Infection of Chicken Embryonic Fibroblasts by Measles Virus: Adaptation at the Virus Entry Level

Abstract

Measles virus (MV) has a tropism restricted to humans and primates and uses the human CD46 molecule as a cellular receptor. MV has been adapted to grow in chicken embryonic fibroblasts (CEF) and gave rise to an attenuated live vaccine. Hallé and Schwarz MV strains were compared in their ability to infect both simian Vero cells and CEF. Whereas both strains infected Vero cells, only the CEF-adapted Schwarz strain was able to efficiently infect CEF. Since the expression of the human MV receptor CD46 rendered the chicken embryonic cell line TCF more permissive to the infection by the Hallé MV strain, the MV entry into CEF appeared to be a limiting step in the absence of prior MV adaptation. CEF lacked reactivity with anti-CD46 antibodies but were found to express another protein allowing MV binding as an alternative receptor to CD46.

Techniques Employed in Production of Traditional Vaccines Commonly Used by Military Forces: A Review

“…In the case of viral pathogens, the population is not a single genotype but a mixed genotype due to rapid mutations in the viral RNA; hence, it is essentially a "quasispecies". This quasispecies is necessary for the survival and virulence of the pathogen as it provides the pathogen with a better chance of survival when infecting an individual by granting the virus to have the ability to adapt to a new environment when infecting a host (7). Degradation in this quasispecies can be brought about by propagating the virus in an atrophic host, resulting in the loss of genetic diversity for successful infection of the trophic host (8).…”

“…The virulence of a pathogen would decrease if the overall genotypic diversity of the population was restricted by subjecting the viral population to continuous genetic variation and competition (14). For example, the measles vaccine is produced by inoculating and passaging the pathogen in chicken embryonic fibroblast, resulting in the attenuation of the virus (7). The vaccine for yellow fever was produced in a similar manner.…”

A CD46CD[55–46] chimeric receptor, eight short consensus repeats long, acts as an inhibitor of both CD46 (MCP)- and CD150 (SLAM)-mediated cell–cell fusion induced by CD46-using measles virus

“…CD46 allows the entry of MV laboratory strains maintained in epithelial and fibroblastic cell lines, including all attenuated virus strains used as efficient human vaccines (Escoffier & Gerlier, 1999 ; Hsu et al ., 1998 ; Kobune et al ., 1990 ; Lecouturier et al ., 1996 ; Parks et al ., 2001 ; Schneider-Schaulies et al ., 1995b ; Tanaka et al ., 1998 ). However, CD46 is not used by recent MV isolates grown in simian B95 B cells (Hsu et al ., 1998 ; Kobune et al ., 1990; Lecouturier et al ., 1996 ; Murikami et al ., 1999 ), or from throat swabs from infected individuals (Ono et al ., 2001b ).…”