Suppression of Lymphocyte Function with Breast Carcinoma I-Active Glycopeptides

Patients with metastatic breast carcinoma (BCa) have defective peripheral blood lymphocyte (PBL) responsiveness to mitogenic and antigenic stimulation. In the following experiments, glycopeptides were isolated from the pronase digests of breast carcinoma tissue. After elution from Sephadex G-50, glycopeptides from BCa inhibited PBL responsiveness to mitogenic (PHA) stimulation. The glycopeptides contained blood group I-antigenic determinants. These experiments demonstrate the presence of blood group I-active peptides in breast carcinoma that suppress peripheral blood lymphocyte functions. Further studies are in progress.