Development of a challenge-protective vaccine concept by modification of the viral RNA-dependent RNA polymerase of canine distemper virus.
We demonstrate that insertion of the open reading frame of enhanced green fluorescent protein (EGFP) into the coding sequence for the second hinge region of the viral L (large) protein (RNA-dependent RNA polymerase) attenuates a wild-type canine distemper virus. Moreover, we show that single intranasal immunization with this recombinant virus provides significant protection against challenge with the virulent parental virus. Protection against wild-type challenge was gained either after recovery of cellular immunity postimmunization or after development of neutralizing antibodies. Insertion of EGFP seems to result in overattenuation of the virus, while our previous experiments demonstrated that the insertion of an epitope tag into a similar position did not affect L protein function. Thus, a desirable level of attenuation could be reached by manipulating the length of the insert (in the second hinge region of the L protein), providing additional tools for optimization of controlled attenuation. This strategy for controlled attenuation may be useful for a "quick response" in vaccine development against well-known and "new" viral infections and could be combined efficiently with other strategies of vaccine development and delivery systems.
Silin
D
D
School of Biomedical Sciences, Queen's University of Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, United Kingdom.
Lyubomska
O
O
Ludlow
M
M
Duprex
W P
WP
Rima
B K
BK
D000818:Animals; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D004195:Disease Models, Animal; D004216:Distemper / Q000517:prevention & control* / Q000821:virology; D004217:Distemper Virus, Canine / Q000201:enzymology / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D004285:Dogs; D005289:Ferrets; D049452:Green Fluorescent Proteins / Q000235:genetics*; D007114:Immunization; D007963:Leukocytes, Mononuclear; D008297:Male; D018613:Microscopy, Confocal; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics*; D011995:Recombination, Genetic; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014709:Vero Cells; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology
D014613:Vaccines, Attenuated; D014765:Viral Vaccines; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D012324:RNA-Dependent RNA Polymerase