This volume of Current Topics in Microbiology and Immunology is concerned with a class of molecules that are the most potent polyclonal stimulators of T lymphocytes of several species. These molecules have been named "superantigens" because they use a mechanism of T cell stimulation closely mimicking MHC-restricted recognition of specific antigen: they act on variable parts of T cell antigen receptors and are presented by MHC class II molecules. Prototypes of these molecules are the pyrogenic exotoxins produced by S. aureus and S. pyogenes, of which the staphylococcal enterotoxins and the toxic shock syndrome toxin are the best known. Superantigens also occur endogen ously in mice, most notably the enigmatic Mis determinants, that have withstood characterization for nearly 20 years. Only very recently was it found that Mis is probably encoded by endogenous retroviruses. The list of candidates that are implicated as being superantigens is growing. In many cases, however, the proof that a given molecule indeed falls into this category is still missing.
This book provides ample knowledge and better understanding of Streptococcus pyogenes and their superantigens. Many illustrations make this a highly informative book. This book elucidates briefly Streptococcus pyogenes as a strict human pathogen possessing an array of virulence factors. These help in evading host immune responses such as by the activation of non-specific T-cell subpopulations by producing superantigens. This book mainly focuses on streptococcal superantigens and explains how they are different from conventional antigens. Moreover, it elaborates those diseases in which superantigens are actively involved. Useful aspects of superantigens and different therapeutic interventions to eradicate superantigens induced diseased are also discussed.
Although the field of superantigens (SAgs) has boomed in recent years, the function of these proteins in bacterial infection remains elusive. This volume begins with a brief introduction, followed by 15 chapters. Among the topics are structural studies of streptococcal pyrogenic exotoxin superantigens; Yersinia infection--the virulence determinants and SAgs they produce; structural features of T cell receptor recognition of SAgs; the pathophysiology of bacterial SAgs in vivo; and antibody targeted SAgs in experimental tumor therapy. Annotation copyright by Book News, Inc., Portland, OR
Since the discovery of viral superantigens in 1991, immunologists have made a number of new discoveries. The discoveries, especially those relating to the interplay between the immune system and viruses producing superantigens, have had a great impact on immunology and virology, as it appears that some diseases are triggered or exacerbated by viral superantigens. Viral Superantigens presents a complete review of this new area of study. Edited by a leading researcher and authored by a distinguished team of contributors, this comprehensive analysis covers every aspect of viral superantigens and related subjects, including critical topics such as effects on the T cell repertoire and viral superantigen-mediated diseases. Immunologists and virologists, clinical practitioners, and graduate students will find this book an invaluable resource to encourage further advances in research.
This book describes the major achievements and discoveries relevant to bacterial protein toxins since the turn of the new century illustrated by the discovery of more than fifty novel toxins (many of them identified through genome screening). The establishment of the three-dimensional crystal structure of more than 20 toxins during the same period offers deeper knowledge of structure-activity relationships and provides a framework to understand how toxins recognize receptors, penetrate membranes and interact with and modify intracellular substrates. - Edited by two of the most highly regarded experts in the field from the Institut Pasteur, France - 14 brand new chapters dedicated to coverage of historical and general aspects of toxinology - Includes the major toxins of both basic and clinical interest are described in depth - Details applied aspects of toxins such as therapy, vaccinology, and toolkits in cell biology - Evolutionary and functional aspects of bacterial toxins evaluated and summarized - Toxin applications in cell biology presented - Therapy (cancer therapy, dystonias) discussed - Vaccines (native and genetically engineered vaccines) featured - Toxins discussed as biological weapons, comprising chapters on anthrax, diphtheria, ricin etc.
The Janeway's Immunobiology CD-ROM, Immunobiology Interactive, is included with each book, and can be purchased separately. It contains animations and videos with voiceover narration, as well as the figures from the text for presentation purposes.
Bacterial pathogenicity factors are functionally diverse. They may facilitate the adhesion and colonization of bacteria, influence the host immune response, assist spreading of the bacterium by e.g. evading recognition by immune cells, or allow bacteria to dwell within protected niches inside the eukaryotic cell. Exotoxins can be single polypeptides or heteromeric protein complexes that act on different parts of the cells. At the cell surface, they may insert into the membrane to cause damage; bind to receptors to initiate their uptake; or facilitate the interaction with other cell types. For example, bacterial superantigens specifically bind to major histocompatibility complex (MHC) II molecules on the surface of antigen presenting cells and the T cell receptor, while cytolysins cause pore formation. For intracellular activity, exotoxins need to be translocated across the eukaryotic membrane. Gram-negative bacteria can directly inject effector proteins in a receptor-independent manner by use of specialized needle apparatus such as bacterial type II, III, or type IV secretion systems. Other methods of translocation include the phagocytic uptake of bacteria followed by toxin secretion, or receptor-mediated endocytosis which allows the targeting of distinct cell types. Receptor-based uptake is initiated by the binding of heteromeric toxin complexes to the cell surface and completed by the translocation of the effector protein(s) across the endosomal membrane. In the cytosol, toxins interact with specific eukaryotic target proteins to cause post-translational modifications that often result in the manipulation of cellular signalling cascades and inflammatory responses. It has become evident that the actions of some bacterial toxins may exceed their originally assumed cytotoxic function. For example, pore-forming toxins do not only cause cytolysis, but may also induce autophagy, pyroptosis, or activation of the MAPK pathways, resulting in adjustment of the host immune response to infection and modification of inflammatory responses both locally and systemically. Other recently elucidated examples of the immunomodulatory function of cell death-inducing exotoxins include TcdB of Clostridium difficile which activates the inflammasome through modification of cellular Rho GTPases, or the Staphyloccocus d-toxin which activates mast cells. The goal of this research topic was to gather current knowledge on the interaction of bacterial exotoxins and effector proteins with the host immune system. The following 16 research and review articles in this special issue describe mechanisms of immune modification and evasion and provide an overview over the complexity of bacterial toxin interaction with different cells of the immune system.
Leading researchers in the biological, chemical, and physical investigation of superantigens describe in step-by-step detail their best experimental techniques to assess the physical characteristics and biological effects of superantigens. Their protocols range from those for investigating the interactions of superantigens with cellular receptors to those for the analysis of their immunological and biological effects, including methods for using BIOcore to determine binding kinetics and establishing various lymphocyte cell culture systems. There are also accounts of such methods as the RNase protection assay, cytokine ELISA, FACS analysis, and cytokine production at the single cell level..
This work provides rapid access to focused information on topics of Immunotoxicology not only for scientists and those dealing with laboratory aspects but also for lecturers and advanced students. Over 200 contributing authors – including many of the world’s top specialists – have contributed full essays on all relevant topics, supplemented by keyword definitions of related terms. Full essays are structured uniformly to provide reader-friendly information on all aspects of Immunotoxicology, including methods of testing and analysis, characteristics of substances, the regulatory environment and the relevance of these to humans. The single A–Z format of both types of entry makes this reference book very easy to use. The Encyclopedic Reference of Immunotoxicology is intended to be a comprehensive work of reference which will provide easy access to relevant information in the fast-growing field of Immunotoxicology.
Our survival as multicellular organisms requires the constant surveillance of our internal and external (mucosal) environments by the multifarious elements of the innate and acquired systems of immunity. The objective of this surveillance, expensive as it is to the organisms, is to recognise and kill invading microorganisms. Over the past fifty years the cells and mediators involved in our immune defences have been painstakingly identified. However, it is only relatively recently that the ability of microorganisms to evade immunity has been recognised and investigated. Bacterial Evasion of Host Immune Responses introduces the reader to the mechanisms used by bacteria to evade both humoral and cellular immune responses, using systems ranging in complexity from the simple quorum sensing molecules - acyl homoserine lactones - to the supramolecular syringe-like devices of type III secretion systems. This book will be of interest to researchers and graduate students in microbiology, immunology, pharmacology and molecular medicine.
