Immunoglobulin Gene Expression in Immunocyte Differentiation

Abstract

Immunocompetent cells appear to exist in at least two distinct subpopulations on the basis of several different observations. (i) In chickens, a sharp dichotomy between lymphoid cells involved in cellular or humoral immune responsesis associated with a separate developmental control by thymus or the bursa of Fabricius (1); (ii) in the initiation of certain antibody responses, thymic derived cells,“T” cells (2), collaborate with non-thymic derived ceils,“B” cells, to induce the latter into active antibody secretion (3); and (iii) in peripheral lymphoid tissues, varying proportions of lymphoid cells carry thymic specific cell surface isoantigens such as theta (4). Whether these three classificationsare all describing the same two cell types is not completely resolved, however it does appear that “T” and “B” cells are distinct in both their ontogenic development and functional capacity. In this article we wish to discuss the development of these two lines in terms of the type of immunoglobulin synthesised by these cells, and therefore responsible for their ability to react with antigen.

This work was supported by USPHS grant No. AM 11234–03.