Use of capillary tube leukocyte adherence inhibition for the detection of tumor-specific immune responses.

The tumor-specific immune response of A/J mice was determined at various times after subcutaneous injection with a transplantable spindle-cell sarcoma (SaI) using a leukocyte adherence inhibition (LAI) assay carried out in capillary tubes. Solubilized antigens prepared by 3M KC1 extraction of the specific tumor, other transplantable tumors and normal A/J liver were used in the evaluation of LAI reactivity. The assay was found to be capable of detecting a significant antitumor response before the subcutaneous tumors became detectable by palpation. The response remained significant until the tumors were greater than 25 mm in diameter. Responsive cell populations did produce an active supernatant, indicating the possible presence of a lymphokine and/or specific cytophilic antibody.