The outcome of poliovirus infections in K562 cells is cytolytic rather than persistent after hemin-induced differentiation.

AUTOR(ES)

Benton, P A

RESUMO

K562-Mu erythroleukemia cells readily establish a long-term persistent poliovirus infection characterized by continuous virus production in the absence of complete p220 cleavage and host translation shutoff (R. E. Lloyd and M. Bovee, Virology 194:200-209, 1993). The mechanism of resistance appears to be modulated at the intracellular level and to be related to decreased virus-mediated cytopathic effects (P. A. Benton, J. W. Murphy, and R. E. Lloyd Virology 213:7-18, 1995). It is well documented that hemin induces the differentiation of K562 cells and alters the expression of several host proteins. We report here that growth of K562 cells in hemin prior to poliovirus infection results in a dose-dependent increase in virus-induced cell lysis and thereby alters the normally persistent outcome of infection to a more lytic phenotype. K562 cells infected after hemin treatment displayed increased host translation shutoff, p220 cleavage, viral protein synthesis, and viral RNA accumulation compared with nontreated cells. Since hemin treatment of K562 cells also induced the increased expression of several heat shock proteins (Hsp70, Hsc70, Hsp90, and cohort p60), we tested the hypothesis that their increased expression may play a role in altering poliovirus infection in hemin-treated K562 cells. However, neither heat stress nor oxidative stress, inducers of heat shock protein synthesis, altered the outcome (of virus infections. In addition, we report the novel finding that subunits of two translation initiation factors, p220 (eIF-4G) and eIF-2alpha, are cleaved as a result of hemin treatment of K562 cells. It is proposed that hemin alters the expression of specific host proteins in K562 cells, probably other than heat shock proteins, which changes the initial response to poliovirus infections from persistent to lytic.

Documentos Relacionados

• Hemin-induced transcriptional activation of the HSP70 gene during erythroid maturation in K562 cells is due to a heat shock factor-mediated stress response.
• Activation of heat shock factor 2 during hemin-induced differentiation of human erythroleukemia cells.
• Constitutive c-myb expression in K562 cells inhibits induced erythroid differentiation but not tetradecanoyl phorbol acetate-induced megakaryocytic differentiation.
• Hemin-induced modifications of the antigenicity and hemin-binding capacity of Porphyromonas gingivalis lipopolysaccharide.
• Persistent infection of K562 cells by encephalomyocarditis virus.