Chapter 11: Lymphocyte Effector Functions

Overview The innate immune system uses both humoral and cellular means to surround, phagocytize, enzymatically degrade, or otherwise kill microbial intruders (Fig. 11.1). The adaptive immune system also uses soluble (or humoral) and cellular defenses. In contrast to the innate immune system, the responses of the adaptive immune system are more narrowly targeted and directed […]

Chapter 12: Regulation of Adaptive Responses

Overview What happens when the immune system goes awry? When functioning properly, the innate and adaptive immune systems recognize and attack nonself while leaving self relatively undisturbed. The innate immune system expresses a finite number of genomically “hard-wired” receptors that recognize molecules widely expressed by potentially pathogenic organisms but not by the host (self). The […]

Chapter 13: The Well Patient: How Innate and Adaptive Immune Responses Maintain Health

Unit IV: Introduction The immune system normally functions smoothly to protect us from the vast numbers of microbes that surround us, many of which would like nothing more than to make a meal of us. We notice those times when it stumbles, when it faces an onslaught by an intruder with which it is unfamiliar […]

Chapter 14: Hypersensitivity Reactions

Overview Excessive or inappropriate immune responses sometimes lead to host tissue damage resulting from prolonged or repeated antigen exposure. These reactions, called hypersensitivity reactions, cause tissue injury by the release of chemical substances that attract and activate cells and molecules resulting in inflammation. These reactions are classified into four hypersensitivity types depending on the mechanism(s) […]

Chapter 15: Immune Deficiency

Overview Sometimes it seems as if the immune system is so complicated that it cannot possibly work. Failure seems almost assured, and indeed, small deficits in the generation of T- and B-cell receptors are common (see Chapter 8). Because redundancy is built in, failure in one component of the immune system may sometimes be covered […]

Chapter 16: Autoimmunity

Overview The innate immune system relies on a set of “hard-wired” genetically encoded receptors that have evolved to distinguish self from nonself. The adaptive immune system faces a much greater challenge in making such distinctions. The B-cell receptors (BCRs) and T-cell receptors (TCRs) of the adaptive immune system are randomly generated within each individual, without […]

Chapter 17: Transplantation

Overview The ability to replace or restore damaged tissues, or even entire body parts, has long been a dream of the healing professions. The broad application of transplantation in human medicine has been available only for the past five or six decades. Among the obstacles that had to be overcome were infection control, the genetic […]

Chapter 18: Immune Pharmacotherapy

Overview It is sometimes desirable to boost or supplement the normal immune response to maintain good health. However, on other occasions, as in the case of transplantation, the normal response of the immune system creates problems. And in other instances, such as allergy or autoimmunity, undesirable immune responses develop. In many of these situations, immune […]

Chapter 19: Tumor Immunity

Overview Cell growth and cell death are normally balanced so that a stable number of cells are maintained in a given tissue. Occasionally, however, cells arise that no longer respond to the usual checks and balances for division and death. These are tumor cells. Development from a normal cell to a cancerous one requires several […]

Chapter 20: Measurement of Immune Function

Overview Clinical laboratories provide a wide range of test procedures that are the foundation of modern medicine. Many routine test procedures are antibody-based. These tests rely on the ability of antibodies to aggregate (agglutination) particulate antigens (e.g., blood-typing) or to precipitate soluble antigens (e.g., radial immunodiffusion, Ouchterlony or double diffusion, immunoelectrophoresis). Other assays rely on […]