Secretion of human monoclonal antibody after fusion of an immortal T cell line and lymphocytes from the peripheral blood of a patient with colon carcinoma.

A series of human hybridomas were derived by the fusion of the immature T cell line, JM, and lymphocytes from the peripheral blood of a colon carcinoma patient in long term remission who was shown to produce anti-tumor antibody. Five of the hybridomas have been selected for further study. These hybridomas express the T cell surface markers CD2, CD3, CD4, and CD8. The human IgG2/kappa antibody produced by these clones has been purified using affinity chromatography and has been used in immunohistiologic staining procedures. Biotinylated monoclonal antibody (MAb) stained colon carcinoma tissue but did not stain normal colon. Positive immunostaining was also seen utilizing colon carcinoma cell lines but not with other cell lines tested. These hybrids were constructed without using the conventional fusion technology which employs 8-azoguanine resistant, HAT sensitive malignant fusion partners. Because the fusion partner was a T cell, we were able to select hybrids on the basis of surface immunoglobulin. This approach was accompanied by stringent selection of patients as lymphocyte donors. Utilizing these unique methods, we have successfully produced hybridomas with T cell surface markers that produce human MAb with reactivity to colon carcinoma.