To obtain a view of the influence of enterovirus infection on host cell gene expression, multiple cellular mRNA levels were first investigated during echovirus 1 (EV1) infection in HOS palpha2AW cells using cDNA array analysis. Visible cytopathic effect and partial shut-off of host cell protein synthesis were observed 6-10 h after the EV1 infection. Simultaneously, approximately 2% of the investigated genes, among them immediate-early response genes and genes involved in apoptotic pathways and cell growth regulation, were activated over twofold and less than 0.5% of genes were downregulated. For comparison, the cellular effects of coxsackievirus B4 and poliovirus 1 infections were studied in HeLa-Ohio cells by cDNA arrays. Gene activation patterns detected in the host cells during the infection by the three enteroviruses were only partially similar.