Lymphoid Cell-Culture Line Derived From Lymph Node of Marmoset Infected With <italic>Herpesvirus saimiri</italic>—Preliminary Report

Abstract

A lymphoid cell line (MLC-1) which grows in suspension culture has been derived from the lymph node of a marmoset infected with Herpesvirus saimiri, a virus of squirrel monkeys producing a lethal disease in marmosets with histological features of malignant lymphoma. Three months after initiation of the cultures, only rare MLC-1 cells containing intranuclear herpesvirus particles were found by electron microscopy, and virus could not be isolated from frozen and thawed MLC-1 cell pellets or culture supernatants. When living MLC-1 cells were cocultivated with Vero monkey kidney cell cultures, however, a virus with morphological characteristics of a herpesvirus was readily isolated. Five months after initiation of the MLC-1 cultures, small amounts of this virus could also be recovered intermittently from supernatants. This herpesvirus, however, produced smaller plaques than H. saimiri and, by neutralization tests, appeared to be related to, though not identical with, H. saimiri. When inoculated into marmosets, it produced a lethal disease similar to that produced by H. saimiri but with more necrosis and less lymphoreticular cell proliferation. It may represent a variant of H. saimiri or a related marmoset herpesvirus. Its relationship to previously described herpesviruses and its role in lymphoreticular cell proliferation remain to be determined.