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Canine distemper virus (CDV) is an important pathogen for Canidae, Mustelidae, Felidae, Procyonidae, Viverridae, Ailuropodidae, Ursidae, Scrofa and even Macaca [9, 13]. Vaccination is an effective measure to control canine distemper in dogs and wild carnivores. For this purpose, several attenuated live vaccines made from cell culture or chicken embryos are often used. Despite that any newly developed vaccine would likely be produced by reverse genetics and carry well-defined attenuated mutations, traditional embryo-adapted live vaccines still take advantages of lower costs and better safety than those from cell culture, especially in wild animals (for example, CDV vaccine), and in human (for example, measles virus (MV) vaccine and rabies virus vaccine).
CDV uses the hemagglutinin protein to bind its cellular receptors [14]. Two CDV receptors, CD150 in lymphocytes [11] and heparin sulfate (HS) in 293 cells [2], have been reported. CD150, also named the signaling lymphocyte activation molecule (SLAM) with a predicted molecular weight of 37 kDa, is a preferential receptor for all members of the Morbillivirus genus. Vero-DST, a Vero cell line stably transfected with canine CD150, has been chosen for more effective isolation of CDV from clinical specimens [7]. However, mechanisms of viral cross-species adaption to chicken embryos or chicken embryo fibroblasts (CEF), as well as corresponding cellular receptors for such animal viruses as CDV and MV remain unclear. We previously reported that an isolate of CDV from an immunized but diseased pet dog, designated as CDV Kunming strain(CDV-KM), could replicate in CEF [5]. Receptors involved in its adaptive infection were subsequently investigated by virus overlay protein blot assays (VOPBA).
Canine Distemper Virus Utilizes Different Receptors to Infect Chicken Embryo Fibroblasts and Vero cells*
- Received Date: 05 December 2010
- Accepted Date: 15 February 2011
Abstract: Inducing animal viruses to adapt to chicken embryos or chicken embryo fibroblasts (CEF) is a common method to develop attenuated live vaccines with full security. Canine distemper virus (CDV) also does this, but the mechanisms and particular receptors remain unclear. Virus overlay protein blot assays were carried out on CEF membrane proteins, which were extracted respectively with a Mem-PERTM kit, a radioimmunoprecipitation assay buffer or a modified co-immunoprecipitation method, and revealed a common 57 kDa positive band that differed from the 42-kDa positive band in Vero cells and also from those receptors reported in lymphocytes and 293 cells, indicating a receptor diversity of CDV and the possibility of the 57-kDa protein acting as a receptor that is involved in adaptive infection of CDV Kunming strain to CEF.