ABSTRACT
The preceding chapters have described some of the important soluble protein mediators of the immune response (antibodies and complement) and we must next turn our attention to the cellular elements of immunity and the lymphoid tissues in which they largely reside. This chapter will discuss the key cells of the adaptive immune system (T and B lymphocytes and plasma cells) and the primary and secondary lymphoid tissues. Primary lymphoid tissues are the sites where the lymphoid cells are formed and undergo initial maturation, whereas secondary lymphoid tissue comprises fully developed lymphoid cells that are capable of participating in immune responses.
