Under the name of programmed cell death (PCD) are included diverse molecular mechanisms of cell suicide which play an essential role in the development of multicellular organisms. The best known PCD mechanism in multicellular organisms is called apoptosis. However, recent studies indicate that PCD is also present in protozoa and unicellular eukaryotes. The eleven chapters of this book give the reader a comprehensive update of the progress in the understanding of the mechanisms of PCD in protozoa. The chapters have been written by experts in this field of research and are arranged following an evolutionary point of view.
Programmed cell death (PCD) pathways are genetically programmed mechanisms that can trigger the cell to die or commit "cell suicide". There are three major forms of programmed cell death that are now recognized: apoptosis (type I), autophagy (type II) and necrotic cell death or necroptosis (type III). While these cell death processes were once thought to occupy discrete cell states, evidence suggests that apoptosis, autophagy and necrosis are often regulated by similar pathways and share initiator and effector molecules and some subcellular compartments indicating that crosstalk exists between these three main forms of cell death pathways, resulting in a balanced interplay by which the cell decides its fate. PCD pathways have important roles in many cellular processes such as development and oncogenic transformation, but PCD pathways also play important roles in host defense and elimination of pathogens. Toxoplasma gondii is a microbial pathogen for which programmed cell death pathways are a key part of the host defense. T. gondii is an obligate intracellular protozoan parasite that infects approximately one-third of the world's population. In most immunocompetant individuals, the chronic infection is asymptomatic due to an effective immune response that eliminates active parasite replication. The parasite has evolved immune evasion strategies that enable it to survive and persist long enough in the host however to establish a chronic infection in which the cyst stage persists within neurons in the brain and skeletal muscle in the periphery. T. gondii has evolved multiple mechanisms to resist killing by apoptotic, autophagic and necrotic cell death pathways, and the parasite's manipulation of host PCD pathways plays a crucial role in host-parasite interactions and maintenance of the chronic infection. While most individuals chronically infected with T. gondii are asymptomatic, severe disease can occur in immunocompromised individuals where the infection reactivates from the brain causing severe necrotizing encephalitis, and increasing evidence indicates chronic cerebral toxoplasmosis in some individuals may lead to neuropsychiatric disorders such as schizophrenia and suicidal behavior. This review will focus on the role of PCD pathways in host defense of T. gondii and the parasite manipulation of these PCD pathways. A better understanding of the molecular components underlying the PCD pathways and the parasite manipulation of these pathways may yield new therapeutic targets for treatment of clinical sequelae of cerebral toxoplasmosis.
Apoptosis is an essential biochemical process in cell turnover, development, and chemical-induced cell death. Current knowledge and ongoing research of apoptosis highlight our understanding in designing the therapeutic approaches for several diseases. This book covers four main sections: "Apoptosis and Necrosis," "Apoptosis Inducers," "Proteasome and Signaling Pathways in Apoptosis," and "Radiation-Based Apoptosis." The first section implicitly describes the differences between apoptosis and necrosis processes. The following section elaborates the small molecule-induced apoptosis. Then, the third section deals with proteasome and signaling pathways and finally, resistance to chemotherapy and electromagnetic radiation is covered in the last section. Overall, the book deals with pathways for manipulating apoptosis and provides a unique perspective to the scientists.
This Ebook provides an interesting and up-to-date overview of Parasite Immunology in terms of a survival battle between hosts and parasites, describing firstly how parasites interact with different B cell compartments and trigger a vigorous antibody response. An Interesting chapter deals with new insights into immune diagnosis in Trypanosoma cruzi infection, while another chapter on malaria vaccines critically reviews their development since the beginning, examining the basis for failures or successes encountered in clinical trials. Chapters on immunological aspects of amoebiasis, giardiasis.
This book is a collection of selected and relevant research, concerning the developments within the Cell Death field of study. Each contribution comes as a separate chapter complete in itself but directly related to the books topics and objectives. The target audience comprises scholars and specialists in the field.
Emerging protozoan pathogens, once thought to be an obscure menace of society, have become a major threat to human health. The last two decades have seen major advances in the understanding of these increasingly important pathogens. Emerging Protozoan Pathogens provides a comprehensive account of up-to-date information on the present status of research in this discipline. Written by experts in their respective subject areas, this book provides a valuable resource for microbiologists and molecular and cell biologists at advanced undergraduate and graduate levels, as well as health professionals and researchers who are interested in these pathogens. The material covered, including biology, genomics, epidemiology, pathogenesis and treatments, makes it an ideal platform on which to base further research projects.
Among the pathogenic protozoa, trypanosomatids stand out due to their medical and economic impact, especially for low-income populations in tropical countries. Together, sleeping sickness, Chagas disease and leishmaniasis affect millions of humans and animals worldwide, yet are neglected by the pharmaceutical industry. The current drugs for trypanosomatid infections are limited and unsatisfactory, with severe side effects leading to reduced quality of life and, in several instances, to the abandonment of treatment. An intense search for alternative compounds has been performed, aiming at specific parasite targets by cellular, molecular and biochemical approaches. One interesting strategy could be interference with the protozoan cell death pathways. However, these pathways are poorly understood in unicellular eukaryotes, with the controversial existence and uncertain biological relevance of programmed cell death (PCD). This chapter will discuss apoptosis-like and autophagic cell death and necrosis in Trypanosoma brucei, Trypanosoma cruzi and Leishmania sp. and the possible implications of these pathways for the parasite life cycle and infection persistence. It will also revisit the genomic and proteomic metadata of these trypanosomatids in the literature to rebuild the map of cell death proteins expressed under different conditions. The interaction of leading candidates with parasite-specific molecules, especially with enzymes that regulate key steps in the cell death process, is a rational and attractive alternative for drug development for these neglected diseases.
"Hydrogenosomes and Mitosomes: Mitochondria of Anaerobic Eukaryotes" provides a summary of the current knowledge of these organelles which occur in unicellular, often parasitic organisms, including human pathogens. These organelles exhibit a variety of structures and functions. This work describes properties such as protein import, structure, metabolism, adaptation, proteome and their role in drug activation and resistance. Further topics include organelle evolution and biogenesis.
Strategies for Evasion, Manipulation and Exploitation of the Immune Response
Author: M. J. Doenhoff
Publisher: Cambridge University Press
The papers in this volume draw attention to both new and recent information on the mechanisms employed by infectious pathogens to underpin their survival in the immunocompetent host and to facilitate their transmission between hosts.
Cellular and Molecular Immunology takes a comprehensive yet straightforward approach to the latest developments in this active and fast-changing field. Drs. Abul K. Abbas, Andrew H. Lichtman, and Shiv Pillai present sweeping updates in this new edition to cover antigen receptors and signal transduction in immune cells, mucosal and skin immunity, cytokines, leukocyte-endothelial interaction, and more. This reference is the up-to-date and readable textbook you need to master the complex subject of immunology. Recognize the clinical relevance of the immunology through discussions of the implications of immunologic science for the management of human disease. Grasp the details of experimental observations that form the basis for the science of immunology at the molecular, cellular, and whole-organism levels and draw the appropriate conclusions. Stay abreast of the latest advances in immunology and molecular biology through extensive updates that cover cytokines, innate immunity, leukocyte-endothelial interactions, signaling, costimulation, and more. Visualize immunologic processes more effectively through a completely revised art program with redrawn figures, a brighter color palette, and more 3-dimensional art. Find information more quickly and easily through a reorganized chapter structure and a more logical flow of material.
Immunology: A Short Course, 7th Edition introduces all the critical topics of modern immunology in a clear and succinct yet comprehensive fashion. The authors offer uniquely-balanced coverage of classical and contemporary approaches and basic and clinical aspects. The strength of Immunology: A Short Course is in providing a complete review of modern immunology without the burden of excessive data or theoretical discussions. Each chapter is divided into short, self-contained units that address key topics, illustrated by uniformly drawn, full-color illustrations and photographs. This new edition of Immunology: A Short Course: • Has been fully revised and updated, with a brand new art program to help reinforce learning • Includes a new chapter on Innate Immunity to reflect the growth in knowledge in this area • Highlights important therapeutic successes resulting from targeted antibody therapies • Includes end of chapter summaries and review questions, a companion website at www.wileyimmunology.com/coico featuring interactive flashcards, USMLE-style interactive MCQs, figures as PowerPoint slides, and case-based material to help understand clinical applications
From an ancient Greek term related to the "leavening of bread" (en, in; zyme, leaven), an enzyme can be defined as a substance showing the properties of a catalyst that is produced as a result of cellular activity. Every proteinaceous enzyme that performs hydrolysis of peptide bonds is appropriately termed "protease" (peptidase). All of them share aspects of catalytic strategy, but with some variation. As a result, the proteases are grouped into six different catalytic families: serine, threonine, cysteine, aspartic, glutamic and metallopeptidases (http://merops.sanger.ac.uk/). The larger families (cysteine, serine, aspartic and metallopeptidases) have a wide range of distribution on living organism groups, and are also present in the "controversial" viruses. As a well-represented family, the cysteine proteases play important roles in events such as signalling pathways, programmed cell death (PCD), nutrient mobilization, protein maturing, hormone synthesis and degradation. In the past two decades, an increased interest was driven to the study of the programmed cell death (PCD), mainly after the discovery of caspase-related proteins and caspase-like activities in organisms not metazoan. Caspases are cysteine proteases that cleave their substrate after aspartate residues and are part of signalling cascades of the apoptotic PCD process (also in inflammatory process), unique of metazoan. The caspase-related proteins are named paracaspases and metacaspases. Paracaspases are found on metazoan and Dictyostelium, whereas the metacaspases are present on plants, fungi and groups of protozoan. On plants, PCD has features that are distinct from that of animals and is an important pathway on developmental events, defensive and stress response (biotic and abiotic). All these events have their own particularities, but the participation of proteases seems to be universal with those responsible for caspase-like activities and metacaspases having an increasing number of reports that put them as important for plant PCD. In this chapter, we tackle important aspects of the proteases, in special that involved in plant PDC, as well as their specific regulators. Aspects of function, catalytic mechanisms and interaction with ligands will be on focus.
A masterful introduction to the cell biology that you need to know! This critically acclaimed textbook offers you a modern and unique approach to the study of cell biology. It emphasizes that cellular structure, function, and dysfunction ultimately result from specific macromolecular interactions. You'll progress from an explanation of the "hardware" of molecules and cells to an understanding of how these structures function in the organism in both healthy and diseased states. The exquisite art program helps you to better visualize molecular structures. Covers essential concepts in a more efficient, reader-friendly manner than most other texts on this subject. Makes cell biology easier to understand by demonstrating how cellular structure, function, and dysfunction result from specific macromole¬cular interactions. Progresses logically from an explanation of the "hardware" of molecules and cells to an understanding of how these structures function in the organism in both healthy and diseased states. Helps you to visualize molecular structures and functions with over 1500 remarkable full-color illustrations that present physical structures to scale. Explains how molecular and cellular structures evolved in different organisms. Shows how molecular changes lead to the development of diseases through numerous Clinical Examples throughout. Includes STUDENT CONSULT access at no additional charge, enabling you to consult the textbook online, anywhere you go · perform quick searches · add your own notes and bookmarks · follow Integration Links to related bonus content from other STUDENT CONSULT titles—to help you see the connections between diverse disciplines · test your knowledge with multiple-choice review questions · and more! New keystone chapter on the origin and evolution of life on earth probably the best explanation of evolution for cell biologists available! Spectacular new artwork by gifted artist Graham Johnson of the Scripps Research Institute in San Diego. 200 new and 500 revised figures bring his keen insight to Cell Biology illustration and further aid the reader’s understanding. New chapters and sections on the most dynamic areas of cell biology - Organelles and membrane traffic by Jennifer Lippincott-Schwartz; RNA processing (including RNAi) by David Tollervey., updates on stem cells and DNA Repair. ,More readable than ever. Improved organization and an accessible new design increase the focus on understanding concepts and mechanisms. New guide to figures featuring specific organisms and specialized cells paired with a list of all of the figures showing these organisms. Permits easy review of cellular and molecular mechanisms. New glossary with one-stop definitions of over 1000 of the most important terms in cell biology.
Influence of Strain Virulence, Apoptosis, and Role of STAT-1
Author: L. Cristina Gavrilescu
In sum, these studies show that death during Toxoplasma infection may be the result of either excessive type 1 cytokine response, or inadequate Th1 differentiation and effector function. My work shows that this outcome depends on both parasite and host genetic background.
This textbook on Protistology provides an excellent information source for a broad audience ranging from students of advanced university courses to senior scientists, for the study of parasitic and/or pathogenic microorganisms; lavishly and unsurpassedly illustrated with about 800 single micrographs, line drawings and diagrams allowing an overwhelming insight into the architectural variety of unicellular creatures and their dynamical properties. The pivotal ecological roles unicellular organisms play in the bionomics of life on earth, at present and in the past as well as the phylogenetic relationships between unicellular and multicellular organisms are thoroughly explained.