Download or read book Complement Receptor 1 Is a Sialic Acid Independent Erythrocyte Receptor of Plasmodium Falciparum written by and published by . This book was released on 2010 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasmodium falciparum is a highly lethal malaria parasite of humans. A major portion of its life cycle is dedicated to invading and multiplying inside erythrocytes. The molecular mechanisms of erythrocyte invasion are incompletely understood. P. falciparum depends heavily on sialic acid present on glycophorins to invade erythrocytes. However, a significant proportion of laboratory and field isolates are also able to invade erythrocytes in a sialic acid-independent manner. The identity of the erythrocyte sialic acid-independent receptor has been a mystery for decades. We report here that the complement receptor 1 (CR1) is a sialic acid-independent receptor for the invasion of erythrocytes by P. falciparum. We show that soluble CR1 (sCR1) as well as polyclonal and monoclonal antibodies against CR1 inhibit sialic acid-independent invasion in a variety of laboratory strains and wild isolates, and that merozoites interact directly with CR1 on the erythrocyte surface and with sCR1-coated microspheres. Also, the invasion of neuraminidase treated erythrocytes correlates with the level of CR1 expression. Finally, both sialic acid independent and dependent strains invade CR1 transgenic mouse erythrocytes preferentially over wild-type erythrocytes but invasion by the latter is more sensitive to neuraminidase. These results suggest that both sialic acid-dependent and independent strains interact with CR1 in the normal red cell during the invasion process. However, only sialic acid-independent strains can do so without the presence of glycophorin sialic acid. Our results close a long standing and important gap in the understanding of the mechanism of erythrocyte invasion by P. falciparum that will eventually make possible the development of an effective blood stage vaccine.
Download or read book Complement and Antibody mediated Enhancement of Red Blood Cell Invasion by Plasmodium Falciparum written by Sergei Biryukov and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasmodium falciparum malaria is responsible for close to one million deaths worldwide each year. The Plasmodium life cycle involves invasion of hepatocytes and erythrocytes. The repeating cycle of erythrocyte invasion and destruction is the root cause of the morbidity and mortality brought about by the pathogen. Development of naturally acquired immunity against the parasite is an extremely slow process taking years to decades to develop, and it does not seem to result in sterile immunity. Attempts to develop a vaccine to block erythrocyte invasion have proven unsuccessful. Clinical data have demonstrated the development of a strong humoral immune response in vaccinated individuals. Although antibodies raised against vaccine antigens inhibit invasion in vitro in the presence of heat-inactivated (HI) serum, there is poor efficacy in vivo. The reasons for this discrepancy are unknown. A number of studies, in both humans and animal models, have shown that the complement cascade is activated during malaria infection. We hypothesize that complement activation and opsonization of merozoites enhances complement receptor 1 (CR1)-mediated invasion of erythrocytes. If we are correct, the parasite can hijack this arm of the innate immune response for its own benefit, avoiding or diminishing the efficacy of antibodies. We tested this hypothesis by studying the effect of mouse monoclonal anti-merozoite surface protein 1 (MSP-1) antibody 5.2 (mAb5.2) and antibodies from recipients of a merozoite vaccine (MSP142) for their ability to enhance or inhibit invasion in a complement-dependent manner. We carried out invasion assays with the above antibodies with appropriate controls in fresh or HI serum, or in complement-depleted or reconstituted serum. In addition, we tested the relevance of the CR1 pathway by inhibiting with sCR1. Invasion of erythrocytes was enhanced by fresh serum relative to 3 min, 5 min, or 30 min HI serum. Furthermore, addition of mAb5.2 to fresh serum increased the enhancement effect. Addition of C2 and Factor B to 3 min HI serum, but not to 30 min, rescued the enhancement of invasion in the presence of mAb5.2. Likewise, Compstatin, a C3 specific inhibitor, and sCR1 negated the enhancing affects of mAb5.2 in fresh serum but not that of fresh serum alone. Furthermore, soluble CR1 had invasion inhibitory activity in 3 min HI serum that was independent of antibody. Purified antibodies from MSP-1 vaccinees showed inhibitory activity in C3/C4 inactivated serum, but inhibition was drastically reduced in C3/C4 reconstituted serum. Passive transfer of anti-P. berghei antibodies into wild type mice enhanced parasitemia in an inverse dose-dependent manner. In addition, C3-deficient mice showed decreased parasite growth relative to wild type mice. In addition, we utilized erythrocytes from individuals with paroxysmal nocturnal hemoglobinuria (PNH), which results in the absence of glycosylphosphatidylinositol (GPI)-anchored receptors, in an effort to identify novel receptors utilized by the parasite for erythrocyte invasion. We found that PNH RBCs were invaded less effectively than wild type RBCs. Therefore, we carried out growth and invasion assays with anti-GPI erythrocyte receptor antibodies against six potential targets with appropriate controls in fresh or HI serum, or in complement-depleted or reconstituted serum. We identified Semaphorin-7A (SEMA7A) as a potential erythrocyte receptor that may interact with complement in promoting erythrocyte invasion by merozoites. Our results demonstrate that merozoites can highjack the complement system to their own advantage in a number of ways. Activation of the complement cascade via the classical pathway can allow merozoites to bind to CR1 and invade via this pathway. In addition, in the absence of antibodies, activation of the mannose binding lectin pathway by default may allow merozoites to bind to other complement receptors on the RBC that mediate invasion. Such mechanisms could explain or contribute to the low efficacy of vaccine-induced anti-merozoite antibodies to block invasion in vivo. These findings are of great importance to the efforts to develop a merozoite blocking vaccine.
Download or read book Neuraminic Acids Advances in Research and Application 2011 Edition written by and published by ScholarlyEditions. This book was released on 2012-01-09 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neuraminic Acids: Advances in Research and Application: 2011 Edition is a ScholarlyBrief™ that delivers timely, authoritative, comprehensive, and specialized information about Neuraminic Acids in a concise format. The editors have built Neuraminic Acids: Advances in Research and Application: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Neuraminic Acids in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Neuraminic Acids: Advances in Research and Application: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Download or read book Stem Cells in Regenerative Medicine written by Julie Audet and published by Methods in Molecular Biology. This book was released on 2009 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, leading experts in the field provide an updated representation of the landscape of stem cell-based therapies in a wide spectrum of tissue systems and ontogenic stages, from the isolation and culture of stem cells to their actual use in vivo.
Download or read book Studies in Malaria written by Hugh Stott and published by . This book was released on 1916 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Immunologic Receptors Advances in Research and Application 2013 Edition written by and published by ScholarlyEditions. This book was released on 2013-06-21 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: Immunologic Receptors—Advances in Research and Application: 2013 Edition is a ScholarlyEditions™ book that delivers timely, authoritative, and comprehensive information about Complement Receptors. The editors have built Immunologic Receptors—Advances in Research and Application: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Complement Receptors in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Immunologic Receptors—Advances in Research and Application: 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Download or read book Advances in Malaria Research written by Deepak Gaur and published by John Wiley & Sons. This book was released on 2016-11-30 with total page 615 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thoroughly reviews our current understanding of malarial biology Explores the subject with insights from post-genomic technologies Looks broadly at the disease, vectors of infection, and treatment and prevention strategies A timely publication with chapters written by global researchers leaders
Download or read book Rodent Malaria written by R. Killick-Kendrick and published by Elsevier. This book was released on 2012-12-02 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rodent Malaria reviews significant findings concerning malaria parasites of rodents, including their taxonomy, zoogeography, and evolution, along with life cycles and morphology; genetics and biochemistry; and concomitant infections. This volume is organized into eight chapters and begins by sketching out the history of the discovery of rodent as well as aspects of parasitology, immunology, and chemotherapy. These concepts are investigated two decades following Ignace Vincke's major discovery and Meir Yoeli's successful establishment of the method of cyclical transmission of the parasite. The following chapters focus on the taxonomy and systematics of the subgenus Vinckeia, with reference to the concepts of species and subspecies of animals and the degree to which they apply to malaria parasites, in particular to those of rodents. The discussion then shifts to how the rodent malaria parasites provide a unique insight into the subcellular organization of Plasmodium species, the use of rodent malaria as an experimental model to study immunological responses, and infectious agents that interact with malaria parasites. The book concludes with a chapter on malaria chemotherapy, with emphasis on the value of rodent malaria in antimalarial drug screening and the use of antimalarial drugs as biological probes. This book will be of interest to protozoologists and physicians as well as those from other disciplines including biochemistry, immunology, pharmacology, cell biology, and genetics.
Download or read book Essentials of Glycobiology written by Ajit Varki and published by CSHL Press. This book was released on 1999 with total page 694 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sugar chains (glycans) are often attached to proteins and lipids and have multiple roles in the organization and function of all organisms. "Essentials of Glycobiology" describes their biogenesis and function and offers a useful gateway to the understanding of glycans.
Download or read book Blood Groups in Man written by Robert Russell Race and published by Wiley-Blackwell. This book was released on 1975-01-01 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Malaria written by Institute of Medicine and published by National Academies Press. This book was released on 1991-02-01 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Malaria is making a dramatic comeback in the world. The disease is the foremost health challenge in Africa south of the Sahara, and people traveling to malarious areas are at increased risk of malaria-related sickness and death. This book examines the prospects for bringing malaria under control, with specific recommendations for U.S. policy, directions for research and program funding, and appropriate roles for federal and international agencies and the medical and public health communities. The volume reports on the current status of malaria research, prevention, and control efforts worldwide. The authors present study results and commentary on the: Nature, clinical manifestations, diagnosis, and epidemiology of malaria. Biology of the malaria parasite and its vector. Prospects for developing malaria vaccines and improved treatments. Economic, social, and behavioral factors in malaria control.
Download or read book Erythrocytes Physiology And Pathophysiology written by Florian Lang and published by World Scientific Publishing Company. This book was released on 2012-07-23 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book covers the functional significance and properties of erythrocytes, their generation, senescence, and suicidal death. It further summarizes knowledge about hormones influencing erythrocyte formation including erythropoietin as well as disorders affecting and involving erythrocytes such as anemia, malaria, and sepsis.This seminal work forms a unique reference on the most abundant cell type in mammals and will be an invaluable resource for students in the life sciences./a
Download or read book Encyclopedia of Immunobiology written by and published by Academic Press. This book was released on 2016-04-27 with total page 3161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Encyclopedia of Immunobiology, Five Volume Set provides the largest integrated source of immunological knowledge currently available. It consists of broad ranging, validated summaries on all of the major topics in the field as written by a team of leading experts. The large number of topics covered is relevant to a wide range of scientists working on experimental and clinical immunology, microbiology, biochemistry, genetics, veterinary science, physiology, and hematology. The book is built in thematic sections that allow readers to rapidly navigate around related content. Specific sections focus on basic, applied, and clinical immunology. The structure of each section helps readers from a range of backgrounds gain important understanding of the subject. Contains tables, pictures, and multimedia features that enhance the learning process In-depth coverage allows readers from a range of backgrounds to benefit from the material Provides handy cross-referencing between articles to improve readability, including easy access from portable devices
Download or read book Malaria Immunology written by Peter Perlmann and published by Karger Medical and Scientific Publishers. This book was released on 2002-01-01 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite extensive efforts to control it, malaria is still one of the most devastating infectious diseases worldwide. This book, now in its second edition, provides a broad and up-to-date overview of the rapidly expanding field of malaria immunology and its importance in the control of this disease. The first section deals with the malaria parasite and its interactions with both the vertebrate host and the mosquitoes which transmit the disease. In the second part, the mechanisms of immunity and their regulation by environmental and genetic factors are discussed. Finally, this volume contains several chapters on malaria vaccine development, describing the application of the most recent vaccine technologies as well as ongoing and planned vaccine trials. Authored by well-recognized experts, this volume not only demonstrates the rapid progress being made in the search for vaccines against malaria, but also broadens our understanding of immunity to infection in general. It is therefore highly recommended reading for all scientists and professionals in the fields of immunology, infection and vaccine development.
Download or read book Complement Activation in Malaria Immunity and Pathogenesis written by José A. Stoute and published by Springer. This book was released on 2018-07-03 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasmodium falciparum malaria is responsible for the deaths of nearly 500,000 people each year. Much attention has been paid to antibody and cellular mechanisms of immunity against this pathogen. By contrast, the role that the complement system plays in immunity and pathogenesis in this infection is not very well recognized or understood. Based on the work of a number of research groups, we know that complement plays an important role in these processes. In this book, some of the leading scientists in the field discuss the mechanisms of complement activation during malaria infection as well as the role of complement in the pathogenesis of key syndromes such as severe malarial anemia, cerebral malaria, and placental malaria. In addition, they review recently-identified complement evasion strategies of P. falciparum merozoites, and how these mechanisms may translate into paradoxical enhancement of infection rather than protection. Finally, they also discuss the role of the mosquito complement system on immunity against the parasite.
Download or read book Evolution of Virulence in Eukaryotic Microbes written by L. David Sibley and published by John Wiley & Sons. This book was released on 2012-06-07 with total page 912 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unique and timely review of the emergence of eukaryotic virulence in fungi, oomycetes, and protozoa, as they affect both animals and plants Evolution of Virulence in Eukaryotic Microbes addresses new developments in defining the molecular basis of virulence in eukaryotic pathogens. By examining how pathogenic determinants have evolved in concert with their hosts, often overcoming innate and adaptive immune mechanisms, the book takes a fresh look at the selective processes that have shaped their evolution. Introductory chapters ground the reader in principal evolutionary themes such as phylogenetics and genetic exchange, building a basis of knowledge for later chapters covering advances in genetic tools, how pathogens exchange genetic material in nature, and the common themes of evolutionary adaptation that lead to disease in different hosts. With the goal of linking the research findings of the many disparate scientific communities in the field, the book: Assembles for the first time a collection of chapters on the diversity of eukaryotic microorganisms and the influence of evolutionary forces on the origins and emergence of their virulent attributes Highlights examples from three important, divergent groups of eukaryotic microorganisms that cause disease in animals and plants: oomycetes, protozoan parasites, and fungi Covers how the development of genetic tools has fostered the identification and functional analyses of virulence determinants Addresses how pathogens exchange genetic material in nature via classical or modified meiotic processes, horizontal gene transfer, and sexual cycles including those that are cryptic or even unisexual Provides a broad framework for formulating future studies by illustrating themes common to different pathogenic microbes Evolution of Virulence in Eukaryotic Microbes is an ideal book for microbiologists, evolutionary biologists and medical professionals, as well as graduate students, postdoctoral fellows, and faculty members working on the evolution of pathogens.
Download or read book Microscopic Haematology written by Gillian Rozenberg and published by Elsevier Australia. This book was released on 2011 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microscopic Haematology 3e is an atlas of Haematology designed for use in a diagnostic setting. the third edition provides over 400 full colour haematological slides of exceptional quality. Arranged in a logical order, it commences with the red cell series describing normoblastic erythropoiesis and then goes on to describe abnormal erythropoiesis and all the red cell disorders associated with anaemia. Each type of anaemia is described with a minimal amount of text and accompanied by coloured haematological slides depicting the red cell changes associated with the particular disorder. the image
