Previous Article | Next Article 
Journal of Virology, June 2000, p. 5382-5384, Vol. 74, No. 11
Center for Biologics Evaluation and Research,
Food and Drug Administration, Bethesda, Maryland
208921; Departments of
Psychiatry2 and
Medicine,4 The Johns Hopkins University,
Baltimore, Maryland 21218; and Department of Biochemistry,
Microbiology and Immunology, University of Ottawa, Ottawa, Ontario,
Canada K1H 8M53
Received 22 November 1999/Accepted 8 March 2000
Neurovirulence of several mumps virus strains was assessed in a
prototype rat neurovirulence test and compared to results obtained in
the monkey neurovirulence test. The relative human neurovirulence of
these strains was proportional to the severity of hydrocephalus in rats
but not to lesion scores in the monkeys.
Neurovirulence testing is performed
to demonstrate that attenuated mumps virus seeds used in the
manufacture of vaccine lack the neurovirulence properties of wild-type
mumps virus strains. Mumps virus neurovirulence testing as currently
performed in monkeys has failed to discriminate between strains with
known differences in human neurovirulence (2, 8, 27, 28).
Similarly, tests in hamsters have also failed to reliably discriminate
neurovirulent from nonneurovirulent human mumps virus strains (12,
19, 22, 34). The difficulty in evaluating the neurovirulence
potential of mumps viruses may be reflected in reports of mumps virus
central nervous system (CNS) infection causally linked to vaccination with some mumps virus vaccines (e.g., Urabe-AM 9, Leningrad-3, and
Sofia-6) (3, 9, 10, 23, 24, 32). Thus, a validated mumps
virus neurovirulence test with greater relevance to human disease
remains an important public health objective.
Because neonatal rat brain is particularly sensitive to damage
following perinatal virus infection (5, 6, 11, 13, 16, 25, 26,
31), it was hypothesized that neuropathology in rats neonatally
inoculated with mumps virus may serve as a sensitive indicator of
neurovirulence potential in the human CNS. Litters of 1-day-old Lewis
rats were inoculated intracranially with 0.02 ml containing
102 PFU of the following mumps virus strains: (i) Jeryl
Lynn vaccine (JL) (15); (ii) RIT 4385 vaccine (JL-RIT),
cloned from JL by limiting dilution (33); (iii) Urabe-AM 9 vaccine (Ur-AM9) (35); (iv) Ur-1004, a cerebrospinal fluid
isolate from a case of Ur-AM9 meningitis (7); (v) Kilham, a
wild-type strain isolated from human breast milk and serially passaged
in suckling hamster brain (20); (vi) Lo1, a wild-type strain
isolated from the saliva of a patient with uncomplicated parotitis
(1); and (vi) 88-1961, a wild-type strain isolated from the
saliva of a patient with parotitis and symptoms of CNS infection.
Rats were euthanized on days 3, 6, 9, and 30 postinoculation, and
brains were removed and either homogenized to determine viral titer by
plaque assay (26) or fixed in 10% formalin for histological
analysis. Two 3- to 4-mm-thick sagittal slices were selected at a
standard distance from either side of the anatomical midline from a
fixed brain, paraffin embedded, sectioned, and stained with hematoxylin
and eosin. The severity of hydrocephalus was determined as the
percentage of the total brain cross-sectional area (excluding the
cerebellum) occupied by the lateral ventricle on each of the two
sections per rat using Image Pro Plus image analysis software (Media
Cybernetics, Silver Spring, Md.). The mean percentage of hydrocephalus
in each experimental group of rats was calculated and designated as the
rat neurovirulence test (RNVT) score.
An example of the range in hydrocephalus severity is shown in Fig.
1, and the resultant RNVT scores are
shown in Fig. 2A. Based on the RNVT
scores, distinctions could be made in the relative neurovirulence (i)
between vaccine and wild-type strains, (ii) among wild-type strains,
and (iii) among vaccine strains. Differences in RNVT scores between
vaccine and wild-type strains were significant (P < 0.001 for all scores compared) and paralleled the known clinical histories of these strains. While there have been no confirmed cases of
strain JL- or JL-RIT-induced CNS infection, infection of the CNS occurs
in up to 1% of Ur-AM9 vaccinees and in approximately 50% of cases of
infection by wild-type mumps viruses (3, 4, 14). Among the
wild-type strains, RNVT scores of strains 88-1961 and Kilham were
greater than that of Lo1 (P
0022-538X/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Evaluation of a Neonatal Rat Model for Prediction
of Mumps Virus Neurovirulence in Humans
ABSTRACT
Top
Abstract
Text
References
TEXT
Top
Abstract
Text
References
0.001 for all scores compared), consistent with the known neurovirulence of the three strains. Of note, the RNVT scores of strains 88-1961 and Kilham were
equivalent, suggesting that while species adaptation may account for
the high scores of the Kilham strain, neurovirulent human isolates can
exhibit high RNVT scores in the absence of adaptation to rodents.
Differences between Ur-AM9 and the JL-based vaccine strains were also
significant (P < 0.02 for all scores compared) and
consistent with their clinical histories as cited above. Differences in
RNVT scores between JL and JL-RIT and between Ur-AM9 and Ur-1004 were
not statistically significant.
View larger version (37K):
[in a new window]
FIG. 1.
Representative sagittal brain sections from rats
inoculated with mumps virus. Arrows indicate the lateral ventricle. (A)
No hydrocephalus; (B) mildly enlarged ventricle occupying 6% of the
total brain cross-sectional area; (C) moderately enlarged ventricle
occupying 12% of the total brain cross-sectional area; and (D)
severely enlarged ventricle occupying 26% of the total brain
cross-sectional area. The sections were stained with hematoxylin and
eosin. Magnification, ×1.5.
View larger version (12K):
[in a new window]
FIG. 2.
Mumps virus strain-specific hydrocephalus and viral
burden. (A) The RNVT scores track with the known clinical history of
all strains. Each bar represents measurements obtained from 12 to 18 rats. (B) Titer of infectious virus per gram of rat brain on days 0, 3, 6, and 9 postinoculation with strain JL (filled circles), Ur-AM9 (open
circles), Lo1 (filled triangles), and 88-1961 (open triangles).
A similar relationship between the virus strains and the resultant RNVT scores was observed at higher (103) and lower (101) doses of virus; however, there was a clear influence of virus dose on RNVT scores (data not shown). As to why the severity of hydrocephalus in rats is predictive of a strain's human neurovirulence potential is difficult to ascertain, since the pathogenesis of mumps virus-induced hydrocephalus is not well understood (29, 30). Studies in hamsters have associated mumps virus infection of ventricular ependymal cells with the development of hydrocephalus (17, 18), suggesting that hydrocephalus severity may reflect the ability of the viral strains to replicate in rat brain. Indeed, as shown in Fig. 2B, a direct correlation between viral titers and RNVT scores for different strains of mumps virus was demonstrated.
Recent reports have indicated that the monkey neurovirulence test (MNVT) is not sufficiently predictive of mumps virus neurovirulence in humans (2, 27). However, based on the observed influence of virus dose on RNVT scores, it was conceivable that the use of higher or lower doses of mumps virus might yield responses in monkeys better correlating with neurovirulence in humans. Consequently, Macaca mulatta rhesus monkeys were inoculated intrathalamically with 1.0 ml (0.5 ml per thalamus) containing 103.5, 104.5, and 105.5 PFU per ml of strain JL, Lo1, or 88-1961. These doses closely approximated those used in the rat study on a per gram of brain tissue basis. Monkeys were euthanized on day 17 postinoculation, and brains were removed, fixed in 10% formalin, blocked, embedded in paraffin, sectioned, and stained with gallocyanin as previously described (21). MNVT scores were determined based on mumps virus-specific inflammation and neuronal destruction as previously described (27). Of note, monkeys do not develop measurable hydrocephalus as a consequence of mumps virus infection.
At a dose of 103.5, all mumps virus strains resulted in
similar MNVT scores (Fig. 3). At higher
virus doses, MNVT scores for strain 88-1961 were greater than both Lo1
and JL MNVT scores, with the differences being statistically
significant in the former comparison (P 0.02 for all
scores compared) but not in the latter comparison (P > 0.08 for all scores compared). Thus, at 104.5 and
105.5 PFU of virus, there was a trend for the MNVT to
discriminate between highly neurovirulent (88-1961) and less
neurovirulent (Lo1 and JL) strains. However, at all doses tested, there
was also a trend of increased neurovirulence of JL relative to Lo1, indicating an overall inability of the MNVT to reliably assess human
neurovirulence. Therefore, pending verification of results in
multicenter collaborative investigations, the data presented here
support the replacement of the MNVT with the RNVT.
|
| |
ACKNOWLEDGMENTS |
|---|
We thank Jerry Wolinsky for providing the Kilham strain, Nando K. Chatterjee for providing the 88-1961 strain, and Ronald Lundquist and Don Fink for critical reviews of the manuscript.
| |
FOOTNOTES |
|---|
* Corresponding author. Mailing address: Center for Biologics Evaluation and Research, Food and Drug Administration, Building 29A, Room 1A-21, 8800 Rockville Pike, Bethesda, MD 20892. Phone: (301) 827-1974. Fax: (301) 480-5679. E-mail: rubins{at}cber.fda.gov.
| |
REFERENCES |
|---|
|
Top
Abstract
Text
References
|
|---|
| 1. | Afzal, M. A., J. Buchanan, A. B. Heath, and P. D. Minor. 1997. Clustering of mumps virus isolates by SH gene sequence only partially reflects geographic origin. Arch. Virol. 142:227-238[CrossRef][Medline]. |
| 2. | Afzal, M. A., S. Marsden, R. M. Hull, P. A. Pipkin, M. L. Bently, and P. D. Minor. 1999. Evaluation of the neurovirulence test for mumps vaccines. Biologicals 27:43-49[CrossRef][Medline]. |
| 3. | Balraj, V., and E. Miller. 1995. Complications of mumps vaccines. Rev. Med. Virol. 5:219-227. |
| 4. | Bang, H. O., and J. Bang. 1943. Involvement of the central nervous system in mumps. Acta Med. Scand. 113:487-505. |
| 5. | Bautista, J. R., S. A. Rubin, T. H. Moran, G. J. Schwartz, and K. M. Carbone. 1995. Developmental injury to the cerebellum following perinatal Borna disease virus infection. Dev. Brain Res. 90:45-53[Medline]. |
| 6. | Beers, D. R., J. S. Henkel, R. P. Kesner, and W. G. Stroop. 1995. Spatial recognition memory deficits without notable CNS pathology in rats following herpes simplex encephalitis. J. Neurolog. Sci. 131:119-127[CrossRef][Medline]. |
| 7. | Brown, E. G., K. Dimock, and K. E. Wright. 1996. The Urabe AM9 mumps vaccine is a mixture of viruses differing at amino acid 335 of the hemagglutinin-neuraminidase gene with one form associated with disease. J. Infect. Dis. 174:619-622[Medline]. |
| 8. | Buynak, E. B., and M. R. Hilleman. 1966. Live attenuated mumps virus vaccine. 1. Vaccine development. Proc. Soc. Exp. Biol. Med. 123:768-775[CrossRef][Medline]. |
| 9. | Cizman, M., M. Mozetic, R. Radescek-Rakar, D. Pleterski-Rigler, and M. Susec-Michleli. 1989. Aseptic meningitis after vaccination against measles and mumps. Pediatr. Infect. Dis. J. 8:302-308[Medline]. |
| 10. | Colville, A., and M. Pugh. 1992. Mumps meningitis and measles, mumps and rubella vaccine. Lancet 340:786[CrossRef][Medline]. |
| 11. | Del Cerro, M., N. Nathanson, and A. A. Monjan. 1975. Pathogenesis of cerebellar hypoplasia produced by lymphocytic choriomeningitis virus infection of neonatal rats. II. An ultrastructural study of the immune mediated pathology. Lab. Investig. 33:608-617[Medline]. |
| 12. | Ennis, F. A., H. E. Hopps, R. D. Douglas, and H. M. Meyer, Jr. 1969. Hydrocephalus in hamsters: induction by natural and attenuated mumps viruses. J. Infect. Dis. 119:75-79[Medline]. |
| 13. | Ferguson, S. A. 1996. Neuroanatomical and functional alterations resulting from early postnatal cerebellar insults in rodents. Pharmacol. Biochem. Behav. 55:663-671[CrossRef][Medline]. |
| 14. |
Forsey, T.
1994.
Mumps vaccines current status.
J. Med. Microbiol.
41:1-2 |
| 15. | Hilleman, M. R., E. B. Buynak, R. E. Weibel, and J. Stokes. 1968. Live, attenuated mumps-virus vaccine. N. Engl. J. Med. 278:227-232. |
| 16. | Ikegami, H., M. Takeda, and K. Doi. 1997. An age-related change in susceptibility of rat brain to encephalomyocarditis virus infection. Int. J. Exp. Pathol. 78:101-107[CrossRef][Medline]. |
| 17. | Johnson, R. T. 1968. Mumps virus encephalitis in the hamster: studies of the inflammatory response and neuropathic infection of neurons. J. Neuropathol. Exp. Neurol. 27:80-95[Medline]. |
| 18. | Johnson, R. T., and K. P. Johnson. 1968. Hydrocephalus following viral infection: the pathology of aqueductal stenosis developing after experimental mumps virus infection. J. Neuropathol. Exp. Neurol. 27:591-606[Medline]. |
| 19. | Kilham, L., and G. Margolis. 1975. Induction of congenital hydrocephalus in hamsters with attenuated and natural strains of mumps virus. J. Infect. Dis. 132:462-466[Medline]. |
| 20. | Kilham, L., and J. R. Overman. 1953. Natural pathogenicity of mumps virus for suckling hamsters on intracerebral inoculation. J. Immunol. 70:147-151. |
| 21. | Maximova, O., E. M. Dragunsky, R. E. Taffs, P. Snoy, J. Cogan, S. Marsden, and I. S. Levenbook. 1996. Monkey neurovirulence test for live mumps vaccine. Biologicals 24:223-224[CrossRef][Medline]. |
| 22. | McCarthy, M., B. Jubelt, D. B. Fay, and R. T. Johnson. 1980. Comparative studies of five strains of mumps virus in vitro and in neonatal hamsters: evaluation of growth, cytopathogenicity, and neurovirulence. J. Med. Virol. 5:1-15[Medline]. |
| 23. | Miller, E., M. Goldacre, S. Pugh, A. Colville, P. Farrington, A. Flower, J. Nash, L. MacFarlane, and R. Tettmar. 1993. Risk of aseptic meningitis after measles, mumps and rubella vaccine in UK children. Lancet 341:979-982[CrossRef][Medline]. |
| 24. | Odisseev, H., and N. Gacheva. 1994. Vaccinoprophylaxis of mumps using mumps vaccine, strain Sofia 6, in Bulgaria. Vaccine 12:1251-1254[CrossRef][Medline]. |
| 25. | Rubin, S. A., J. R. Bautista, T. Moran, G. J. Schwartz, and K. M. Carbone. 1999. Viral teratogenesis: brain developmental damage associated with maturation state at time of infection. Dev. Brain Res. 112:237-244. |
| 26. |
Rubin, S. A.,
M. Pletnikov, and K. M. Carbone.
1998.
Comparison of the neurovirulence of a vaccine and a wild-type mumps virus strain in the developing rat brain.
J. Virol.
72:8037-8042 |
| 27. | Rubin, S. A., P. Snoy, K. E. Wright, E. G. Brown, P. Reeve, J. A. Beeler, and K. M. Carbone. 1999. The mumps virus neurovirulence safety test in rhesus monkeys: a comparison of mumps virus strains. J. Infect. Dis. 180:521-525[CrossRef][Medline]. |
| 28. | Sassani, A., H. Mirchamsy, S. P. Ahourai, J. Razavi, M. R. Gholami, A. Mohammadi, A. Ezzl, M. Rahmani, G. Fateh, and T. Paravandi. 1991. Development of a new live attenuated mumps virus vaccine in human diploid cells. Biologicals 19:203-211[CrossRef][Medline]. |
| 29. | Takano, T., Y. Mekata, T. Yamano, and M. Shimada. 1993. Early ependymal changes in experimental hydrocephalus after mumps virus inoculation in hamsters. Acta Neuropathol. 85:521-525[Medline]. |
| 30. | Takano, T., S. Takikita, and M. Shimada. 1999. Experimental mumps virus-induced hydrocephalus: viral neurotropism and neuronal maturity. Neuroreport 10:2215-2221[Medline]. |
| 31. | Takano, T., M. Uno, T. Yamano, and M. Shimada. 1994. Pathogenesis of cerebellar deformity in experimental Chiari type I malformation caused by mumps virus. Acta Neuropathol. 87:168-173[Medline]. |
| 32. | Tesovic, G., J. Begovac, and A. Bace. 1993. Aseptic meningitis after measles, mumps and rubella vaccine. Lancet 341:1541[Medline]. |
| 33. | Usonis, V., V. Bakasenas, A. Kaufhold, K. Chitour, and R. Clemens. 1999. Reactogenicity and immunogenicity of a new live attenuated combined measles, mumps and rubella vaccine in healthy children. Pediatr. Infect. Dis. J. 18:42-48[CrossRef][Medline]. |
| 34. | Wolinsky, J. S., and W. G. Stroop. 1978. Virulence and persistence of three prototype strains of mumps virus in newborn hamsters. Arch. Virol. 57:355-359[CrossRef][Medline]. |
| 35. | Yamanishi, K., M. Takahashi, S. Ueda, Y. Minekawa, T. Ogion, M. Suzuki, and Y. Okuno. 1973. Studies on live mumps virus vaccine. V. Development of a new mumps vaccine "AM9" by plaque cloning. Biken J. 16:161-166[Medline]. |
Journal of Virology, June 2000, p. 5382-5384, Vol. 74, No. 11
0022-538X/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Chambers, P., Rima, B. K., Duprex, W. P.
(2009). Molecular differences between two Jeryl Lynn mumps virus vaccine component strains, JL5 and JL2. J. Gen. Virol.
90: 2973-2981
[Abstract] [Full Text] -
Malik, T. H., Wolbert, C., Nerret, L., Sauder, C., Rubin, S.
(2009). Single amino acid changes in the mumps virus haemagglutinin-neuraminidase and polymerase proteins are associated with neuroattenuation. J. Gen. Virol.
90: 1741-1747
[Abstract] [Full Text] -
Malik, T., Wolbert, C., Mauldin, J., Sauder, C., Carbone, K. M., Rubin, S. A.
(2007). Functional consequences of attenuating mutations in the haemagglutinin neuraminidase, fusion and polymerase proteins of a wild-type mumps virus strain. J. Gen. Virol.
88: 2533-2541
[Abstract] [Full Text] -
Lemon, K., Rima, B. K., McQuaid, S., Allen, I. V., Duprex, W. P.
(2007). The F Gene of Rodent Brain-Adapted Mumps Virus Is a Major Determinant of Neurovirulence. J. Virol.
81: 8293-8302
[Abstract] [Full Text] -
Williams, B. L., Yaddanapudi, K., Hornig, M., Lipkin, W. I.
(2007). Spatiotemporal Analysis of Purkinje Cell Degeneration Relative to Parasagittal Expression Domains in a Model of Neonatal Viral Infection. J. Virol.
81: 2675-2687
[Abstract] [Full Text] -
Wilson, R. L., Fuentes, S. M., Wang, P., Taddeo, E. C., Klatt, A., Henderson, A. J., He, B.
(2006). Function of Small Hydrophobic Proteins of Paramyxovirus. J. Virol.
80: 1700-1709
[Abstract] [Full Text] -
Rubin, S. A., Amexis, G., Pletnikov, M., Vanderzanden, J., Mauldin, J., Sauder, C., Malik, T., Chumakov, K., Carbone, K. M.
(2003). Changes in Mumps Virus Gene Sequence Associated with Variability in Neurovirulent Phenotype. J. Virol.
77: 11616-11624
[Abstract] [Full Text] -
Orvell, C., Tecle, T., Johansson, B., Saito, H., Samuelson, A.
(2002). Antigenic relationships between six genotypes of the small hydrophobic protein gene of mumps virus. J. Gen. Virol.
83: 2489-2496
[Abstract] [Full Text] -
Tecle, T., Bottiger, B., Orvell, C., Johansson, B.
(2001). Characterization of two decades of temporal co-circulation of four mumps virus genotypes in Denmark: identification of a new genotype. J. Gen. Virol.
82: 2675-2680
[Abstract] [Full Text]
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»