1. The Current State of Knowledge on Innate and Adaptive Responses
during FMDV Infection
Bryan Charleston

2. FMD virus at mucosal sites
Diagnostic windows
FMDV-sequence of events
antibody response
Clinical
lesions
Transmission
FMD virus in blood
MEASUREMENT
FMD virus at mucosal sites 1 2 3 4 5 6 7 8
● ● ● ● 14
DAYS 2

3. Effect of CD4 T cell depletion on neutralising antibody response to
vaccination

4. T-dependent response to antigen
Day 1
Day 7
Day 7
Memory B cells:
Recirculate between blood and tissues in a quiescent state (do not spontaneously secrete Ab)
Long-lived plasma cells:
Spontaneously secrete Ab for a long period of time.
Only detectable when transiting from the lymphoid organs towards specific niches (bone marrow, red pulp of spleen)
Short-lived plasma cells:
Supposed to secrete Ab in situ for a short period of time within the lymphoid organ in which they are generated
McHeyzer-Williams, L.J. & McHeyzer-Williams, M.G. Antigen-specific memory B cell development. Annu Rev Immunol 23, (2005).

5. Antigen presentation Mice
FMDV infection of mouse BMDCs is abortive, infected cells lose their ability to stimulate T-cells and differentiate towards a macrophage-like phenotype.
Generalized suppression of T-dependent responses has been observed in vivo in mice between 3 and 5 days p.i., thought to be mediated in part by
MHC class II and CD40 downregulation on DCs and by IL-10.
FMDV infection induces a reduction in splenic plasmacytoid dendritic cells (pDCs) and conventional DCs (CD11c+ /CD8a+).

6. Antibody mediated infection/ uptake of virus and antigen
Pigs
FMDV infection of porcine pDCs, monocyte derived DCs (MODCs) and BMDCs is abortive.
Porcine MODCs respond in vitro by increasing expression of MHC class II and CD86,
But data generated in vitro from cells derived from infected pigs are more
consistent with the suppressive responses described in vitro and in vivo in mice.
Cattle
FMDV infection of bovine MODCs is productive and infected cells
die, losing their ability to stimulate T-cell proliferation in vitro.
Immune complexs induce low quantities of IFN from pDC
No reports of generalized immunosuppression during the acute phase of FMDV infection in cattle.
Antibody mediated infection/ uptake of virus and antigen

7. Acute FMD: naïve buffalo
Windsor et al., 2011
Reid et al., 2011

8. Acute FMD: naïve buffalo
Buffalo leucocyte count (n = 16)
Windsor et al., 2011

9. Bovine B cell response to antigen
TD antigen-specific response
FMDV-specific response

11. MLN 38DPCI LZ
FMDV D46 DZ
80 µm
FMDV D46 DAPI

12. FMD: buffalo Budras, Bovine Anatomy Follicles with central crypt
Casteleyn et al.,
Budras, Bovine Anatomy
Follicles with central crypt
M Hofmeyr

13. Fundamental differences between cattle and human antibodies
Variable (VH)
Diversity (DH)
Junctional (JH)
Constant (CH)
Germline X
Gene segment recombination
-S-S-
3.6 x 106 potential combinations of heavy and light chains
Translation λ
Gene segment recombination X κ λ
Variable (VL)
Junctional (JL)
Constant (CL)
Germline

14. Bimodal bovine CDR3 distribution

15. Bovine antibodies – long CDR3
Oyen et al., 2011
J. Mol. Biol. 407, 138
Wang et al., 2013
Cell

17. And there are revolutions in electron microscopy… Wonderful new detectors, that collect 4k movies, and allow virus particle movements to be tracked in software … so we can see atomic detail Live virus in cryo – in a water ‘glass’ Expensive – hence a National Facility for the UK

18. 70hrs Collection on Polara

19. Pirbright Oxford/ Diamond Reading Clare Grant Veronica Carr
John Hammond
Claudine Porta
Nick Juleff
Mirrie Windsor
Eva Perez
Julian Seago
Oxford/ Diamond
Dave Stuart
Liz Fry
Abhay Kotecha
Anna Fowler
Marton Munz
Gerton Lunter
Reading
Ian Jones