Interferon Production in Cell Lines Derived from Patients with Infectious Mononucleosis

Discussion and Summary In a previous report, it has been shown that biopsy material from patients with Burkitt's lymphoma gave rise to continuous cell lines in vitro (4,5). The lines appear to be lymphoid in character, produce interferon, contain a herpes-like virus (6,7) and synthesize immunoglobulins (8). In studying the peripheral leukocytes from patients with heterophile positive acute infectious mononucleosis, we have successfully isolated continuous cell lines in vitro. These lines possess the biological features of continous Burkitt cell lines (1). In these studies an inhibitor present in the established cell suspensions was identified as interferon on the basis of criteria used for the classification of interferons. Recently it has been reported that lymphoblastoid cells derived from fibroblastic elements of bone marrow of patients with infectious mononucleosis produced interferon (9). Although the inducer of interferon synthesis has not been identified, preliminary electron microscopy data in our laboratory indicates the presence of unusual 22 mμ particles in all of the cell lines studied for antiviral activity (10).