The Immune System: Comparative Histophysiology

This text covers aspects of cell biology, histology and current experimental immunology in the broadest context, and at the same time delves into these phenomena in ectothermic vertebrates, birds and a few unique mammals such as the monotremes and marsupials. It aims to answer questions relating to an understanding of the intricacies of the immune system by choosing ectotherms to answer certain basic questions concerning immunity. The authors think that there are certain problems/solutions for which these animals can be used appropriately. The achievement which produced a conceptual and functional bifurcation in the world of immunology came on the scene when Metchnikoff discovered phagocytosis in invertebrates and established, as it were, the universal macrophage. Immunology grew and has maintained a two-prolonged approach - cellualr and humoral, thymus and bone marrow/bursa of Fabricius, T-cell and B-cell, Ig receptor and TCR. The book is cellular and tissue in its flavor and yet the authors aim to envliven the text by presenting that which is more functional and sometimes molecular. The authors explore the main objective of presenting the structure and, to some extent, the function of the immune system in vertebrates, emphasizing conditions in fish, amphibians, reptiles, birds and certain exotic mammals such as monotremes. In many instances, the condition in mammals and humans has been used as the structural basis for making comparisons; however, when certain organs are unique they will be described as such without reference to any non-existing mammalian counterpart. Early views on the immune system were relatively restricted to the lumphatic system composed of a system of vessels containing lymph, in which many of the same plasma proteins (e.g. gamma globulins) are found as well as large numbers of cells mainly lymphocytes and scattered masses of lymphoid tissue associated with these vessels.

Table of Contents:
Part 1 Development, structure and organization of the immune system: the lymphatic vessels; functional dissociation within the immune system; cellular migrations and central versus peripheral regions; general features of the immune system in fish, amphibians, reptiles, birds and mammals; what happens during an immune reponse?; environment and the immune system. Part 2 Cells of the immune system: monocytes and macrophages; granulocytes; lymphocytes and plasma cells. Part 3 The bone marrow and its equivalents: the bone marrow in lower vertebrates; histological organization of the bone marrow; bone marrow as immune organ; bone marrow equivalents in cyclostomes; bone marrow equivalents in modern fish. Part 4 The bursa of fabricius: anatomy; histological organization; ontogeny; function. Part 5 The thymus: the situation in cyclostomes; the thymus in vertebrate gnathostomes. Part 6 The spleen: primitive fish - chondrichthyes-ganoids, dipnoi; advanced fish - teleosts; amphibians; reptiles; birds. Part 7 Lymph nodes: fish; amphibians; reptiles; birds; mammals - monotremes. Part 8 Lymphoid aggregations associated with the gut (GALT), lungs (BALT) and urogenital system (UALT): the gut-associated lymphoid tissue (GALT); the pineal system; harderian gland. Part 9 Seasonal variations in the immune system: season-dependent changes in the number of circulating lymphocytes; seasonal changes in lymphoid organs of ecothermic vertebrates; seasonal influences on the immune reactivities of ectothermic vertebrates; causative agents of seasonal modification of the immune system. Part 10 Recapitulations and directions: the genesis of vertebrate immunity - sites of hemopoiesis, lymphoid precursor stem cells, bone marrow and bursa of fabricus; another primary organ - was the thymus necessary?; moving to the secondary organs - the spleen and blood flow as an important component for initiating immune responses; what about flow of lymph and connections to other secondary centers such as lymph nodes?; immune components associated with the epithelium; what does the milieu do to the immune system - the case for hormones, temperature and light.