A monoclonal lewis rat myocyte line that responds to interferon-gamma: responsiveness with the potential to influence subsequent interactions with the immune system.

In order to begin asking questions about immunopathology associated with the model of the neuromuscular disease experimental autoimmune myasthenia gravis, a monoclonal myocyte line, LE1, has been prepared from the Lewis rat. The LE1 myocyte clone was selected from among several clones produced based on its ease of maintenance in culture and for the stability of its phenotype, which is very similar to that reported for in vivo muscle and other cultured myocyte lines. Thus, LE1 cells were observed to produce, constitutively, the myocyte-associated neural cell adhesion molecule (CD56), the intracellular adhesion molecule (ICAM-1), and the acetylcholine receptor. LE1 cells were also observed to constitutively secrete relatively low levels of IL-6 and TGF-beta. Moreover, the LE1 cell line may be of use for predicting muscle responses to various immune mediators. For example, the inflammatory cytokine interferon-gamma (IFN-gamma) has been recently reported by others to play a role in experimental myasthenia gravis. Thus, it was of interest that LE1 cells could be activated by IFN-gamma to express increased levels of immunopathologically relevant membrane molecules such as ICAM-1 and Class II major histocompatibility molecules (i.e., RT-1B).