Attachment and penetration of canine herpesvirus 1 in non-permissive cells

Canine herpesvirus 1 (CHV-1) has a relatively narrow host cell range when c ompared to other alphaherpesviruses. The early events of CHV-1 infection in a permissive Madin-Darby canine kidney (MDCK) and non-permissive cell line s. In order to quantify attachment and penetration, were investigated quant itative competitive PCR (QCPCR) method was established for quantitation of CHV-1 DNA. In all non-permissive cells tested, no significant decrease in v iral attachment was observed. When CHV-1 was treated with heparin, viral at tachment to MDCK cells was reduced by 25% of the input CHV-1 attached to MD CK cells even in the presence of 50 mu g /ml heparin. However, the attachme nt of CHV-1 to non-permissive cells was severely impaired by heparin treatm ent. In permissive MDCK cells, about 80% of attached CHV-1 penetrated into cells. However, only 4-10 % of CHV-1 attached to non-permissive cells penet rated into cells. Our data indicated that CHV-1, like other herpesviruses, attached to permissive MDCK cells through two mechanisms: the first one is through the interaction mediated by heparan sulfate (HS) on the cell surfac e and the second involves unidentified viral component and the cellular rec eptor. In contrast, the non-permissive cells lacked the cellular receptor f or the second attachment mechanism and the defect in viral penetration into non-permissive cell might be related to the lack of the cellular receptor.