Sibylle Schneider-Schaulies, Jürgen Schneider-Schaulies, M. Bayer, S. Löffler, V. ter Meulen

• The expression of measles virus (MV) in six different permanent human glioma cell lines (D-54, U-251, U-138, U-105, U-373, and D-32) was analyzed. Although all celllines were permissive for productive replication of all MV strains tested, U-251, D-54, and D-32 cells spontaneously revealed restrictions of MV transcription similar to those observed for primary rat astroglial cells and brain tissue. In vitro differentiation of D-54 and U-251 cells by substances affecting tbe intracellular cyclic AMP Ievel caused a significant reduction of tbeThe expression of measles virus (MV) in six different permanent human glioma cell lines (D-54, U-251, U-138, U-105, U-373, and D-32) was analyzed. Although all celllines were permissive for productive replication of all MV strains tested, U-251, D-54, and D-32 cells spontaneously revealed restrictions of MV transcription similar to those observed for primary rat astroglial cells and brain tissue. In vitro differentiation of D-54 and U-251 cells by substances affecting tbe intracellular cyclic AMP Ievel caused a significant reduction of tbe expression of tbe viral proteins after 18, 72, and 144 b of infection. This pronounced restriction was not paralleled to a comparable Ievel by an inhibition of tbe syntbesis and biological activity in vitro of virus·specific mRNAs as sbown by quantitative Northem (RNA) blot analyses and in vitro translation. The block in viral protein syntbesis could not be attributed to tbe induction of type I interferon by any of tbe substances tested. Our findings indicate tbat down-regulation of MV gene expression in human brain cells can occur by a cell type-rlependent regulation of tbe viral mRNA transcription and a differentiation-dependent regulation of translation, botb of wbicb may be crucial for the establisbment of persistent MV infections in tbe centrat nervous system.…