Based on the assumption that invertebrates as well as vertebrates possess factors regulating hematopoiesis, response to infection or wounding, studies dealing with the evolution of immunity have focused on the isolation and characterization of putative cytokine-related molecules from invertebrates. Until recently, most of our knowledge of cytokine- and cytokine receptor-like molecules in invertebrates has relied on functional assays and similarities at the physicochemical level. As such, a phylogenetic relationship between invertebrate cytokine-like molecules and invertebrate counterparts could not be convincingly demonstrated. In the present book, recent studies demonstrating cytokine-like activities and related signaling pathways in invertebrates are critically reviewed, focusing on findings from molecular biology and taking advantage of the completion of the genome from the fly Drosophila and the worm Caenorhabditis elegans.
This book contains the proceedings of the first meeting on invertebrate immunity ever sponsored as a summer research conference by the Federation of American Societies for Experimental Biology (FASEB). The conference was held in Copper Mountain, CO from July 11-16, 1999. It was a an extension of a New York Academy of Sciences meeting entitled "Primordial Immunity: Foundations for the Vertebrate Immune System" held on May 2-5,1993 at the Marine Biological Laboratories in Woods Hole, MA. The proceedings of that meeting were published in The Annals of the New York Academy of Sciences (volume 712). At that meeting all the attendes agreed that this type of conference (a relatively small focused gathering) allowed for participation by investigators at all levels of their careers. We further agreed that we should search for a forum that would allow this meeting to continue. The FASEB Summer Research Conference was an excellent vehicle for this type of meeting. Furthermore, this year's participants decided to continue this meeting as a regularly scheduled FASEB sponsored event. This was a unique conference in the sense that it focused upon mechanisms of development and defense in protostome and deuterostome invertebrates and lower vertebrates. There was a strong emphasis on evolutionary cell biology, phylogenetic inferences and the evolution of recognition and regulatory systems.
Immunology of Annelids provides a state-of-the-art review of the biological and biochemical processes involved in defense reactions of annelids. The book covers phylogeny, taxonomy, and fundamental body structure to provide basic information essential to developing a full understanding of the defense system of an organism. Physiological aspects of the relationship between the immune systems and cells and their limitations are discussed in detail, and the role of cells in cellular defense, transplantation, and humoral defenses is explained. The importance of annelids and their defense reaction from the phylogenetic standpoint is examined in a chapter comparing vertebrate and invertebrate defense strategies. Immunology of Annelids is a practical reference for cell biologists, immunologists, evolutionary and developmental biologists, and other researchers who need insight into the development and hierarchy of immune reactions.
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.
The comparative approach to immunology can be traced to the era of Pasteur and Metchnikov in which observations regarding foreign recognition in invertebrates was a factor in the develop ment of the principal concepts that created the foundation of what now is the broad field of immunology. With each major experimental and conceptual breakthrough, the classical, albeit essential, question has been asked "are the immune systems of phylogenetically primitive vertebrates and invertebrates similar to that of mammals?" Somewhat surprisingly for the jawed verte brates, the general answer has been a qualified form of "yes", whereas for agnathans and invertebrate phyla it has been "no" so far. The apparent abruptness in the appearance of the immune system of vertebrates is linked to the introduction of the somatic generation of the diversity of its antigen specific receptors. Therefore the questions regarding the origin and evolution of the specific immune system revolve around this phenomenon. With respect to the origin of the system (aside from the or igin of the rearranging machinery itself, the study of which is still in its infancy) one can ask questions about the cellular and mo lecular contexts in which the mechanism was introduced.
The multitude of cells, signaling pathways, receptors, novel genetic recombination mechanisms and interactive pathways of receptor function and cell differentiation that constitute the vertebrate adaptive immune system are integrally linked with the multicomponent innate immune system. At first glance, the levels of complexity seen in both systems at the phylogenetic level of mammals present what seem to be insurmountable hurdles in terms of achieving a systematic understanding of the evolution of immunity. New research directions and approaches suggest that resolution of many long-standing questions in this area is now possible. Historically, immunologists considered lower vertebrates and invertebrates as “simpler” forms, i.e., they were expected to possess more basic (less layered) levels of immunological complexity and thus potentially would serve as important resources. By considering the systematic placement of representative species in the context of phylogeny, characterizing their immune receptors, co-receptors as well as accessory molecules and evaluating responses to immunologic stimuli, it was thought that a clearer picture of immune evolution would emerge. There is no doubt that this approach has achieved some notable successes but for the most part it has fallen short in terms of achieving a broad understanding of the immunologic needs of many relevant models and how adaptive change in immune function is effected. Even if a structurally relevant ortholog of an immune effector is identified in a model organism, there is no reason to assume that it functions in a corresponding manner in disparate phylogenetic taxa. For example, survival of a sessile marine invertebrate, whose anatomical form puts it in open and contiguous contact with a literal sea of microorganisms and viruses, would be thought to depend, at least in part, on a “capable” immune response; however, at present, we have no real understanding of how this is achieved in an integrated manner. Furthermore, questions arise as to whether or not phenomena that are considered integral components of vertebrate-type immunity such as memory, tolerance, somatic change and clonal selection exist in invertebrates and if their functions parallel those recognized in mammals. More often than not, our interpretations are guided by preconceived notions that are based on observations made in distant species that often do not apply to far- removed taxa. We anticipate that major advances in our understanding of this broad subject are now forthcoming as resources exist or are being developed for examining important model organisms in their natural environments instead of within the confines of in vitro systems of potentially remote physiological significance. Taking a wide range of hypotheses, observations and interpretations into account, in this special topic, contributors have developed a comprehensive overview emphasizing new directions and interpretations for understanding basic aspects of immunity that consider unique features inherent to various model systems, their life histories and habitats. Approaches applied with key model organisms maintained and confronted with relevant challenges under natural conditions are emphasized. Current concepts of self and nonself are addressed not only in terms of immunity but also reproductive fitness. How genetic variation in immune effector molecules is achieved and maintained in natural populations is examined; particular attention is directed to response interfaces that factor in symbiotic interactions. Gene expansion and mechanisms of genetic diversification are explored. How diverse molecules and a variety of effector cells contribute to our broad understanding of the evolution of a remarkably complex, integrated system and how this work is facilitating our understanding of mammalian immunity is addressed.
This work is the first book-length publication on the topic of insect immunology since 1991, complementing earlier works by offering a fresh perspective on current research. Interactions of host immune systems with both parasites and pathogens are presented in detail, as well as the genomics and proteomics, approaches which have been lacking in other publications. Beckage provides comprehensive coverage of topics important to medical researchers, including Drosophila as a model for studying cellular and humoral immune mechanisms, biochemical mediators of immunity, and insect blood cells and their functions. Encompasses the most important topics of insect immunology including mechanisms, genes, proteins, evolution and phylogeny Provides comprehensive coverage of topics important to medical researchers including Drosophila as a model for studying cellular and humoral immune mechanisms, biochemical mediators of immunity, and insect blood cells and their functions Most up-to-date information published with contributions from international leaders in the field
The Evolution of the Immune System: Conservation and Diversification is the first book of its kind that prompts a new perspective when describing and considering the evolution of the immune system. Its unique approach summarizes, updates, and provides new insights on the different immune receptors, soluble factors, and immune cell effectors. Helps the reader gain a modern idea of the evolution of the immune systems in pluricellular organisms Provides a complete overview of the most studied and hot topics in comparative and evolutionary immunology Reflects the organisation of the immune system (cell-based, humoral [innate], humoral [adaptive]) without introducing further and misleading levels of organization Brings concepts and ideas on the evolution of the immune system to a wide readership
It can be seen that the insects are the still attracting most research and researchers. However, an increasing interest is emerging to study new invertebrate groups, especially those where the genome is known. Even though Drosophila has been and still is an excellent model for immune studies, it is now clear that there are great differences between immune responses in Drosophila and that of several other invertebrates, which indeed calls for more research on other invertebrates
