Maintenance of Antigen Specificity by Human Interleukin - 2 - dependent T Cell

The in vitro growth ofT cells obtained from localized anatomic sites of pathology may offer a new approach to the investigation of certain human autoimmune diseases. However, if interleukin2-dependent T cell cloning is to be useful in helping to elucidate putative pathogenetic antigens in these diseases, the expansion of the small number of T cells obtainable from localized anatomic sites of pathology will often have to be accomplished in the absence of these, as yet undetermined, antigens. At present, it is a generally held belief that antigen-responsive, interleukin-2-dependent T cell lines and clones will lose antigen responsiveness if propagated in the absence of specific antigen. Thus, the use of T cell cloning might be viewed as being of limited usefulness in the investigation of certain human autoimmune diseases. In this report we demonstrate that, when propagated in the absence of antigen, human tetanus toxoid-specific, interleukin2-dependent T cell lines will indeed lose antigen reactivity. However, if propagated in the absence of antigen but in the presence of antigen-presenting cells, the tetanus toxoid reactivity of a subset of such lines can be maintained. Moreover, the propagation with OKT3 antibody, in addition to antigenpresenting cells, may be even more effective in maintaining antigen reactivity. These results may suggest a new approach to the use of T cell cloning technology in the investigation of certain autoimmune diseases.