Establishment of stable human T-T hybridomas

Human T-T hybridomas potentially provide an invaluable resource for a variety of immunoregulatory molecules that modulate the immune response. To date, success in this technology, using human cell populations, has been hampered by several problems associated with proliferative and functional instability of the hybrid cells. These forms of instability are the result of a multifactorial process, with 1 parameter of importance being the chromosome number of the malignant parent cell line used for fusion. The present studies describe the production of a stable human T-T hybridoma generated by fusing a near diploid (modal chromosome number of 48) aminopterin-sensitive T cell line, CEM TG E11, and lectin-stimulated human peripheral blood lymphocytes. The rapidly growing hybrid cells have been clonally selected for the production of a B cell growth factor. Hybridization was documented by the presence of HLA phenotypes reflecting the combined antigens of the fusion partners. Fusions with 4 other partners besides CEM TG E11, where the majority of the cells had modal chromosome numbers ranging from 78 to 94, were proliferatively unstable. To date, hybrid cells derived from the CEM TG E11 fusion have been doubling approximately every 48 h for greater than 12 months, and selected clones constitutively produce B cell growth factor.