Isolation of helper T cells from the peripheral blood of normal donors, using serum from a patient with agammaglobulinemia

Serum from a patient with agammaglobulinemia was found to contain antibody reactive with a subset of normal T lymphocytes. This subset, designated AGG+, was shown to express the properties associated with helper T cells. The addition of AGG+ cells to B cells caused an increase in the number of plaque-forming cells, whereas the AGG− population was unable to enhance Ig production. In addition, the AGG+ population was unable either to recognize or to kill allogeneic cells, with recognition and killing events being carried out by AGG− T cells. The relationship of this subset to other subsets defined by reactivity with auto- or heteroantibody was examined.