Human-human B cell hybridomas from in vitro stimulated lymphocytes of patients with common variable immunodeficiency.

Human-human B cell hybridomas have been established from the peripheral blood lymphocytes of patients with common variable immunodeficiency (CVI) by fusion with an HGPRT-negative B lymphoblastoid cell line. IgM-secreting hybridomas were successfully obtained from CVI lymphocytes after stimulation for 5 days in vitro with a combination of PWM and Staphylococcus aureus strain Cowan I. Fusion of peripheral blood lymphocytes that were stimulated for 5 days in vitro with a single mitogen resulted in no viable hybrids from a total of 600 X 10(6) CVI lymphocytes. The combination of PWM and Cowan I did not induce appreciable Ig secretion from the CVI lymphocytes during the 5-day course, although it did so in normal lymphocytes. After the 5-day stimulation with this mitogen combination, however, a large percentage of the original number of peripheral blood cells were recovered, and these had a fusion frequency of approximately 1 to 2 per 10(6) with the B lymphoblastoid line. Fifteen cloned IgM-secreting hybridomas have been isolated from five different CVI patients. These hybridomas are tetraploid and have been stable in culture for 6 to 12 mo. All of the hybridoma lines that were examined contain a functionally rearranged IgM heavy chain gene from the B cell parent of the CVI patients. These human-human B cell hybridoma lines will enable a more thorough characterization of the B cell defects involved in CVI at the cellular and molecular levels.