W O R L D H E A L T H O R G A N I Z A T I O N
ORGANISATION M O N D I A L E D E L A SANTÉ EXPERT COMMITTEE ON YELLOW FEVER
E n t e b b e , 9-15 M a r c h 1971 .
VIROLOGY
S t r u c t u r e , r e p l i c a t i o n , p h y s i c a l and c h e m i c a l p r o p e r t i e s by
W i l b u r G. Downs, M.D.
Department o f E p i d e m i o l o g y and P u b l i c H e a l t h Y a l e U n i v e r s i t y S c h o o l o f M e d i c i n e
V I R / Y F / 7 1 . 1 5
E N G L I S H ONLY
INDEXEO
S e v e r a l s t u d i e s o f s i z e o f y e l l o w f e v e r v i r u s p a r t i c l e s a s d e t e r m i n e d by e l e c t r o n m i c r o s c o p y have been r e p o r t e d :
A u t h o r s Y e a r M a t e r i a l S i z e
Reagan and B r u e c k n e r 1953 YF(17D) i n f e c t e d mouse b r a i n and s p i n a l c o r d s
50-55 nm B e a r c r o f t 1960 A s i b i i n f e c t e d l i v e r
c e l l s o f monkeys
55-61 nm
B a y e r and N i e l s e n 1961 A s i b i i n KB c e l l s 25-27 nm
B e r g o l d and W e i b e l 1962 M i c e and v a r i o u s c e l l s 38 nm + 5 nm
The s i z e d e t e r m i n a t i o n s f a l l w i t h i n t h e r a n g e o f s i z e s r e p o r t e d f o r s e v e r a l o t h e r g r o u p B a r b o v i r u s e s and a r e somewhat s m a l l e r t h a n s i z e s r e p o r t e d f o r g r o u p A a r b o v i r u s e s ( a p p r o x - i m a t e l y 55 nm) and c o n s i d e r a b l y s m a l l e r t h a n t h o s e o f t h e Bunyamwera s u p e r g r o u p ( 9 8 nm) a s r e p o r t e d by Murphy e t a l . ( 1 9 6 8 ) . F i l t r a t i o n s t u d i e s s u p p o r t t h e s e o b s e r v a t i o n s .
The v i r u s p a r t i c l e s ( B e r g o l d , 1962) a r e s p h e r i c a l , and show a l i m i t i n g membrane ( ? e n v e l o p e ) . He d e s c r i b e s and i l l u s t r a t e s t h e p a r t i c l e s i n a s t r o c y t e s o f mouse b r a i n a s a l w a y s a c c u m u l a t e d w i t h i n c i s t e r n s and d u c t s o f t h e e n d o c y t o p l a s m i c r e t i c u l u m . I n s a l i v a r y g l a n d c e l l s o f Aedes a e g y p t i he d e s c r i b e s p a r t i c l e s o c c u r r i n g f r e e i n t h e c y t o p l a s m and w i t h i n c i s t e r n s p r o b a b l y b e l o n g i n g t o t h e e n d o c y t o p l a s m i c r e t i c u l u m . O t h e r g r o u p B a r b o v i r u s e s h a v e been d e s c r i b e d a s b u d d i n g a l m o s t e x c l u s i v e l y upon p r o l i f e r a t i n g i n t r a c y t o - p l a s m i c membranes w i t h a c c u m u l a t i o n o f e n v e l o p e d v i r u s p a r t i c l e s w i t h i n d i s t e n d e d c i s t e r n a e (Murphy, 1968) and Murphy p r e s e n t s a s i m p l i f i e d c o m p a r a t i v e schema, w i t h g r o u p A a r b o v i r u s e s c h a r a c t e r i s t i c a l l y s h o w i n g an a r r a y o f n u c l e o i d s , g r o u p B a s above, and w i t h Bunyamwera
s u p e r g r o u p v i r u s e s , an a c c u m u l a t i o n o f v i r u s p a r t i c l e s i n d i v i d u a l l y i n v a c u o l e s and i n raassei i n membranous e n c l o s u r e s .
The issue of this document does not constitute formal publication. It should not be reviewed, abstracted or quoted without the agreement of the World Health Organization. Authors alone are responsible for views expressed in signed articles.
Ce document ne constitue pas une publication.
Il ne doit faire l'objet d'aucun compte rendu ou résumé ni d'aucune citation sans l'autorisation de l'Organisation Mondiale de la Santé. Les opinions exprimées dans les articles signés n'engagent que leurs auteurs.
V I R / Y F / 7 1 . 1 5 p a g e 2
The v i r u s i t s e l f i s r e l a t i v e l y u n s t a b l e i n media o f low p r o t e i n c o n c e n t r a t i o n , but c a n be s t o r e d f o r l o n g p e r i o d s o f t i m e a t low t e m p e r a t u r e i n media s u c h as 7.5% b o v a l b u m i n , pH 7.0, and i n media c o n t a i n i n g w h o l e serum, o r serum i n c o n c e n t r a t i o n s o f 5 0 % o r l o w e r . D o t h i n f e c t i v i t y and h a e m a g g l u t i n i n t i t r e s a r e r e t a i n e d b e t t e r when p r e p a r a t i o n s a r e s t o r e d
i n m e d i a o f h i g h pH, 7,0 o r h i g h e r .
Y F v i r u s i s n o t a p p r e c i a b l y i n a c t i v a t e d by non-immune s e r a o f a number o f v e r t e b r a t e s p e c i e s (man, r a b b i t , mouse, monkeys o f many s p e c i e s , h a m s t e r s and g u i n e a - p i g s , h o r s e ) . The s i t u a t i o n v i s - a - v i s s e r a o f r u m i n a n t s i s n o t so c l e a r and i t i s p o s s i b l e t h a t s e r a o f some s p e c i e s , o r i n d i v i d u a l s may c o n t a i n a v i r u s i n a c t i v a t i n g s u b s t a n c e . The v i r u s w i t h s t a n d s d e s i c c a t i o n w e l l .
A number o f l i p i d s o l v e n t s and l i p i d e m u l s i f y i n g a g e n t s , s u c h a s sodium d e s o x y c h o l a t e , c h l o r o f o r m and e t h e r r a p i d l y i n a c t i v a t e t h e v i r u s , p o s s i b l y by s p l i t t i n g a l i p i d - c o n t a i n i n g e n v e l o p e , p e r m i t t i n g r i b o n u c l e a s e s t o a c t upon t h e i n f e c t i o u s v i r u s RNA.
Cheng (1958) has shown t h a t Y F , i n common w i t h o t h e r g r o u p B a r b o v i r u s e s he t e s t e d i s r a p i d l y i n a c t i v a t e d by p r o t e a s e s ( t r y p s i n , c h y m o t r y p s i n and p a p a i n ) , w i t h d e s t r u c t i o n a l s o o f h a e m a g g l u t i n i n s , where as t h e g r o u p A a r b o v i r u s e s r e m a i n u n a f f e c t e d . He p o i n t s out t h a t t h i s a c t i v i t y o f t h e enzymes i s a t r u e e n z y m a t i c a c t i v i t y , a p p a r e n t l y d i r e c t e d a g a i n s t t h e v i r u s p a r t i c l e s , r a t h e r t h a n an a c t i v i t y d i r e c t e d a g a i n s t o t h e r components o f t h e mouse b r a i n p r e p a r a t i o n s he u s e d , r e s u l t i n g i n a s e c o n d a r y v i r u s i n a c t i v i n g m o i e t y . T a k e h a r a e t a l . ( 1 9 6 1 ) showed t h a t t r y p s i n and a l s o p a n c r e a t i c d i p a s e i n a c t i v a t e d p a r t i a l l y p u r i f i e d Y F v i r u s .
They a l s o d e m o n s t r a t e d an i n a c t i v a t i o n o f WEE by t h e s e enzymes. The r e s u l t s o f t h e s e two r e p o r t s a r e n o t c o m p a r a b l e s i n c e d i f f e r e n t v i r u s p u r i f i c a t i o n m e a s u r e s w e r e e m p l o y e d , and e x p o s u r e t o enzyme p r e p a r a t i o n s was c o n s i d e r a b l y l o n g e r i n t h e T a k e h a r a e x p e r i m e n t s .
N i e l s e n e t a l . (1961) e x t r a c t e d i n f e c t e d baby mouse b r a i n w i t h p h e n o l , and showed t h a t t h e r e s u l t i n g m a t e r i a l , w i t h a U-V a b s o r p t i o n s p e c t r u m c h a r a c t e r i s t i c o f RNA had a b o u t 0.03%
o f i n f e c t i v i t y o f t h e o r i g i n a l p r e p a r a t i o n , and t h a t t h i s m a t e r i a l was r e a d i l y i n a c t i v a t e d by RNA a s e b u t n o t by DNA a s e . They a l s o showed t h a t t h i s m a t e r i a l was i n a c t i v a t e d by t r y p s i n .
T h e r e a r e no d e f i n i t i v e r e p o r t s o f t h e c h e m i c a l c o m p o s i t i o n o f Y F v i r u s . D e t e r m i n a t i o n s o f Ada e t a l . ( 1 9 6 2 ) f o r M u r r a y V a l l e y E n c e p h a l i t i s v i r u s o f 1 1 % l i p i d s , and RNA c o n t e n t
7.8%, w i t h a d e n y l i c a c i d 25.5, g u a n y l i c a c i d 27.5, c y t i d i l i c a c i d 21.5 and u r a d i l i c a c i d 25.5 may be r e l e v a n t . S t e l l a r e t a l , ( 1 9 6 6 ) r e p o r t f o r dengue 2 v i r u s , an RNA c o n t e n t o f 7%, and n u c l e o t i d e s i n t h e 45S ( i n f e c t i v e ) f r a c t i o n o f a d e n i n e 30.6, g u a n i d i n e 26,4, c y t i d i n e 21,3 and u r i d i n e 21,6.
Mussgay ( 1 9 6 4 ) p r e s e n t s a u s e f u l s y n o p s i s o f t h e g r o w t h c y c l e o f a r b o v i r u s i n v e r t e b r a t e and a r t h r o p o d c e l l s , w i t h i n f o r m a t i o n on t h e r a n g e o f v e r t e b r a t e and a r t h r o p o d c e l l s i n w h i c h Y F v i r u s c a n be grown. S p e c i f i c i n f o r m a t i o n as t o d y n a m i c s o f t h e g r o w t h c y c l e o f Y F v i r u s e s i s n o t a b l y l a c k i n g . B o r r o w i n g from dengue 2 s t u d i e s , S t e v e n s e t a l . (1962) h a v e shown t h a t r e l e a s e o f i n f e c t i o n s dengue 2 v i r u s by KB c e l l s o c c u r s a f t e r an a v e r a g e l a t e n t p e r i o d o f 12 h o u r s and i n f u r t h e r s t u d i e s o f v i r u s k i n e t i c s S t e l l a r e t a l . ( 1 9 6 6 ) c o n c l u d e t h a t s y n t h e s i s o f e s s e n t i a l RNA b e g i n s s i x h o u r s a f t e r i n f e c t i o n o f c e l l s and p r e c e d e d r e l e a s e o f m a t u r e v i r u s by s i x t o s e v e n h o u r s . They d e s c r i b e a 45S-RNA f r a c t i o n , c o n t a i n i n g t h e i n f e c t i o u s ( s i n g l e s t r a n d e d ) v i r u s and a 20S-RNA f r a c t i o n c o n t a i n i n g d o u b l e s t r a n d e d m a t e r i a l .
V I R / Y F / 7 1 , 1 5 page 3
REFERENCES
Ada, G.L,, A n d e r s o n , S.C. & C o l l i n s , F,D, (1962) P a r t i c l e c o u n t s and some c h e m i c a l p r o p e r t i e s o f M u r r a y V a l l e y e n c e p h a l i t i e s v i r u s , J . gen. M i c r o b i o l . , 29, 165-170 B a y e r , M.E. fc N i e l s e n , G. (1961) Z u r M o r p h o l i g i e d e s G e l b f i e b e r v i r u s , A r c h , f . d .
Gesamte V i r u s f o r s c h u n g , 11, 303-306
B e a r c r o f t , W.G.C. (1960) E l e c t r o n - m i c r o s c o p e s t u d i e s on t h e l i v e r c e l l s o f y e l l o w f e v e r - i n f e c t e d r h e s u s monkeys, J . P a t h . B a c t . , 80, 421-426
B e r g o l d , G.H. k W e i b e l , J , (1962) D e m o n s t r a t i o n o f y e l l o w f e v e r v i r u s w i t h t h e e l e c t r o n m i c r o s c o p e . V i r o l o g y , 17, 554-562
Cheng, P . Y . (1958) The i n a c t i v a t i o n o f g r o u p B a r t h r o p o d - b o r n e a n i m a l v i r u s e s by p r o t e a s e s , V i r o l o g y , 6, 129-136
Murphy, F.A., H a r r i s o n , A.K. & T z i a n a b o s , T. (1968) E l e c t r o n m i c r o s c o p i c o b s e r v a t i o n s o f mouse b r a i n i n f e c t e d w i t h bunyamwera g r o u p a r b o v i r u s e s , J . V i r o l o g y , 2,
1315-1325
Mussgay, M. (1964) Growth c y c l e o f a r b o v i r u s e s i n v e r t e b r a t e and a r t h r o p o d c e l l s , P r o g r . med. V i r o l . , 6, 193-267
N i e l s e n , G. & M a r q u a r d t , J . (1961) E i n e I n f e c t i o s e U n t e r e i n h e i t von R i b o n u c l e i n - s a u r e - c h a r a k t e r aus G e h i r n e n G e l b f i e b e r v i r u s - i n f i z i e r t e r Mause, A r c h , f . d.
Gesamte V i r u s f o r s c h u n g , 12, 335-345
Reagan, R.L. & B r u e c k n e r , A . L . (1953) E l e c t r o n m i c r o s c o p y o f y e l l o w f e v e r v i r u s (17D), Amer. J . P a t h . , 27, 1157-1159
S t e v e n s , T.M., S c h l e s i n g e r , R.W. & S c h u l z e , I . T . (1964) C o n c u r r e n t i n c r e a s e o f p l a q u e - f o r m i n g and h e m a g g l u t i n a t i o n a c t i v i t i e s d u r i n g growth o f dengue v i r u s i n KB c e l l s , B a c t . P r o c . (Am. Soc. M i c r o b i o l . ) , 62, 132
S t e l l a r , V., S t e v e n s , T.M. & S c h l e s i n g e r , R.W. (1966) S t u d i e s on t h e n a t u r e o f dengue v i r u s e s , I I . C h a r a c t e r i z a t i o n o f v i r a l RNA and e f f e c t s o f i n h i b i t o r s o f RNA s y n t h e s i s , V i r o l o g y , 30, 303-312
T a k e h a r a , M, & H o t t a , S. (1961) E f f e c t o f enzymes on p a r t i a l l y p u r i f i e d J a p a n e s e B e n c e p h a l i t i s and r e l a t e d a r b o r v i r u s e s . S c i e n c e , 134, 878-1880
