A latent infection of herpes simplex virus type 2 in a human neuroblastoma cell line IMR-32

Abstract

Human neuroblastoma (IMR-32) cells were infected with herpes simplex virus type 2 (HSV-2) at a multiplicity of infection (MOI) of 2 plaque-forming units (PFU)/cell and were cultured at 40 degrees C for 14 days. Then neither infectious virus particles nor virus capsids were detected in these cells whereas the presence of virus-specific antigens was observed by immunofluorescent antibody staining technique in 16.9 +/- 3.2 per cent of the infected cell population. When the cultivation temperature was shifted down from 40 degrees C to 35 degrees C, reactivation of virus growth occurred after lag periods of 2-9 days. These findings indicate that the IMR-32 cells can be latently infected with HSV-2 at 40 degrees C and that virus growth may be inhibited at the level of synthesis of virus-specific macromolecules or at some step preceding nucleocapsid formation.

Macromolecular synthesis at the early stage of herpes simplex virus type 2 (HSV-2) latency in a human neuroblastoma cell line IMR-32: repression of late viral polypeptide synthesis and accumulation of cellular heat-shock proteins

“…I1V[R-32 cells were grown in Eagle's minimal essential medium (MEM) supplemented with 5 per cent fetal bovine serum, 5 per cent newborn calf serum, 2 mM L-gIutamine and non-essential amino acids (Flow Laboratories, i~ockville, MA, U.S.A.) in the presence of 5 per cent CQ in a temperature gradient incubator at 37 ° or 40 ° C, as previously described (34). Vero and HEp-2 cells were gro~u~ in MEM supplemented with 5 per cent newborn calf serum and 2 mM L-glutamine in a 5 per cent COe incubator at 37 ° C. IMt~-32 cells were purchased from Flow Laboratories.…”

“…Recently, we report a latent infection of HSV-2 in a human neuroblastoma cell line IMR-32 (34); in this case, the infected cells cultured at 40 ° C could survive and the virus growth in them was arrested; as a consequence, the latently infected state in IMR-32 cells could be established without any materials such as serum antibody, interferon, some chemical inhibitors or a combination of these agents, which were described previously as necessary tools for the establishment of latent HSV infection (17,20,30,31). This indicates that thermal treatment of HSV-2-infected IMR-32 cells plays a critical role in the processes of establishment of a latent HSV infection.…”

“…One of the most reliable means for the establishment of an in vitro HSV latency is to elevate the cultivation temperature of HSV-infected cells (20,24,30,31,34). Recently, we report a latent infection of HSV-2 in a human neuroblastoma cell line IMR-32 (34); in this case, the infected cells cultured at 40 ° C could survive and the virus growth in them was arrested; as a consequence, the latently infected state in IMR-32 cells could be established without any materials such as serum antibody, interferon, some chemical inhibitors or a combination of these agents, which were described previously as necessary tools for the establishment of latent HSV infection (17,20,30,31).…”

Interaction of Herpes Simplex Virus Type 2 with a Rat Glioma Cell Line

“…during in vivo latency (8,22). However, the isolated rat and human neuronal cells (16,42,43) and neuroblastoma cell line (1,17,30,47) were permissive or semipermissive for the replication of HSV in vitro. As described in this paper, a mouse neuroblastoma cell line, N1E-115, was also permissive to both types of HSV.…”

“…These included latency of HSV-2 in human fetal fibroblasts (24), human embryonic lung cells (6,7,29), and human neuroblastoma cell line (47). All the in vitro models for HSV-2 were developed under artificial conditions similar to HSV-1, and no spontaneous latency model was established.…”