The problem that virtually all cells have in discriminating between "self" and "non-self" molecules and cells has been considered at great length in immuno biology. However, cells that clearly are incapable of carrying out mammalian type immune functions can exhibit exquisite specificity in their capacity to discriminate among syngeneic, allogeneic, and xenogeneic cells. In this volume of Contemporary Topics in Immunobiology we have chosen to consider the general problem of self/non-self discrimination as it is manifest in recognition reactions of plants and invertebrates and in the evolutionary development of the immune response of vertebrates. A broad, many-faceted approach is taken toward fundamental issues in immunobiology in order to develop innovative concepts of receptor function as well as to delineate traditional views. The capacity of plants to discriminate between self and non-self is addressed in Chapter 1 by R. B. Knox and Adrienne E. Clarke. These authors provide examples of cell-cell recognition in plants that parallel those occurring in in vertebrates and vertebrates. In general, tolerance (acceptance) of grafts is re stricted to plants within closely related genera. Recognition is mediated by callus cells, which proliferate at wound surfaces in higher plants, and there is a correlation between cell and tissue type and antigenic markers detectable with the use of mammalian antibodies. Certain flowering plants exhibit precise discrimination in fertilization, when pollen must be from the same species, but fertilization occurs only if the pollen is genetically non-self.
Table of Contents1 Discrimination of Self and Non-self in Plants.- I. Introduction.- II. Biology of Recognition Systems in Vascular Plants.- A. Some Case Histories of Somatic Interactions.- B. Some Case Histories of Sexual Interactions.- III. Immunobiology of Recognition Systems.- A. Antigenic Determinants of Somatic Cells and Protoplasts.- B. The Search for the S -Gene Product of Self-Incompatibility.- C. Recognition at the Pollen-Stigma Interface.- IV. Conclusions.- V. References.- 2 Discrimination of Self and Non-self in Invertebrates.- I. Introduction.- II. Non-self Recognition.- III. Serum Factors.- IV. Graft Studies and Invertebrate Histocompatibility Antigens.- V. References.- 3 Phylogeny of the Emergence of T-B Collaboration in Humoral Immunity.- I. Introduction: Primary and Secondary Lymphoid Sites.- II. Evidence of Lymphoid Heterogeneity: Differential Mitogenesis.- III. Evidence of Lymphoid Heterogeneity from Thymic Ablation.- IV. Evidence of Cell-Cell Collaboration in Ectotherms.- V. Conclusion: Some Speculations with Respect to the Evolution of Immunity.- VI. References.- 4 Lymphoid-Cell Cooperation in Immune Responses of the Chicken.- 5 Salamanders and the Evolution of the Major Histocompatibility Complex.- I. Introduction.- II. Does the MHC Exist in any Ectothermic Vertebrate?.- III. Do Salamanders Have the MHC?.- A. The Immunogenetic Basis of Allograft Rejection.- B. The Mixed Lymphocyte Reaction (MLR).- IV. Concluding Comments.- V. References.- 6 Membrane Immunoglobulins of Vertebrate Lymphocytes.- I. Introduction.- II. A Note on Methods for the Demonstration of Membrane Immunoglobulins.- III. Surface Immunoglobulins of Vertebrate Lymphocytes.- A. Universality of Lymphoid Heterogeneity in the Vertebrates.- B. B-Cell-Surface Ig.- C. T-Cell-Surface Ig.- D. Direct Demonstration of T-Cell Ig.- E. Molecular Properties of T-Cell Ig.- IV. Function of Lymphocyte-Surface Immunoglobulins.- V. Concluding Comments.- VI. References.- 7 Idiotypes, T-Cell Receptors, and T-B Cooperation.- I. Introduction.- II. Immunoglobulin Genes.- III. The Major Histocompatibility Complex.- A. The K/D Loci.- B. The/Region.- IV. Antigen Recognition by T Cells.- A. Recognition of Antigen by T Cells Is Very Precise.- B. Recognition of Antigen by T Cells Always Involves MHC Structures.- V. Subpopulations of T Cells.- A. Lyl Cells.- B. Ly23 Cells.- C. Ly123 Cells.- VI. The High Frequency of Alloreactive T Cells and Their Responsiveness to Nominal Antigen.- VII. T-Cell Receptors for Antigen Are Encoded in Conventional VH Genes.- A. T-Cell Receptors for Non-self MHC Antigens Carry Idiotypic Determinants.- B. T-Cell Receptors for Conventional, Non-MHC Antigens Carry Idiotypic Determinants.- VIII. Self/Non-self Discrimination by T Cells.- IX. The Association of Nominal Antigens with MHC Structures.- X. Cellular Interactions in Antibody Responses.- A. T-Cell-Macrophage Interaction in T-Cell Priming.- B. T-Cell-B-Cell Interaction in Antibody Responses.- C. Regulation of Immunoglobulin Quality by T Helper Cells.- D. Suppressor T Cells in Antibody Responses.- E. Feedback Loops in Immunoregulation.- F. Idiotypic Networks and Immunoregulation.- XI. Discussion.- XII. Summary.- XIII. References.- 8 An Immunologic Network.- I. Introduction.- II. The Immune System and Connectivity through Antigen.- III. Connectivity through Antigen and A Cells.- IV. Complementary Idiotypes.- V. A Minimal Network.- VI. Regulation.- VII. Is the Network Too Complex?.- VIII. The Network and Disease.- IX. Summary.- X. References.- 9 The Biological Function of the Major Histocompatibility Complex: Hypotheses.- I. Introduction.- II. Allograft Reaction.- III. Genetic Control of Immune Responses.- IV. Genetic Control of Complement Levels.- V. MHC Associations with Susceptibility and Resistance to Disease.- VI. Genetic Control of Traits Not Currently Classified as Immunological.- VII. Further Analyses of the Importance of MHC Antigens and Genes.- A. Frequency of H Mutations.- B. Adaptive Value of H-2 Polymorphism.- VIII. Conclusion.- IX. References.- 10 Molecular Interactions and Recognition Specificity of Surface Receptors.- I. Introduction.- II. Ground Rules.- III. Cell-Surface Molecules Implicated as Receptors.- IV. Structural Relationships among Surface Receptors.- V. Binding Parameters of Receptors.- VI. Combining Sites of Lectins and Antibodies.- VII. Primary Binding and Subsequent Early Membrane Events.- VIII. Conclusions: Primary Binding and Activation.- IX. References.