Section I: T Cell Receptors and T Cell Activation.- T Cell Receptor Structure and Function: Analysis by Expression of Portions of Isolated Subunits.- The T Cell Antigen Receptor Tyrosine Kinase Pathway.- Dissection of the Hb(64-76) Determinant Reveals That the T Cell Receptor May Have the Capacity to Differentially Signal.- CD28 Receptor Crosslinking Induces Tyrosine Phosphorylation of PLC?1.- Structure and Function of CD45: A Leukocyte-Specific Protein Tyrosine Phosphatase.- Multidrug Resistant Gene 1 Product in Human T Cell Subsets: Role of Protein Kinase C Isoforms and Regulation by Cyclosporin A.- Integrins, T Cells, and Autoimmunity.- The Interleukin-2 Receptor: A Target for Immunotherapy.- Section II: T Cell Development.- Lymphocyte Development in Mice Deficient for MHC Class I Expression.- Generation of Mutant Mice Lacking Surface Expression of CD4 or CD8 Gene Targeting.- Alteration of T Cell Lineage Commitment by Expression of a Hybrid CD8/CD4 Transgene.- Differential Involvement of Protein Tyrosine Kinases p56lck and p59fyn in T Cell Development.- Mechanism of Tolerance Induction.- Section III: B Cell Development, Activation, Proliferation, And Differentiation.- B-Lymphocyte Lineage-Committed, IL-7 and Stroma Cell-Reactive Progenitors and Precursors, and Their Differentiation to B Cells.- Regulatory Cells and Cytokines Involved in Primary B Lymphocyte Production.- The Role of IL-7 and Its Receptor in B-Cell Ontogeny.- Role of Contact and Soluble Factors in the Growth and Differentiation of B Cells by Helper T Cell.- B-Cell Activation Mediated by Interactions with Membranes from Helper T Cells.- The Low Affinity IgE Fc Receptor (CD23) Participates in B Cell Activation.- Section IV: Adhesion Molecules: Structure, Regulation and Functions.- T Cell Adhesion Cascades: General Considerations and Illustration with CD31.- Analyses of VLA-4 Structure and Function.- On the Regulation of ?2 Integrins.- Leukocyte-Endothelial Cell Adhesion as an Active, Multi-Step Process: A Combinatorial Mechanism for Specificity and Diversity in Leukocyte Targeting.- Contributors.