The family Filoviridae includes Ebola virus and Marburg
virus, which are associated with sporadic outbreaks and high case fatality
rates. A maximum containment laboratory (Biosafety Level-4) is required
to study infectious forms of these viruses, and we have a full-suit BSL-4
laboratory at Texas Biomed. Our laboratory is interested in multiple
aspects of filovirus biology with a view to exploiting this knowledge to
further the development of vaccines and therapeutics.
Typically, RNA viruses have high spontaneous mutation rates
due to error prone RNA-dependent RNA polymerases. The consequences of
high spontaneous mutation and replication rates are populations composed of
heterogeneous swarms of related variant sequences, sometimes called quasispecies.
We are investigating the importance of this diversity to filovirus replication
and pathogenesis in vitro and in vivo and are particularly interested in
exploiting the mutation rate as a therapeutic mechanism. Specifically, we
work to understand the roles of the individual genotype populations in virus
infection; for example, in any Ebola virus population there is a mixture of
genotypes that appear to control the expression of different forms of the virus
glycoprotein (GP). The ratios of the genotypes is dynamic and changes
dependent on the origin species of cells used to propagate virus, and even in
an infected animal. These changes are certainly important for the
development of vaccines and therapeutic â€“ that require animal models â€“ but also
for viral pathogenesis.
Many of these studies exploit recent advances in
sequencing. We have several Illumina sequencing machines on our campus
and a miSeq in our laboratory. This system permits quantification of the
individual viral genotypes in a sample and we have developed techniques to
rapidly sequence whole viral genomes, including the 5â€™ and 3â€™ termini. We
are expanding the use of these machines into other areas including gene
expression and ribosomal profiling of cells and tissues infected with BSL-4 pathogens.
K. Alfson, L. Avena, M. Beadles, H. Staples, J. Nunneley, A.
Ticer, E. Dick, M. Owston, C. Reed, J. Patterson, R. Carrion, and A. Griffiths. Particle to plaque-forming unit ratio of Ebola virus influences disease course and survival in cynomolgus macaques. Journal of Virology. In press.
M.-H. Lee, M. Rostal, T. Hughes, F. Sitam, C.-Y. Lee, J.
Japning, M. Harden, A. Griffiths, M. Basir, N. Wolfe, J. Epstein, P.
Daszak. Macacine herpesvirus 1 in long tailed macaques, Malaysia,
2009-2011. Emerging Infectious Diseases. In press.
K. Alfson, L. Avena, M. Beadles, H. Menzie, J. Patterson, R.
Carrion, and A. Griffiths. Genetic changes at the glycoprotein editing site associated with serial passage of Sudan virus. Journal of Infectious
Diseases. In press.
Alfson, K.J., M.W. Beadles, A. Griffiths. A new approach to determining whole viral genomic sequences including termini using a single deep sequencing run. J Virol Methods 208 (1-5): 2014
Fan Q, Amen M, Harden M, Severini A, Griffiths A, Longnecker R. Herpes B virus utilizes human nectin-1 but not HVEM or PILRÎ± for cell-cell fusion and virus entry. J Virol. 2012 Apr;86(8):4468-76.
Shurtleff AC, Garza N, Lackemeyer M, Carrion R Jr, Griffiths A, Patterson J, Edwin SS, Bavari S. The impact of regulations, safety considerations and physical limitations on research progress at maximum biocontainment. Viruses. 2012 Dec;4(12):3932-51.
Shurtleff AC, Biggins JE, Keeney AE, Zumbrun EE, Bloomfield HA, Kuehne
A, Audet JL, Alfson KJ, Griffiths A, Olinger GG, Bavari S; Filovirus
Animal Nonclinical Group (FANG) Assay Working Group. Standardization of the filovirus plaque assay for use in preclinical studies. Viruses. 2012 Dec 6;4(12):3511-30.
Amen MA, Griffiths A. Packaging of Non-Coding RNAs into Herpesvirus Virions: Comparisons to Coding RNAs. Front Genet. 2011 Nov 17;2:81.
Amen MA, Griffiths A. Identification and expression analysis of herpes B virus-encoded small RNAs. J Virol. 2011 Jul;85(14):7296-311.