Many proteins involved in antigen processing and presentation are encoded by genes within the major histocompatibility complex Malignant lymphocyte tumors frequently carry chromosomal translocations that join immunoglobulin loci to genes regulating cell growth Downstream events are mediated by proteins that associate with the phosphorylated tyrosines and bind to and activate other proteins Cell-adhesion molecules control interactions between leukocytes and endothelial cells during an inflammatory response

The 9th edition also includes updates on recent developments in multiple immunology subfields. Notably, the section on innate immunity has added a discussion of immune effector modules, which are critical to understanding the pathogenesis of inflammatory bowel disease, intestinal infection, and several other diseases. The section on therapeutics now contains a discussion of chimeric antigen receptors, an active and important area of cancer immunotherapy research. A particularly significant feature of this edition is an overhaul of the end-of-chapter questions and the addition of an instructors’ question bank. The 9th edition replaces the handful of often open-ended review questions at the end of each chapter with multiple-choice and true-false questions, providing an easier avenue for instructors to test the material. In the absence of inflammatory stimuli, the normal response of the mucosal immune system to foreign antigens is toleranceActivated CD8 T cells and some CD4 effector T cells express Fas ligand, which can also activate apoptosis

Repeated immunizations lead to increasing affinity of antibody owing to somatic hypermutation and selection by antigen in germinal centers HIV accumulates many mutations in the course of infection in a single individual and drug treatment is soon followed by the outgrowth of drug-resistant variants of the virus The development of transplantable tumors in mice led to the discovery that mice could mount a protective immune response against tumors This advance enabled the World Health Organization to announce in 1979 that smallpox had been eradicated (Fig. 1.2), arguably the greatest triumph of modern medicine.The course of an infection can be divided into several distinct phases. & 10-2 Infectious diseases are caused by diverse living agents that replicate in their hosts

Complement control proteins regulate all three pathways of complement activation and protect the host from its destructive effects The effector functions& of T cells are determined by the array of effector molecules they produce. 8-18 Cytokines can act locally or at a distance Antigen recognition leads ultimately to the induction of new gene synthesis by activating transcription factors

Transcription of the HIV provirus depends on host cell transcription factors induced upon the activation of infected T cells Allergy can be treated by inhibiting either IgE production or the effector pathways activated by cross-linking of cell-surface IgE The notion of immunity— that surviving a disease confers greater protection against it later—was known since ancient Greece. The nonspecific responses of innate immunity are necessary for an adaptive immune response to be initiated The ITAMs associated with the B-cell and T-cell receptors are phosphorylated by protein tyrosine kinases of the Src family