ABSTRACT
This chapter discusses the nature of the cells involved in the different stages of induction of immune responses, from antigen-presenting cells to effector populations of lymphocytes. The mechanisms of recognition of targets and activation of the different types of adaptive immune response and the different ways in which the cells mediate their protective function are described. The second section of this chapter is dedicated to the description of lymphoid organs and tissues, including the thymus, bone marrow, lymph nodes, spleen, and mucosal associated lymphoid tissues. This description includes anatomical and functional considerations. The last section of the chapter is dedicated to lymphocyte traffic and its regulation by cell adhesion molecules and chemokines that control the traffic of lymphoid cells both in physiological and pathological conditions.
