Interferon production and virus replication in lymphoblastoid cells infected with different viruses.

A semicontinuous infection system was used to test viral replication and interferon induction in lymphoblastoid cells: measles virus, Newcastle disease virus (NDV), Sendai virus, human parainfluenza virus (type II and III), Semliki forest virus (SFV) and Vesicular stomatitis virus (VSV). With the exception of Sendai virus, all viruses replicated in the Namalva cell line. Only measles virus was able to induce high levels of interferon. Three other cell lines, NC37, Raji (TK+-variant) and Raji (TK--variant) were tested using measles virus as inducer. The interferon yields from these cells were inferior to those obtained from Namalva cells.

Interferon induction and action in human lymphoblastoid cells infected with measles virus.

Virus replication, cytopathic effect and interferon production were measured in Namalva lymphoblastoid cells infected with measles viruses. Eight virus strains of different origin or passage history were compared. An inverse relationship seemed to exist between the abilities of strains to induce interferon and to replicate to high titres. Two representative strains were found to be highly sensitive to lymphoblastoid cell interferon, when tested in a line of monkey kidney cells (Vero). In contrast, Namalva cells were found to be highly insensitive to autologous interferon when challenged with measles or Semliki Forest virus (SFV).

Induction of interferon in human lymphoblastoid cells by Sendai and measles viruses.

Sendai and measles viruses were tested for their interferon-induced capacity in human lymphoblast cells. Sendai virus reproducibly induced considerable amounts of interferon (I research reference interferon unit/10(3) cells), but no increase in infectious virus titre was observed. Two Edmonston-Enders strains of measles virus grew very well. The attenuated (A) strain was a good interferon inducer (4 units/10(3) cells), while the virulent (V) strain induced only minimal amounts at a high multiplicity of infection. Pre-treatment of the cells with 5-iododeoxyuridine (IdUrd) had no effect on the growth of Sendai or EE measles virus and on interferon yields induced by Sendai virus. It slightly potentiated interferon induction by EE measles virus. Partial u.v.-light-inactivation of Sendai virus infectivity resulted in a parallel loss in interferon-inducing capacity.