realized that the immune system could go awry and, instead of reacting against foreign antigens, could focus its attack on self-antigens. He termed this con- dition\horror autotoxicus \We now understand that while mechanisms of self-tolerance normally protect an individual from potentially self-reactive lymphocytes, there are failures They result in an inappropriate response of the immune system against self-components termed autoimmunity In the 1960s, it was believed that all self-reactive lymphocytes

lure can have dire consequences. Nude Mouse (nu/nu) elf and begins to attack hich is Primary Immunodeficiencies AIDS and Other Acquired or Secondary Immunodeficiencies at birth differentiated from immunodeficiencies in which the non- specific mediators of innate immunity, such as phagocytes or ed. Immunodeficiencies are conve- by the type or the developmental stage of overall cellular de g the locations of prevennon stra

the early vaccination trials of Edward Jenner and oneering efforts, vac nce of diseases such ng cougl Vaccination with DN A Active and Passive Immunization Designing Vaccines for Active Immunization mWhole-Organism Vaccines Purified Macromolecules as Vaccines Recombinant-Vector Vaccines DNA Vaccines Multivalent Subunit Vaccines mmon usage. Experience has shown that not every vaccine

susceptible host, a series of coordinated events must rcumvent both innate and adaptive immunity. One of the first and most important features of host innate immunity is the barrier provided by the epithelial surfaces of the skin and the lining of the gut. The difficulty of penetrat- ing these epithelial barriers ensures that most pathogens never gain productive entry into the host. In addition to pro viding a physical barrier to infection, the epithelia also pro duce chemicals that are useful in

effector molecules that act to remove antigen b ren various mechanisms described in previous chap es antigen without A Second Exposure to Poison Oak May Result in Delayed-Type Hypersensitivity Gell and Coombs Classification IgE-Mediated (Type I) Hypersensitivity Antibody-Mediated Cytotoxic(Type) Hypersensitivity aImmune Complex-Mediated (Type Ill) Hypersensitivity

part of the body to another. This is espe- ially true of lymphocytes, which circulate ly in the blood and lymph and, in common with at sites o Lymphocytes Attached to the Surface of a High-Endothelial Venule sLymphocyte Recirculation Cell-Adhesion Molecules Neutrophil Extravasation Lymphocyte Extravasation Chemokines-Key Mediators of Inflammation Other Mediators of Inflammation The Inflammatory Process

ne system assume different roles in pro- the host. The effectors of the humoral molecules f cells Big CTL Attacks Little Tumor Cell Effector Responses General Properties of Effector Cells Cytotoxic T Cells Natural Killer Cells Antibody-Dependent- Cell-Mediated- Cytotoxicity Experimental Assessment of Cell-Mediated Cytotoxicity

of the humoral branch of the immune system Research on complement began in the 1890s, when Jules bordet at the institut pasteur in paris showed that sheep antiserum to the bacterium vibrio cholerae caused lysis of the bacteria and that heating the antiserum destroyed its bacteriolytic activity. Surprisingly, the ability to lyse the bacteria was restored to the heated serum by adding fresh serum that contained no antibodies directed a The Functions of Complement

response involves lymphoid cells, inflammatory cells, and hematopoietic cells. The complex inter- lls are mediated by a group of pro- les to denote their role in secreted by body in activity of cyto- Class I Cytokine Receptors receptors,signal ptors, the role of cytokine Properties of Cytokines

production of plasma cells and memory B cells can be divided into three broad stages: generation of mature, immunocompetent B cells(maturation), activa- Initial Contact between b and T cells tion of mature B cells when they interact with antigen, and differentiation of activated B cells into plasma cells and memory B cells. In many vertebrates, ng humans B-Cell maturation and mice, the bone marrow generates B cells. This process