Transcript Example of Recovery of Infectious virus from Negative Strand RNA

Measles: Need for Continued Vaccination and Novel
Vaccines Post Virus Eradication
S. Louise Cosby
Professor of Microbiology – Queen’s University Belfast, UK
and
Head of Virology Branch, Agri-Food and Biosciences
Institute (AFBI), Veterinary Division, Stormont, Belfast , UK
Queen’s University Belfast
AFBI Veterinary Science Division
Measles Clinical Presentation and General
Complications
Measles rash
Koplik spots
General Complications: giant cell pneumonia; otitis media
Highly infectious disease
Spread by aerosol
462,186 cases in 2014 (World Health Organisation)
CNS Complications
Subacute Sclerosing Panencephalitis
• Slowly progressing degenerative disease of the brain
• Occurs in children and young adults
• Clinical Symptoms - 4 main stages
(i) Mental and behavioural changes
(ii) Disturbances of Motor functionsmonoclonic jerks, epileptic fits
(iii) progressive cerebral degeneration with
symptoms and signs of decortication.
• Progresses to death 1 to 10 years
CNS Complications
Measles Inclusion Body Encephalitis (MIBE)
• Occurs in immunosuppressed patients
• Clinically similar to SSPE
• However, much more rapid and proceeds to
death within months.
• Common in children with leukaemia
undergoing axial radiation therapy
• Also-HIV positive children
Cell Types Infected in Subacute
Sclerosing Panencephalitis Brain
neuron
Perivascular cuff
astrocyte
oligodendrocyte
endothelial cell
Measles Eradication
• In May 2010, the World Health Assembly agreed
to interim targets as milestones towards measles
eradication, including reducing measles mortality
by 95% by 2015.
• Measles virus (MV) is mem.ber of morbillivirus
genus within the Paramyxoviridae
• Morbilliviruses induces cross neutralising
antibody to other members of the genus.
• After eradication, if measles vaccination is
discontinued, are humans at risk of infection with
veterinary morbilliviruses?
Morbillivirus Genus (Family Paramyxoviradae) Phylogeny
Cetaceans
Dolphin
Porpoise
morbillivirus
Primates
Ancestral
virus
Measles
virus
Canine
distemper
virus
Rinderpest
virus
Phocine
distemper
virus
Ruminants
Peste des petits
ruminants virus
Carnivores
CDV and PDV are More Highly Neurovirulent in
the Natural Host than MV
PDV in the Seal CNS
Subacute sclerosing
panencephalitis- rare
complications of measles infection
CDV Jump into None Canine Species- Large Cats
and Hyenas
Transmission
hyenas feed on ?
dog carcases
?
?
Transmission
lions steal kills
?
from hyenas
and prey on
wild dogs
CDV Samples
Collected in
1993/1994
from the
Serengeti
National
Park
Major Threat - CDV infection now in Non Human Primates
• 1989- case of encephalitis in a Japanese monkey
(Macaca fuscata)
- CDV inclusions in the CNS were found to be CDV.
-Serologically, 22 monkeys in same group as
diseased monkey had relatively high titres of
neutralizing antibody to CDV, but not to MV.
Yoshikawa et al. (1989) Vet. Microbiol.20,193-205
• 2006 and 2008- outbreak of CDV in hand-feeding
Rhesus monkeys in Beijing.
- 20 monkeys –12 animals died.
- Gross pathological examination showed lesions in the
lungs consistent with pneumonia and diffuse
haemorrhage in the CNS. Sun et al. (2010). Microbiol. 141,
374-378 ; QIU et al. (2011) Emerg. Infect. Dis. 17, 1541–1543
• 2008 in Japan, a CDV outbreak in cynomolgus monkeys
imported from China. In that outbreak
- 46 monkeys died from severe pneumonia
Sakai et al. J. Virol. 87(2):1105-14. doi: 10.1128/JVI.02419-12
Morbillivirus Structure
N
 Genus in the the
Paramyxoviridae

ssRNA enveloped virus

The ss RNA is encased in
a helix of nucleocapsid
protein
Cell-derived
lipid
envelope
P
L
M
H
F
Envelope
glycoproteins
Ribonucleocapsid
H – Haemagglutinin cell receptor attachement protein- may
need to mutate to allow infection in new species
Virus Cell Entry Receptors –
A Major Determinant of Cross Species Infection
•
Viruses hijack receptors on the cell surface to enter cells or to modulate
the host immune system.
•
Use of common cell receptors by morbilliviruses- facilitation of cross
species transmission.
•
Does mutation in morbillivirus virus receptor attachment protein (H)
occur to adapt to new species
•
Consequence for human population lacking cross immunity to veterinary
morbilliviruses when MV eradicated.
•
Could zoonosis occur??
Known Cell Entry Receptors for WT MV, CDV and PDV
1
MV
binding
Signalling
lymphocyte
activation
Molecule
O-linked
(SLAM or
sugars
CDw150) membrane
SC
R1
SLAM
Staining in
perivascular
cuff in SSPE
brain tissue
2
3
C3b/C4b
4 binding region
cytoplasm
Ser/Thr/P
ro
rich
domain
C-terminus
Cytoplasmic
tails
PVRL-4 (nectin-4)
• basal receptor polarised epithelial
cells
• is up-regulated by MV infection in
human brain endothelial cells
(McQuaid and Cosby,
Laboratory Investigation, 2002).
Mühlebahc et al., 2011, Nature. 480:530-533
Noyce et al.,2011, PLoS Pathog. 7:e1002240
Abdullah et al. 2013. J. Neuropath. Exp. Neurol
Wild Type Measles Virus Infection of Human
Neuronal Cells in Culture
SHS5Y5 cells
hNT2 cells
Virus green
MAP-2 green
Virus
red
CDV and PDV Infect SHS5Y5 Human Neuroblastoma
Cells
WT CDV
Use of Receptor X?
WT PDV
Receptor X Expression is Down-Regulated in Infected
Areas in SSPE Brain
MV Negative
Receptor X
MV Positive
MV
WT MV infects and Binds to Vero Cells Expressing Neuronal
Receptor X
Vero
VeroHumanSLAM
Vero X
***
***
Flow cytometry
Virus binding to receptors
Three Approaches- Mucosal
Vaccination for Paramyxoviruses
• Vaccines for Bovine
respiratory syncytial virus
and bovine parainfluenza 3
• Inactivated Nanoparticle
vaccines
• Live recombinant vaccine
• Infectious recombinant
particles
The SiSafe® Technology Platform
• Patented elemental nano-silicon with a porous structure
and massive surface area.
These particles, each 100 times smaller than a human hair, contain microscopic reservoirs that can hold and
• Molecules
incorporated
within
nanopores
which it cannot b
SiSafe® is fully patented but also requires
specific trade-secret
know-how
to the
produce.
And because
stabilizes unstable molecules and provides very
significant increases in the bioavailability of even the
most hydrophobic compounds.
• SiSafe® biodegradable and kinetics of drug release
depend on the rate of biodegradation of the matrix.
SiSafe® has very high
Rate of onset and release can be customized by altering
drug-loading capacity
physical factors of the carrier including particle size,
(requiring low ratio of
porosity, linkage method and pore width.
carrier) compared with
• SiSafe® has very high drug-loading capacity (requiring low
other drug carriers.
ratio of carrier) compared with other drug carriers.
• Biocompatible SiSafe® fully dissolves to orthosilicic acid,
the natural form of silicon absorbed from food.
Orthosilicic acid has a positive safety and toxicological
profile – edible.
Recovery of Infectious
virus from Negative
Strand RNA viruses using
plasmid cDNAs
Both live and infectious
particles vaccines –use of
animal paramyxovirus
vectors which are nonpathogenic in humans and
cattle
Mutation of virus
glycoproteins to more
highly immunogenic
forms.
Proc Natl Acad Sci U S A. 1996 December 24; 93(26):
14998–15000.
Summary
• MV Receptors shared with other morbilliviruses
• WT CDV and PDV cross species barriers
• Only 3 mutations required in virus H protein to allow infection
of human leucocytes using SLAM receptor .
• Epithelial receptor Nectin-4 (PVRL-4) shared by
morbilliviruses.
• CDV and PDV infect human neuronal cells- likely to share
same receptor.
• Need to continue vaccination for measles/ veterinary
morbillivirus / MV–veterinary morbillivirus recombinant.
• Production and testing or novel inactivated (nanoparticle) and
recombinant veterinary paramyxovirus vaccines in cattle.
• Prototypes for measles and other human paramyxovirus
vaccines.
Acknowledgements
Cosby QUB
Cosby AFBI
Dr Ultan Power QUB
Dr Haniah Abdullah
Dr Michael McMenamy
Dr Bia He ( University of
Georgia, USA)
Adam Jeffers
Dr Kate Duffy
Dr Barney Graham NIH, USA
Michael Cooper
SiSaf
Department of
Agriculture,
Environment and
Rural Affairs
(DAERA)