A view of recent highlights of rotavirus research

Ulrich Desselberger, M.D.Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 0QQ, U.K.

Ruth Bishop Lecture, 13th International Rotavirus Symposium, Minsk/Belarus, 29-31 August 2018

Discovery of rotavirus as cause of infantile acute gastroenteritis

“Almost all particles had a highly electron-dense core, 33 nm in diameter, surrounded by a moderately densecapsid zone, 67 nm in diameter, about 10 percent ofparticles appeared to be enveloped (88nm in diameter). …The particles bear a marked resemblance to EDIM virus,the etiologic agent of epizootic diarrhea of infant mice.”

Electron microscopy of fecal suspensions: “In some of the specimens particles were discovered closely resembling reoviruses…”

Flewett TH, Bryden AS, Davies H.Virus particles in gastroenteritis. Lancet 1973 Dec 29; 2(7843): 1497.

Bishop RF, Davidson GP, Holmes IH, Ruck BJ. Evidence for viral gastroenteritis. N Engl J Med 1973 Nov 15; 289(20); 1096-1097.Lancet 1973 Dec 9; 2(7842): 1281-1283.

From: McClain B et al, J Mol Biol 2010; 397; 587-599.Settembre EC et al, EMBO J 2011; 30: 408-416.

A B

Rotavirus particle structure

Rotavirus structure-functions: VP1 = RdRp

From: - Lu X et al, Structure 2008; 16: 1678-1688. - Harrison S, Dormitzer P, Viral Gastroenteritis, pp 89-102, Elsevier, Amsterdam.

A B C

Rotavirus structure-functions: NSP2-NSP5

From: Jiang XF et al, J Virol 2006; 80: 10829-10835.

A B C

From: Sastri NP et al, Viral Gastroenteritis, pp 145-174. Elsevier, Amsterdam, 2016

A

Intracellular NSP4 Extracellular NSP4

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NSP4: structure and functions

Structure of dsRNA in particles of the Cypovirus genus of the Reoviridae

From: Liu HR, Cheng LP, Science 2015; 349: 1347-1350. Zhang X et al, Nature 2015; 527: 531-534.

A B C

Rotavirus growth in human enteroids

From: Saxena K et al, J Virol 2016; 90: 43-56.

E)

Rotavirus viroplasms: interaction with lipid droplets

From: Cheung W et al, J Virol 2010; 84: 6782-6798.

From: Crawford SE, Desselberger U, Curr Opin Virol 2016;19:11-15.

Inhibitory effects on rotavirus replication of different compounds affecting lipid droplet homeostasis

Compound Treatment Viral RNA Infectivity of

of cells replication rotavirus progeny

[rel. values*] Diff log TCID50/ml** Diff

Isoproterenol - 1.00* 8.2

+ IBMX1 + 0.25 4-fold*** 6.5 50-fold

Triacsin C1 - 1.00 7.5

+ 0.26 3.8-fold 6.2 20-fold

TOFA2 - 1.00 8.4

+ 0.17 6-fold 6.7 50-fold

* Calculated from densitometric values of RNA gels** SE values not shown *** Underlining indicates statistical significance

1 From: Cheung W et al, J Virol 2010; 84: 6782-6798.2 From: Gaunt E et al, J Gen Virol 2013; 94; 1310-1317.

Rotavirus genome assortment and packaging: possible molecular mechanism

From: Borodavka A et al, eLife 2017; 6: e27453.Borodavka A et al, Curr Opin Virol 2018; 33: 106-112.

1 2 3 4

Rotavirus pathogenesis: molecular mechanism of vomiting

From: Hagbom M et al, PLoS Pathogens 2011; 7: e1002115.Hagbom M and Svensson L, Viral Gastroenteritis, pp 189-218. Elsevier, Amsterdam, 2016.

NTS, nucleus of the tractus solitarii; AP, area postrema

Rotavirus reverse genetics, helper virus-dependent

From: Trask SD et al, Proc Natl Acad Sci USA 2010: 107: 18652-18657.

Also achieved with various procedures using helper virus:

Komoto S et al, Proc Natl Acad Sci USA 2006; 103: 4646-4651.

Troupin C et al, J Virol 2010; 84: 6711-6719.

Navarro A et al, J Virol 2013; 87: 6211-6220.

Rotavirus reverse genetics, plasmid only-based I

From: Kanai Y et al, Proc Natl Acad Sci USA 2017; 114: 2349-2354.

A B

C D

Rotavirus reverse genetics, plasmid only-based II

From: Komoto S et al, J Virol 2018; 92: e00588-18.

Rotavirus reverse genetics, plasmid only-based III

From: Philip AA et al (JT Patton), Recombinant rotavirus expressing the Unagi fluorescent protein. American Society for Virology, Annual Meeting, July 2018 (with permission of the authors)

A

B CM 1 2 3

D

M, size marker1, mock2, rSA113, rSA11/NSP1-FUnaG

Cross-neutralization specificity and titers of human mAbs isolated from human small intestine

From: Nair N et al, Science Translat Med 2017; 9: eaam5434.

VP6-specific rotavirus vaccine candidate

From: Lappalainen et al, Arch Virol 2015; 160: 2075-2078. Heinimaeki et al, Antiviral Res 2018; 157: 1-8.

A B

Reduction in virus shedding**

VP6 triv IM 67%VP6 triv IN 66%VP6 triv IM+IN 83%

*Adult mouse model (infection, not disease)

*

* Trivalent: RV VP6 tubules + NoV GI.3 and GII.4 VLPs

Neonatal RV3-BB (G3P[6]) vaccine candidate

Trial group Number of Participants Vaccine efficacy P valueparticipants with severe RV AGE % (95% CI)

_________________________________________________________________________Placebo 504 28 (5.6%) - -

Neon. Vac. Gr. 498 7 (1.4%) 75 (44-91) <0.001Inf. Vac. Gr. 511 14 (2.7%) 51 ( 7-76) <0.03

Comb. Vac. Gr. 1009 21 (2.1%) 63 (34-80) <0.001_________________________________________________________________________

From: Bines JE et al, N Engl J Med 2018; 378: 719-730.Based on: Barnes et al, Vaccine 2002; 20: 2950-2956; and earlier reports.

Summary: Recent highlights of rotavirus (RV) research*

Topic Major research groups______________________________________________________________________________• RV structural proteins and functions Harrison, Prasad, others • RV non-structural proteins (NSP2, NSP4) Prasad, Estes, others• RV replication in enteroids Estes, others• RV viroplasms interaction with lipid droplets Desselberger, Lever, others• RV RNA assortment and packaging Borodavka, others• RV pathogenesis Svensson, others• RV reverse genetics helper virus-dependent Patton, Taniguchi, Garbarg-Chenon• RV reverse genetics plasmid only-based Kobayashi, Komoto, Patton, others• Human RV broadly cross-neutralizing Mabs Greenberg, others• Novel human RV vaccine candidates Vesikari, Blazevic, Bines, Greenberg, others_______________________________________________________________________________

* Apologies to the many authors whose original and important work was not included here, due to time limitations. UD