* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Differentiation of Rubella Virus Strains by Neutralization Kinetics
Survey
Document related concepts
Herpes simplex wikipedia , lookup
Swine influenza wikipedia , lookup
Eradication of infectious diseases wikipedia , lookup
Hepatitis C wikipedia , lookup
Middle East respiratory syndrome wikipedia , lookup
Human cytomegalovirus wikipedia , lookup
2015–16 Zika virus epidemic wikipedia , lookup
Ebola virus disease wikipedia , lookup
Orthohantavirus wikipedia , lookup
Marburg virus disease wikipedia , lookup
West Nile fever wikipedia , lookup
Influenza A virus wikipedia , lookup
Hepatitis B wikipedia , lookup
Antiviral drug wikipedia , lookup
Herpes simplex virus wikipedia , lookup
Transcript
J. gen. Virol. (198o), 49, 423-426 423 Printed in Great Britain Differentiation of Rubella Virus Strains by Neutralization Kinetics (Accepted 20 February ~98o) SUMMARY The neutralization of rubella virus was investigated and shown to proceed by first order kinetics over the first Io to i5 min. A comparison of the rate constant of neutralization (K) for six strains of rubella virus was carried out over this period of the reaction. Two particularly antibody-sensitive isolates were detected. It was noted that the three strains isolated from in utero infections were poorly neutralized by heterologous antisera when compared to postnatal strains. Although several highly sensitive serological tests have been used successfully for the assay of rubella virus antibodies, including radio-immunoassay (Meurman et al. 1977), enzyme immunoassay (Gravell et aL t977) and enhanced plaque neutralization (Sato et al. 979b), none are readily adaptable for the characterization of antigenic differences between various rubella virus isolates or strains. Simple haemagglutination inhibition has been applied to this type of analysis (Banatvala & Best, I969), but neither this nor the kinetic haemagglutination inhibition test devised by Best & Banatvala 097o) could detect a difference in the antigenic make-up of the various strains of rubella virus examined. The neutralization test is, however, highly suitable for comparative studies (Mandel, I978); Oxford (t 969) was able to demonstrate small antigenic differences between strains of rubella virus using a 5o % infectious dose assay of surviving virus. In the same year Fogel & Plotkin (I969) demonstrated some antigenic differences by cross-neutralization tests employing a plaque reduction method. The development of a highly reliable and reproducible method of plaque assay in GL-RK13 ceils (Gould et al. 197z), has made detailed investigation of the neutralization of the virus possible. This report presents an examination of the neutralization kinetics of a standard strain and a comparison of the rates of neutralization of six other strains of known history. Six strains of rubella virus of varied history were selected for study (Table 1). Stocks of virus were grown in Vero cells and stored at - 7 o °C. The standard virus used was a pool of the RA27/3 strain grown in WI-38 cells, lyophilized and stored at - 2o °C. Veto cells were obtained from the Public Health Laboratory Service at Colindale, U.K., and GL-RK13 cells from the National Institute of Health, Bethesda, U.S.A. The growth medium for both cell cultures consisted of Eagle's MEM containing o.t 1% N a H C Q and 5 % foetal calf serum, while maintenance medium contained o.22 % NaHCO~ and 28 % foetal calf serum. Details of the plaque assay are given elsewhere (Gould et al. I972). California strain rabbits received four successive intravenous inoculations of undiluted virus at 7 to Io day intervals and were bled out from the heart I3 weeks after the first inoculation. Rabbits receiving virulent virus were housed separately from those receiving the attenuated strains and untreated rabbits housed with both failed to produce detectable antibody to rubella virus at any time. Sera were separated and stored at - 2 o °C. The standard pool of hyperimmune serum used was produced against the Edmunds strain of rubella virus (Banatvala & Best, I969). Dilutions of antiserum (2 ml) were mixed with equal volumes of virus suspension containing approx lo 33 p.f.u. The mixture was incubated in a sealed Bijoux bottle in a water Downloaded from www.microbiologyresearch.org by oo22-I317/8o/oooo-4o25$o2.oo © I98O SGM IP: 88.99.165.207 On: Thu, 11 May 2017 06:59:38 Short communications 424 T a b l e 1. K values for replicate tests on six systems of homologous antiserum and antigen mixture Antigen Origin Passage history Mean K value Mean NK* Lesley HPV-77 Cendehill Dunning Adult with rubella Adult with rubella Adult with rubella Rubella syndrome infant Rubella syndrome infant Rubella-infected conceptus MK(3) MK(78) YRK(5~) RKaa(4) 2'94 _ o 2"72 + 0-05 I'6O_+O'O3 2"5o ___o"I4 Ioo + o 1oo + 1-63 Ioo_+ 1"63 lOO+ 3'26 RKxa(3) 2.55 ---o.18 lOO_+4"31 H EK(4) WI-38(32) 1.6o +_o"13 I oo _+8"16 Thomas RA27/3 * Mean normalized K value. Table 2. Normalized K values for each antiserum assayed separately with the six different antigenic types Antigens Antisera RA27/3 HPV-77 Cendehill Dunning Thomas Lesley RA27/3 HPV-77 Cendehill Dunning Thomas Lesley Ioo 53'3 73 67 66 3o Io9"5 ioo 135 80 81 117 46 55"5 IOO 70 53 51 88 100 91 5o 57'5 66 61 '5 27 111 218 I45'5 210 102" 5 56 1(30 125 44 ioo bath at 32.5 °C. Samples (o.I ml) were withdrawn at intervals and t i t r a t e d in m o n o l a y e r cultures o f GL-RK13 cells. Mixtures o f p r e - i m m u n e serum with virus a n d s t a n d a r d s e r u m with s t a n d a r d virus were similarly treated. T h e surviving virus was plotted on a l o g a r i t h m i c scale against time on a linear scale and the rate o f neutralization per minute, the K value, was calculated from the initial slope o f the curve where the reaction was a p p a r e n t l y first order, i.e. a straight line passing t h r o u g h the origin (Dutbecco et al. 1956 ). A c o m p a r i s o n o f the neutralization o f one antigen with different antisera is only possible if the K values are n o r m a l i z e d (McBride, 1959), because the a n t i b o d y c o n t e n t o f each p o o l o f a n t i s e r u m c a n n o t be standardized. N o r m a l i z e d K values represent the rate at which a particular serum neutralized a h e t e r o l o g o u s virus as c o m p a r e d to the rate at which it neutralized the h o m o l o g o u s virus, which is t a k e n as IOO. In any one test, one serum was assayed against all the strains o f rubella virus to minimize variations between separate experiments. It was f o u n d t h a t a dilution o f 1/8 o f the s t a n d a r d a n t i s e r u m ( E d m u n d ) gave a reaction curve with a s t a n d a r d p o o l o f R A 2 7 / 3 virus in which first o r d e r kinetics were observed for a p p r o x i m a t e l y the first lo to 15 min. T h e results for thirteen replicate tests showed a g o o d level o f reproducibility, with a s t a n d a r d deviation o f + 6-920 for the n o r m a l i z e d K value. F o r all other investigations of the test sera, a dilution o f 1/8 was also used and t h e K values determined for the first I o rain o f reaction time. T h e K values for all six h o m o l o g o u s reactions, which were done in triplicate, showed very little v a r i a t i o n between replicates (Table l). T h e normalized K values for each antiserum d e t e r m i n e d with all the antigens u n d e r study are given in T a b l e 2 and each value represents the m e a n o f two experiments. T w o strains o f virus, HPV-77 and Lesley, a p p e a r e d to be p a r t i c u l a r l y sensitive to h e t e r o l o g o u s a n t i b o d y . Thus, the n o r m a l i z e d K values for h e t e r o l o g o u s antisera with Lesley were, in all cases, Downloaded from www.microbiologyresearch.org by IP: 88.99.165.207 On: Thu, 11 May 2017 06:59:38 Short communications 425 higher than the homologous value. For HPV-77 virus, only two antisera, that is Dunning and Thomas gave normalized K values less than IOO.With the other strains of virus, RAz7/3, Cendehill, Dunning and Thomas, heterologous antisera often gave normalized K values which were much less than Ion. In one instance with Thomas antiserum there was evidence of identity with a heterologous antigen, Cendehill, but the relationship was not reciprocal. The virus strains originating from cases of intra-uterine infection, RA27/3, Dunning and Thomas, showed a reaction of identity only with homologous antisera whereas the other strains, all isolated from post-natal infections we]'6 efficiently neutralized by some or all of the heterologous antisera. The mechanism and nature of the neutralization test is still unresolved (MandeI, I978), but results reported here are in b.greement with Rawls et al. 0967), in that, for rubella virus, neutralization proceeds by first order reaction over the first i o to 15 min. On this premise, it is concluded that the varying K values recorded for different rubella virus isolates imply some antigenic diversity and the most interesting feature of this diversity is the differentiation between viruses isolated from intra-uterine and post-natal infections. The apparent differences between viruses isolated from in utero and post-natal infections deserves further examination, if only to determine whether the prolonged in vivo growth of the former types might result in the selection of variants sufficiently different antigenically from the parental strain to account for the persistence of the virus. Such antigenic drift has already been reported for equine infectious anaemia virus (Kono et al. I973) and Visna virus (Narayan et al. I977). There is no doubt that prolonged in vitro cell passage of rubella virus in cell culture may lead to alterations in certain properties such as virulence of vaccine strains for man (Parkman et al. 1966; Plotkin, i969), loss of ability of RA27/3 to exhibit intrinsic interference (Kleiman & Carver, 1977) and diminished plaque size in two fresh isolates (Gould et al. I972). In this regard, however, Sato et al. 0979a) found plaque characteristics of the vaccine strains preserved after five serial subcultures, which confirmed a similar observation made by Gould et al. (1972). The unique properties of Cendehill virus, such as the unusual pattern of antigenicity for rabbits and monkeys (Oxford & Potter, I97O; Zygraich et aL t97I), the delayed antibody response in man (Moffat et al. I972) and the characteristic plaque morphology (Gould et aL I972; Sato et al. I979a), may be due to the prolonged passage history in rabbit kidney cells. This has not been investigated, however, but it would be of great interest to compare the serological and other properties of the vaccine strains with the original isolates from which they were developed. Whether or not antigenic changes develop during passage of the virus in cell cultures has not been shown although it is also worth noting that extensive passage of virus isolates in cell culture did not seem to influence antigenic specificity or diversity, since Lesley virus, with only three subcultures, was heterospecific as was HPV-77 virus after 83 subcultures and, incidentally, both were from post-natal infections. Furthermore RA27/3 virus, isolated from an intra-uterine infection and which had undergone 32 subcultures, was just as homospecific as Thomas virus, which also originated from an intra-uterine infection, with only five subcultures. Wellcome Research Laboratories Beckenham, Kent, U.K. ~5 JANINE J. GOULD MICHAEL BUTLER V I R 49 Downloaded from www.microbiologyresearch.org by IP: 88.99.165.207 On: Thu, 11 May 2017 06:59:38 426 Short communications REFERENCES BANATVALA, J. E. & BEST, J. M. 0969). Cross-serological testing of rubella virus strains. Lancet i, 695-697. BEST, J. M. & BANATVALA,J. E. (I970)- Studies o n rubella virus strain variation by kinetic h a e m a g g l u t i n a t i o n inhibition studies. Journal of General Virology 9, 215-223. DULBECCO, R., VOGT, M. & STRICKLAND, A. G. R. (I956). A s t u d y o f the basic aspects of neutralisation of two a n i m a l viruses, W e s t e r n equine encephalitis a n d poliomyelitis virus. Virology 2, 162-2o 5. FOGEL, A. & PLOTKIN, S. A. (1969). M a r k e r s of rubella virus strains in RK13 cell culture. Journal of Virology 3, 157-163. GOULD, J. J., LAURENCE, G. D. & BUTLER, M. (t972)- A n u n u s u a l plaque variant o f rubella virus. Journal of Hygiene (Cambridge) 7o, 49-53GRAVELL, M., DORCETT, P. H., GUTERSON, O. & ELY, A. C. 0977). Detection o f antibody to rubella virus by enzyme-linked i m m u n o s o r b e n t assay. Journal of Infectious Diseases I36, $3oo-$3o3. KLEIMAN, M. B. & CARVER, D. H. (I977)- Failure o f R A 2 7 / 2 3 strain o f rubella virus to induce intrinsic interference. Journal of General Virology 36, 335-34o. KONO, Y., KOBAYASHI,K. & FUKUNOGO, Y. (1973). Antigenicdrift of equine infectious a n a e m i a virus in chronically infected horses. Archivf~r die Gesamte Virusforschung 4 x, I-lO. MCBRIDE, W. D. (I959). Antigenic analysis o f polioviruses by kinetic studies o f s e r u m neutralisation. Virology 7, 45-58. MANDEL, B. (I978). Neutralisation o f animal viruses. Advances in Virus Research 23, 205 -268. MEURMAN, O. H., ARSKILA, P. P., PANALIUS, M., REUNAMAN, M. L., VALJANEN, M. K. & HtALONEN, P. E. (1977). Solid-phase r a d i o i m m u n o a s s a y detection o f rubella virus I g G antibody in s e r u m a n d C S F of patients with multiple sclerosis. Acta pathologica et microbiologica Scandinavica B 83, I t 3 - I I 6 . MOFFAT, M. A., GOULD, J. J., FORBES, F. A., FREESTONE, D. S. & MACDONALD, A. (I972). Studies with rubella vaccine ( R A 2 7 / 3 ) using the s u b c u t a n e o u s a n d intranasal routes. Scottish Medical Journal I7, 14o. NARAYAN, O., GRIFFIN, O. E. & CHASE, J. 0977). Antigenic shift o f visna virus in persistently infected sheep. Science x97, 376-378. OXFORD, J. S. (I969). A c o m p a r i s o n of s o m e ' w i l d ' a n d ' a t t e n u a t e d " strains of rubella virus. Symposium Series in Immunobiologieal Standardisation x x, 181- 186. OXFORD, J. S. & POTTER, C. W. 0970). A n i m m u n o l o g i c m a r k e r technique for the Cendehill vaccine strain o f rubella virus. Journal oflmmunology xo$, 818-823. PARKMAN, P. D., MEYER, H. M., KIRSCHSTEIN, a. L. & HOPPS, H. E. (1966). A t t e n u a t e d rubella virus. I. Developm e n t a n d laboratory characterisation. New England Journal of Medicine z75 , 569-574. PLOTKIN, S. A. (1969). D e v e l o p m e n t o f R A 2 7 / 3 a t t e n u a t e d rubella virus g r o w n in WI-38 cells. Symposium Series on Immunobiological Standardisation rx, 249-260.. RAWLS, W. E., DESMYTER, J. & MELNICK, J. L. (I967). Rubella virus neutralisation by plaque reduction. Proceedings of the Society for Experimental Biology and Medicine x24, 167-173. SATO, H., ALBRECHT, a. & ENNIS, F. A. 0 9 7 9 a ) . A novel plaque m e t h o d for a t t e n u a t e d rubella virus in Vero cell cultures. Archives of Virology 59, 281-284SATO, H., ALBRECHT~p., KRUGMAN, S. & ENNIS, F. A. (I979b). Sensitive neutralisation test for rubella antibody. Journal of Clinical Microbiology 9, 259-265. ZYGRAICH, N., PEETERMANS, J. & HUYGELEN, C. (I971). In vivo properties o f attenuated rubella virus ' C e n d e hill' strain. Archiv Ftr die Gesamte Virusforschung 33, 225-233- (Received I2 November 2979) Downloaded from www.microbiologyresearch.org by IP: 88.99.165.207 On: Thu, 11 May 2017 06:59:38