Quail cell lines supporting replication of Marek's disease virus serotype 1 and 2 and herpesvirus of turkeys

Marek's disease virus (MDV), a highly cell-associated alphaherpesvirus, can be isolated and propagated in chicken kidney cells (CKC) and chicken or duck embryo fibroblast cells (CEF or DEF, respectively). Two recently developed cell lines, CU447 and CU453, developed from methylcholanthrene-induced tumors in Japanese quail, were examined for their suitability to propagate the three serotypes of MDV. The MDV strain RB-1B (serorype 1) was passaged for more than 30 passages in CU447 without causing cytopathic effects (CPE). Polymerase chain reaction analysis of RB-1B-infected CU447 cells demonstrated the presence of MDV DNA using primers specific for ICP4, pp38, and gB. The 132-bp direct repeats within the BamH1-H and -D fragments were amplified to the same level as RB-1B that was passaged in CKC or CEF. Different passages of RB-1B in CU447 were examined for expression of gB and pp38 transcripts, and pp38, gB, gE, and VP22 protein expression. Irrespective of the passage level, these transcripts and proteins were detected in the RB-1B-infected CU447 cells. Infectious virus was rescued by cocultivation of RB-1B-infected CU447 with CKC. Herpes virus of turkeys was propagated in CU447 and CU453 causing CPE in both cell lines. SB-1 did not cause CPE in either cell line but a few SB-1-infected cells could be detected using a monoclonal antibody specific for serotype 2 MDV.