| Abstract: | We have reported finding antigen-specific activity in human leukocyte dialysates (DLE) containing TF in the leukocyte migration inhibition (LMI) assay. To analyze this activity further, we have used polystyrene bound to antibody or to antigen as immunoadsorbent for DLE before pulsing nonimmune cells in the LMI assay. Candida-(CAN) immune or diphtheria toxoid-(TOX) immune DLE were depleted of all antigen-specific activity after absorption with specific antigen but not affected by absorption with specific antibody, respectively, and depletion of activity with antigen was abrogated by coating bound antigen with specific antibody before absorption of DLE. CAN-immune, TOX-immune DLE was selectively depleted for either CAN activity or TOX activity after absorption with CAN- or TOX-coated polystryrene, respectively, retaining its CAN-activity when absorbed with TOX and conversely retaining its TOX activity when absorbed with CAN; thus the antigen-specific activity binds to related but not unrelated antigen. The polystyrene-bound antigen-specific activity could be recovered by treatment with 8 M urea. We interpret these findings to suggest that such antigen-specific activity may be either a dialysable fragment of a T cell antigen receptor site, or a portion of the V-region, or a unique Ir gene product that assists in antigen presentation to other T cells. |
