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Development of Restrictions in the Expression of Immunoglobulin Specificities by Lymphoid Cells

The introduction of an immunogen to an individual with the capability of mounting an immune response may result in the production both of delayed hypersensitivity and of circulating antibody (Figure 1). Delayed hypersensitivity is mediated by specifically sensitized cells (lymphocytes) (Sell & Asofsky 1968). Circulating antibody consists of a group of structurally related molecules (immunoglobulins) produced by plasma cells (LeDuc, Coons & Connolly 1963, Nossal 1962). Both sensitized cells and immunoglobulin antibody have the capacity to recognize and react with specific antigen. The initial recognition of antigen by the specifically responding cells (primary immune response) may depend upon the presence on or in the responding cell of immunoglobulin molecules capable of binding antigen (Sell & Asofsky 1968). It is the purpose of this article to review the immunoglobulin response to immutiization and the capacity of plasma cells and lymphocytes to express different immunoglobulin specificities. This review will mainly cover data collected by the author and his collaborators. Many other workers have made significant contributions to this area, but no attempt will be made to review the literature systematically.