ELECTRON-MICROSCOPY OF INFLUENZA-VIRUS GROWTH IN A HUMAN LYMPHOBLASTIC-LEUKEMIA CELL-LINE, MOLT4 CELLS

We studied the interaction of influenza virus and a human lymphoblastic line, MOLT4 cells, as a model for that of influenza virus and human T lymphocytes. Influenza virus was found to grow relatively poorly in MOLT4 cells in terms of yield of plaque forming units (PFU) in the presence of trypsin. However, electron microscopy of infected cells revealed that a lot of viral antigens were accumulated in the cytoplasm as well as in the nucleus, and a number of budding virions were on the cell surfaces. Consistently, gel electrophoresis of infected cells demonstrated that the synthesis of virus proteins was abundant. These findings indicated that MOLT4 cells were permissive to influenza virus growth, with production of a relatively smaller number of infectious particles in terms of PFU. Production of interferon (IFN)-alpha and -gamma were not detected in this system by ELISA.