This book on phylogeny and immunity reconstructs the history and evolutionary pathways of immunity among the various forms of life. The authors argue that the immunity could have evolved different adequately successful patterns in the animal sub-regnum which are strictly determined by the morpho-physiological possibilities of the animals. They state that the vertebrate type of immunity evolved only in the chordate branch. The publication devotes special attention to the arthropods and molluscs, as they have attracted more investigative efforts than any other invertebrate taxa. The authors selected Agnatha, Chondrichthyes, and Osteichthyes from the vertebrate taxa in order to show where and how the morphofunctional basis of the truly adapative immunity of the endothermic tetrapods gradually evolved. Each chapter gives the description of the origin and interrelationships of the representatives of the taxon in question. Also given are the main biological, morphological, non-morphological and immune attributes. Emphasized throughout the book is the central idea that immunological reactions are a part of the overall biological phenomena and should be studied only from this aspect. The authors express that the fields of comparative and evolutionary immunology will provide inspiration for further investigations in biomedicine in the near future.

This book explores existing and potential strategies for using the genome sequences of human, mouse, other vertebrates and human pathogens to solve key problems in the treatment of immunological diseases and chronic infections. The assembled genome sequences now provide important opportunities for solving these problems, but a major bottleneck is the identification of key sequences and circuits controlling the relevant immune reactions. This will require innovative, interdisciplinary and collaborative strategies of a scale and complexity we are only now beginning to comprehend. Specific problems addressed include the following: What kinds of information are we lacking to understand how the genome sequence specifies the differentiation and response of immune system cells, and system behaviour such as immunological memory and tolerance? Which genome sequences and cellular circuits cause or prevent pathological immune responses to foreign pathogens, allergens or self-tissues? Which host and pathogen genome sequences and cellular circuits explain the failure of sterilizing immune responses to sophisticated human pathogens such as the agents of tuberculosis, malaria, metazoan parasites and chronic viruses? Containing contributions from a range of leading experts in the field, this book provides an important new perspective for clinical immunologists and basic researchers alike.

The evolution of metazoans has been accompanied by new interfaces with the microbial environment that include biological barriers and surveillance by specialized cell types. Increasingly complex organisms require increased capacities to confront pathogens, achieved by co-evolution of recognition mechanisms and regulatory pathways. Two distinct but interactive forms of immunity have evolved. Innate immunity, shared by all metazoans, is traditionally viewed as simple and non-specific. Adaptive immunity possesses the capacity to anticipate new infectious challenges and recall previous exposures; the most well-understood example of such a system, exhibited by lymphocytes of vertebrates, is based on somatic gene alterations that generate extraordinary specificity in discrimination of molecular structures. Our understanding of immune phylogeny over the past decades has tried to reconcile immunity from a vertebrate standpoint. While informative, such approaches cannot completely address the complex nature of selective pressures brought to bear by the complex microbiota (including pathogens) that co-exist with all metazoans. In recent years, comparative studies (and new technologies) have broadened our concepts of immunity from a systems-wide perspective. Unexpected findings, e.g., genetic expansions of innate receptors, high levels of polymorphism, RNA-based forms of generating diversity, adaptive evolution and functional divergence of gene families and the recognition of novel mediators of adaptive immunity, prompt us to reconsider the very nature of immunity. Even fundamental paradigms as to how the jawed vertebrate adaptive immune system should be structured for “optimal” recognition potential have been disrupted more than once (e.g., the discovery of the multicluster organization and germline joining of immunoglobulin genes in sharks, gene conversion as a mechanism of somatic diversification, absence of IgM or MHC II in certain teleost fishes). Mechanistically, concepts of innate immune memory, often referred to as “trained memory,” have been realized further, with the development of new discoveries in studies of epigenetic regulation of somatic lineages. Immune systems innovate and adapt in a taxon-specific manner, driven by the complexity of interactions with microbial symbionts (commensals, mutualists and pathogens). Immune systems are shaped by selective forces that reflect consequences of dynamic interactions with microbial environments as well as a capacity for rapid change that can be facilitated by genomic instabilities. We have learned that characterizing receptors and receptor interactions is not necessarily the most significant component in understanding the evolution of immunity. Rather, such a subject needs to be understood from a more global perspective and will necessitate re-consideration of the physical barriers that afford protection and the developmental processes that create them. By far, the most significant paradigm shifts in our understanding of immunity and the infection process has been that microbes no longer are considered to be an automatic cause or consequence of illness, but rather integral components of normal physiology and homeostasis. Immune phylogeny has been shaped not only by an arms race with pathogens but also perhaps by mutualistic interactions with resident microbes. This Research Topic updates and extends the previous eBook on Changing Views of the Evolution of Immunity and contains peer-reviewed submissions of original research, reviews and opinions.

An interdisciplinary account of the recent advances made in understanding fundamental molecular aspects of the pre-biological and biological evolution of life.

Boyd's Textbook makes pathology easy to understand and interesting to learn through its unique and inimitable style of presentation. This is a friendly and standard text that has served the needs of many generations of students and faculties across many countries. The Tenth Edition retains the original style and flavour of Boyd while presenting a contemporary and updated exposition of pathology.

There is a long-standing evolutionary battle between viruses and their hosts that continues to be waged. The evidence of this conflict can be found on both sides, with the human immune system being responsive to new viral challenges and viruses having developed often sophisticated countermeasures. The “arms race” between viruses and hosts can be thought as an example of the “Red Queen” race, an evolutionary hypothesis inspired from the dialogue of Alice with the Red Queen in Lewis Carroll’s “Through the Looking-Glass”. At the same time, viruses have a minimal genomic content as they have evolved to hitchhike biological machinery of their hosts (or other co-infecting viruses). The minimalistic viral genome could be thought as the result of a “Black Queen” evolution, a theory inspired from the card game Heart, where the winner is the one with the fewest points at the end. The effects of this arms race are evident in the evolution of the human immune system. This system is capable of responding to diverse viral challenges, utilizing both the ancient innate immune system and the more recently evolved adaptive immune system of jawed vertebrates. It is now well-known that the two systems are linked, with innate immunity hypothesized to have provided raw material for the emergence of the adaptive immune response. The adaptive immune response comprises several protein families (including B and T cell receptors, MHC and KIR proteins, for example) that are encoded by complex and variable genomic regions. This complexity enables for responsive genetic changes to occur in immune cells, such as the ability of genomic hypervariable regions in B cells to recombine in order to produce more specific antibodies. Indeed, the human immune system is thought to be continually evolving via various mechanisms such as changes in the genes encoding immune receptors and the regulatory sequences that control their expression. For example, there is some evidence that exogenous viral infections can alter the expression of endogenous retroviruses, some of which contribute to the immune response. Viral countermeasures can include encoding decoy receptors for the signalling molecules of the immune response, altering the gene expression of adaptive immune cells during chronic infection or using host enzymes to facilitate viral immune escape. As the articles herein show, the immune system continues to be challenged by viral infections and these challenges continue to shape how the immune system combats pathogens, thus viruses and human immunity are continuously part of “Red and Black Queen” evolutionary dynamics. We had the pleasure of working with Jonas Blomberg as a reviewer during the course of the Research Topic and his untimely passing was a great loss. Prof. Blomberg made significant contributions, including to the nomenclature of endogenous retroviruses (ERVs), the evolution and characterization of specific human ERV (HERV) and the contribution of ERVs to diseases such as cancer. It is with great respect for his contributions to the ERV field that we dedicate this eBook to his memory.

Vols. for 1963- include as pt. 2 of the Jan. issue: Medical subject headings.

One of the most controversial contemporary debates on the concept of health is the clash between the views of naturalists and normativists. Naturalists argue that, although health can be valued or disvalued, the concept of health is itself objective and value-free. In contrast, normativists argue that health is a contextual and value-laden concept, and that there is no possibility of a value-free understanding of health. This debate has fueled many of the, often very acrimonious, disputations arising from the claims of health, disease and disability activists and charities and the public policy responses to them. In responding to this debate, Ananth both surveys the existing literature, with special focus on the work of Christopher Boorse, and argues that a naturalistic concept of health, drawing on evolutionary considerations associated with biological function, homeostasis, and species-design, is defensible without jettisoning norms in their entirety.