic effect of these loci was on progression to depletion of CD4+ T cells, which suggests that a protective response of NK cells involving KIR3DS1 and its HLA class I ligands begins soon after HIV-1 infection.

1,171 citations

Journal ArticleDOI
TL;DR: A gene map of the xMHC is presented and its content in relation to paralogy, polymorphism, immune function and disease is reviewed.
Abstract: The major histocompatibility complex (MHC) is the most important region in the vertebrate genome with respect to infection and autoimmunity, and is crucial in adaptive and innate immunity. Decades of biomedical research have revealed many MHC genes that are duplicated, polymorphic and associated with more diseases than any other region of the human genome. The recent completion of several large-scale studies offers the opportunity to assimilate the latest data into an integrated gene map of the extended human MHC. Here, we present this map and review its content in relation to paralogy, polymorphism, immune function and disease.

1,047 citations

Journal ArticleDOI
TL;DR: In this article, the authors tested the idea that recognition of these molecules by killer immunoglobulin receptors (KIRs) on maternal decidual NK cells is a key factor in the development of preeclampsia.
Abstract: Preeclampsia is a serious complication of pregnancy in which the fetus receives an inadequate supply of blood due to failure of trophoblast invasion. There is evidence that the condition has an immunological basis. The only known polymorphic histocompatibility antigens on the fetal trophoblast are HLA-C molecules. We tested the idea that recognition of these molecules by killer immunoglobulin receptors (KIRs) on maternal decidual NK cells is a key factor in the development of preeclampsia. Striking differences were observed when these polymorphic ligand: receptor pairs were considered in combination. Mothers lacking most or all activating KIR (AA genotype) when the fetus possessed HLA-C belonging to the HLA-C2 group were at a greatly increased risk of preeclampsia. This was true even if the mother herself also had HLA-C2, indicating that neither nonself nor missing-self discrimination was operative. Thus, this interaction between maternal KIR and trophoblast appears not to have an immune function, but instead plays a physiological role related to placental development. Different human populations have a reciprocal relationship between AA frequency and HLA-C2 frequency, suggesting selection against this combination. In light of our findings, reproductive success may have been a factor in the evolution and maintenance of human HLA-C and KIR polymorphisms.

1,018 citations

Journal ArticleDOI
TL;DR: The analysis provides informative tag SNPs that capture much of the common variation in the MHC region and that could be used in disease association studies, and it provides new insight into the evolutionary dynamics and ancestral origins of the HLA loci and their haplotypes.
Abstract: The proteins encoded by the classical HLA class I and class II genes in the major histocompatibility complex (MHC) are highly polymorphic and are essential in self versus non-self immune recognition. HLA variation is a crucial determinant of transplant rejection and susceptibility to a large number of infectious and autoimmune diseases. Yet identification of causal variants is problematic owing to linkage disequilibrium that extends across multiple HLA and non-HLA genes in the MHC. We therefore set out to characterize the linkage disequilibrium patterns between the highly polymorphic HLA genes and background variation by typing the classical HLA genes and >7,500 common SNPs and deletion-insertion polymorphisms across four population samples. The analysis provides informative tag SNPs that capture much of the common variation in the MHC region and that could be used in disease association studies, and it provides new insight into the evolutionary dynamics and ancestral origins of the HLA loci and their haplotypes.

780 citations


Cited by
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Journal ArticleDOI
TL;DR: The GATK programming framework enables developers and analysts to quickly and easily write efficient and robust NGS tools, many of which have already been incorporated into large-scale sequencing projects like the 1000 Genomes Project and The Cancer Genome Atlas.
Abstract: Next-generation DNA sequencing (NGS) projects, such as the 1000 Genomes Project, are already revolutionizing our understanding of genetic variation among individuals. However, the massive data sets generated by NGS—the 1000 Genome pilot alone includes nearly five terabases—make writing feature-rich, efficient, and robust analysis tools difficult for even computationally sophisticated individuals. Indeed, many professionals are limited in the scope and the ease with which they can answer scientific questions by the complexity of accessing and manipulating the data produced by these machines. Here, we discuss our Genome Analysis Toolkit (GATK), a structured programming framework designed to ease the development of efficient and robust analysis tools for next-generation DNA sequencers using the functional programming philosophy of MapReduce. The GATK provides a small but rich set of data access patterns that encompass the majority of analysis tool needs. Separating specific analysis calculations from common data management infrastructure enables us to optimize the GATK framework for correctness, stability, and CPU and memory efficiency and to enable distributed and shared memory parallelization. We highlight the capabilities of the GATK by describing the implementation and application of robust, scale-tolerant tools like coverage calculators and single nucleotide polymorphism (SNP) calling. We conclude that the GATK programming framework enables developers and analysts to quickly and easily write efficient and robust NGS tools, many of which have already been incorporated into large-scale sequencing projects like the 1000 Genomes Project and The Cancer Genome Atlas.

20,557 citations

Journal ArticleDOI
02 Aug 1990-Nature
TL;DR: Three families of cell-surface molecules regulate the migration of lymphocytes and the interactions of activated cells during immune responses.
Abstract: The adhesive interactions of cells with other cells and with the extracellular matrix are crucial to all developmental processes, but have a central role in the functions of the immune system throughout life Three families of cell-surface molecules regulate the migration of lymphocytes and the interactions of activated cells during immune responses

6,595 citations

Journal ArticleDOI
Shaun Purcell1, Shaun Purcell2, Naomi R. Wray3, Jennifer Stone2, Jennifer Stone1, Peter M. Visscher, Michael Conlon O'Donovan4, Patrick F. Sullivan5, Pamela Sklar2, Pamela Sklar1, Douglas M. Ruderfer, Andrew McQuillin, Derek W. Morris6, Colm O'Dushlaine6, Aiden Corvin6, Peter Holmans4, Stuart MacGregor3, Hugh Gurling, Douglas Blackwood7, Nicholas John Craddock5, Michael Gill6, Christina M. Hultman8, Christina M. Hultman9, George Kirov4, Paul Lichtenstein8, Walter J. Muir7, Michael John Owen4, Carlos N. Pato10, Edward M. Scolnick1, Edward M. Scolnick2, David St Clair, Nigel Williams4, Lyudmila Georgieva4, Ivan Nikolov4, Nadine Norton4, Hywel Williams4, Draga Toncheva, Vihra Milanova, Emma Flordal Thelander8, Patrick Sullivan11, Elaine Kenny6, Emma M. Quinn6, Khalid Choudhury12, Susmita Datta12, Jonathan Pimm12, Srinivasa Thirumalai13, Vinay Puri12, Robert Krasucki12, Jacob Lawrence12, Digby Quested14, Nicholas Bass12, Caroline Crombie15, Gillian Fraser15, Soh Leh Kuan, Nicholas Walker, Kevin A. McGhee7, Ben S. Pickard16, P. Malloy7, Alan W Maclean7, Margaret Van Beck7, Michele T. Pato10, Helena Medeiros10, Frank A. Middleton17, Célia Barreto Carvalho10, Christopher P. Morley17, Ayman H. Fanous, David V. Conti10, James A. Knowles10, Carlos Ferreira, António Macedo18, M. Helena Azevedo18, Andrew Kirby2, Andrew Kirby1, Manuel A. R. Ferreira1, Manuel A. R. Ferreira2, Mark J. Daly1, Mark J. Daly2, Kimberly Chambert2, Finny G Kuruvilla2, Stacey Gabriel2, Kristin G. Ardlie2, Jennifer L. Moran2 
06 Aug 2009-Nature
TL;DR: The extent to which common genetic variation underlies the risk of schizophrenia is shown, using two analytic approaches, and the major histocompatibility complex is implicate, which is shown to involve thousands of common alleles of very small effect.
Abstract: Schizophrenia is a severe mental disorder with a lifetime risk of about 1%, characterized by hallucinations, delusions and cognitive deficits, with heritability estimated at up to 80%(1,2). We performed a genome-wide association study of 3,322 European individuals with schizophrenia and 3,587 controls. Here we show, using two analytic approaches, the extent to which common genetic variation underlies the risk of schizophrenia. First, we implicate the major histocompatibility complex. Second, we provide molecular genetic evidence for a substantial polygenic component to the risk of schizophrenia involving thousands of common alleles of very small effect. We show that this component also contributes to the risk of bipolar disorder, but not to several non-psychiatric diseases.

4,573 citations

Journal ArticleDOI
18 Oct 2007-Nature
TL;DR: The Phase II HapMap is described, which characterizes over 3.1 million human single nucleotide polymorphisms genotyped in 270 individuals from four geographically diverse populations and includes 25–35% of common SNP variation in the populations surveyed, and increased differentiation at non-synonymous, compared to synonymous, SNPs is demonstrated.
Abstract: We describe the Phase II HapMap, which characterizes over 3.1 million human single nucleotide polymorphisms (SNPs) genotyped in 270 individuals from four geographically diverse populations and includes 25-35% of common SNP variation in the populations surveyed. The map is estimated to capture untyped common variation with an average maximum r2 of between 0.9 and 0.96 depending on population. We demonstrate that the current generation of commercial genome-wide genotyping products captures common Phase II SNPs with an average maximum r2 of up to 0.8 in African and up to 0.95 in non-African populations, and that potential gains in power in association studies can be obtained through imputation. These data also reveal novel aspects of the structure of linkage disequilibrium. We show that 10-30% of pairs of individuals within a population share at least one region of extended genetic identity arising from recent ancestry and that up to 1% of all common variants are untaggable, primarily because they lie within recombination hotspots. We show that recombination rates vary systematically around genes and between genes of different function. Finally, we demonstrate increased differentiation at non-synonymous, compared to synonymous, SNPs, resulting from systematic differences in the strength or efficacy of natural selection between populations.

4,565 citations

Journal ArticleDOI
TL;DR: The Janus kinases and signal transducers and activators of transcription, and many of the interferon-induced proteins, play important alternative roles in cells, raising interesting questions as to how the responses to the interFERons intersect with more general aspects of cellular physiology and how the specificity of cytokine responses is maintained.
Abstract: Interferons play key roles in mediating antiviral and antigrowth responses and in modulating immune response. The main signaling pathways are rapid and direct. They involve tyrosine phosphorylation and activation of signal transducers and activators of transcription factors by Janus tyrosine kinases at the cell membrane, followed by release of signal transducers and activators of transcription and their migration to the nucleus, where they induce the expression of the many gene products that determine the responses. Ancillary pathways are also activated by the interferons, but their effects on cell physiology are less clear. The Janus kinases and signal transducers and activators of transcription, and many of the interferon-induced proteins, play important alternative roles in cells, raising interesting questions as to how the responses to the interferons intersect with more general aspects of cellular physiology and how the specificity of cytokine responses is maintained.

4,026 citations